Sub panel off a sub panel?

[Jim Johnstone]

Hi guys,

I am upgrading the electrical in my garage, to a 100 amp sub panel off my house panel. I want to know if there is any code problems running another 60amp sub panel from that 100 amp panel, over to a dedicated compressor room?

Thanks,
Jim

 

[Norcal]

As long as conductors are sized correctly, grounding & grounded conductors are separated I cannot see any issues.



Edit: Comments are made according to the NEC, did not not notice OP's location until after posting.

 

[Jim Johnstone]

Ok thanks. I checked on a Canadian based home improvement website, and it shouldn't present any problems at all.

My question now becomes, would this be the best way to put electrical in that compressor room? This is more long term planning, but my intentions are to have 2 compressors in that room. One is currently a 5hp drawing around 23 amps. The other will likely be a 7.5hp drawing around 29 amps IIRC. I have the ability to run them at alternate times so my load isn't excessively high at one time. I also want to put some lighting, and provide 120 volt power for the auto moisture drains on the machines.

The compressor room is going to be about as far away from the garage's main panel as it can get, so the 60 amp sub panel was my first thought. Any better suggestions?

Thanks,
Jim

 

[Falcon67]

I would just price it both ways - one, running separate feeds from the 100A panel and using the appropriate disconnect at the compressors, then running a single big wire run plus panel, breakers, etc. Thinking likely #10 for the 5HP and #8 for the 7.5 - maybe, depending on run, wire, etc. Your lights could be just part of one of your normal lighting circuits, drain power part of a normal plug run. If you are not running anything else way over there, then the panel may be most convenient without regard to cost.

 

[79firebird]

should be fine. Where my shop is they have a new 200 amp service feeding the old 125 amp panel then it goes to my shop panel there 60 amp in it. then has a small 20 amp panel off that for a motor hole. all passed fine.