"Switch" for compressor

[scott37300]

I have a 3HP rolair compressor that is wired directly to the panel right now. To turn it on and off I have just been using the breaker. I would like to put a switch in close to the compressor to turn it on and off instead of using the breaker.

Something like this, http://www.grainger.com/Grainger/SQUARE-D-General-Duty-Safety-Switch-1H252?Pid=search

It's a 220 compressor and the motor plate says F.L.A. 14.4-15 amps.

Don't know exactly what I need. Would like to be able to just pull the handle to turn the compressor on and off instead of using the breaker.

Thanks

 

[dittle fart around]

That should work another choice might be push button switch mounted on the compressor. My compressor has a switch on the motor already.

 

[ishiboo]

If you don't shut it off frequently while it's running, Menards sells Leviton standard wall rocker switches in both 20A dual-pole and 30A dual-pole.

Runs ~$30 for the 30A and ~$22 for the 20A last I checked. I bought one for my 2000W halogen, it works nice.

 

[scott37300]

That should work another choice might be push button switch mounted on the compressor. My compressor has a switch on the motor already.

Thanks, I am looking to mount something on the wall by the compressor and then run some sealtite to the compressor. Trying to find out exactly what I need. Not to familiar with what all is out there for electrical switches.

 

[dave63]

Do you have a magnetic starter? They get complicated real quick.

 

[930dreamer]

I buy up all the good/used disconnects at the Restore Store. Look for a 30 amp(seems to be a common size) new or used and install 20 amp fuses.

 

[ptschram]

If you don't shut it off frequently while it's running, Menards sells Leviton standard wall rocker switches in both 20A dual-pole and 30A dual-pole.

Runs ~$30 for the 30A and ~$22 for the 20A last I checked. I bought one for my 2000W halogen, it works nice.

I found those and bought the 30 amp instantly. It is very comforting to know that I can throw a switch that breaks both legs and can handle motor start-up current with no problem.

Now, if I could just remember to turn it back on in the morning!

Edit-I turn the compressor on and off in the morning and in the evening. Once in a great while, it will kick on when I throw the switch, but it's not very often. If it starts to become intermittent, trips the breaker, or starts to smoke, I'll spend another $35!

 

[dave63]

I would venture that if you have a reset button on your motor and you use a 30amp double pole switch you would probably be OK. I would use a starter if the motor does not have a reset button.

 

[KCarGuy]

I also use the Double Pole Switch on my 220VAC Compressor.
I mounted an Outdoor box and Outdoor switch cover as added insurance.
It works perfect, as said...dont make it a habit to turn it off running. And it should last a lifetime!

 

[ptschram]

I would venture that if you have a reset button on your motor and you use a 30amp double pole switch you would probably be OK. I would use a starter if the motor does not have a reset button.

Why?

Most of the compressors that most of us will use have a simple switch contact in the pressure switch. Using the switches shown, or worse, the breaker do little more than break the circuit slightly more distant from the motor. If they meet maximum (motor-start) current, why would one need a more complicated switch?

I think those of us that are using switches rather than circuit breakers are probably better off as the switches are designed for continually being turned on and off,whereas circuit breakers are protection devices, not switches (although that may be how they function).

 

[Gary S]

My 5hp 240v compressor has a two position pressure switch. My small 120v compressor has it too.
The switches can be in OFF, or AUTO. Check yours. It might have the built in switch you need.

 

[dave63]

Just for motor protection, otherwise the combo pressure switch on-off head unloader your talking about is just fine.

 

[rlitman]

That first switch shown should be fine.
The green Leviton "spec grade" 30A switch is NO GOOD.
The current is NOT what is not the most important part of the switch rating, and neither is the motor full load starting current.

You must have a switch that is rated for the Horsepower of your motor. The 30A spec grade switch is probably only rated for 3/4" horsepower, and is really designed at that 30A rating for resistive lighting or heating loads. Using that switch on your compressor repeatedly will trash it in short order (it will trash the breaker eventually too), if you turn it off while the motor is still running.

That's the catch. The switch posted by the OP is probably rated for 10 or 15HP, and has the contacts required to be able to shut the motor while it is running. That's exactly what he needs.

 

[ishiboo]

That first switch shown should be fine.
The green Leviton "spec grade" 30A switch is NO GOOD.
The current is NOT what is not the most important part of the switch rating, and neither is the motor full load starting current.

You must have a switch that is rated for the Horsepower of your motor. The 30A spec grade switch is probably only rated for 3/4" horsepower, and is really designed at that 30A rating for resistive lighting or heating loads. Using that switch on your compressor repeatedly will trash it in short order (it will trash the breaker eventually too), if you turn it off while the motor is still running.

That's the catch. The switch posted by the OP is probably rated for 10 or 15HP, and has the contacts required to be able to shut the motor while it is running. That's exactly what he needs.

The 30A is rated for a 2 HP motor, but as I said when I recommended it - you would want to shut it off when the compressor is not running... with that use or the occasional break when running, it'll still last a very long time in that application.

 

[rlitman]

The 30A is rated for a 2 HP motor, but as I said when I recommended it - you would want to shut it off when the compressor is not running... with that use or the occasional break when running, it'll still last a very long time in that application.

2HP, ok, yeah, that's pretty close if you don't frequently shut it while it's running. The last time I looked at one of those though, the one I saw was rated under 1HP.

Besides, that SquareD switch has SquareD pricing.
I paid about $25 for a Cutler Hammer 15HP rated version of the same thing.
I got it at Lowes right next to the air conditioner disconnects. Mine happens to be the raintight version with a sliding switch on the inside (instead of the exterior handle), but whichever is cheaper will do.
Since it comes with the box, it's not going to cost more than paying for a metal box and a spec grade switch anyway.

 

[Falcon67]

I use this: http://www.grizzly.com/products/110-220V-On-Off-Switch/H8238

It's a bit of a pain to wire since the screw contacts on the back are a bit small. But it does the job on my 3HP compressor.

 

[PT Doc]

Leviton ms602 might be an option.

 

[ishiboo]

I use this: http://www.grizzly.com/products/110-220V-On-Off-Switch/H8238

It's a bit of a pain to wire since the screw contacts on the back are a bit small. But it does the job on my 3HP compressor.

You win!