compressor disconnect

[Imcrazy]

I am hardwiring a IR 5hp 2 stage compressor (230/1) in my shop. I would like to wire a disconnect switch in line that will be able to handle being turned off and on several times a day.

So far all I have found are A/C unit disconnects at HD and Lowes. I am afraid that these are suitable for only occasional use? Am I wrong?

Are there any other options out there that are reasonable in cost?

 

[pattenp]

This is so cheap you can replace it when it wears out.

http://www.lowes.com/pd_95578-82364...RL=/pl__0__s?Ntt=disconnect+switch&facetInfo=

or this may last longer...

http://www.lowes.com/ProductDisplay...gId=10051&cmRelshp=req&rel=nofollow&cId=PDIO1

 

[matt151617]

Go to an electrical supply store and ask for a DPST switch. Any 4 pole switch will work for 240v. A supply store should sell machinery switches. I'm assuming you have it wired to a 30amp circuit? Just make sure you specify that when go to the store.

 

[sberry]

I always got to ask when someone wants to add extra,,, why would this need to be turned off and on several times a day? My ideal is breaker to box, p[lug and cord for service disconnect and to the unit with as little funny stuff in between as I can have. If this has cont actor one doesn't need to have load rated switching, a control switch might work as well or better

 

[pattenp]

http://www.automationdirect.com/adc...r_Controllers/Toggle_Motor_Controllers/30002D

 

[Imcrazy]

It is wired as a 60 amp circuit because I didn't know what I would end up with when I did the wiring. I definitely didn't want to get caught short in case I went bigger on the compressor. The current compressor only specs at 28 amps.

Thanks for the links, I will go check out Lowes tomorrow.

 

[rlitman]

If he wants to hard wire it, then a switch is a suitable disconnect. I hard wired mine, because a switch was about $15 (for one with a 10hp rating), vs a plug which would cost at least that much, plus the receptacle, plus the cost of the SO cord all adds up to about triple that price.

You don't -need- the HP rated switch if it has a contactor, but if you're going to turn it off while running (for whatever reason), you'll want one, and it's not like it is expensive. The ones listed above look fine (at first glance).

I believe I used this one:
http://www.lowes.com/ProductDisplay...gId=10051&cmRelshp=req&rel=nofollow&cId=PDIO1

I liked the on/off slider rather than the pull out style used for air conditioners, and it was even cheaper.

 

[Imcrazy]

My ideal is breaker to box, plug and cord for service disconnect and to the unit with as little funny stuff in between as I can have. If this has cont actor one doesn't need to have load rated switching, a control switch might work as well or better

I've got that part taken care of I think.

I was initially thinking I would like to have some way of shutting the system off if I was going to be gone a while or overnight or weekend. There is a switch on the compressor but it seems rather flimsy to me.

I was also thinking I would like to have some sort of noticeable indicator light downstream from the switch because I have a tendency to forget and leave it on sometimes. Seems that if the compressors is not actually running I forget that it is still on.

 

[srmofo]

Ive got a AC disconnect on mine. Mine is a 60a non-fused flip switch made by squareD. I got it at HD for about $14 IIRc.

I also saw one at Menards that a breaker on it and looked a lot cooler with the big pull down handle on the side but it was $60.

Im not out there much and its right next to the man door

 

[torqueman2002]

I run my 240VAC Single phase, 2-stage compressor through a fused safety-switch.

I got 2 from eBay 3 years ago, NIB for $23/ea. Had to buy both though.

I used 3 conductor + ground romex above ceiling then through conduit. The 120V LED indicator is run off 1 leg of the switched 240VAC plus a non-bonded neutral (because it comes from a garage sub-panel).

Good luck.

Oh, the auto drain is now powered from the switched 120VAC outlet; it's piped to discharge through the exterior wall; scares the h3ll out of my neighbor when it goes off and he's mowing the side yard!

 

[ktm010]

I'am currently wiring my garage now planning a circuit for the compressor, 240 volt. what is the advantage for a disconect ?

 

[DoyleDee]

Why not use a contactor with the coil voltage of 120- so that you can wire it to a standard wall switch?

