I am having an electrician come in tomorrow to rewire my Delta Contractor grade table saw from 110v to 220v. I got the impression from reading that this was not a major piece of work. Am I wrong? Can anyone give me a rough idea as to what such a job might cost? I live in Middlesex County New Jersey where things can be more expensive than in less populated areas.
ADDENDUM: 1-23-03
Had the electrician (actually 2 very young ones came) in this morning. They wanted $385.00 to rewire the motor from 110v to 220v. No way Jose.
Did get some additional info. The “box” in the shop(garage) has a 50amp capacity and does have 220v capability (2 legs I think is the expression).The motor label does indeed say 1.5/2.0 hp so the motor can be changed. As another responder noted, I think beside changing the configuration inside the motor itself all I really need is a new plug and a new receptacle. All comments welcome.
Edited 1/23/2003 2:21:24 PM ET by mike
Edited 1/23/2003 2:21:46 PM ET by mike
Edited 1/23/2003 2:32:17 PM ET by mike
Replies
It will depend on what needs to be done.
If it is just a new cord on the motor and moving one or two wires in the motor. 1/2 hour will be stretching it. If he needs to bring a new wire from the power box to the saw 1 to 2 hours. plus the wire breaker.
Why are you rewiring the saw? The only benefit I see you you can use 14 gage wire instead of 12 gage wire. It uses 1 more amps to get the same horse power. It will make a different in voltage drop on 200 foot run. with 12 gauge 240 v instead of 8 gauge on 120 v to keep your voltage up 200 foot run, I think that is what I found out after cheeking.
Many thanks for the info. I'm rewiring mainly to have a 220v line in the shop in case I trade up to a cabinet saw or buy some other piece of equipment that needs that extra power. Also, I have read that rewiring the motor for 220v gives the saw an extra 1/2 HP which could be helpful on occasion.
I'm afraid I don't really understand the significance of your comments re voltage and wires etc. He will be working from a box only 10 feet from the saw and will put in a new breaker, a new line to the saw and configure the inside of the motor to accept the higher voltage. I think your estimate of 2 hours plus is probably close enough to the mark to give me a good idea of what he might charge.
Many thanks
It won't give an extra half horse power. Verify what you read by asking local motor repair shop.
Rich, in his case rewiring to 240 volts will give him an extra 1/2 HP. Delta supplies a motor dual voltage motor that produces 1.5 hp at 120 volts and 2.0 hp at 240 volts. The amperage is something like 13 amps at 120 and 7.5 amps at 240. It's really a 2.0 hp motor that is electrically "detuned" when run with an input voltage of 120.
I've been thinking of rewiring my saw to 220 also. Any ideas if a Rockwell motor also gets any horsepower increase? From memory it's a 1.5 HP @ 3400 RPM's. I'll have to look at the name plate when I get home. Maybe it'll say.
I doubt it. Check the motor nameplate. If it is a dual horsepower motor it will say 1.5/2.0 HP. If it only mentions 1.5 HP then that's all it's ever going to be.
I posted an addendum to my query about rewiring my table saw. Perhaps you could take a look? I think I will do this job myself if I can find a source for some specific directions. Any ideas?
If your subpanel is 10 feet away this job should take a qualified electrician no more than an hour. I could do it in less time and I'm pushing 60 and not that fast any more. To change the cord for the saw is a few minutes at most. The rest of the time will be running a new circuit 10 feet.
By the way, I'm in favor of twist lock plugs for 220 circuits. The cord can't accidentally come loose during operations of between operations. I'd have him install these rather than a simple push plug.
John
Please recommend brand/model numbers for plug & receptacle.
I'd have to go to my local Home Depot to get the actual brand name and model number. (HD is closer than my shop ... I live in a townhouse.)
The receptacle is round and requires a cover with a single circular hole. It's very heavy duty and has the prongs arranged in a circle. The plug goes in and twists to lock it. Thse type of plugs are common on Skilsaws where the framing carpenters do not want to have the saw come unplugged if they yank on the cord.
I'll check the model # but won't be able to post back until Monday at the earliest.
John
For 240V, 20A operation, it's a NEMA 6-20R receptacle, 6-20P plug. Locking versions are L6-20R and L6-20P. 30A versions, which are physically larger, are 6-30R/P and L6-30R/P. HD sells Leviton, I think. They will all say 250V on the strap, along with the amperage, by the way, so check the actual device rather than trusting the box (folks switch them).
Edit: Here's a link to a straight blade NEMA chart on Leviton's web site. Sniff around and you may find the twist lock chart. http://www.leviton.com/sections/techsupp/nema.htm
Be seeing you...
Edited 1/24/2003 3:10:48 PM ET by Tom Kanzler
I don't understand why a new cord would be required? Bumping up to 230v will reduce the amperage draw, not increase it, therefore the existing cord will be more than adequate. Of course, he does need a new plug.
You're correct. Just a new plug is required.
Depends on the cord. If the cord is black white green internally I guess you could use the white wire but black and red with a green would be more standardized. The if you cheap out and use the black white alternative, mark the white as a conductor with tape as an indicator on either end.
As for the wall. Don't just use the std wire. get new wire with 2 conductors 1 white and a bare ground. And as long as you are doing it buy 12 gauge wire. 14 is for individual lighting circuits at the end of a run. The difference in $ is about 2 bucks a roll. You drop that much in wirenuts in a day.
In short you can get away with saving the nickles on the cord by using the white but this is where people get hurt. Skilled people don't use the white for other than a common unless marked (and then only when the wire is imbedded in the wall.) Unskilled people make assumptions and start wiring that white to the other commons in the box.
Do yourself a favor and buy the right cord and this time make it longer so you can move the saw easily.Jack of all trades and master of none - you got a problem with that?
I've personally never seen a cord that is black/red/green. It *is* a good idea to mark the white wire with black/red/blue tape (anything but green) to make sure somebody else knows it's a hot wire.
John
SO cord comes in many varieties. If you look there may be one like that. I sell 5 or 6 manufacturers each of which has 10-30 varieties in each gauge. Now if you want to get into insulation types the list gets bigger.
Whatever color it is it shouldn't be white or green or bare for a current carrying conductor. Period. You can stripe the white or wire tag it but that is the tradition.Jack of all trades and master of none - you got a problem with that?
I know - just tear down the shop and rebuild it with a 240 volt saw in mind.
Or just bury your head in the sand , let it burn, then you can rebuild.
Possibly you can wire it the right way with what is there, but having a ground and a common is pretty essential. I didn't pick up that there were 4 wires from the box to the 240 volt outlet in the description of the project. Without that it isn't code, legal, or smart. I think there is a responsibility for the guy wiring to make it safe for the next schmoe that buys the house from him. After all we're trying to elevate ourselves and others in these forum. If all the wires were tagged with the correct information it could be OK but why not do it the right way.
Frankly the guy rewiring the motor seems a bit gunshy of the project. Shows some intelligence in being cautious. It isn't essential he does it now. Jack of all trades and master of none - you got a problem with that?
With only three wires it IS code and legal, at least where I live. You do not need the neutral wire on a 220 circuit. Tom
I can't speak for code. Why a 120 volt outlet needs a separate ground and a common and a 220 volt needs only the ground. Why wouldn't that be redundant as well. I don't see the sense.Jack of all trades and master of none - you got a problem with that?
Booch,
Respectively, just how would you wire that? A 240 volt circuit with a neutral? I don't think it's required. In my system, I get 120 v across either hot and the neutral, and 240 across the two hot legs. The bare ground is for safety in the event of a wiring snafu.
jdg
I concede that there is not a reason to have a neutral for a 220 volt circuit. Functionally that is true.
Ground surfaces need to be near the outlet for the 220 volt outlet. The earth ground needs to terminate back at the load center. Let me state that more specifically.
The reason for that is the conduit, box, metal face plate, and the ground prong of the plug need to provide the ground for the circuit. They need to provide a better ground path for inadvertent voltage (cruddy wiring) than your body does.
If you don't have a ground, then the machine you are running is not grounded. IF it is not grounded, then any bad internal wire connection that touches the machine turns the machine into a 120 volt source looking for a ground path. You can get a hell of a poke if that happens. If the machine is grounded, then the breaker can sense the overcurrent and trip.
Now the difference between neutral and ground is similar to mass and weight in my mind. Follow the wire, they are nearly the same. Yes you could mark it (the neutral) as ground, or just put a wire nut on it and keep it to the side for later use.
As for the 120 / 240 off the same circuit breaker. By design the breakers are dual trip devices, either leg can pull overcurrent. You can run both 240 and 120. My inspector only insists that the 240 must come off of a two-pole breaker. I run a detached garage with 120 switched (from the house)for the outdoor light, and 120 (the other leg) for the garage door opener. The only downside is that I need to leave the exterior light on while I run the table saw outdoors. Outdoor mass ripping is lots easier on the lungs.Jack of all trades and master of none - you got a problem with that?
