Double Pole switch???

[J.C.]

I bought a Double pole switch. Why, I don't know. I looked in my trusty electrical handbook and my copy of the 2007 NESC handbook (to most wasted $65.00 I've ever spent) and nowhere is there a reference to a "Double Pole Switch". So, what is a "Double Pole Switch" and what is it used for.

I've used many a single pole switch and a number of 3 way switches in my time but this one's got me a bit baffled.

TIA

JC

[Art Todesco]

[Jeff Wisnia]

Since you don't seem to know what double pole switches can do, you may also not know what "double throw" means either.

If that switch has six terminal screws on it, not counting a frame ground screw, then it is a "double pole - double throw" switch, most often used for multilocation switch control of a light or other load, i.e when more than just the two switches provided by a "three way" switch system are desired.

If it only has four terminal screws on it, than it's a "double pole - single throw" switch, and others have already told you what it can be used for.

HTH,

Jeff

[Steve Barker]

another application would be if you had such a number of lights as to exceed the capacity of one circuit, but you wanted them all on one switch. Two separate circuits, one switch, many lights. perhaps a gym, or an auditorium.

[Goedjn]

Well, a double-pull double-pole switch can be used as a crossover switch in the middle of a multi-switch run. A single-pull double-pole switch is used to turn off two things simultaneously, or both legs of a 240V branch.

--Goedjn

[Mark Lloyd]

I've seen double-pole double throw (DPDT) switches used with DC motors, that could run in either direction depending on polarity.

A "4-way" switch is logically (physically?) a DPDT switch with opposite contacts internally connected, so it has this reversing function. /----------\\ | |

-------------O| |O--+--\\ | - - | | | /----O| |O--+--+----------- | | |

--------+----O O--/ | | | | | \\-------------/ | \\-------------------------------

[mm]

I used a little DPDT slide switch with my analog VOM, voltmeter, to reverse the test leads. Made it very quick on the ohmmeter setting to test diodes in both directions, to test capacitors by watching them charge then discharge and charge again. Didn't do this until after ran out of regular probe wire and was using speaker wire for my test probes.

I put a blob of silicone sealant over the solder connections so I wouldn't zap myself. 25 years, still fine.

A single-pull

[J.C.]

Thanks folks. I believe I've got it straightened out now.

JC