Compressor switched through lighting.

[MFortie]

Decided to start a separate thread so as not to distract too much from the OP's thread: https://www.garagejournal.com/forum/threads/on-off-light-for-compressor.490716/#post-9355337

I would like to setup my compressor to be 'switched' along with the lighting. This is the contactor I found: https://www.amazon.com/gp/product/B07GSC14G4/?tag=atomicindus08-20 for the project. My compressor is on the other side of the MH and there isn't any room to walk in front/behind, so I have to exit and go in the other door to turn it on/off.

This is my wiring diagram (along with a couple of questions):



Am I on the right track?

The contactor will be housed in a j-box mounted just under the subpanel (surface mounted on a backboard).

The compressor is a Quincy QT-54, 5HP, 24A, 5' (+/-) from the subpanel.

TIA.

 

[jeepxj]

Wall Switch on Mag Starter Compressor

I still have a 120V small compressor on a wall switched outlet at the door to conveniently turn off everything in the shop as I leave. I recently installed a large compressor 230V 5HP with a mag starter. Also wanting to have this compressor switched off at the door when I leave. Suggestions...

www.garagejournal.com

easier IMO.

 

[MFortie]

Well, more wiring would be required to add the switch by the door (where the light switches are). Plus I have O/H rollup doors to navigate that aren't shown. The lighting j-box (for that bank) is only 15' or so from the subpanel. My lighting is split into (3) 'bays' and I have multiple 4-lamp T8 fixtures in each bay. I typically only flip on two of the lamps at a time (they're independently wired in sets of two), so I was going to use the switch for the lamps I don't usually turn on for the compressor contactor.

 

[wyliesdiesels]

Contactor rated for 7.5HP @ 230v so youre good to go there

 

[jeepxj]

Well, more wiring would be required to add the switch by the door (where the light switches are). Plus I have O/H rollup doors to navigate that aren't shown. The lighting j-box (for that bank) is only 15' or so from the subpanel. My lighting is split into (3) 'bays' and I have multiple 4-lamp T8 fixtures in each bay. I typically only flip on two of the lamps at a time (they're independently wired in sets of two), so I was going to use the switch for the lamps I don't usually turn on for the compressor contactor.

bring the pressure switch wires up to an overhead light and use a 120-120 contactor there to control it.

Amazon.com

 

[MFortie]

Any comments on the diagram should I choose to go that way?

 

[PoorUB]

Looks ok to me, but as far as code? I don't know.

I assume the motorized valve is to shut off the air outlet on the compressor? I assume the valve take very little power.

 

[fitter30]

Use a 24vac contactor at the compressor, at light switch 40 va transformer 120 x24vac run 18 gauge thermostat wire from transformer to contactor. Light świtch change it to a two pole switch one pole for lights one for transformer.

 

[MFortie]

Thank you for the alternate suggestions, but I’m planning to go with the relay off the lighting circuit as I posted. I already have most everything (the relay will be here this week).

My pathways are existing as well.

What I basically needed to know is whether my wiring diagram is correct, and less importantly, if my plan to pass the conductors through the panel is acceptable. Not having this inspected, but prefer to be code compliant.

 

[jeepxj]

312.8 nec covers panelboards as raceways. given its not low voltage i personally would wire it up and not give a ****.

only one is required to break the circuit

the motorized valve: it spring closes when power cut? is it 100% duty cycle rated for when its on?

 

[MFortie]

Thank you. I figured as much.

As to the valve, yes, spring loaded. It's made for the application, so I presume 100% duty cycle. Cutsheet below:

 

[jeepxj]

yup. just making sure it wasn't a solenoid valve. those have a duty cycle rating and can burn out.

side thought: it'd be interesting to use a photo eye to trigger this. would need to invert the signal somehow. but it could be localized to the compressor area and just point up at your lights.