Booch,
Ok,
I appreciate the post. Where do we go from here?
jdg
Hi,
To answer your question, the neutral (common) wire is a current carrying conductor whereas the ground is a protective conductor. Since electricity takes the shortest route to ground, when you ground the frame of the equipment it provides a safe path for the current to flow in the event of a short circuit. For example, lets say the 110V feeder conductor vibrated loose from the equipment mounted motor switch and laid against its metal enclosure. If the equipment were not grounded it's entire metal frame would become hot and since there is no current flow to ground, the overcurrent device feeding it would not trip. Therefore if the operator was grounded when he touched the frame he would become a conductor and could receive a nasty and possibly fatal shock. But since the equipment is grounded, the current will flow hard and fast the instant the conductor touched the metal and will cause the overcurrent device (breaker, fuse, etc) to trip and protect the operator.
If you were to ground the neutral to an ungrounded equipment frame, it would turn the frame into a current carrying conductor and create a safety hazard for the operator by possibly subjecting him/her to feedback voltages from other devices in the system.
With that said, ALWAYS GROUND YOUR EQUIPMENT with a separate grounding conductor. The NEC code has a pretty extensive section devoted entirely to this. If in doubt, hire a pro.
Booch,
A 220 circuit does *not* require 4 wires. The 4th wire, the white (neutral) would only be required if the device used both 220 and 110 volts (like an electric oven, where the 110 volts runs the clock).
A circuit that is strictly 220 volts requires two wires for the hot legs and a 3rd wire for the ground. Typically (for conduit) these wires would be color coded black and another color that was not white or green (for the hot legs) and the 3rd wire would be green. For a circuit that was run using romex the colors would be black, white, and the third would be bare (for the ground). In this case the white whire would be wrapped with colored tape in both the subpanel and the outlet box, to signify that it was not a neutral.
WARNING: There has been lots of discussion here about what is legal and what is not, etc. This topic isn't rocket science, but anybody who is not absolutely sure of what they're doing should consider hiring an electrician to add a new circuit. See my earlier posts about safety, etc. This can be an extremely hazardous thing to do.
John
John
Very good explanation of this. Didn't realize there was this much confusion out there on this.
When/if I wire my saw 220 I will wire in a neutral (4 wires), but only because I will be adding an auxillary outlet. Which I will use to run the shop vac I currently use for a dust collector, and possibly a work light.
Question, I had planned to put in a box mounted round glass fuse to seperately protect this 110VAC outlet. I'll screw a 15 amp slow blow fuse in, the saw circuit will be 20 Amps. I realize this isn't really necessary, but do you think this is a good idea, and is this the best way to do this? Oh, my saw motor says it draws around 8 amps at 220 and the vacumn is supposedly 6 amps 110.
Thanks
Billy
Billyg,
You're complicating this and what you propose is, I think, not code.
A 220 volt circuit should be dedicated. You're proposing using one of the hot legs of the 220 volt circuit for a separate 110 volt outlet. What that'll do is use up more juice on one of the hot legs of the 220 volt circuit. I'm sure that's not code. A 220 volt circuit that includes a neutral is not for separate devices ... it's so that the 220 volt device can run a very small 110 volt "function". A separate dust collector wouldn't fall into that category.
You should wire up a dedicated 220 volt circuit and have another (15 or 20 amp) circuit for the 110 volt outlet. No need to complicate things.
We're getting far afield here from the general topic of fine woodworking. My general advice would be this: if you're familiar with the national electric code and feel that you can handle wiring tasks safely, then go for it; if you're not, hire a competent electrician.
John
Thanks, I did have some reservations on unbalancing the load. Just have some 4 pin locking connectors I got on clearance and trying to keep it all in one plug. Your right, I should keep it simple. I'll probably do that by leaving the motor 110. I may use the 4 pin connectors and a 220 breaker and run two 110 circuits to the saw, one for the motor, and one for other things.
Thanks for the help.
I am familiar with the code, but haven't cracked a code book in 3-4 years, not working with electrical stuff professionally anymore, and haven't even looked at the latest NEC codebook.
I have reached the point where I am competent with single phase systems, but completely clueless on 3-phase systems. If I ever need help on code things I'll ask my neighbor for clarification. He's a real electrician.
Be Safe.
Billy
Actually, what you're proposing is not a violation per se, and is considered a multiwire branch circuit. Article 210.4(c) Multiwire Branch Circuits, Line-to-Neutral Loads, states "Multiwire branch circuits shall supply only line to neutral loads.", but Exception No. 2 states: Where all ungrounded conductors of the multiwire branch circuit are opened simultaneously by the branch-circuit overcurrent device." A 2-pole breaker would satisfy this requirement. 210-4(b) also requires a multiwire branch circuit serving two devices on a single yoke, like the 120V and 240V combination devices they sell in HD (240V 15A on top, 120V 15A on the bottom), or a duplex 120V receptacle served by two different branch circuits (with common neutral), to similarly be opened simultaneously as described above. That way someone thinking they they've shut off the power to the receptacle doesn't get zapped by the other ungrounded conductor. The NEC Handbook even shows several examples of what I've described.
But I agree with johnhardy that it's not a very good way to wire a saw. I wired the garage in my last house that way only because there was a leftover 10-3-G from a JennAir right where I need it inside the wall, and it was extremely hard to run new cable (mostly slab, mini basement at the opposite end). I was able to install a couple of 120V 20A receptacles and a 240V 20A receptacle for the saw and other tools as a multiwire branch circuit (there was only one 15A circuit in the garage, on the family room circuit - not good for larger motors). But I only ever run one machine at a time, with no lights or anything on machine circuits. Now that I have a better house, 120V and 240V circuits are separate.
Keep it simple if at all possible.Be seeing you...
Thanks, good to know it wouldn't be a code violation. I didn't think it was, but wasn't totally sure. You guys have convinced me though, I won't mix 110 & 220 circuits unless I have no other choice.
Just thinking of options for wiring my shop. I've been picking up components for the last couple years. Got them stacked around everywhere. Got all the expensive stuff, just need some more boxes and maybe some wire. Time to get serious, draw up a plan, and install stuff.
In a past life as a general contractor (specializing in solar heating), I had lots of run-ins with plumbing and electrical inspectors. That taught me to keep things simple so I didn't have to argue whether what I did was code or not.
In your case, the 10/3 wG was a 30 amp circuit. If you ran the wire to a 220 outlet and several 120 outlets, I suspect that you violated code in that the wiring was 30 amps and the outlets (and, perhaps, the wiring from your Jenn-Air box to the other boxes) were only rated at 20 amps. That is, unless you replaced the 30 amp breaker with a 20 amp one.
What I'd have done in your case was use the 30 amp breaker to supply a mini-subpanel and then run separate circuits from there. You could have had a dedicated 20 amp 220 volt circuit and several 20 amp 120 volt circuits.
In any event, I would recommend to anyone rewiring their shop/garage to at least pull a permit and have the work inspected. This is cheap insurance to ensure that it's done properly. Not to mention the fact that if there is a problem and someone is hurt or there's a fire ... and the wiring was non-standard and not permitted or approved ... that the insurance company could legitimately deny any and all claims. That could get *very* expensive.
John
I had replaced the breaker with a 20A. And you're also right it would have been cleaner to simply install a small subpanel. I had tossed the Jenn-Air; that's why I knew the cable was in the wall (actually a brick enclosure in the kitchen that backed up to the garage wall) where I stored the machines. It started as a 240V circuit only, with the neutral coiled and nutted, but the need for 120V that wouldn't darken the family room and the garage (with me in the middle of a cut) every time I used it caused me to expand it to 2 120V receptacles.
Legal or not, it's not the best way to power a saw and other machines, and I'm not recommending anyone else do it this way. And I also wouldn't normally do something that would have to be argued with the inspector (there's a thread running on Mike Holt's forum about the breaker size for 12 ga powering an A/C condenser unit, and no, it's not 20A max, though the inspector says it is). If I hadn't known I wasn't staying in that house for only a little while, I'd have invested the time to put in a 60A subpanel, but in hindsight, the 30A would probably have served just fine.Be seeing you...
Can't rebuild it - you don't have anyplace to plug your 230 volt saw into. LOL
Rewiring the saw itself to 220 is generally not a big deal and most instruction manuals show you how to do it. But since you're having to rewire your shop to 220 you definitely need an electrician. I think your reasons for installing 220 are sound.. and you might ask your electricial if 3 phase is available to your home should you one day need that, too.
I posted an addendum to my query about rewiring my table saw. Perhaps you could take a look? I probably will do the job myself if I can find directions somewhere. My Delta manual does not contain the info. Any ideas? Thanks for the initial response.
I don't have that saw, but it is common for the connection diagram to be either on the nameplate, or under the junction box cover (where the cord enters).Be seeing you...
Many thanks. Will check it out
To all who responded to my query about rewiring my table saw, I am well and truly touched. I found your advice (all good) and, even more importantly, the underlying caring quite remarkable.
