Hello all,
I am compitent in regular residential wiring, and I have worked on three phase systems to a much lesser extint, enough that I understand the concept but not so much the mechanics. Before I call the utility company and have them pull the lines from the pole I want to understand what I am asking for. I know that 3 phase is more expensive because it is carged as a comercial account, but this is a whare house so I would think that it will be charged that way any how. As of now I have no three phase machines but, I am excited about taking advantage of the cheeper prices of 3 phase machinery (shapers, RAS, air compressors).
My question right now is how does one normally seperate the 1 phase from the 3 phase? 90% of the shop will be single phase so I want a traditional single phase two pole 150 amp panel. I also want a smaller three phase panel that could hold 4 circuits. When I’ve worked in 3 phase panels trying to get 110 or 220 it was always a PITA. Rearanging breakers to get the right combination of poles wasted a lot of space. I will also be splitting the space with another guy and I don’t whant him to have to deal with a 3 phase panel. To further complicate matters the meter and current panel are in “his space” on the oppisite side of the wharehouse from my shop. Obviously the 3 phase panel and single phase panel for my shop need to be on in my shop for safety reasons, not to mention to minimise the wire runs. So how do I set this up.
I was thinking that I would use some sort of distribution panel after the meter, then feed a normal 1 phase 220v line to the box in my partiners side, another to my side then a 3 phase line to my side as well. Is that right? If so what does the distribution panel look like.
Thanks every one,
Mike
Replies
Here is a drawing of the shop area to help make sence of the shop layout.
Thanks again,
Mike
Do you know for sure that your local electric utility is willing to install a three phase service? They usually look at the revenue (i.e. how much money will they make off you), and if it's not enough they may not be interested. Also, it's possible that they don't have three phase power available close by your building - if you're in a commercial area they may, but it's not always guaranteed. If they have to bring it in from a few blocks away it's going to cost a LOT of money. So, check with them first.What voltage are you talking about? Nowadays most utilities will provide 277/480 volts or 120/208 volts. 120/240 three phase is sort of a dead dodo, at least around here - there are still plenty of older buildings with 120/240 three phase service in place, but the utility company does not install new services at that voltage anymore. If you're talking about a 277/480 volt service, you'll need a transformer to step down to 120/240 volts to supply any single phase panels.If the occupant of the other side of the building and you share the same electric service and meter, do you have something worked out for sharing the power bill? This may be the time to have a separate meter and service installed.If the new service is going to come into the building at the same location as the existing one, the main three phase disconnect will need to be located right there on his side of the building as well.To be honest, I think that in order to do this correctly and safely you're going to need to bring in a qualified electrician or engineer to take a look at things.
Stuart,
OK, you gave me a lot to digest. I am not sure what type of three Phase I need. Isn't there a normal type for wood working machines in the 3 to 5 HP range? In the Grizzly catalogue I see the 7 horse 3 phase machines require "220 volt 3 phase" on the Delta site I see that the 5 horse shaper uses a "three phase, tri-voltage (200-230/460) motor". I don't understand all the differences, but I assume there must be a standard of some sort for 3 to 5 horse machines. Any 3 phase machines that I buy will likely be older machines of the sort you see on Ebay. I'm sure that I sound like a complete idiot here, and maybe I am. I'll get an electrician involved when I get to that point, my goal right now is just to understand what I need so when I call the electric company I know what to ask. I know that they might not want to supply my meager requirements, but there is three phase right behind me so they might not care.
Thanks,
Mikeplease excuse my spelling.
Mike as Stuart stated there is different voltage levels for 3 phase power the depending on were you are located you could be suppled with 4 or 5 different ways from the utility transformer on the pole. It is best to call the local utility company and tell them were you are at and what type service you are looking for IE 220 3 phase or 480 3 phase , most but not all 3 phase motors can be connected for ether voltage
Depending on what is close to you the utility company will set a transformer for you to supply the voltage that you will need .But it will most likely cost you
Thanks for answering my questions. I have noticed that in the Grizz catalogue it looks like 440 volt motors are optional and 220 is the norm. There are 3 Phase transformers right behind me (maybe 50 feet) but they are supplying BIG BIG machinery, so it might be an even higher voltage. I know that this is a dumb question but here I go.....When I call the electric co do I need to tell them that I also want regular single phase service as well? In the 3 phase panels I've worked in before there were three busses two read 110 to the common one read 220, but they all read 220 between each other. So by picking the two 110 legs we set up a regular two 220 single phase sub panel. Therefore I think that all three phase power has single phase legs in it. Is that right?
