OT: Shop Electrical Question

Three-Way Switch *LINK*

Hoa Dinh in Alameda

>Mark,

It's called a "three-way switch."

If you DC is 240V, you may have problem finding correct components for it. And they are costly if available.

I myself like a remote control such are the Long Ranger. I have a small rare earth magnet at each dust generating machine to attach the remote control to.

-- Hoa


Install A Three-Way Switch

Re: OT: Shop Electrical Question

Kent in Emmaus, PA

>Mark, look in any electrical wiring book under "three way switch."

Re: OT: Shop Electrical Question

Jim Swank

>You'll need a 3-way switch at each location, a wire from the DC to each switch, and a wire between them. When I say a "wire", I mean a piece of Romex, not a single conductor. If you can't find connection information, email me and I'll sketch it up for you. Like others, I'm assuming the DC is 120V. If it's 240V, something like the long ranger is clearly the way to go.

Use a relay for 240V...

John in New Mexico

>the 120V switches can activate the relay, and as long as its contacts are DPST or DPDT and rated for the DC's HP or more, everything should be ok.

Re: OT: Shop Electrical Question

Barry Irby

>Mark, there are other options. If your DC is 120 volts, you can hook up the three way switch as suggested, but you can also buy remote control switches sutch as the Long Ranger which works either on micro switches on the blast gates or with a remote.

You can also get switches that are "radio" operated. One switch looks (from the outside)like a regualr switch, but laso has an internal solenoik opperated by a remote switch. The remote switch has a little radio sender in it and when you flip that switch, it sends a signal to the first on and IT turns on the DC. The only real advantage to this is you don't need to run a wire from switch to switch. These are great for adding in a three way where you forgot.

There are also devices that allow remote control (X-10 I think). These send signals through the wiring. They may not be rated for enough amps for a DC.

Also, there are about six different ways to wire standard trhee way switches, depending on where the feed and laod are in relation to the switches. Study them carefully. And, If you want another switch, you can add a Four Way. Actually, you can add as many four way switches as you want. Go for it.

PS.....

Barry Irby

>The wire that runs between the switches has to be four conductor wire and one of them is called the carrier (usually red). So you will need some four conductor cable for this.

Re: PS.....

Rod Peterson -- Ormond Beach

>Ladies and gents, refer to the diagram below. It captures the essence of how three way switches do their thing and if you can get your arms around this simple representation, you will be able to engineer all the complex possibilities of through-the-fixture, line-through-switch, fixtures-between-switches, etc., that you'll likely run across.

The switches are single pole, double throw (SPDT). The diagram only shows the hots. The neutrals are never part of the switching circuit (household, for all intents and purposes—there may be special circumstances, such as SPDT switches wired in tools with dual voltage motors). For the purposes of this discussion we will consider the line (hot lead from load center) to the right as labelled, and the load (light) to the left. A ground wire is not shown, because it has no part in understanding the 3-way switch. Naturally, you would include all appropriate grounding in your application.

This circuit as depicted is currently (ha, ha) open. No current is flowing. The light would be out. Throw either switch (the short bar at either end of the colored bars), and you complete a circuit from line to load (and back through the invisible neutral not depicted. The light will then be lit. Throw either switch again, and the light goes out as the circuit is interrupted.

So long as you understand that there are always two travellers and that nothing is installed on either traveller, (even if they are wirenutted together in a fixture as the wire goes through from line to switch), you should be able to extrapolate the principal to other circumstances. In other words, the travellers are always between  the switches, and the load and line are always outside  the switches.

Theoretically, you could switch 240V with a pair of DPDT switches and another pair of travellers. I have no idea if this is an acceptable practice—just that it's electrically possible.

Now, as it happens, my warped mind happens to grasp this concept easily. It probably explains a lot of things, but if your mind has other strengths than this, don't feel stupid. Everyone has aptitudes—they're not all the same.

Rod

Addy Protocol: Experienced amateur electrician. Not an engineer, clearly not much of an artist.

Get the book *LINK*

Phil Joines Krum Texas

>Wiring Simplified has been around forever and is updated regularly. It covers just about every thing you need to know to wire a shop or a house. I got my first copy at school in 1965. $12.95


Wiring Simplified

Re: OT: Shop Electrical Question

Jay St. Peter - Southern MD

>For a 110V DC, you can use 3-way switches. Make sure you get them rated for the circuit (i.e. 20-Amp capable for a DC).

For a 220V DC, you can wire a 110V 3-way circuit and use it to switch a 220V relay. This is how I set up my air compressor so it can be turned on from either the garage or my shop. I have drops in both. I also wired in a lighted indicator to show the current status.

I used a relay to switch my 220V DC also. But, I use a remote control "lamp" switch from radio shack to switch the relay. I prefer a remote for the DC since I switch it much more often than the air compressor. I hang the remote from my pants waist and just hit the button wherever I'm standing to fire it up.

The power relay is available at an electrical supply place (not home center). They run right around $20. Plus you need a box to put it in and some wire to hook it all up. Dennis Peacock wrote an article sometime back detailing his DC hookup using this method. I'm not sure if it is here or over at SMC.

Jay St. Peter

OT: Shop Electrical Question - Thanks All

Mark Kauder, Phenix City, AL

>Thank you all.