Appearances to the contrary, I am not - at least where electricity is concerned, an impetuous guy. When I was young and foolish I worked around high pressure boilers in the Navy and so have had a fair amount of training and experience in how not to be stupid.
I have actually done some electrical work over the years (I put in a new thermostat today that the electrician wanted $146.00 to do and it took about 25 minutes ). Usually I am just following the way it was done before which I am generally good at since I tend to be quite anal (as Billyg83440 aptly expressed it) at times and write everything down and make diagrams as I go along.
In any event, I am a long way from touching anything just yet and I do have a brother-in-law who is a licensed electrician that I can run things buy even though I can't get him up to the house.
Again, many thanks for the great responses.
P.S. I was in touch with Delta earlier today and yes the motor can be upgraded to 220v and they are in the process of gathering up some technical info which should help. I'll let you all know when the baby is birthed.
My message to AmP was supposed to go to ALL the people who responded.
I don't have the expertise yet to send to multiple recipients so please read
10177.29 for my comments.
If you need a book for your wiring, get Fine Homebuilding's book on residential wiring. It's one of the best I've read.
BJGardening, cooking and woodworking in Southern Maryland
Make sure you get the motor leads correctly switched when doing this. I just recently had two of my tools converted and there was a misprint in the manual about which two wires to switch. My bandsaw motor "popped" and then started smoking a couple of seconds after I turned it on. It turns out I fried the capacitor. The manufacturer admitted the misprint and is sending the new part. I converted my DC also but didn't turn it on long enough to blow. Be careful.
Call Delta (number on their website) and ask if your model number saw can be rewited to 220v. If so, ask for them to mail you a schematic that illustrates the rewire. You will be able to do this youself, no problem.
Following this thread I see those who encourage you to attempt the 220 rewire in your garage box and the conduit run to your saw. Unless you are a qualified electrician you should not, under any circumstances, attempt to do this yourself. If you don't like the $385 estimate get another one. You should be able to get someone to do this job for about a hundred dollars less even if he/she has to pull a permit.
Please don't be tempted to do anything that you don't feel 100% competent and confident about when it comes to electricals. Some mistakes you can make only once.
bill
The nameplate on my Delta Contractor's saw states it's HP @ 1.5 at 115 volts and 2.0 at 230 volts, and the current draw is 12 amps @ 115 volts and 8.6 amps at 230 volts. By re-wiring, all other things being equal, you'll get 33% more power with a 43% higher electric bill expense. Electric bill due to the saw that is. Do it. Pay the difference.
jdg
Edited 1/22/2003 9:23:55 PM ET by jdg
Edited 1/22/2003 10:26:14 PM ET by jdg
Many thanks to all who responded to my query regarding the rewiring of my table saw. The information was very helpful.
When the job is done, I'll be back to let you know about any changes (pro or con)in the saw's performance.
Many thanks to all who responded to my query regarding the rewiring of my table saw. The information was quite helpful.
I'll be back when the job is done with any pros and cons as to the saw's performance.
This is the first time I have used this forum and the experience was very positive. Thanks again.
The $385 is outrageous for this assuming you only need to run the new 220 circuit about 10 feet.
However, if you are not familiar with wiring you should stop right now, have a cup of coffee, and rethink this entire process. You could kill yourself really quickly if you make a mistake. I'd recommend running the saw off of 120 volts and forgetting the project. Unless, of course, you could get another electrician to give you a reasonable quote.
What part of the country are you in? If it's Los Angeles, I'd be willing to come over and do it for you, as long as you'll take the time to show me your shop and let me chat for awhile. But you're probably not in this area.
I can't stress strongly enough that you should stay away from the subpanel. I could give you detailed instructions and I'd still be frightened to death that you'd make a mistake.
John
John:
Thanks very much for the feedback (really). It is sound advice and I know it.
I am in New Jersey which is a shame as I would be happy to take you up on your generous offer.
Let me describe the physical layout here to see if you change your mind about me going forward on my own.
My shop is in my garage which is about 75 feet from the main box in my basement. The garage has its own "box" with a 50amp capacity. There are about 6 or 8 circuits in there now with at least four being 20amps. Currently, a dedicated line runs from a 20amp breaker to the saw which is about 8 feet away. As I understand it now, what is needed is as follows
1. open the motor and change the setting to 220v (or as they say 230v)
2. change the plug on the saw's cord.
3. put in a new 220v receptacle and attach the line from the box to it.
All the above done while the power is shut off at both the auxiliary box in the garage and the main box in the house.
The only danger I see is when I throw the master switch back on (which I do with some rubber insulated pliers) and when I put the saw on which I do the same way.
What do you think?
Take care.
Your methodology sounds fine. Don't get the rubber pliers, but can't hurt.
I would recommend getting a decent book on residential wiring. One with lots of pictures. Well worth the money. Also get a electrical test pen and use it to verify there is no power before you touch anything. Probably $25 for the book and $10 for the pen. Both will be useful for later electrical projects.
What you're doing isn't difficult. It's just electrical work is one place where you need to be excessively anal.
First make sure there is a wiring diagram in the motor connection box. If there isn't take it to a motor shop and have them switch it. If you don't fully understand the diagram take it to a motor shop. Should be fairly cheap for them to do that. I bought a used saw. Had to have the motor fixed. Was a good deal, but they wired the motor to turn the wrong way. Was pretty simple to change. 110-220 isn't usually difficult either, with a diagram.
You didn't mention if there was any extra room in your box. You will need to replace the 20Amp 110 breaker w/ a 20Amp 220 breaker, which will use 2 slots instead of one.
You may need to run some conduit to your new saw plug. If there's room in the box I'd just leave the old saw outlet alone and add a new circuit.
If you're not totally sure what to do, study until you are. Make sure you pull a permit and get it inspected if required in your area. Check w/ the local electrical inspector before you begin. Even if not required they may inspect your wiring before you power up. Usually w/o a charge. Never hurts to get a pro to look at your work. Even electricians make mistakes on occassion.
If you decide to do this. Good luck. Learn lots. Electrical work is fun, and you can save some serious bucks doing it yourself. Just do it right.
Forgot to mention. Look at the book before you buy it to make sure it covers what you are doing. Some of these books are pathetic, and some are really good. HD's is not very good, got it as a gift once. Don't even think it covers 3-way switches, much less 220 wiring. Know it had nothing on 4-ways. Doesn't even acknowleded galvanized plumbing pipe exists. Pretty useless book.
Edited 1/23/2003 3:25:54 PM ET by BILLYG83440
I found your message really great: at every level. The need for caution and patience came through loud and clear. I will pay attention!
I have looked around (mostly at HD and Woodworkers Whse) and couldn't find any dealing with this subject- especially the kind with lots of pictures. I will look around some more and F/U on the test pen as well.
I don't know if you were/are a teacher but if you aren't you could/should be.
Again, many thanks. Will let you know when I get this project done.
Thanks for the compliment. I have thought often of going into teaching. My distaste for restarting college has stopped me for a long time. Too lazy I guess.
I wish I remembered the books my electrical instructor recommended. From a poor memory I believe that Popular Mechanics puts out a good one. But, there may be better ones. I'd go to a Barnes & Noble or look in the bookstore at this site.
Maybe someone with more knowledge will have some recommendations on specific books.
Not to worry. I am a real book hound and will find the right one before long.
If you get a chance, take a look at 10177.29 and 10177.30
Mike,
I agree with Billy on this, get the book and circuit tester! It's not that difficult (I did it myself in my shop), but I wouldn't have tried it without reading about the wiring in a book. 220 is a little different animal (you've got two "hot" wires instead of one). I also agree with the advice to stop and have a cup of coffee and think before you do anything.
Be Careful,
Jim
What you need to logically do is this:
1. Shut off power to the subpanel in your garage. There should be a 50 or 60 amp breaker in the main panel which handles the garage subpanel.
2. Replace the 20 amp breaker which powers the saw circuit with a 20 amp 220 breaker. This breaker can be the same size as the current breaker or can be twice as wide. Depends on the manufacturer. There is usually a way to incorrectly install a 220 breaker so that it provides 110 volts on each leg but from the same buss bar. The potential between the two legs wouldn't be the required 220 volts. You need to have the 220 breaker attached to both buss bars in order to have 220 volts (potential between the two hot legs).
3. Run another hot wire to the saw outlet box. You can pull the white wire out and have it drag along a colored wire ... anything but white or green. I'd go with red or blue.
4. Attach the black wire from the original run plus the new colored wire to the two screws on the breaker. Each of these wires will supply 110 volts (one from each of the two buss bars) and together they supply 220 volts.
5. Hook up the two colored wires to your 220 volt receptacle.
6. Take the current power cord and replace the plug with one that is compatible with the receptacle. As I said in an earlier post, I prefer lockable plugs and receptacles for 220 volts.
7. Open up the saw and change the black and white wires so that they are in the 220 volt position. There should be an obvious diagram.
