I am building a short extension cord for my shop to carry 240V from one side of the shop to the other. The cable will be routed along the ceiling to eliminate the cords lying on the floor, where they constantly leap up and entange me at present.
One end is a standard 15A plug that plugs into the existing wall socket. The other end I am planning on having a box with a 15A duplex receptacle. I will plug both my bandsaw and my tablesaw into the box. The problem is that the #10 stranded wires in the cable are WAY too thick to attach properly to the wimpy screw connectors on the duplex receptacle. The receptacle appears to be designed for a smaller gauge of wire, likely the typical #14 solid.
I know that #10 is capable of carrying much more current than the 15A that the receptable and circuit breaker are rated for. But it is what I have on hand. And I think it might have been specified in my bandsaw manual (Minimax 16″), although I cannot locate the manual at this moment.
I have been unable to locate any receptables designed specifically to allow attachement of #10 gauge wire. I am considering using pigtails made of #12, but that would kind of cancel out any benefit of the #10 for most of the run.
Any suggestions?
Dan
Replies
You're talking about 220v... if you're talking about a 15A 220V receptacle, I can't believe it won't accept #12, which is fine for a 15A load.
It's fine to run #10 for the bulk of your circuit and pigtail #12 to the outlet -- you still get the benefit of reducing voltage drop over your run. Not sure what benefit you're missing here... #12 is wholly adequate for 15A.
I am considering using pigtails made of #12, but that would kind of cancel out any benefit of the #10 for most of the run.
No it won't. Short pigtails have essentially no resistance. G ahead an use them.
I'm a bit unclear about your description so just in case:
You speak of a "standard 15 amp outlet", I assume you mean a "standard 240v 15 amp outlet". The plug should NOT be able to be inserted into a standard 120v. receptacle. There must be no way to plug any120v devise into the outlet.
Thanks guys for all the advice. I will go ahead and make the connections with pigtails. And Steve, yes this is all 220/240 volts, it is not 110. The receptacle is a different shape from the 110V plugs/receptacles.
Dan
Great, I was pretty sure that was the case, but someone reading might not have gotten the message.
I second on the twist lock connectors and outlets. They easily accept 10 guage stranded wire. Should you ever acquire some tools with 3 or 5 hp motors you'll want a circuit rated to handle more than 15 amps for sure. Remember a circuit can only be safely rated as high as it's weakest point so in your case make sure your breaker is only 15 amps since that's what your outlets are.
Twist Locks are commonly available in 20 or 30 amp options. The 20 amp ones are more common. They look identical but won't work with each other. Some HD and Lowes don't carry them but most do.
The best way to do this is to get receptacles meant for heavy duty use and which are twist lock. Home Depot carries these under the Bryant name (I think that's it anyway). You would need to buy two of them, because they are not duplex at all. You'd need to cut the plug off of the cord coming from your machine and put the proper matching plug onto the cord. I've done just that with my Jet cabinet saw and my Laguna bandsaw. I find that the twist lock connection is much better in terms of not coming loose.
If this isn't clear, I'll get the part number for you. They have models rated for 30 amps and for 20 amps. I think the 20 amp one accepts #10 wire and is slightly cheaper. That'd do you just fine.
John
I believe that you can only have one 240 volt recepticle on a circuit at one time. I would not recommend that you plug both pieces of equipment in to one circuit. Even though you will have a 15 amp rated circuit ( is the breaker 15 amp also) it could stillover load the circuit if both pieces are used at the same time. you should consult an electrician. You may be better off to wire into your electric panel two seperate circuits rated for the use you need or even a little more( with their own specfic breaker). Also consider what the other recepticle that you are jumpering from is used for. Don't say I will never use both pieces at the sme time.
I am not aware of a duplex receptacle for this voltage. Maybe from England or Europe, but putting one in your workshop would probably violate the Electircal code as they wouldn't be UA, or CSA approved. Besides, there is no real advantage to a duplex receptacle @ that voltage.
The Electrical code tends to size up breakers based on the size of load being used. For example if you were to use a 1.5 hp motor, on you bandsaw, you would read the FLA (full load amperage) and use this figure to determine the breaker. The FLA on my bandsaw is 5.5V. This is not to be confused with the running amperage which is quite a bit lower.
