Whats the purpose of a double pole switch? In wiring up some new switches I accidentally got the double poles instead of the single poles. I went ahead and exchanged for the single poles to do what I always do for standard switch wiring by breaking the hot leg into the switch and then wire nutting the common. Is that all the douuble pole switch does is allow you to run the commons thru the switch body or is there some other advantage or safety issue involved here. As an afterthought is it ok to use a double pole switch and just run the hot leg thru it and not bother with attaching the commons as long as they are nutted in the standard fashion? just curious.
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Usually use to shut of both legs of a 230 volt system.
Do you mean doulbe pole single throw (DPST), used to shut off both legs, ie, 230 volt, or do you mean double pole double throw (DPDT), which is used for a 4 way?
You should never switch the neutral.
One application I saw for a double pole switch was at a church. Restrooms where back to back with a common vent fan. One pole of the switch was used to operate the lights in that restroom. The other pole was paralleled with the like switch in the other restroom to operate the fan.
Do you mean single pole switches vs. three-way switches?
A 3-way switch is a single pole switch, SPDT, single pole double throw.
http://www.misterfixit.com/wirediag.gif
Edited 4/21/2004 3:29 am ET by Uncle Dunc
What I had was called a double pole switch. It was a single throw. There were four screw terminals on the switch and according to the wiring diagram that came with the switch you attached the hot leg in the usual fashion although the two screws were those at the top of the switch body on opposite sides. You then put the common coming back from the device on one of the bottom screws of the switch body and the common from the original source on the other. Perhaps I misunderstood the diagram but thats what it appeared to be. Bottom line is it didn't make any sense to me which is why I went and got the standard switch. Like I said I was just curious about what the application for such a switch would be.
Is the work that you are doing on a standard 120 Volt, 15 amp or 20 amp circuit for lighting? If so, it sounds like they gave you four-way switches the first time. Four-way switches would have four screw terminals.
A single pole switch is for lighting switched from one location.
Three-way switches are for lighting switched from two locations.
Four-way switches are for lighting switched from three locations. In this application, two of the switches would be threew-way switches, while the "middle" one would be a four-way switch.
-Steve
No, as he describes the switch is was a DOUBLE POLE, SINGLE THROW switch. Those are readily available. A double pole switch is used either to control to independent circuits with one switch or to break both legs of a 240 circuit.
A 4-way switch is a special version of a double pole, double throw switch. A basic DPDT switch has 6 contacts. But some of the connections are just internal and only 4 terminals are brought out for external connections.
any switch can be used as a SP switch in a pinch, just tape it up .and you must not switch the neutrals . wiring diagrams vary with manufacturers. but unless you want (serious) problems leave neutrals off of all switces, 4ways like 3ways have toggles that are smooth - not marked on and off . DP switches do indicate on and off, the only switches that get a neutral would be those that have a neon pilot light for indication but then the neutral is only for the PL
"the only switches that get a neutral would be those that have a neon pilot light for indication but then the neutral is only for the PL"
And some "electronic" switches such as X-10.
BTW, there is a case where it is required to switch the neutral. And that is on gas pumps. At least the breaker needs break the neutral. Don't know if is allowed and/or required if a switch is used as a disconnect.
While not common there is at least one application that requires that the neutral is broken.
I thought he was talking about his house not a gas station, my mistake
Thanks, I figured Icould have just used the switch I had and taped off the unused terminals but decided to play it safe and get the regular single pole switch.
NP
The use I've seen is to switch a split recepticle (kitchen recepticles here are split with a shared common, each on its own circuit). Specifically it was done because the homeowners had lots of equipment out on the kitchen counters (e.g. food-processor, stand mixer, toaster oven, etc.) and small children.
Phill Giles
The Unionville Woodwright
Unionville, Ontario