Ask Me Help Desk - Wiring my subpanel

I just built a workshop/shed. Its approximately 50 ft from the main panel on the house. I just purchased 6/3 simpull romex to run from the main panel on the house to my subpanel. Ok, don't laugh. I scored a 120v 70amp max Square D sub panel that was originally on a travel trailer that was being stripped to the frame. Anyway, the sub panel has two 20 amp breakers and one 15 amp breaker already in it. Someone told me I'll need to run 6/3 wire for 2 hots, 1 neutral, and one ground. When I looked in the sub panel tonight, there is the original power cable coming off it, that was at one time for plugging the travel trailer into a generator, etc.. Well, the power supply cord for the panel only has 3 wires total. The black goes to the circuit breaker bar, the neutral goes to the neatral bar, and the ground to the ground bar. There is no where as I see it, to connect the red wire that will be in the 6/3 I just purchased. I know the 60 amp breakers have 2 poles, if I connect the black to one of the poles, and the red to the other pole on the circ breaker, where do I tie it into at my sub panel? Can I just connect both the black and the red to the same connector in the sub panel?? Someone help me. I am on a tight budget. Haven't worked in 4 months, due to the actors strike, and child support, alimony is killing me. I do welding/fabrication for the movie industry, and built the shop for a place to do side jobs,etc..

Thanks for all your help,
Mike

You will not care for this answer.

Assuming since the shed is 50 feet away from the home, it is a separate building.

If this is the case, the Romex can only be used inside a building, either the home or the shed. It cannot be used outdoors. It cannot be buried, even in conduit, not can it be run overhead through the air.

If you install the feeder in the ground, then you can use UF able, URD cable, USE wire, or PVC, steel or aluminum rigid conduit with pulling wire with THHN/THWN or XHHW insulation.

The "subpanel" in the shed will need a disconnect, or main breaker, 60 amp breaker sized to the #6 feeder cable, or no more than 6 branch circuits will be allowed, as up to 6 breakers can act as the disconnect.

The 'subpanel" will need at least one ground rod, maybe more depending on local soil conditions, and #6 copper wire connecting the ground bar in the panel to the rod(s).

The fourth wire, bare or green equipment ground, needs to connect to a ground bar bolted directly to the metal panel box. Only this equipment ground and all other green and bare grounds connect to the bar.

The neutral bar in the panel will only be for white neutral wires, and must be isolated from the panel box. Look for a jumper wire or screw connecting the bar to the box, this must be removed.

If the subpanel gets a main breaker, connect black to one terminal and the red to the other. If you use the 6 switch rule, then connect the black to one main lug, and red to the other.

I think I addressed most of your issues, if not, get back with more questions.

Quote:

Originally Posted by socaliwelder

I scored a 120v 70amp max Square D sub panel

The answer to the question of how you wire this for 240V is right there, you can't. That being a 120v panel, it will only have one buss bar. If you need 240v in your shop, and since you weld I assume you do, you will not be able to use this panel for your purpose. You will need a 120/240 panel.

What is a 70A 120V panel??

I'm not trying to get 240V. I have a 70amp 120volt sub panel. I only want 110 in my shed/shop. I am going to have a female washer receptacle right at the fuse panel that I can run a 240 volt extension cable, when and if I need it. My tig welder, plasma cutter, and mig welder all have the capability to run on either 110/220. Their all dual voltage machines. But since the panel only has 1 lug for me to connect a hot lead to, I was wondering what would happen if I connect both poles from the circuit breaker to a single lug in the sub panel??