Mikeplease excuse my spelling.
Bring in the utility guy to look at your needs, and explain exactly your situation and advise. In my area, if you will be using a small quantity of 3 phase power, there is a very substantial minimum charge.....high enough that when I ran new power to my shop and had to make a decision between 30' and 40' poles (40 footers run three-phase here), and after talking to the utility guy, I knew there was no way I could justify 3-phase. Much simpler to go single-phase, and add a phase converter for any three-phase gear I added. I know you're not dealing with poles, but my point is the utility is best placed to advise you.cabinetmaker/college woodworking instructor. Cape Breton, N.S
Thanks Adrian,
Interesting stuff. There are big poles right behind the shop, in fact they are supplying a major water pumping station. The pumps are massive so there is obviously some serious power enterting there.
I admit that after reading all these posts it is looking like it is more complicated than I figured. I'll be calling the power co today and trying to get a hold on what the cost will be. If it is more than $50 a month higher I would just use a phase converter.
Mikeplease excuse my spelling.
(In the 3 phase panels I've worked in before there were three busses two read 110 to the common one read 220, but they all read 220 between each other. So by picking the two 110 legs we set up a regular two 220 single phase sub panel. Therefore I think that all three phase power has single phase legs in it. Is that right?)This is correct. The motor plate will have the wiring diagram on the label or under the cover.
Good one Keith.A reasonable smile should stay on my face for the rest of the day.
Oh, and trust me , for I am an electrician....
Hey Mookroid, How many Volts and Hz are standard down in NZ? If I could bring a motor from here to down there with a long enough cord that I didn't unplug it, would coriolis cause it to rotate backwards, and how big would the conductor need to be to run a 1 HP motor without too much voltage drop? Since you have not jumped in to help Mike, I figured you had not had a hard enough question to challenge you. This is a pop-quiz, you only have five minutes to get the right answer or loose your liscense. GO. K
Yah Keith,
You know, I failed on two counts.I was unable to locate suitable motors fast enough to be able to read the labels inside the covers: this activity was also disrupted when I heard that the world is consuming 2 barrels oil for every barrel discovered....Also I had to look up the word 'coriolis'.
I guess my licence is lost. But on the oil one -trust me I was a floorman for 26 months. <GJ>
Keith,
Over here we do things so different, that I would not be concerned about the Voltage drop to NZ.
By the time the Kiwi's get the other other end of the cable, they won't know what to do with it.
As far as I know, no one else talks about electrical wires in numbers, they use different colors, they even spell color different (Colour). They do'nt supply two opposing phases, referred to as "hot" into residential and call it "single phase", they don't refer to 240 volts as 220 volts when it is actually 240 and they don't refer to 120 volts as 110, when it is actually 120.
Their light bulbs last twice as long as ours and they don't run their 3 phase motors in star.
If the Kiwi's manage to figure this all out and they connect your cable, they will find their motor turning about 20% faster than it should.
Please don't run that cable, you will cause the confusion of the century.
Edited 7/23/2005 3:48 pm ET by Willie Martins
LOL thats funny.
Mikeplease excuse my spelling.
As far as I know, no one else talks about electrical wires in numbers, they use different colors, they even spell color different (Colour). They do'nt supply two opposing phases, referred to as "hot" into residential and call it "single phase", they don't refer to 240 volts as 220 volts when it is actually 240 and they don't refer to 120 volts as 110, when it is actually 120.Haha Willie, you guys also say "aluminium". Its aluminum....we should know, we invented it....But seriously, voltage is supplied in 3 flavors in the US. The one I get is 208 which is the supplied level on Maui. We have transformers to convert to what the rest of the world uses when necessary. But our dictionaries dont do "aluminium"..... aloha, mike
Mike,
I'm one of "us" guys, live in California.
I have been around though and we sure have a unique way of doing things.