8. Put the cover back on the subpanel in the garage.
9. Turn off the new circuit breaker, and then turn on the main circuit breaker in the house. Since the new circuit breaker isn't on, everything should be fine at this point.
10. Turn on the new circuit breaker with nothing plugged into the new receptacle. All should be well here. If the circuit breaker pops you've got a short.
11. I'd use a volt meter (get an inexpensive one at the hardware store) to check for 220 volts across the two hot leads of the new receptacle. If you don't have 220 volts here, you've got the breaker installed incorrectly ... it's not across the two buss bars in the subpanel.
12. If you have 220 volts, plug in the saw (with the switch in the off position, of course).
13. Turn on the saw and see if it runs.
WARNING: If you're not comfortable doing this safely I'd leave this as a 120 volt setup. You can cause deadly results if you don't know what you're doing. If you've never worked with electricity before this is not the time to start. For instance, do you even know how to wire up a plug? Which way to you face the loop of wire over the screw before you tighten it? Do you know how to strip wires without nicking them? If you nick the wire you have created a problem. I haven't covered lots of things here, and really cannot do so adequately in a post to a forum.
RECOMMENDATION: Leave the saw on 120 volts.
John
Edited 1/23/2003 7:48:48 PM ET by johnhardy
Please see 10177.29 and .30 for some comments. Your post was great. As an aside and just for the record, I am not the kind of guy who would respond to a kindness with self serving rationalizations e.g. suing someone if I happened to injure myself as a result of my own ignorance . Neither is my wife.
I will be very careful and thorough.
Mike,
A book I found useful for wiring not only my tablesaw but for housewiring in general is "Wiring Simplified," by H. P. Richter and W. C. Schwan (38th ed.), published by Park Publishing, Inc. of Minneapolis. It's basically a condensation of the 1996 National Electrical Code and is available at Home Depot in the electrical dept. If you're indeed anal (like me) you'll read it cover to cover (but chap. 14, "Wiring of Heavy Appliances," chap. 17, "Farm Wiring," and chap. 18, "Electric Motors," are the ones you want).
Edited 1/23/2003 8:55:19 PM ET by CHEAKAMUS
OK, if you're going to proceed you need to get the Richter book (I was looking for the author and title and someone beat me to it ...) and read it well.
Next, make sure you have absolutely no live wires in the subpanel when you take the cover off. All of the breakers should be dead when you throw the breaker in the main panel which controls the subpanel.
Pull a breaker and see what the manufacturer and model is. Take that information and go buy a 220 breaker from the same manufacturer. Ideally, take the breaker with you in case there are questions.
Note that there are two main buss bars in the subpanel. Each of those is fed from the live wire coming from the main panel. The potential from one buss bar (110 volts) to the other (110 volts) is 220 volts. Ensure that you install the new breaker so that it "straddles" both buss bars.
When you run the new wire, ensure that it does not get nicked in any way. Buy some wire strippers so that you can strip the ends of the wire without nicking it.
If you need to put an end of the wire around a screw in the receptacle, take some needle nose pliers and create a 270 degree semicircle which you can slip under the screw head ... and ensure that the loop runs clockwise. This way the tightening of the screw will tend to close the loop, rather than open it.
Always ensure that your wire ends do not touch anything other than the desired metal ... i.e., the screw on the receptacle. If you strip the wire with too long an end, and it sticks out, it could contact the metal electrical box and create a live situation which could be deadly.
Lastly, I think you got some good advice from someone else to get a permit and have this inspected. The inspector will be very nice to you and point out anything wrong. You seem careful, and if you do the above you should be OK. But I'm still of the opinion that you really don't need to change the voltage of the saw and you could leave it as is ... which would save some $$$ and a potential problem, serious or otherwise.
Good luck in whatever you decide to do.
John
Thanks again John. Will keep in touch
Got the tester at HD today. They didn't have the Richter book but I ordered it through Barnes and Noble today and it should be here in a couple of weeks. Gives me some time to do a little more research. I already have the correct cable, receptacle and plug info and have asked Delta for a schematic although there is a diagram right on the motor housing.
I'm in pretty good shape and think increasing the saw's power by 33% is worth the effort. It's too cold to do anything out there right now so I'll wait for the book to arrive and meanwhile gather the necessary material.
Will keep you in the picture. Thanks for all the help.
You don't describe the plug and receptacle. Locking ones aren't "required", but whatever you do you should *not* use a normal receptacle and plug. You need to prevent folks from inserting normal plugs into the receptacle and getting a nasty surprise. Good luck with this project.
John
$375 is outrageous, but electricity isn't to play with. I've done some wiring, but first I paid a Master Electrician for a morning to do two circuits and teach me. Then I asked him to inspect my wiring the next two times and to put the circuit breaker in the box. The subpanel is SCARY! It's quite easy to make a mistake because there's no evidence of how dangerous it is. If you are sure you want this 220 circuit, do everything up to placing the circuit, and hire an electrician for 15 minutes. (Even in NJ that shouldn't be more than $60.)
Good luck.
"...do everything up to placing the circuit, and hire an electrician for 15 minutes."
Doing this requires that you open the subpanel to run another wire to the outlet box. That is extremely dangerous if you don't know what you're doing. Never, never, work in a subpanel with the power turned on. Trip the breaker which powers the subpanel before doing anything inside.
My warning to leave the saw as 120 volts still stands. If an electrician needs to be hired, I'd hire him for the entire job. I could do the above work in an hour or less and I'm almost 60 years old. I ran an entire new 220 volt circuit for my son's hot tub in an hour recently, and that involved running up a garage wall, across the roof of the garage, down the other side, and punching through the wall to install an outside panel. All was done in conduit and it was complete in an hour.
If you know what you're doing this doesn't take long. If you don't know what you're doing this may be the last thing you ever do on this earth.
John
> ...1. open the motor and change the setting to 220v (or as they say 230v)
Yes, that's usually only a matter of changing a couple of wires from on terminal to the other. There should be a diagram on the inside of the plate that covers the wire connections on the motor. At least every elec. motor I've looked at that was dual voltage had such a diagram.
> ...2. change the plug on the saw's cord.
Yes. But you should find out what amperage the motor is designed to draw at 220/230 volts and get the appropriate plug/outlet combination. Your "trim" devices should match the loads they will be subjected to. I know the advice to use twist lock plugs is alluring but I don't necessarily subscribe to that approach.
> 3. put in a new 220v receptacle and attach the line from the box to it.
Yes ... and no. You'll need to install a 220/230v breaker in the panel. You'll have three wires to contend with: red, black and white. The red wire goes to on lug of the dual post breaker, the black goes to the other. The white wire goes to the nuetral bar of the panel. This wire goes out of the panel to the new 22/230 outlet where you plug in the saw.
> All the above done while the power is shut off at both the auxiliary box in the garage and the main box in the house.
If throwing the breaker at the main panel kills the garage/shop panel, there's really no need to turn off all the electricity in the house to install the new breaker. If you're worried about someone accidentally turning that breaker on while you're working on the project, just go out to the elec. meter, snip the seal on the meter base cabinet and pull the meter out. That kills everything from the meter base to the house side. But that's kinda overkill. And handling an electric meter isn't kid's play, either.
...........
Dennis in Bellevue WA
[email protected]
Thanks very much for the info. The only question in my mind now is whether I need to change the wire currently in place running from the 20A -110V circuit breaker to the receptacle. The wire is 12AWG/2 and the guy at HD was quite insistant that a new line was required that had 3 wires inside for proper connection to the new receptacle.
Any thoughts?
Thanks again.
Mike
Mike,
Tons of good advice here. Some not so good in my opinion. Bottom line: You don't need an electrican. I'm no electrician and I replaced my whole panel (maybe 4 hours max including shopping) when I wanted to add a 50 amp welding outlet. Yes guys, my feeder was properly sized for the upgrade.
Suggestion: go to your home center and spend the $10 to $20 bucks for a well illustrated complete guide to home wiring - or any other book that covers the work you're going to do. My Black & Decker book doesn't cover motors, but the diagram on the motor should be sufficient. Another suggestion: Don't shock yourself - but if you do, you'll probably be ok. Don't hold me to that.
The 12/2 WG (assuming that you do have a bare ground wire in there) that you have will work. What you'll be doing is changing the white wire from a neutral to a hot by moving it from the neutral bus in your panel to the second hot terminal on the new two pole 240 volt breaker that you'll be installing. The bare wire will still remain as your ground. You don't need to replace the white wire with a colored wire or anything like that, but in the sake of prudence, you should mark the white wire on the outlet end with either black electricians tape or a black marker as hot - someone may come behind you.
I've attached a drawing of the changes you'll be making in your panel. Check me out guys. Make sure I don't have anything afoul here.
jdg
Edited 1/26/2003 10:53:58 AM ET by jdg
Very, very helpful - especially the drawing. Thanks a lot for the info and your time.