 

[Charles (in GA)]

http://www.automationdirect.com/adc...r_Controllers/Toggle_Motor_Controllers/30002D

Excellent choice. Most double pole switches (that look light light switches) even if they are 30 amp rated, are not motor rated to 5 hp. This one is motor rated to 15 hp.

EDIT: Looking at the SPECS for this switch, I see that at 240v it is rated for 5 hp. The 15 hp is at 600v. Still, its a good switch for the purpose.

Charles

 

[sberry]

I'am currently wiring my garage now planning a circuit for the compressor, 240 volt. what is the advantage for a disconect ?

In some cases the breaker in the panel is suitable for a service disconnect, may be in the same general location so a guy can see a bud turning it on while working on it, you have to disconnect the power, (these have auto start also). If its in a different room it needs further disconnect for service, cord is good because its a no brainer visual deal, unplug and its safe to work on.
Turning it on on occasion is a different deal than the first post, turning on and off several times a day also,, and was said, if there is a contactor it maybe able to be switched differently.
Personally I leave the thing on, keep hoses in good condition etc and I want air as live as I want electric or water, its just another one of the utilities. Put a valve on outgoing manifold, could shut it off, can service any part of the air system without shutting down, draining etc.
I serviced mine the other day after reading one of these threads, took it right out, fixed some drains, steamed it off, adjusted belts, changed its oil, put synth in, going to forget about it, power hadn't been interrupted to it in 15 yrs. This oil is so much better than it used to be, looked cherry on draining, old time oil used to be crappy after a while but this stuff, thousands of hours on it, looks, feels new, sample would have been interesting, it won't get drained again unless it needs service work.

 

[ktm010]

The welder outlets are going in 2 gang boxes, would I just do the same for the compressor. And what is the main purpose of the disconnect ? Is it just a big switch that can be locked out. Sorry for acting stupid !! I just want to do this once and right

 

[sberry]

Read above,, ha,,, but in some cases it would be advantageous to be locked out, especially with factory, multiple users/service people/. In your own garage you are under your own supervision, not everyone might be fooling with it, its not in a remote location.
A welder is an example, in large plant the panel might not be near the machine, it may be heavily wired directly without plug, a disconnect is required for service safety, when the service man disconnects on location it he can be sure, same as a cord at home or on small factory cord supplied unit, cord can supply this function.

 

[sberry]

Another condition requiring a disconnect may be multiple machines on one circuit, needs disconnect to keep it from interrupting this line and possibly specialized over current protection., maybe hooked to a buss way, etc. When you are at home you can provide dedicated circuit and correct wire/breaker.

 

[ktm010]

Thank You !! That clears things up for me, double gang box wired for a plug

 

[Charles (in GA)]

You don't want a double gang box. Those are switch boxes that have ears for mounting switches and then you install a regular cover plate. No way to mount a receptacle in the middle of them (easily) get a 4x4 box and a cover to mount the receptacle. Just be sure and use a plug and receptacle that are MOTOR RATED for the horsepower you have. It might cover the amperage you need but may not cover the horsepower, so check.

Charles

 

[PT Doc]

This is also an option:

http://www.leviton.com/OA_HTML/ProductDetail.jsp?partnumber=MS602-FW&section=40132&minisite=10251

 

[Charles (in GA)]

This is also an option:

http://www.leviton.com/OA_HTML/ProductDetail.jsp?partnumber=MS602-FW&section=40132&minisite=10251

$54.95 at Fruitridge Tools (link is for this switch).

30 amp version, good for 5 hp (FR Tools web site is incorrect on the hp info, see the Leviton brochure)

$26.95 Leviton MS302-DS

$21.95 Leviton MS302-S

FR Tools is great on shipping, for one switch I ordered, it was like $3 and another time when I ordered 3 switches, they combined it and I think it was about $8 or less.

Charles

 

[Imcrazy]

I run my 240VAC Single phase, 2-stage compressor through a fused safety-switch.

I got 2 from eBay 3 years ago, NIB for $23/ea. Had to buy both though.

I used 3 conductor + ground romex above ceiling then through conduit. The 120V LED indicator is run off 1 leg of the switched 240VAC plus a non-bonded neutral (because it comes from a garage sub-panel).

Good luck.

Oh, the auto drain is now powered from the switched 120VAC outlet; it's piped to discharge through the exterior wall; scares the h3ll out of my neighbor when it goes off and he's mowing the side yard!