Additionally, you can "branch" the 220/240 V circuit to a second recptacle if the total load of both circuits does not excceed the rated circuit breaker amperage of 15 amps. An electrical supplier or an electrician can tell you if this is necessary. Most fo the staff at Home depot are ex-electricians.
220/240 V 15amp receptacles are twist lock and should easily accept 10 gauge wire. Please make sure you wire the recetacle and plug exactly the same. Green wire to ground, white to neutral (silver screw), and the red / blacks to brass coloured screws.
240V duplex receptacles are not often seen but are available; e.g, a leviton 5662 http://www.twacomm.com/catalog/model_5662.htm
They're of limited utility because most equipment is 240V because of high power needs. This being the case two of them cannot usually be used on the same branch without tripping the breaker.
The FLA on my bandsaw is 5.5V.
Your bandsaw's full load rating is probably 5.5A, not 5.5V. :)
you can "branch" the 220/240 V circuit to a second recptacle if the total load of both circuits does not excceed the rated circuit breaker amperage of 15 amps. An electrical supplier or an electrician can tell you if this is necessary.
That may or may not comply with code and local regulations. Here in Redmond it does not -- I had to have a separate home run for each 220V outlet.
Most of the staff at Home depot are ex-electricians.
Not at mine. Also, electricians make more $$ than Home Depot clerks... so why are they ex-electricians?
220/240 V 15amp receptacles are twist lock and should easily accept 10 gauge wire.
You can get both twist lock (typically used for generators) and straight-in plugs and receptacles. Just match the amperage and voltage, and all is well. Home Depot and Lowes only carry the twist version (at least mine do) but an electrical supply house will have the full range.
Please make sure you wire the recetacle and plug exactly the same. Green wire to ground, white to neutral (silver screw), and the red / blacks to brass coloured screws.
This isn't right, sorry. 220V wiring doesn't carry a neutral. Normal 10/2 + ground used for 220 should have three conductors. The ground could be green-encased, but is more likely bare. This goes to the receptacle's ground, and also should be pigtailed to the box ground if the box is metal. The two lives are functionally identical. In some wire sets they'll be black and white, in some they'll be black and red, but the 220V is present across the two; they attach to the live blades. Some inspectors may require you to mark any non-black wires to black, to indicate their function.
I'd suggest following the instructions that come with the receptacle and plug, but then check it with your own common sense too... make sure the ground from the wall goes through to your machine's ground, and the two supply wires go to the right place in your machine as well.
Well thank you everyone who has cotributed so far to this thread. I thought I would go ahead and post some pix to give people a better sense of exactly what I am trying to do.
I've got one photo of my breaker box, showing the breaker used for he 240V cicuit, it's the one with the bar across the two 15A breakers. Note that it is in the off position for when I take the rest of the photos!
Then I have a shot of my existing duplex wall outlet. It is the same as the Leviton 5662 suggested by BarryO.
Then there is a shot of the wiring inside the current wall receptacle's box. You can see that the wiring appears to be standard 14 gauge, and as FatherJohn suggestes, both 'live' wires have been covered with dark tape.
The next one show the angled plug I am using. It plugs into the existing wall receptacle and runs across the ceiling to the other side of the shop. Recall my original objective in doing this was to get the darn cables for the table saw and band saw off the floor so I stop tripping on them.
Finally there is the photo of the new box, the new receptacle, some marrettes I plan to use, and the other end of the cable that is attached to the angled plug in the previous photo. So I plan to wire the receptacle to the end of the cable, and then plug both my saws into it. Done.
From a load point of view, nothing has changed, since before I had both saws plugged into the wall receptacle, now I will build an 'extension cord' and put it in between the wall receptacle and the two saws.
This whole problem has been brought on by the fact that my 3HP Powermatic 66 saw calls for 10 GA wire running to it, and the 10 GA is too fat to connect to the 15 A receptacle in the extension cord box.
Now that I see the 14 GA wire running from the breaker box to the wall receptacle, I figure I may as well use a 14 GA pigtail to connect the 10 GA wire to the receptacle in the box.
Dan
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