Shared circuit for compressor and auto drain?

[DanielVetpath]

Hi Folks: I am running a 220 circuit to my compressor. I thought I read it was okay to use one of the legs to run an associated 110 circuit for the auto drain but couldn't find a post. Am I correct or all washed up? If okay, what size wire do I use for the 20 amp outlet? 12 gauge or the same wire as the 220 circuit. Thanks for setting me straight! Daniel

 

[pattenp]

If the 240V circuit is 20A then that's okay. If greater than 20A then the 120V outlet branch needs its own 20A breaker protection.

 

[Terry D]

Your compressor needs (2) hots and a ground. You would need a neutral also to get 120 volts. If its just a 20 amp circuit feeding the compressor, then you could run a 4-wire cable to also get 120 volts. But in my own opinion, I would leave the compressor wiring just for the compressor and get the 120 volt from another source. Its only a solenoid valve, doesn't have to be a dedicated circuit. Find a close 120 volt circuit to tap on to.

 

[nadogail]

How about a control transformer to get 120 volts from your 240 supply? I used to service Bailers and Compactors, they were wired the this way for their controls and relays.

 

[DanielVetpath]

Thanks for keeping me straight everyone. A separate circuit is no big deal. Happy New Year to all. Daniel

 

[wyliesdiesels]

What is the HP rating on the comp?

 

[BreeStephany]

To run both your compressor and the auto drain on the circuit, as others have said, you will need 2x line voltage conductors, a neutral conductor and a ground conductor. The minimum conductor size for a 20A circuit is #12 THHN, but you may need to upsize your conductors based on the length of the run / voltage drop from the panel.

Put in a 2 pole 20A breaker to land both the line conductors so that both lines feeding the compressor motor can be turned off at the same time. If the panel is not within sight of the compressor, I suggest adding a disconnect at the compressor to make it compliant.

Also make sure that the receptacle for your auto drain is GFCI protected, regardless of location.

Just my two cents.

 

[alfredeneuman]

Put in a 2 pole 20A breaker to land both the line conductors so that both lines feeding the compressor motor can be turned off at the same time.

Where did he say that the compressor would be on a 20A circuit?

12 gauge or the same wire as the 220 circuit.

 

[4x4Pete]

How about a 220v solenoid for the auto drain?

 

[alfredeneuman]

How about a 220v solenoid for the auto drain?

https://www.amazon.com/dp/B07DPFXVWM/?tag=atomicindus08-20
and an inline fuse
https://www.amazon.com/dp/B00GLK9LNA/?tag=atomicindus08-20