Mike
Mike -
How old is the existing wiring that runs from the panel to the existing plug? Hard to imagine it would be merely 12/2 (without a ground). But then, the ground wire in this wire is probably bare rather than insulated as is the case with a true 220v circuit.
This wire would work but as mentioned before, you'd have to tape both ends of the white conductor with (probably red) tape to indicate that it's now a "hot" wire and no longer a neutral conductor. You'd connect the existing black wire and the white wire with the red tape marking to indivdual, separate lugs on the new breaker. But I agree with the guy at HD - this isn't a proper installation ... in my view. For the measely cost of a few feet of wire, just replace it. If the wire's hidden in the wal, abandon it and use flexible metal conduit and wire it on the surface of the wall.
Replace the wire is my suggestion.
...........
Dennis in Bellevue WA
[email protected]
Codes may be different from stste to state but I have 11 220 circuits in the panel in my shop and all use 12/2 or 10/2 awg with ground. The ground is not insulated on any of them and most were installed by an electrician when the house was built, the others were added as I aquired equipment. I would say the wire you have installed is fine. I don't put a whole lot of stock in home depot advice. You do need to check the ocal codes though.Tom
The garage was only wired up about 18 months ago. I checked the wire twice and the labeling on the sheathing is 12 AWG/2. They have a nice chart in the electrical dept at my local HD and I spoke at length to the guy there (who is licensed and retired) so he knows what I'm up to. The consensus seems to be that the best route would be to replace the wire from the panel to the saw with 12/3.
As I said elsewhere, I'll wait till that book arrives so I can have some visual representation of what's being discussed here.
Thanks again.
Edited 1/26/2003 5:15:12 PM ET by mike
Edited 1/27/2003 8:55:57 AM ET by mike
I seem to remember asking this before, but just what exactly are you going to do with the extra wire with only three pins on the plug?Be seeing you...
Tom's question is subtle - but it is all you need to ask yourself. What are you going to hook all those wires up to? Replace that wire and you'll find yourself at the end of your project asking why you went to that trouble just to cut a wire short, coil it up and hook it to nothing. The plug you'll be using has three prongs. Two are juice. One is ground. The ground is just like on your extension cords and stuff and the bare wire hooks up to that one. The other two prongs are hot and the black and white hook up to those. Add any other wires and you'll have to add a few extra prongs to your plug to accomodate them, or what you'll do with them I don't know. You only need two insulated hot wires, and one ground and the ground can be bare.
jdg
Edited 1/27/2003 6:55:06 AM ET by jdg
So far the only person telling him he *had* to replace the wire is the guy (retired electrician) at the store. I suggested he change the wire since proper 220/230v circuits are wired with three wires, black, red and white. The white wire is the neutral and it goes to the nuetral terminals on the plug and on the plug. There are still only three wires. No bare ground wire as with 12wground. 12/3 has only three wires. And I maintain that if you disconnect any 22v appliance in your house, stove, dryer or the like, you'll find the plug has an insulated ground/neutral wire.
Yes, the 12/2 will probably work. But remember what the neutral ground wire is for - it's to carry any short cirtuit back to the panel where the circuit breaker is designed to open the ciruit and prevent fire or other damage. The ground wire in the 12/2 may not be sufficient to carry the amperage plus not being insulsated if there's a ground fault it could present an electrical hazard.
There's a reason why 220v wiring is done the way it is. I don't see any reason not to do the job properly since it's only the cost of a few feet of wire.
Nor do I intend to get into a shouting match over the subject. It's just my opinion and no, I'm not an electrician. Just a dumb architect with nothing better to do than turn otherwise useful dead trees into sawdust and shavings. (grin)
...........
Dennis in Bellevue WA
[email protected]
Dennis,
Perhaps I could have found a better way to say what I had to say. :)
I'll refer to my book:
There are three types of 240 volt circuits listed in the reference that I have
1) 240 volt, 20 amp appliance (as in a small window unit AC [or a table saw]) receptacle - wired w/ 12/2 WG - bare ground - black & white insulated conductors with the white coded for hot.
2) 240 volt Baseboard Heaters - wired w/ 12/2 WG - bare ground - black & white insulated conductors with the white coded for hot.
3) 120 / 240 volt 50 amp (like a kitchen range) Appliance Receptacle - wired w/ 6/3 WG with the bare ground wire - the black and red are connected to the terminal screws on the breaker. The white to the neutral buss in the panel and to the neutral terminal on the four hole outlet. The ground to the ground buss in the panel and to the metal outlet box. This raises a question for me that I don't have the answer to. Four holes on this 50 amp outlet and three wires connected to it? Seems the book overlooks hooking the bare ground to the fourth terminal on outlet as well. Some 50 amp outlets are 3 hole, some four. Though the photo in my book shows a four hole outlet, the wiring diagram seems to be for a three hole outlet.
jdg
Edited 1/27/2003 7:31:18 AM ET by jdg
Edited 1/27/2003 7:31:35 AM ET by jdg
Edited 1/27/2003 8:28:55 AM ET by jdg
jdg - it sounds like the book is either using the wrong graphic, or the receptacle grounds through the strap, which of course would only work if the box is metal (and the device is listed for it). Here's a link to a NEMA straight-blade plug/receptacle schedule. The old style dryer and range receptacles/plugs were 3-pole, 3-wire devices, for 2 hots and a neutral (no ground) a la 10-30R/P and 10-50R/P, and ground was via the neutral (with the little green jumper inside the j-box on the back of the dryer/range). As of (I think) the 1996 Code, new installations (and usually moving of the dryer or range, depending on local AHJ) required 3-pole, 4-wire grounding receptacles/plugs, a la 14-30R/P and 14-50R/P.
Notice on both that the neutral is considered a pole, since the neutral is a Current Carrying Conductor, and it is the grounded conductor. That's not to be confused with the Equipment Grounding Conductor (EGC), which is the bare ground in the case of the 4-wire 120/240V system, and the 3-wire 240V system (think Unisaw). The grounding conductor spends its entire life carrying no current, God willing, but when it's needed in the case of a ground fault, it has to carry potentially thousands of amperes for long enough to trip the breaker and clear the fault (measured in milliseconds).
DENNIS02 - I think you're confusing the Equipment Grounding Conductor and the Grounded Conductor. The grounded conductor is needed in a 120/240V Edison system to get 120V, no other reason (as far as branch circuits go). All neutrals in typical residential systems are grounded; it's the center tap of the transformer, and it's tied to mother earth and the neutral at the service entrance only. If one of the ends of the transformer secondary was grounded instead, you'd have 120V at the mid-tap and 240V at the other end as measured to ground, both at the same polarity (both positive or negative at the same time). In a residence, the highest potential to ground is 120V (ok, purists, it's ~170V at the top of the sine wave, but who's counting), so during a ground fault the bare grounding conductor will handle the same voltage potential regardless of whether the branch circuit is wired 120V or 240V. The neutral is grounded by definition, so it's not called a "grounded neutral". I'm not trying to be pedantic for the sake of it, but there is a distinction, both in the Code and in practice. In fact, I believe the Code requires the ground conductor to be either bare or green; white is neutral only, and is always a current carrying conductor, whether it's carrying any or not at any particular time (think multiwire branch circuits with balanced loads). It also is usually required to be on it's own terminal in the panel, not shared with any other, whereas grounds can be shared (sometimes, if the lugs are listed for it).
Sorry for the long tirade. The coffee's good this morning.
http://www.leviton.com/sections/techsupp/nema.htm
Be seeing you...
Sometimes, just when you need it most, someone will come along and clear things up. Thanks Tom. You're a wealth of information that was needed here.
jdg
"And I maintain that if you disconnect any 22v appliance in your house, stove, dryer or the like, you'll find the plug has an insulated ground/neutral wire."
The plug does but the receptacle does not. Your welcome to come open eiher panel at my house and you will find that all 15 of my 220v circuits have a bare ground. The ones that have 3 wires and a ground are 220/120 circuits (dryer/range) and they have 12/3 and a bare ground. All installed by an electrician and inspected to meet code.
Maybe your area has a different code requirement.Tom
To: Tom Kanzler, Dennis02, JDG
Thanks for the info. Having said that, I should also say I am probably going into overload. In the wire designation 12/2, I know the 12 refers to the wires thickness with a lower number meaning greater thickness which in tern relates to how much electricity can pass through that wire safely. I was under the impression - obviously wrong - that the 2 referred to the number of wires under the sheathing. From reading your various postings, it appears that 12/2 has 3 wires (leads?) inside and 12/3 would then have 4. Is this correct? The plug I have selected does indeed have 3 pins in the plug. Assuming 12/3 has 4 wires then I do have an extra and don't have an answer to your question.
Regards
Mike
The sheath of NM (Romex) will say 12/2 with ground, 12-2-G, 12/2/G, something like that if it has 2 current carrying and one ground (bare) conductor. It will say on the sheath whether or not there is a bare ground, but I'd be amazed if there wasn't. Open the box or panel and look at the cable; one black, one white, one bare. This is the normal style used to wire branch circuits for 120V or 240V (but not 120/240V) in most houses these days. There are special cases where 12/3/G (or 10, 14, or some other gauge, for that matter) are used, such as electric baseboard heat with receptacles, ceiling fans, three- and four-way switches, and "multiwire branch circuits" (shared neutral circuits), to name a few.
