switching a 220 circuit

[oiler]

Hi all I'm just wondering how to go about this
I want to be able to switch my compressor on/off from the other side of the shop
It will be a 220 circuit but I'm not sure about the switch rating or type?
I am in the process of wiring the shop and thought it would be a nice feature
Thanks for the help
Jeff

[sberry]

There are several ways to do this but,,,,, I would really consider the real "need" for it. Depending on the comp, if it has a starter it would make it easier.

[Voltron]

Will be expensive and difficult if you run the main feeds for the compressor across the shop[ and back again. Most common way to achieve this sort of "remote switching" si to have the compressor controlled by a contactor, with a circuit off the the contactor coil across to your remote switch. This cuts down on the size needed for cable/fittings etc. You would then probably be able to get away with using a regular light switch to control it. Cant help with switch ratings etc as we use completely different voltages where i'm from, suffice to say that as long as the voltage rating is correct, the switch will only have to handle a very small current (less than a light bulb)

[oiler]

I see what you mean
scrap that idea
Thanks guys
Jeff

[Junkman]

Installing the contactor to control the compressor isn't much of a big deal. At work, I had the electrician install a whole lot of contactors that were all controlled by a single switch. Flip the switch, and every light in the entire 3600 square foot store came on. It even controlled the water main. When the lights went off, the water line was shut down. Having someone leave the water line open once too may times at night was the reason. No more flooded store after we made this change. I believe the contactors are about $60 each.

[oiler]

so a contactor would just be another word for a relay?
control big voltage with little voltage=relay
Jeff

[Torque1st]

Yes, a contactor is a type of heavy duty relay.

[tdkkart]

When I get around to finishing out the shop here at my new place intentions are to do a similar setup. Use a conatactor to control the compressor so that it is powered only when the lights are on. My contactor will be wired in series with the pressure switch also which will take the load off the contacts in the pressure switch.
Mechanical failures(air lines), and pressure switch contacts are the cause of 99% of compressor problems. Dealing with these problems up front will make future air production much more pleasant.

[sberry]

I dont know about you guys but my comps never turn off.

[buening]

Most larger air compressors use a starter box (contactor and coil). My 7.5hp 80 gal compressor has one. Here is a picture of one.

http://i6.ebayimg.com/07/i/000/f1/3a/a7c3_1.JPG

I have a disconnect box at the wall to turn off power to the compressor when I am doing any kind of maintenance or simply want to prevent it from turning on. Example of the disconnect box:

http://i18.ebayimg.com/07/i/001/15/4e/235f_1_sbl.JPG


Disconnect boxes are often used at Central Air conditioner units. This is a bit of a bulky switch and not the best for those fancy garages.

What size compressor motor are we talking about? If only a few HP then you can buy a 30A switch and the wire size wouldn't be that large.

[The Alchemist]

This is a question I have as well. I recently got a new compressor and would like to install it in the basement for sound and space reasons. I would rather not have to go downstairs, turn on the breaker, then go back upstairs to the garage, then back down to the basement to turn off the breaker when I'm done, so I'd really like to put a switch or breaker in the garage. It's only going to add +/- 10 feet of wiring since I'm only going to go right into the garage, then back down to the basement.

Do I need a double pole switch for the 220?

Thanks.

[sberry]

You dont "need" it to control the circuit but using a single pole doesnt act as a service disconnect. I opt for disconnecting both poles but you will need a heavy motor rated switch.

[D KRAGER]

I think it's called a double throw double pole switch.... It switches off both phases, but just looks like a regular light switch. Watch amperage ratings though. I imagine a 20 amp is the biggest they make. Or you could use like a central air breaker/disconnect switch that they mount by central air units, I'm sure you can get those in almost any amerage.

[The Alchemist]

Well, I picked up a 60amp/250v non fusable disconnect switch which is typically used for a/c units, which is exactly what I needed.

[Charles (in GA)]

I think it's called a double throw double pole switch.... It switches off both phases, but just looks like a regular light switch. Watch amperage ratings though. I imagine a 20 amp is the biggest they make.

Leviton and Pass and Seymour both make 30 amp DPST "toggle" switches that have standard plastic light switch toggles. I used them as light switches for my multiwire circuits for my overhead lighting. I used 30 amp ones because I got them on a clearance for real cheap at Home Depot compared to the regular price. They are motor rated.

http://www.passandseymour.com/pdf/A02.pdf

Charles

[Torque1st]

You can also get the wall switches here:
http://op4.triadinet.com/STRASSER/nlcatalog.asp
If that link does not work use the online catalog here:
http://www.strasser-hardware.com/
Strasser Hardware is an excellent company to do business with. There should be a large GOOD hardware store in most larger cities. Electrical supply houses will also have the switches.

At the strasser website go:
online catalog
electrical & lighting
Switches
Switches double pole

Item #172742 20A, 120/277V $12.99ea. Mfg Part # CSB20AC2I
Item #379602 30A, 120/277V $22.99ea. Mfg Part # PS30AC2ICC6

A disconnect upstairs and down will work as well. Just label each location re the other switch.