Holy Cowabunga I love that light. I probably wouldn't forget about that one.

Good ideas guys, Thanks

 

[torqueman2002]

Holy Cowabunga I love that light. I probably wouldn't forget about that one.

Good ideas guys, Thanks

You're welcome!

As far as the light - it's my 2nd try. There's actually a 240VAC pilot on top of the switch, just above the 'ON'. I thought I'd see it from across the shop before I went back into the house. Nope, I still found my self leaping out of my skin when the compressor would cycle ON, while I was just the other side of the shared wall sitting in the Lazy-Boy.

When I saw that 120VAC LED light I had to have it! There were several to choose from.

Here's the story behind the light. http://tinyurl.com/BigLED

 

[Imcrazy]

I'm finally done wiring this up. I know I am SLOW.

Big thanks to PattenP and Charles in GA, the switch from Direct Automation was just what I needed. Thanks for all of your help!

Heres a couple of photos

 

[sharkytm]

Do you have a mag starter hooked up? It doesn't look like it, and that 5HP/2-phase motor should require one. I'm in the same situation, and looking for a mag starter with an on/off switch.

 

[pattenp]

I must have missed it, but where are you getting 2-phase motor from?

Do you have a mag starter hooked up? It doesn't look like it, and that 5HP/2-phase motor should require one. I'm in the same situation, and looking for a mag starter with an on/off switch.

 

[Imcrazy]

Do you have a mag starter hooked up? It doesn't look like it, and that 5HP/2-phase motor should require one. I'm in the same situation, and looking for a mag starter with an on/off switch.

It was a new IR comppressor in single phase 220 so I just wired it up per the instructions that came with the compressor. I assume that the starter is an integral part of the motor.

Thanks again for the help guys. I think it came out just like I wanted.

 

[madstat]

I may be missing something but did the OP say this dedicated circuit was 60amps? I wonder if that is above the maximum over-current protection rated for this compressor, hence some additional over-current protection is needed. If that's the case I would have used a fuse-able safety switch. Or perhaps its common for compressors to have their own fuse, either-way you don't want to get into some situation where you are drawing more current than rated for your device.

 

[HAP]

I used a 50A welder plug/recp for my compressor. This way I can use the circuit for something else or use my welder on this circuit if need be. Plus, when I unplug it for maint its harder for someone to surprize me...

R,
HAP

 

[Zeke]

Wouldn't you want one of these?

 

[PRH44]

I would not recommend using attachment plugs for disconnecting under load. Nor would I use them for frequent disconnect applications with or with out load. The arcing and/or frequent use will soon degrade the devices and you could have a melt down on your hands.

 

[mebedave]

I run my 240VAC Single phase, 2-stage compressor through a fused safety-switch.

I got 2 from eBay 3 years ago, NIB for $23/ea. Had to buy both though.

I used 3 conductor + ground romex above ceiling then through conduit. The 120V LED indicator is run off 1 leg of the switched 240VAC plus a non-bonded neutral (because it comes from a garage sub-panel).

Good luck.

Oh, the auto drain is now powered from the switched 120VAC outlet; it's piped to discharge through the exterior wall; scares the h3ll out of my neighbor when it goes off and he's mowing the side yard!

I like the light idea!! In my case i have a detached shop 300' from house I think I'll steal this idea but mount the light outside that way if I forget to turn off the compressor I'll see the light from the house.

 

[Norcal]

Wouldn't you want one of these?

Not on a air compressor, & a mag starter or contactor would also be required to use that push button station also.

 

[Sureshot]

I leave my compressor on all the time. I soap tested any connections and keep things in good leakfree condition.

One thing I have considered though is a motion sensor in the shop so the compressor will only run when someone is in there or for 30-60 minutes after. It may have to go through a relay or something but it would not be too hard to set up.

 

[Fred43]

Hey Fellows,
A 5 HP motor requires a switch or motor starter with heater elements to protect the motor. The compressor high and low limit switches will turn it on and off automatically and SAFELY. If you wire it to code requirements you would have less insurance liability if something went wrong. A Two pole safety switch and a Magnetic Starter is the proper and safe way to wire this unit.