Does this sound like enough for 5hp compressor or welder?

[thammel]

I'm finally trying to finish the wiring so I can insulate and heat before the winter!! I"m running 8 gauge 3+g to a nema 14-50 (or smaller) for my future 5hp compressor. I'm thinking this circuit would also accommodate a decent welder if I get one in the future. Does this sound adequate from all your experiences? I'm placing the outlet at 48" above floor.

I"m dreaming of a 2 stage champion compressor. I was hooked on Quincy but I tend to think Champion may even have them beat.

So...have I got the circuit sized right?

Thanks,
Tom

 

[Aceman]

Yes.

You only need 2 conductor for a compressor or welder though. Just an FYI, 50 amp receps only carry a 3HP rating. It's usually better to run two separate circuits, one to hardwire to a compressor and another with a 50 amp recep for the welder.

 

[thammel]

Good point - I didn't know the 14-50 receptacle had a 3hp limit. How would you hard wire the compressor - type of box on the way and then how to run the wire from the box to the compressor - flex conduit? I'm thinking a dual gang box in the wall to accommodate the 50 amp receptacle. Of course, I've seen lots of EMT conduit connections.

Tom

 

[pattenp]

Use a A/C dissconnect like this.... http://www.homedepot.com/p/Square-D...t-Protection-QO200TRCP/202353314#.UgMXVpLCbLQ

View media item 16457

 

[LG63]

I'm not arguing the point, but why is a 50 amp receptacle only rated 3 HP? The prongs on that plug look like they would easily handle the typical 22 amp /220V / 5HP motor. I realize startup current will be around 100 amps for a a couple seconds but even at that it still looks like there's enough brass there to handle it.

 

[zkling]

I do believe it is because of the start up surge of the motor. If high enough it could weld the plug to the receptacle or cause

​

other not so good issues. Is is likely no, but electrical code is all about worst case scenario and safety.