Flexible cords, such as SJ, SO, etc. count the ground conductor along with the current carrying conductors, so your saw cord would say 12/3 (or some variation) for 2 hots and a ground, or hot/neutral/ground. The ground is those cords is insulated (green), and so is counted with the other conductors. Your saw almost certainly has one black, one white, and one green. If a 4 conductor cord is used, the fourth is red.
So, the answer to my question ("...just what exactly are you going to do with the extra wire with only three pins on the plug?") is, you shouldn't have an extra wire, but if you do, because you already replaced the existing cable, just coil up the white wire at each end (wire nutted so it doesn't become hot by laying against anything) and use only the black, red, and bare. If you haven't replaced it yet, install a 2-pole breaker, put the black and white under the two screws (you may want to cut a little off the end of each and restrip without nicking the copper), leave the bare on the ground bus, tape the white with black tape at each end (to indicate it's hot and not a neutral), change the receptacle to a NEMA 6-20R (actually, I'd do that before connecting the new breaker), which your Unisaw should plug into right out of the box, TEST IT with a VOM or other tool to make sure there is 240V +/- between the hots, and 120V from each hot to ground, and cut some wood. Shut off the panel, or both if it makes you feel better, before you pull any covers.
By the way, are you SURE there isn't anything else on the circuit you intend to change to 240V? It would stink to fry your garage door opener, but worse, anything with an exposed neutral (like the screw base of a light bulb) would then be at 120V.
If you're as uncomfortable doing this as you seem to be, call a different electrician. With the wiring in place already, this whole job would take 15 minutes if he/she takes their time. Seriously.Be seeing you...
Mike,
12/2 would be romex with two insulated wires, black and white, with no ground wire. I'm not even sure that wire is sold. 12/2 w/G would be the same two wires but with an uninsulated (bare) copper wire for the ground.
If you have romex running to the current outlet box, it is probably 12/2 w/G. The black carries the 110 volts, the white is the neutral, and the bare wire is the ground.
You really don't need to run new wire for the new 220 volt circuit. What you'd do is use the black and white wires as the two hot leads for the new circuit (which does not have a neutral). But good practice is for you to wrap the white wire in both the subpanel and the outlet box with black tape (or blue or red tape) to show that it is not a neutral wire anymore.
A 220 volt outlet has two connections for the not leads and one connection for the bare ground.
A somewhat more anal retentive method of running the new circuit would be to use conduit on the outside of the wall, and run a black insulated wire, a red insulated wire, and a bare ground wire. This way it's absolutely clear (in the future) that this is a 220 volt circuit.
John
Mike, the cost is correct, the result will be correct and..... Finally... don't take a lot of stock in the advice you get here about electricity....Yes, I do know the correct answer and it is simply to hire a qualified electrician.
I don't agree. In my woodworking as in my life in general, I am committed to the belief that we can change and grow and learn. Electricity is dangerous which suggests caution and respect. It is not brain surgery and rewiring a table saw is not one of the more complicated procedures within the discipline according to the many non electricians who have successfully completed the task.
As to the price, again I don't agree. I think it had more to do with the inexperience of the two "kids" the owner sent and how that owner believed he could most profitably use their time. They had never rewired a motor before and seemed quite inexperienced. Maybe it was the bosses way of getting out of an awkward situation. He wanted $146.00 to install a thermostat which I had already purchased. I did it myself later in the day (correctly and safely) in 25 minutes. I have found (many times) that you don't always ( nor in today's world even mostly) get what you pay for .
Please don't take this personally. You sound like you might be an electrician and if you are, I'm sure you do good work but I'm also sure you don't need me to tell you that there are a lot who don't.
A competent, experienced electrician could have done that job in less than an hour with, at most, $25.00 in materials costs. Even by today's standards, $360.00 per hour for labor is off the wall.
P.S. The job was described in detail over the phone when the appointment was made. I thought the two guys should have been more prepared and the boss should not have sent workers who had never rewired a motor before.
Edited 1/23/2003 9:38:16 PM ET by mike
This is not a big deal. I changed my Delta contractor's saw from 110 to 220 in 1995. It is so simple, it is ridiculous. This assumes that your motor is capable and wired to change from 110 to 220. If that is not the case, then all bets are off. Elecitricity and plumbing are the bane of my existence, but this went just fine. Just make sure you get a plug that will fit into the socket when you are done!
BB
It is the case. It says so right on the motor housing plus a wiring diagram.
I already have the receptacle and plug but am waiting for a book that was suggested so I have a clear overview of the job. I spoke to a licensed electrician at HD this morning and he told me that I would need new cable . I now have 12AWG/2 which only has two lines in it and 220v requires 3.
Thanks for the feedback.
P.S. I think increasing the saws power by 33% is worth the effort at
least until I move up to a cabinet model ( Iike this saw very much but always kind of wished I had gone with the Grizzly 1023s)
Edited 1/24/2003 3:24:31 PM ET by mike
I spoke to a licensed electrician at HD this morning and he told me that I would need new cable . I now have 12AWG/2 which only has two lines in it and 220v requires 3.
240V requires exactly the same wiring as 120V, ie 2 current carrying conductors and a ground conductor. The only difference between the two is that, for 120V circuits, one of the current carrying conductors is grounded (the neutral) and is white, and for 240V circuits, no current carrying conductors are grounded. White is acceptable for one of the current carrying conductors if it's taped black or red at each end (to indicate that it's hot, and not a neutral). The ground conductor and neutral (if present) are both connected (to each other) at the main panel only.
Perhaps some confusion comes from nomenclature. NM building cable is marked 12-2 w/ground, or some other variation. Flexible cord such as SO, coming from your motor and terminating at the plug (or cord cap), would be marked 12/3, where all three conductors are insulated, the ground being green. But either way, they all have three conductors; two for carrying current (you need a loop, after all), and one for grounding the equipment. As far a being a circuit, regardless of voltage, it still takes two wires.
One last thing. SOME equipment operates at both 120V and 240V simultaneously, and therefore need 3 current carrying conductors and ground (2 hot, 1 neutral, 1 ground). Electric clothers dryers (30A typically) and kitchen ovens and ranges (40 to 50A typically) have motors and/or controls plus lights that operate at 120V, while heating elements operate at 240V. NM cable for a clothers dryer might typically be 10-3 w/ground. The only reason I can think of for anyone suggesting you need 12-3-G is that your local AHJ insists on you having a neutral, even though it won't be connected. And be just as wary of "licensed electricians" in HD as on the internet. Call your local authority and ask them. Or call an electrician. The job should take less than an hour, including coffee break.
Here's a link to something I wrote a while back. Go to the pictures at the bottom, and look at the connection diagram. You'll see what's going on inside the motor, just for you edification. http://forums.taunton.com/n/mb/message.asp?webtag=tp-breaktime&msg=24512.21#a34Be seeing you...
Great stuff. Many,many thanks. I sent away for the Richter book today and am keeping copies of any of these responses with technical info in them.
It will be a couple of weeks before I get the book which is fine as it is much too cold here (NJ) to be out in the shop with the power off.
I will visit the site you included and copy anything relevant.
Thanks again.
Hi Mike,
The price that you were quoted is way out of line! Just to give you a little background, I have been doing electrical for almost five years now,both residential & commercial work. What you are trying to do is fairly simple,but considering you have little knowledge of electricity,I suggest trying to find another electrician. The work you want done should take no longer than an hour. The materials alone shouldn't be more than $50 add another $50 to $75 for labor. I wouldn't pay anymore than $150 for the whole job! Changing your motor from 120v to 220v isn't really a big deal,but if you screw it up, chances are you will ruin your motor,which could cost you a couple of hundred bucks. An electrician can change it over, literally in a couple of minutes.
If you do decide to do it yourself,turn off the breaker that feeds your sub-panel. You will find that breaker in the main panel,it should be a 50 or 60 amp breaker. One last thing! BE CAREFUL!!! ELECTRICITY CAN BE VERY UNFORGIVING.
Edited 1/24/2003 9:48:42 PM ET by WoodChuc1
If you get a chance, read my 10177.35 in response to 10177.34.
I worked in the Fireroom (where the boilers are) aboard Destroyers for 4 years when I first got out of high school. I had the bad luck to see a Machinist Mate killed by electricity in the Engine Room . Bad luck but extremely educational. I haven't/won't forget. High pressure (600 lbs.) steam is , in someways, like electricity. What is inside the line can kill you. To protect yourself, we were taught to shut down EVERYTHING on either side of where you are working BEFORE you do anything else. I still practice that procedure especially when I am working around electricity.
