Welder and compressor wiring

[jrcampbe]

Hey guys, couple questions about wiring a new welder and compressor.

My main house panel is in my garage, which is nice. It's 250A service.

There is a 100A 240V breaker that controls a small panel in the basement. There is a 30A 240V breaker for the AC.

First question: I know you can't permanently attach two wires to a breaker lug unless it is designed that way, but since it is winter I just disconnected the wires to the air conditioner and ran the wires to my compressor into the air conditioner 30A breaker. Works great. Now, to permanently do this, I think I need to cut the wires leaving the breaker and going to the air conditioner and use a wire nut to put the compressor on that circuit. If the compressor starts when the AC is on, then I guess that breaker will trip. That's ok, right? I don't need to use a circuit breaker large enough for both loads? Isn't that the same as having lots of outlets on a circuit? You plug in too many things and the breaker trips. I will turn off the AC when I want to use the compressor.

Second question, similar to the first: I just bought a welder and I want to connect it to the 100A breaker that feeds the basement panel. Again, I know I can't just stuff the wires into the breaker. Do I do the same thing? Cut the wires coming out of the 100A breaker, then use a wire nut to attach wires going to the welder? These would go to a disconnect junction box to provide a disconnect for the welder.

I know that will "work". Can someone confirm this is the right way to do it according to NEC?

There is no room in the panel for additional breakers...

Thanks,

Jim

 

[jrcampbe]

I know these kinds of questions are asked frequently. I did search for similar situations.

It seems to me that what I want to do is the equivalent of having multiple 240V outlets on a single breaker, which should be totally fine. Only everything is hard wired and no outlets are used. Just more than one device on the circuit. As I understand it, this is totally fine.

Am I wrong?

 

[Malczewski]

I'd recommend you call your power company and ask there.They're generally really good about helping out a person which will be enslaved by them the rest of his life .
Personally I prefer an extra 200 amp service for the Boy Toy area , even with a separate meter and billing.
I have 4 200 amp services and 2 transformers at the road.

One for the house.
One for the attached garage/shop.
One for the barn shop(coolers-lights-milking machines)
One for the real shop shop( welding, brakes, mill,lathes, air etc.

Disclaimer: I also have 2 PO boxes for recieving bills(and tools).
One for "Us". The one with the $90 electric bill.
One for ME

 

[dw1]

Can you not get and add a 30 amp breaker where the compressor would be on its own circuit, I would not rely on the breaker to trip if overloaded with Air Cond and Air Comp. on same 30 amp breaker (Fire Hazzard) same with welder, what amperage is welder, I would say 100 breaker is over sized for welder. Get the correct breakers and do the job right, you are not talking that much money for parts.


In Edit:
OK, just seen that panel is full, lets go to plan B, can you set a sub panel next to main panel? take air cond breaker out, put a bigger breaker in exsisting panel to feed new sub panel and then feed air cond out of new panel along with air comp and welder

 

[CNGsaves]

Where in the world are you?? Update GJ Profile with City/State/Country.

Also, let's SEE what you're talking about. Post up PICS that tell thousand words.

Include PICs of compressor including HP, and motor plate of compressor.

 

[JACDes]

NO.

The AC circuit is a dedicated circuit and sized only for the AC unit.
I would not add anything to it, even if you consider diversification a 3HP compressor and A/C will overload the circuit... "turning off the A/C when I use the compressor" is not a good enough reason to do this wrong.

Same with the welder..


As suggested already install a sub-panel next to your main panel and do this the right way.

 

[BD1]

If you have room add a sub panel. Pull the 30 AC breaker, replace with new breaker sized for sub panel, run new wire to sub panel and add required breakers.

 

[pattenp]

Second question, similar to the first: I just bought a welder and I want to connect it to the 100A breaker that feeds the basement panel. Again, I know I can't just stuff the wires into the breaker. Do I do the same thing? Cut the wires coming out of the 100A breaker, then use a wire nut to attach wires going to the welder? These would go to a disconnect junction box to provide a disconnect for the welder.

I know that will "work". Can someone confirm this is the right way to do it according to NEC?

There is no room in the panel for additional breakers...

Thanks,

Jim

No. The wire coming off the 100A breaker would need to be sized to handle 100A which is way to large to use for any outlet for a welder. You can come off the small panel if space is available to feed a second sub-panel for the compressor and welder.

 

[jrcampbe]

Thanks, guys. Duh. A small sub panel is clearly the answer.