Switches for 220

[Chris Jenkins]

I would like to install a switch for a 220 line. I know enough about electricity to be dangerous. I was wondering is it bad to run a typical house hold style switch and run it in-line of one (or both, would require dual switches) wires?

60024

If this is a bad idea, how do you go about running a proper switch for 220? I know I could use a Mag Switch, but I'm not looking to spend that much.

Thanks

[Phillip Thorne]

make sure to get a double poled switch as each leg in the 220 circuit is carrying 120v

[Michael Lutz]

I second using a double pole switch. I put one in for my dust collector, but since I upgraded to a Gorilla I haven't needed to use it.

Mike

[Jim Becker]

Double pole...you have two "hot" leads that need to be broken to kill the circuit.

[Vernon Taylor]

I would go to your local electrical supply house not a big box,I am sure they can reccomend a practical soulution. I a have found this too be an invaluable resource on several occassions.

[Steven Wilson]

You're turning on and off a motor correct? Then use a horsepower rated motor switch. You're switch needs to be sized in accordance to the motor you are turning on and off. I like GE CR101's but they can be a little pricey. Check your local electrical supply store. BTW, some look like normal light switches, some have start/stop buttons. It really doesn't matter what the outside looks like, it's the guts that are important and they need to be sized to properly handle your motor load (i.e. a 3hp rated switch for a 3hp motor, etc).

[Jim Becker]

The alternative to Steven's recommendation is to use a contactor controled by 120v or LV to apply/remove power to a motor-driven device, such as a dust collector. (That's how my DC is hooked up) The contactor needs to be rated appropriately for the load. They can be bought at the local electrical supply or via "that auction site". Mine was $25 and purchased locally.

[Chris Jenkins]

Jim & Steve,

I was thinking I may need to go the route of a disconnect switch, but wasn't sure if their was another way. I read about guys having their compressors on switches in the basement when the compressor is outside or something. This is what I am trying to do.

I want to either A) put a switch in the basement for the compressor in the garage or B) add some type of 220 timer so this thing doesn't turn on in the middle of the night. I prefer the switch cause then I know their is no power and no way of it running and running and running when I am not home.

[Jim Becker]

Chris, talk to your local electrical supply about your specific application and have the motor plate information with you. They should be able to recommend an appropriate disconnect.

[Richard Butler]

I would like to install a switch for a 220 line. I know enough about electricity to be dangerous. I was wondering is it bad to run a typical house hold style switch and run it in-line of one (or both, would require dual switches) wires?

60024

If this is a bad idea, how do you go about running a proper switch for 220? I know I could use a Mag Switch, but I'm not looking to spend that much.

Thanks
You need a double pole switch. Depending on the load you may be able to use a common double pole switch from HD or Lowes. Failing that, here is a link for a industrial switch that should handle anything you throw at it.



http://www.factorymation.com/s.nl/it.A/id.4527/.f


That should do it.



(http://www.factorymation.com/s.nl/it.A/id.4527/.f)

[Steve Clardy]

Double pole, single lever switch is what I put on my jet edge sander.

About $10.00 at a Elec. Supply house

[Randy Denby]

Best bet and cheapest ,is to install a contactor with a 120v coil. This will save you from having to run larger wire from switch to the compressor, and add length to that motor circuit/wire. You can use a regular light switch since the switching circuit will be drawing minimal amps (milliamps). Simplistically speaking, The switch turns on (powers) the coil of the contactor. 220 volts is wired to one side of the contactor, and when you switch it "on "the 220 circuit is completed thru the "contacts" to the compressor.


BTW, usually the contactor is installed fairly close to the compressor in a protective enclosure depending on the area. ...outside= raintite, etc

[Jim Becker]

Randy, contactors can also be had with low voltage coils on the control side which means you can use very meager wire to control them if getting Romex between "point a and point b" would be challenging.