Thanks very much for the info . Funny, your price was pretty much what I had in mind when I called that outfit. Sender # 10177.34 saw it differently. I find this site both informative and quite lively.
I'll get this done although I am in no hurry especially with this cold spell. As I said elsewhere, I think an increase of 33% in the saws power is worth the effort. Learning something new is no small benefit either.
Will send an "all hands" bulletin when the job is done.
Thanks again.
Hello Again,
Just finished reading the post's you mentioned. He does have a point about having it done right,but at that price? I don't think so!!!! If the price you were quoted was only for getting power to your saw,well it's a rip off. This is a job a second year apprentice can do without breaking a sweat. Find another electrical contractor!!!
Best of Luck
Bill Bleiler
Mike:
Your decision to go to 220V is very sound. All of your equipment will draw 1/2 the amperage than they do @ 110V. I am no electrician, but my father has been for nearly 40 years. My shop has 220V for EVERYTHING that can be wired 220V. My tablesaw, bandsaw, jointer, compressor and dust collector.
When the electrician comes he will need at least two open slots in your panel. 220V is almost as simple as it sounds. When he referred to two legs, he needs to have two 110V legs running to a two pole breaker in the panel. This is why for each breaker you have in your panel you will need two slots for the breaker.
I have 200 Amp service in my home. I have a 60 Amp breaker in the basement and 3/6 ga. Rolmex running to a subpanel in the garage. I have 1 - 15 Amp 110V, 3 - 20 Amp 110V, 1 - 30 Amp 220V, 1 - 20 Amp 220V and 1 - 15 Amp 220V in the subpanel. Since is usually only me in the garage I am only running one tool and the dust collector at a time. My tablesaw only draws 9A at 220V and the dust collector like 4 or 5 Amps. The lights are wired to the main panel. So the subpanel is never taxed.
You will need new outlets for 220V and a new plug on the wire to the motor. Rewiring the motor didn't take my father but 5 minutes. There should be a diagram in the owner's manual and all it is is a matter of some wirenuts.
Best of luck.
Thanks for the feedback.
Delta is sending me all the info I'll need re my model table saw. I'm waiting for a suggested book (with pictures) and I think I have just about all the info I need from this thread. The response has been great.
I do have one last question. The saw now runs on a 20A 110V circuit (the service to the shop is 220). The wire (or is the correct word cable) a licensed electrician used and which a town inspector passed on is 12AWG/2. Will this wire have to be changed to include a third line inside it so as to connect to the new receptacle properly? The HD guy said absolutely and was pretty aggressive about it.
Thanks again.
Mike
I see no one has convinced you this is too hazardous to do yet.
You may wish to look at these sites. They cover some of what you're after. I used to know of a better site, but couldn't find it.
http://www.homewiringandmore.com/switchoutlet/dryer/dryershowall.html#2
http://theoak.com/rick/Electricity_in_the_Shop.html
http://www.danswiringpage.com/
Didn't really relook at these much, but they may help some.
Good luck
Edit: Posted twice (post wouldn't take), so emptied out the first try after it did take. Oops.
Edited 1/27/2003 1:13:36 PM ET by Tom Kanzler
The last link has exactly what he needs. Here's a link to the particular page:
http://www.danswiringpage.com/diagrams/220_ac.jpg
Mike, notice that the ground and neutral in the diagram are not connected, or bonded, and your subpanel should be the same way. The 4 leads coming off the box go to your main panel (you said there was a breaker there for the subpanel, I think). Reread the thread while looking at this diagram.
But if you have any doubts about this, please get an electrician to make the connections. Be seeing you...
To All (who responded)
I have info coming out my ears. As I mentioned, I have the Richter book coming in a few weeks and I have made copies of all the posts that contained specific info so that I can go to the recommended web sites at my leisure. This is just the gathering stage for me. As I mentioned (I think) earlier on, I tend to be quite methodical (I was an accountant in another life) so won't actually touch anything until I have the whole job doped out and reviewed/verified by some Higher Power (joke).
Before I even get to that project I want to Really set up and align my table saw in a professional manner (I recently sat in on a presentation by Kelly Mehler) as well as put on a Delta Deluxe Uniguard that UPS just delivered to my door (I had as it appears have many others, fallen into the habit of working without a guard). Rewiring the saw will be the last item on my list of things needed to bring the saw as close to perfection as I can make it and in the process really learn how its made which will help I think when I begin to focus on how to use it safely and effectively. Again as I mentioned (I can on occasion be quite anal at least in the way most of us understand that word) or in more simple times what used to be called persnickety.
Thanks to all of you for all your help. I'll come back into this thread when I am almost ready to actually do the work and run the game plan by you. You have earned that and I am greatly appreciative.
Mike
I thought about doing this too some time ago, have same saw, but read article in Fine Woodworking, I think "get alot of mag's" and article suggested if your motor is 1.5 hp or less it wasn't worth it so I didn't. But besides that doing it is not that hard. Good luck.
I have found it is best to pay by time and materials rather than a flat fixed rate. I had major electrical done and was charged $52/hr for the licensed guy and $32/hr for his apprentice. They basically charged double what they paid for materials at the local supply house. They estimated what it would take to get the service upgrade done, and were just about spot on their estimate for time and materials. For what you are getting done, I'd expect to pay no more than 3 hrs labor (most likely 2hrs) for one guy and maybe $50-75 in materials, figuring a $6 breaker, 10-15 ft of conduit and 4 15 ft lengths of 12 ga wire, a 4x4 box and the appropriate plugs and receptacles. This sounds like a simple job. The motor re-wire is just swapping a couple of wirenuts to make a parallel connection into a series connection. If you are flexible with when it gets done, these guys do like little jobs to fill out partial days on other sites.
I'm leery of trademen who quote jobs as a fixed cost, since I suspect they are looking at their normal rate times a worst case scenario of labor. If the job takes half the time, then they get double their rate. I had a new water service line put in, and got quotes of $1400, 1900, and 2 at $2300 for a 40 ft run of 1" copper in the ground and another 20 ft to connect inside the house. I went with the 1400 guy, and two of them did the entire job in about 6 hrs, which went pretty quick as they bored a 2" hole out to the meter and my yard was pretty soft dirt (an unknown until the boring was done). Figuring $200 for materials, they each got $100/hr. Now think what the other guys would have made per hour. My electric service change cost about the same, and I got alot more labor and materials in the job, so maybe this explains why electricians islike plumbers. ;-)
HI,
I'm an industrial electrician and agree 100% with the person that said to leave it to the pros. $385 sounds a little high but depending on what is required and the area of the country you live in, it may be close. The electrician will have to change the plug, the motor configuration, the breaker in the panel ( will need a 2 pole breaker), and the associated wiring and possibly conduit to the saw. There's a little more involved than just changing around a few wires. Get a few estimates and go with the best. But is it really worth the expense for an additional 1/2 HP.
As you can see, I got a ton of feedback on this thread.
As it turns out, It doesn't seem at this point that the additional 1/2 HP makes that much difference in the saw's performance.
I'm going to go ahead with the project just to have 220v available in the shop in case I ever move up to a cabinet saw or have installed some kind of heating/air conditioning system down the road.
I hope you won't take this amiss, but I don't agree with your opinion about the costs. I have all the materials at hand (new breaker, Romex cable, box,receptacle, plug and diagram to change the motor configuration). All told they might have cost $40.00 if that. That would have left the electrician with somewhere around $350.00 net income for the job.
A lot of guys who responded to this thread calculated that the work could be done in an hour or so. I stand in my shop and look from my electric panel to my table saw some 6 feet away and say to myself " self, I couldn't do this in an hour because it would be the first time but if I had done it many times and did that kind of work for a living, I really believe I could". I also believe that the time involved combined with the level of experience and expertise required does not add up to $350.00. On top of that, I will get a great deal of personal satisfaction when I do the work myself which I have a feeling is a quite a common psychological characteristic of woodworkers in general.
I'd like to interject a personal note here. In 1994, I came down with Rheumatoid Arthritis. Since then, doctors offices and hospitals have become a regular part of my existence and have left a deep impression me. Last Monday, many of the doctors here in New Jersey pulled what would have been a strike if they had been union electricians. The cause of the mini strike/slowdown whatever was the cost of liability insurance (caused in turn by huge negligence awards) which was eating into their net income. You might have seen our President speaking about this subject on TV a week or two ago.
Having spent so much time around and inside the medical establishment over the last few years I have come to believe that medical professional's perception of their financial entitlements has harmed people like me and our country in general. I believe the same could be said for many other professions and crafts.
Somewhere back in this thread, someone posted that they never contract work on a flat rate basis. It's material costs plus labor at a fixed rate per hour times the hours actually worked. Contractors in my area (all of them in all the trades and crafts which I don't think is an accident) won't work that way anymore. They throw a number at you and then stare silently at you to see if you will accept it. If not, they either begin to negotiate downwards or walk out depending on how full their book is. I would not feel comfortable doing my, or any, business that way. May sound sanctimonious, may even be sanctimonious, but I really believe this "something for nothing" stuff has got to stop somewhere and it won't until the "payers" go on strike.
