[Captflx]

My 3.5 h.p. air compressor will be wired with 10/2 with ground. Compressor will be outside of shop under cover. I'd like to be able to control power to the outside compressor disconnect with the use of a 240V, 30 amp relay with 24V coils. It will be near the outside disconnect. That way I can cut the power to my compressor with a switch as I leave my shop. Is there a code violation with this set up?

 

[joecaption]

What code are you working under in your area?
Why not a simple 30 amp switch?

 

[teamo]

Use a two pole 30 amp switch. No need for the relay.

http://www.homedepot.com/p/Leviton-...ble-Pole-Switch-White-R62-03032-2WS/100356941

 

[Captflx]

after a 2 month delay in my air compressor project, I'm back into it. My double pole wall switch ( 30 amp, 240 v) to control my compressor also says "rated for 2 h.p." which takes into account the start up current spike. I know my 3.5 h.p. motor rating is misleading at best. My motor has a current rating of 16 amps. Should I be concerned withe the lower 2 h.p. switch rating?

 

[Jim Port]

Is the breaker for the compressor available instead of a separate seitch?

 

[micromind]

I would have no problem at all using that switch with that compressor.

Yes, technically, it is a code violation but I simply would not worry about it.

If you want to be completely compliant, a Square D 2510-KO5 is a 2 pole toggle switch that's rated for 3HP at 230 volts. For calculation purposes, the code lists a 3HP single phase motor at 230 volts as 17 amps.

Other manufacturers have similar switches, the reason I listed the Square D model is because I use a lot of them and can remember the part number.

Rob

 

[Captflx]

The breaker is not readily available as I exit my shop and I really don't want to be flipping the breaker each day I enter and exit for the day.

I really do want to be code compliant, so I'll look for higher rated switches such as the SQ D. Thanks for the input.

 

[Plumbvoltage]

You could use a switch like below. I have one like this but the 60 amp version for my 5hp compressor.

http://www.leviton.com/OA_HTML/Levi...ductFamily=Safety Switches and Motor Controls

 

[Captflx]

Thanks for the leviton recommendation.

 

[concrete_joe]

i would use a 50A SSR, and low V on the switch to the SSR.

 

[Captflx]

Thanks for all suggestions. I looked at the Leviton site and was able to order the 30 amp starter switch (MS302-DS) that appears to be in the N3302-DS starter switch with housing. This allows me to use a deep wall electrical outlet box.