[Jim O'Dell]

The down side of using a lower voltage contactor trigger is that you then have to have a matching voltage transformer to power it. I have my cyclone rigged like Jim B. does, 110 volt trigger contactor. It would be easy to add a remote or a timer to the setup I made. My sprinkler system uses a 24 volt trigger for the pump at the creek, but then the transformer is built in to the control box. Jim.

[Jim Becker]

The down side of using a lower voltage contactor trigger is that you then have to have a matching voltage transformer to power it.

Very true...but in the odd instance that something small like bell wire is easier to route, it's an option despite the transformer requirement.

[Rob Russell]

Folks - Jim does not "need" a double pole switch to turn the compressor on and off. A single pole, HP-rated switch will work just fine. Just make sure the switch is rated for the voltage (250v), which it should be.

I wouldn't depend on the switch to kill the circuit for purposes of working on the wiring - the disconnect is the circuit breaker.

Rob

[T. Scott Nalley]

Hi Chris,

I think what you should do is run a contactor type switch (like what is on your air conditioner or heat pump) or a disconnect type switch for you unit. I am a HVAC mechanic and work with electricity all the time. The reason why you just don't want to break the connection to one of the power lines in a 220V circuit is that the other line will be "hot" up until the switch where you are breaking the other power line. Your heat pump or air conditioner outside is a perfect example of how 220V appliances should be controlled. They have a low voltage control circuit controlling a double pole contactor that breaks all power to the motors (fan motor and compressor). The way I have my table saw/dust collector/air compressor wired in my garage is that I have the power going into a disconnect box. Where the power is going in, I have the table saw and the dust collector wired to the hot side, and the air compressor wired to the other switched side. Here is the reason why. I only use the table saw/ dust collector with the disconnect off to the air compressor because that is all the amps that the circuit can handle. I have both the table saw and dust collector on separate circuit wires coming from the disconnect switch and have the dust collector on a relay circuit with a current sensing relay on the table saw, so that when I turn on the table saw, the dust collector comes on automatically. I also have a separate toggle switch on the dust collector relay so that I can flip it so just the collector comes on to use it with other tools. It is all pretty easy if you see it in action; I could take pics and send them to you if you like. To keep this all cost effective, you could get a 120V or 240V to 24V transformer, disconnect and a contactor from a discarded AC or heat pump unit (for the contactor) and or a furnace (for the transformer) at your local landfill metal recycling center or local heating and air conditioning service company.

[Rob Haskell]

Hi T Scott
A few pictures would be great. I have cabinet shop that needs some help of this sort. Do these parts only come from an AC distributer or can you get them online or at a big box store? I'll start looking for parts at remodel jobs but just in case it would be good to know where to buy them.
Thanks
Rob

[T. Scott Nalley]

Here are a couple of pics of my setup. My disconnect supplies power to my tablesaw, dust collector and my air compressor. I use the disconnect only to cut off the power to the air compressor only so it doesn't run while I am using the saw or DC. Power is always on to the saw recepticle. The power to the DC is controlled in 2 ways. The first way is by using a current sensing relay that senses the current flowing to the saw and closes the contactor, sending power to the DC. The second way is with a toggle switch, so if I want to use it with other tools I can flip the toggle and it closes the contactor also. In the pic of the outside, you can see the small toggle switch. On the interior pics, the power comes in from the top of the box and connects to the bottom. You can see the current sensing relay (black box with yellow wires) that attaches to one of the saw power legs. Also on the bottom of the box is the contactor. The orange wires going to the back of it are hot, the smaller wires are the control wires for the relay and toggle, and the wires in front are the power out wires to the recepticle for the DC. In the middle is a transformer to step down the power to 24V for the toggle and relay.

You can get the contactor and transformer from a local electrical parts store, Graingers, Ebay or even at a dump or metal recycling yard (they would be in a AC or heat pump and a furnace). The current sensing relay has to be bought though because the chances of coming across it at the recycling yard is very slim.

[Rob Haskell]

Thanks
That is a great setup. I hope a brother who is an electrical engineer can help me out to set up what you have. An electrician friend made up one of these for me years ago and it worked realiably in a 10 person shop.
Rob