The way they wire these stick houses in California, I'm surprised a third of them don't burn to the ground.
Sorry Willie, I thought you were a Kiwi for some weird reason. haha, couldnt tell from the keystrokes I guess.
One more thing to add... someone correct me if I'm wrong(PLEASE). Most motor controls are single phase, even on 3 phase. So make sure that the two 110 leads are the ones that go to the motor controls. If the motor is running in the opposite direction needed, reverse only those two 110 leads, not the the one that measures 220.
Another thing is when you are talking to the engineer/planner at the electric company, let him know of your plan usage(maybe inflate it a little) and tell him that most of the use will be in the off peak time. This will possible give them the incentive to supply you with the three phase power and put you in another price bracket. In SoCal this was called the the 3p2 or 3p3(maybe not right, it's been awhile). They can also put a demand meter on and if you peak to often during the demand times of the day, the price really KW price really goes up, along with the monthly service charge. Some electric companies will give you credits towards installing power to help cover the cost. But then again this was 10+ years ago.
Also let the landlord(you?) know of the increased future potential for leasing to other businesses that require 3 phase. There are machine shops that require true 3 phaes, not converted, unless they use a "purifier" or whatever the correct term is
To reverse a 3 phase motor you reverse any two of the motor legs not the control power.
yes, that's true, but on a motor with a high leg, you only switch the other two(which are the one's that go to the contoller). Not doing this correctly can burn up a controller
Some machines have the controller hooked to L1 and L2, and some ohters are hooked to L1 and L3.
The issue here is knowing what the coil needs. If it needs 120 V, then you should make sure that is what runs through the start stop buttons, then the coil, then the heaters, then out to the common on the other end.
Mike
That last panel were you read 110,110 240 was a delta tapped transformer in some parts of the world that is called a 120 volt with a high leg. if the transformer is connected as a star then you will have three legs that all read 120 v to ground or neutral and 208 from leg to leg. If you get 480v star you will have 277v to ground and 480 leg to leg. In this configuration you will need to add a control transformer to the machine that you bring the power to. most machine tool controls have 120v coils in the starter.And the start stop buttons will have 120v power in the circuit to start the machine. If you can get the lower voltage you will have less problems with the control circuits.
What state are you in? f you are in Northern Ill or Southern WI I could help you. I am a electrician. and work with 3 phase all the time. Motor control is what I do most
Wow,
Thank you so much. That was the most usefull information I have gotten yet. Some one told me that aformentioned panel was some wierd tapped situation.
My goal is to have as little trouble as possible using commonly availible 3 phase machinery in the 3 to 7 HP range. Obviously I will also need a standard 220 v "single phase" panel for my current mavhines, powertools, lighting and the all importaint radio! I am afriad that I will ask for the wrong type of service. Most of the motors on the machines that I look at seem to say 220/440 volt. If I ask for 220 3 phase will I get 120 v. as well?
Mikeplease excuse my spelling.
well, I've (we, the electrician and I) spent most of the last two days wiring a 3 phase refridgeration system - I'm not an electrician but have superficial knowledge -
there are two transformers on the pole serving my residence/business - one for single phase, one for the 3 phase - they both run thru the same meter - the single phase runs to a standard 200 amp breaker panel and circuits are run as needed -
the 3 phase runs thru a disconnect box and is fed to a 'bus-bar' distribution system that I scored at an industrial salvage place - along the length of the system are boxes containing switches and fuses - machines are wired out of these boxes in conduit -
this works fine, but is a bit of overkill for my relatively modest power needs - I've ended up with some machinery fairly far from the bus-bars - rather than running several circuits, we ran one 200 amp circuit to a subpanel located at a strategic place - this subpanel resembles common panels, in that it contains circuit breakers protecting the various pieces of equipment served -
and it is possible to pull single phase power out of it - the current project (hey! a pun!) included a 110 v control circuit which runs off a single pole breaker in sub-panel, located right above the 3 pole breaker for the compressor -
so....I'm gonna suggest you involve your electrician at this point - I'd suggest you think heavier - the difference in price at this point between a 150 amp panel and 400 amp is not much - I think you're likely to run out of room in the small panels you contemplate - "there's enough for everyone"
Ok, I'll go out on a limb here and post some picts - this first is of the entrance - meter is located outside the wall to the left, heavy cables come out the back of it and into the square conduit - the box in the middle is a 200 a breaker box, the box on the right is the 3 phase disconnect switch - the box on the left is a switch on the 200 a run to the house -"there's enough for everyone"
OK, here's the bus-bar distribution - shown is one switch box that runs the forklift charger -
"there's enough for everyone"
here's a pict of the 3 phase subpanel -"there's enough for everyone"
Mike I'll bet the power company will require you to have a licensed electrician provide the correct connections and meter loop on your building and have an inspector sign off on it before they will bring it to the shop, so you might as well start by talking to one of them.
