I need to wire an NEMA L6-30 (220V) circuit for a 3hp table saw. Could you please explain how to wire this from panel to receptacle? Any additional restrictions if I run the circuit under part of the shop floor? Obviously, I will use UF. Also, this is in my “residential shop”, the panel is a 60amp subpanel. Thanks for your help.
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My guess is you need some help on site in addition to anything you get online. Do you have a dirt floor shop? Are you fishing a wire through dirt under a slab. Those would seem to be your UF applications.
I'm getting ready to wire an identical saw outlet in my shop. I haven't poured the floor in that area yet so i'll bury a pvc eletrical conduit. Inside the conduit i'll use 10 guage stranded wire.
joe d
B. Hackford:
1) How far is the run from the panel to the saw? I'm guessing 10 ga.
conductors minimum.
2) Don't use UF, bury conduit and pull THHN of the appropriate size.
You'll need four conductors. Black/White/Red/Green.
3) This is a 220V circuit, so you'll need two adjacent spaces on the panel for a dedicated 220/2pole circuit breaker of the size specified by your Saw's manufacurer. (20 or 30 amp I'd guess) Rate the breaker to the Motor's specification... not just the outlet rating. You CAN use a 30A rated outlet and a 20A rated 2-pole breaker IF that is
the motor's specification.
4) Kill ALL the power to the Panel first.
Then make-in the conduit connector, pull the wire in, make up your outlet first, follow the schematic in the box. Next make into your panel... the ground first (green), the neutral next (white), and finally the two legs of the power in (black & red) to the appropriate lugs of the breaker.
5) Knock out the spaces on the panel cover, re-install the panel cover,
and re-power the panel. Turn on the new 2-pole breaker, you should be
able to power-up your saw next.
ANY PART OF THIS YOU FEEL UNCOMFORTABLE WITH... CALL AN ELECTRICIAN.
-gwc
NEMA L6-30 is a 30 amp plug/recptacle designation in a twist lock configuration. It is also a three prong configuration, so the green wire is unneccessary. Both the male plug and receptacle are expensive in the twist lock configuration. If you want to save a few bucks, you can use the NEMA 6-30 straight blade plug/recptacle combinaation. It is still a 250v/30amp set up and is acceptable by most local codes.
The #10 awg size is correct for a 30 amp circuite, and the conduite is better than the direct burial typ NM/UF cable. In either case you need to be aware that there are minimum depths for buried electrical wiring. Check with your local electrical inspector to be sure you meet your local code requirements.
Now, before someone jumps up and down about leaving out the green wire, let me say, it sounds like you need one if you have dirt floor. If that is the case, I would use a NEMA 15-30 straight blade configuration or a NEMA L15-30 iiin a twist lock confguration. Be sure to case ground the green wire to the saw housing for it to be effective.
Hope this helps a little
Dave
" It is also a three prong configuration, so the green wire is unneccessary."
NO, NO, NO!!!!
Yes, it is 3 prong configuration. 2 hots and a GROUND.
YOU MUST HAVE A GROUND (GREEN OR BARE WIRE) CONNECTION! ANYTHING ELSE IS UNSAFE ANYPLACE!
This is a simple 240 configuration. There is no need for a neutral.
My plan was to use 10-2UF, 30amp 2 pole breaker and mark the white as hot. The reason I using UF is because the wire will run under the shop floor which is concrete. I spent the day cutting up the floor and excavating. I am also planning to use NM conduit when the wire comes the floor just as an added safety measure.
I have done 220 lines for dryers and such before; however, I have never done a L6-30. The part I am confused about is: why isn't there a neutral? Then since there is no neutral and the panel is a sub panel that has separate ground bus, do you connect the green to ground bus or green to neutral bus. The sub panel has it's own grounding rod and is grounded to the main panel. The sub panel is 60 amps fed by 6-3.
Thanks inadvance for the advice.
Edited 4/6/2002 9:06:27 PM ET by BHACKFORD
Bill, don't get your shorts in a wad. I missed the sub panel part.
You are correct in that it is a straight 240v motor and the neutral is not needed. Not knowing how much someone knows about electrical work should lead to the most conservative advise. That I gave in the last paragraph. Use the NEMA L15-30!
Dave
I am on correct path with post #6?
Hook the green tho the ground bus. You are are on the right track, except fo the type uf cable being placed inside non- metallic conduit. I am not sure if that is allowed for long pulls unless the conduit is oversize for heat dissipation reasons.
Dave
UF can not be embedded in concrete. You would need some separator to isolate it from the concrete when you patch the slot.
As you will be using the conduit to protect the wire where it exits the concrete I would use use conduit for the full run and then pull individual wires.
Why can't UF be in contact with concrete? I have and no many who have done jobs with UF incontact with cement. (i.e lamp posts, outbuilding feeds, etc).
The code says that it can't be EMBEDDED in concrete.
I worded my message ambiguously. In my view UF just laying on the bottom of a trench is not going to be perfectly flat and will end up within the concrete when it is poured and worked.
Now if you anchor it and put a layer of sand or something a barrier then it would meet code (but you still need to sleave it if it enters or exits through the concrete.