If you knew me, you would know that I tend to be quite free with money if I have it and do without when I don't. The dollars involved in that guy's quote didn't bother me as dollars. It bothered me because I believed it was a rip-off and as such reflected this man's opinion on me and the great unwashed mass of non electricians that we were too lazy,stupid and timid to seek alternatives. I believe that statement could me made about : tilers,bricklayers,carpenters,doctors,accountants,lawyers etc., etc.,etc,. It's an attitude I'm going on about here not a specific craft or profession.
Rheumatoid Arthritis took away a great deal of my body's ability to take care of my world . It hasn't however touched my intestinal fortitude so I will continue to try to do things for myself, resist those who I believe are behaving less than properly as I understand the ward and trust that my judgment earned over 60 odd (literally and figuratively) years will keep me out of harms way.
Sorry for the speech. I hope it is obvious that it has nothing to do with you personally.
Many thanks for your feedback.
Mike,
Respectfully, I think it's interesting that you seem to view people who are trying to maximize their income from their work as people who are trying to rip you off. Since when did you or anyone else become the keeper of such people? When did you decide they were put here to serve you?
Here's the deal. Deal with it.
There's people out there who are working there arses off and wish they had more. When times are good and people have money, they are smart enough to capitolize on that by quoting prices that will bring them more money for their efforts. They are intitled to do that. When times are not so good, they often don't get enough. Now as a buyer, you are not obligated to be sucked into a deal at too great of an expense. You may neogtiate or simply say no, and get another price. You are free to ask them to do it time and materials, or by the hour. You can do it yourself. You can say "hey - what kind of fool do you think I am. That jobs not worth half that and half that's all I'm willing to pay."
But don't fault the guy for quoting you a price that you don't like. That's you that doesn't like it. He likes it just fine. The problem is with you. Lol.
Let me ask you this? Would you be PO'ed if Bill Clinton told you his fee for a lecture was $500,000.00. No, you just would decide that you didn't need to hear what he had to say that bad. Would you be upset if Sam Maloof told you his chairs were $25,000.00. No. You would just say I don't think I'll take one home today. Well - that electrican thinks somehow he deserves that amount. Let him think so. He does in fact - He'll probably get it right down the street from you.
Find yourself another electrican, and blow that guy off. But don't waste your energy on the one that was out of your budget, cause it wasn't about screwing you. It was about him maximizing his profit. Good for him.
jdg
I think that, to some extent, we said the same thing just in a different way. It sounded to me from your post that a person's right to maximize their income was somehow one of the supreme rights in your opinion. I don't agree.I think rights and responsibilities go hand and hand. When we adopt a philosophy of "whatever the traffic will bear" then eventually we run the risk of losing sight of what is valuable period. I also think it contributes a lot toward the breakdown of trust and a sense of community. It helps lead us toward the jungle where it is every man for himself and the devil takes the hindmost I don't think that needs to be.
I think an honest craftsman knows how long it will take him to do a job and how many years it took him to acquire the skills to perform the work. Out of that knowledge can come a price that will earn him or her a living commensurate with the laws of supply and demand and an internal sense of fairness. As an aside, I'd like to mention here that I don't include in my comments those aspects and levels of "woodworking" that are Art in the truest sense of the word.
As I mentioned early on in this thread, I think something else was going on back at the main office and the quote's real purpose was to blow the job off (probably because the guys sent out seemed to be new on the job).
We have gotten quite a bit away from woodworking here which my response to "lectro" must carry most if not all of the responsibility. I am new to the Internet and more specifically to this Forum. I figured I had the right to speak against a price if someone else had the right to in effect defend it by acting as advocate for professional electricians.
It seems to me that perhaps I was wrong. Your response seemed both personal and angry to me. Would it qualify as "a flamer"?. If it doesn't, I'd like to be told so (by non-electricians) so I can get a feel for the ground rules. I'm new to all this but while I have written posts that disagreed with someone I believe I have been polite and non personal in my choice of words. If rough house is permitted, that's O.K. I can generally hold my own in verbal jousts.
Edited 2/9/2003 1:25:44 AM ET by MikeE
Mike,
>> Your response seemed both personal and angry to me. Would it qualify as "a flamer"?.
Sorry about that. I was probably blunt and rude. Maybe just a tad opinionated - lol. Flamer? I don't think so. I should have been softer and a touch friendlier. Please accept my apology. I respect you and your opinion and the spirit within you, and my post should have been more of a reflection of that.
>> I think that, to some extent, we said the same thing just in a different way.
Not really. You seem to see it only from the buying angle. I think I see it from both angles. I've bought enough services to fully understand why you feel it was unfair. But I think that if that bothers you, that's your problem. Not theirs. I don't mean that to be offensive or disrespectful - only truthful.
>> When we adopt a philosophy of "whatever the traffic will bear".
This is how contractor's survive. Those who don't know this are not contractors. As a matter of fact, other companies in other industrys as well. It's capitalism, isn't it? I think I like it. The alternative is socialism.
>> I also think it contributes a lot toward the breakdown of trust and a sense of community.
I respect and share your sense of community - to some extent. More of that would only improve our world. But what business is not about maximizing profits? Come on... get real! and I mean that in the nicest way.
>> I think something else was going on back at the main office and the quote's real purpose was to blow the job off (probably because the guys sent out seemed to be new on the job).
Possibly. And this is within their rights. Contractors who work in the home industry (any industry for that matter) are exposed to all sorts of stuff they are not interested in fooling with. One way of handling it is to hum a fat price at it that will make it tollerable - even fun, if awarded.
Mike, I just deleted an epistle I wrote about how contractors generally approach bidding their work. Bottom line is that they get what they can. This is responsible business. And that as buyers, it's our responsibility to get the best service we can for the best price. Contractor / consumer relationships have a tendency to be an adversarial from the get go. The challenge for both parties is to be smart enough to make it a win / win deal. Buyers who put forth more energy shopping will find better service for better prices.
You seem like a kind and gentle person. I respect that. I wish you the best with your table saw re-wiring.
Hey, here's an offer you can't refuse (expires in 10 days). I'll come wire it for you - free. All you got to do is smile. Let me know if you're interested in this unusually rediculous offer. Where are you anyway?
jdg
I liked your reply very much. In particular I liked the method of addressing each item separately and in order. I often take that approach myself as I find it helps me organize my thoughts.
As to the different perspectives of buyer and contractor, I think it best that we simply agree to disagree and get back to business of sharing our knowledge and experience. In my case, at least where electricity and woodworking are concerned, that generally means benefiting from other's experience. I am very aware of that fact and have tried, with sincerity, to voice my appreciation in my posts.
One last response concerning your perception of me as a "king and gentle" person. I think that is a perfect illustration of why we all must exercise such caution in these types of forums. The fact is that the vast majority of us whose lives touch so briefly and infrequently are complete strangers to one another. One man's ironic humor could be experienced by another, perhaps in a vulnerable place in their life, as traumatic personal assault.
I don't want to leave you with the thought that that statement somehow reflects where I am as a person right now nor how I experienced your post. I'd rather leave you with a simple truth about myself. Kindness and gentleness are both genuine aspects of my nature. So too however are rage and a well developed capacity for verbal violence (as the twig is bent so grows the tree) Knowing this, I try very hard to nurture the former and restrain the latter. I have been taught by wiser, calmer people that written communication fosters both those aims. Personal experience has enabled me to accept that belief as part of my own philosophy for living.
Last comment. I wish you did live closer but if you did and did the work, I would NEVER let you do it for nothing . I am a weird mix of the old and the new and the old - perhaps harder - part of me believes that all one should expect to get for nothing is nothing.
Thanks a lot for all your valuable input over this thread. As I mentioned earlier on, when I get the job done (which includes review by a professional and inspection by the local authority) I'll come back and pass along any info regarding the saw's performance as well as a diagram of the wiring layout (provided I can learn how to connect an attachment to these posts).
Thanks again. Be well down there in the land of James Lee Burke.
Regards,
Mike
Edited 2/9/2003 11:56:22 PM ET by MikeE
Mike,
>> The fact is that the vast majority of us whose lives touch so briefly and infrequently are complete strangers to one another. One man's ironic humor could be experienced by another, perhaps in a vulnerable place in their life, as traumatic personal assault.
Good point. I understand. Yep. I'm still learning.
>> Kindness and gentleness are both genuine aspects of my nature. So too however are rage and a well developed capacity for verbal violence (as the twig is bent so grows the tree) Knowing this, I try very hard to nurture the former and restrain the latter.
Your wisdom is visible. I pray for your success in nurture and restraint. You appear to be succeeding.
>> land of James Lee Burke
So you're a fan, huh? I've read and enjoyed a couple of his novels. Louisiana definitely has character. Some of it's characteristics need help. Lol.
jdg
Good stuff. Many thanks. Will keep in touch.
Regards,Mike
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