If you don't own this building, I would think you will be better off staying with single phase, and getting a variable frequency drive instead.
Aloha,
Don't know where you are located in the world, but being an old, retired meter engineer, here's how three phase power works. There are two different types of connections, commonly called star or wye (think of a Y) or delta (think of a equilateral triangle). In the delta connection there is no neutral and the voltage available is what apears from corner to corner of the delta. E.g. 240/240/240. One leg of the delta may be centertapped to provide a half voltage e.g. 240/120. Otherwise you need another transformer.
In the star or wye connection there is a neutral that is connected to the midpoint of the Y. The voltage from point to point of the Y is 1.732 times the voltage from point to neutral. E.g 120/208.
There are advantages to either of the connections which is why you need an engineer involved. Different utilities do things differently.
Also, unless the NEC has changed since I retired 13 years ago. The main panel will have to be at the service entrance with subpanels at the other locations.
Every one,
Thanks for all the info. at least I understand what to ask for. I be calling the power co next week.
Mikeplease excuse my spelling.
Mike:When you talk to the power company, make sure you get __all__ the estimated charges for bringing in 3-phase. They can also tell you exactly what service you've got, you may only require changing the meter and entrance wiring.Around here, AEP charges for bringing it in from the nearest 3-phase line, which can be substantial, depending on distance. Permits are not included in AEP's charges, and here an installation like that is regarded as improvements to the property, which also increases the property taxes.Good luck,Leon Jester
Hello every one,
Great news! Three phase is no problem. It is metered the same as single phase (.09 per Kwhr). There are no additional charges for it. The only issue now is that since there is no supply or transformer to the building it will cost $1300 to $1600 to install the service, the range reflects the difference between 3 phase and single phase transformers and the extra wire. Oh yea, also 120/ 240 three phase is no problem. The electric co guy was very accomodating. Plus the building is in unincorperated county so no permits are necessary. Thank God for Texas!
Mike.please excuse my spelling.
Where in Texas are you Mike.....
DFW, or Grapevine/ South Lake area. More specifically Trophy Club (the poor side of Trophy Club). The whare house is 10 miles away in Tarrant Co. right on the Fort Worth border.
Do you know the area?
Mikeplease excuse my spelling.
Live in Woodway Texas, near Temple/Waco. Been to DFW of course, but not Grapevine/ South Lake/Trophy Club specifically. Great to hear there are some FWW'ers nearby.
There are a couple of other guys I've seen from around here and the Austin area. There are even more on the Breaktime forum.
Mikeplease excuse my spelling.
Mike, you should have been with me today. I found and bought a nice Marathon 5 hp 3 ph Black Max and some air hold-down stuff for $25. I left a couple of 25 HP motors out there.
Power distribution is not my area of EE, but I know that in plants that use 3-phase and single phase, that they have to take care of how much single phase is fed off each of the legs. Imbalance in a leg can lead to voltage issues and problems with the running of your three phase equipment. If you really interested, I can ask our power EE what to be careful of.
I thought that was the case. And I worry that might be an issue since we will be using 90% single phase. Ant help is apreciated.
Mikeplease excuse my spelling.
Hello all,
My eyes are glazing over from looking at all the three phase load center products out there. It is looking like a simple 3 phase 200 amp panel costs $300, not including breakers! Then the breakers seem to be outrageous! Like $90 each. That can't be right. I am having a hard time finding an internet supplier with a catalogue. I tried Granger, but they seemed to have little to show on the net and I tossed the catalogue.
I talked to the utility co today and we will meet on the site wensday, but it sound good so far. The guy recomended 110/220 three phase. Does that sound right?
Thank you all very much,
Mikeplease excuse my spelling.
"I talked to the utility co today and we will meet on the site wensday, but it sound good so far. The guy recomended 110/220 three phase. Does that sound right?"
120/208Y sounds more like what they'd be supplying, but who knows. Be advised that not all motors are rated for 208 (in fact, most these days aren't), but at reduced load, it wouldn't matter. Be seeing you...
I'm pretty sure he mentioned both. I don't know if he was interchanging the terms for the same supply, I got the impression he ment two different things.
I'm just crossing my fingers that it will be cheap.
Mike
please excuse my spelling.
My only point is that you should know exactly what you want to end up with before you meet with the POCO, and see what they can do to give it to you. New facilities we've built have always been supplied with 480V three-phase only (or 4160V to the premises, and they supply the 1-2 MVA transformer, installed on our pad, for 480V). It's always been our responsibility to create single-phase from the supplied 480V, using our own transformer(s) in the building. Your situation could very well be different, but you should know exactly what they will give you, and what, if anything, you have to do on your end to make it fit your needs. Buying transformers can get costly.
I would strongly suggest you bring your electrician with you to the meeting. Your electrician should specialize in commercial/industrial work, which includes three-phase. He/she and the POCO should be able to come up with a plan in short order, since they'll both be speaking the same language.
Good luck, and let us know how the meeting goes.Be seeing you...
I am familiar with the set up you are describing , that is a very large comercial set up. From what I understand it is not that the electric co refuses to provide your transformers, it actually costs the company less to do it themselves. Plus you have easy access to make big changes if needed, without bugging the electric co. The guy sounded like he would be able to provide what I want, I meet him tomorrow......we'll see.
Mikeplease excuse my spelling.
Mike just so you know. You may have to make a decision to bite the bullet when it comes to the cost for getting it into the shop. However, once you have it, the deals are easy picking thereafter. I can find 3 ph motors in the 1 -15 hp size almost any time for around $20 often with controls. It is not unusual to find very good industrial size equiment cheaper than the used cabinet shop level tools go for.
Keith
That is exactly my motivation. I am in the market for a big old 3 horse radial arm saw, 24" planer, a 5 HP shaper, and an 8"-12" jointer. Oh yea and a good drum sander. Like you said all these machines sell for 60% the cost of their single phase counterparts. pluss the wireing is cheeper. I am pretty confident that it won't cost much more than single phase service. I am 30' from power lines that are definately three phase, and right now there is no transformer or service at all for my building. There isn't much price difference in a 3 phase transformer set and a single phase set so we'll see.
Any advice on what brand and type of load center set up I should use would be greatly apreciated.
Mikeplease excuse my spelling.
This is one of those questions I immediately regretted asking our power EE, after a half hour of explanation my eyes were glazing over. There appears to be a lot involved in three phase distribution. What I was told is that you want the secondary of the transformer that feeds your panel to be configured “Y” for best results. Yes it is true that balancing is important as an unbalanced situation will leave current flowing on the neutral/ground leg, which means it is wasted. When using a three phase panel with a mixture of three phase usage and single and double phase usage, you still 2want to balance usage. To oversimplify the whole thing, balance the number of 120v and 220v circuits coming off each off each of the three hot legs for best results. As I said, this is an oversimplification, but close. I would suggest get in touch with your power company engineering department to determine what you’re dealing with in your particular installation.
Bioman,
Thanks very much for taking the time to ask you EE. I really apreciate it. I think that I am begining to understand what I need. And like you said three phase power distribution is very complicated. Once I get the power into the panels I know that I can handle the wireing from there. It is the service and enterance that I am trying to figure out. I have a few friends/subs who are master electricians, but they only do residential wireing so they have forgotten (or never knew) about all this transformer stepping down wye 208/110 stuff! I will very likely have an electrician wire the enterance and panels/ buss system. But I don't like not understanding things. So I will first figure all this crap out and then I will be able to make the best decisions about what to do. Also I want to be able to buy the panels I need on the used market. You generally aren't going to find an electrician to do that them selves.
Again thank you for the help,
Mikeplease excuse my spelling.
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