# Double Pole Switch



## jproffer (Feb 19, 2005)

OK guys, believe it or not, I'm fairly experienced with electrical work. I wouldn't claim to be 480 or JB or MD, but I know enough. This one kind of threw me a curve.

I was looking for a keyed switch for an outside receptacle and in my search I found a "double pole keyed switch"....and I (think I) kind of get the idea...it switches both the hot and the neutral, correct? If so, questions:

1. Why?...what's the point?

2. On amazon, I found 2 relatively identical switches (same rating, manufacturer, etc) and the single pole is almost twice the cost of the double pole....again, why? I'm assuming because the DP's are simply less in demand.

3. Would switching both legs be more/less safe for an outdoor rec.? Or does it make any difference?

Whichever type (SP or DP) would be better, can anyone recommend keyed switch (not the generic keys that control a toggle switch hidden behind slot, a REAL key) that doesn't cost an arm and a leg

Thanks in advance :thumbsup:


----------



## Leo G (May 12, 2005)

What about 220v. Switching off both hots.


----------



## DuMass (Feb 6, 2008)

If you don’t need both poles of a DP switch, you don’t have to use them both.
I don’t know if it is a typo or not, but the Leviton 1221-2KL barrel lock single-pole switch in the link below says it's $29.95. This same switch sells for like $75.00 at Grainger and many other places.

http://www.fruitridgetools.com/stor...SFItemDetail.aspx?sfid=136763&c=0&i=244734464


----------



## jproffer (Feb 19, 2005)

Double Pole and Single Pole

These are the ones...rated for 120/277 volt. It could very well be made to 
switch both hot legs of a 220V circuit and maybe you only use one "pole" (one side) for use on a 110V circuit. That don't sound right to me but like I said, I'm not sure the purpose or function of this type of switch (meaning DP....keyed or not)

It could be that this is not even an option for what I want to do. The outside rec. I'm putting in is a 120V 20A GFI rec on the outside of a SFD, I.E.-residential.

EDIT: 



> If you don’t need both poles of a DP switch, you don’t have to use them both.


OK so that answers that part of the question. Thanks DuMass :thumbsup:

and if it really is only $30, that is the cheapest I've seen so far.


----------



## TimelessQuality (Sep 23, 2007)

You have to go out back and look at the service entry...

Are the wires hanging from a single pole? or a double pole:jester:


----------



## jproffer (Feb 19, 2005)

It starts at a single pole, but then is supported by a double pole closer to the house.....so I need BOTH switches right? :jester::laughing:

please advise soon


----------



## griz (Nov 26, 2009)

Single pole + Double pole = 3 pole:whistling:jester:


----------



## MplsGC (Feb 11, 2011)

When we run a circuit to a garage the inspectors in one particular city want to see this switch used as a "disconnect" Grounded on one side and ungrounded on the other. They have not given me an explanation of why and now we have state electrical inspectors so it may have changed. Anyone know why they wanted this or if there is a code reference?


----------



## jproffer (Feb 19, 2005)

OK, so it sounds like if I get a DP switch I can use one "side" for the hot and the other for the neutral, correct? 

Or I could just use one side for the hot and the other side for....nothing?

It's the last device in the circuit so I don't think it would hurt anything to break the neutral in this case, unnecessary as it may be.

There are no local inspections beyond a guy coming by and plugging his little $6 gfi tester into it and pushing the button, so I don't think he would know....or care...if I break both legs or just the hot.


----------



## 480sparky (Feb 1, 2009)

*404.2(B) Grounded Conductors.* Switches or circuit breakers
shall not disconnect the grounded conductor of a circuit.

_Exception: A switch or circuit breaker shall be permitted
to disconnect a grounded circuit conductor where all circuit
conductors are disconnected simultaneously, or where
the device is arranged so that the grounded conductor cannot
be disconnected until all the ungrounded conductors of
the circuit have been disconnected._






But what do I know.... I'm an electrician.


----------



## jproffer (Feb 19, 2005)

Ok, fair enough 480 :thumbsup:

For the sake of getting myself a price break then, could I use a DP switch and leave one side empty and use it as a SP switch?

From other replies, this is what I'm gathering but as I said, I've never really messed with a DP before.

Also, out of curiousity, what WOULD a DP switch be used for in a 120V circuit if you can't break the neutral?

OR

Does it say it's for "120/277 Volt" because it CAN be used as a SP switch?


----------



## Tinstaafl (Jan 6, 2008)

jproffer said:


> For the sake of getting myself a price break then, could I use a DP switch and leave one side empty and use it as a SP switch?
> 
> ...
> 
> Does it say it's for "120/277 Volt" because it CAN be used as a SP switch?


You can absolutely use only one side of a DP switch if you want to. It's just two identical switches in one assembly. As for the voltage rating, that simply means that it can be used on either type of circuit.

Even though I looked at your links, it makes no sense that a SP would cost more, unless it's a really slow mover. :blink:


----------



## jproffer (Feb 19, 2005)

Didn't make sense to me either, but if it don't matter I'll order the DP and use one side of it


----------



## 480sparky (Feb 1, 2009)

Using a DP switch to control a 120v circuit, breaking both the ungrounded and the grounded, is legal.

Dollar-wise, it's a waste of money.

However, if you're needing a keyed switch, they come in SP flavors as well.


----------



## aptpupil (Jun 12, 2010)

jproffer said:


> Does it say it's for "120/277 Volt" because it CAN be used as a SP switch?


i believe that's the answer, but it still begs the question about the pricing of the 1p switch.


----------



## jproffer (Feb 19, 2005)

> Dollar-wise, it's a waste of money


I would have thought so too but the DP is cheaper and they seem to be equal quality other than SP/DP.


----------



## jproffer (Feb 19, 2005)

> i believe that's the answer, but it still begs the question about the pricing of the 1p switch


Indeed....if I cared enough to take time to do it, I'd call and ask :w00t: ..........but I don't care enough :no: :whistling

LOL :jester:


----------



## 480sparky (Feb 1, 2009)

jproffer said:


> I would have thought so too but the DP is cheaper and they seem to be equal quality other than SP/DP.



Probably a result of supply and demand.... same reason a 4' fluorescent lamp costs less than a 2'.


----------



## RedHeadElectric (Feb 11, 2011)

If I remember right, there is something in the code about switching the hot and grounded conductor at the same time on a switch or disconnect for gas pumps...but that's about the only time I would know that would want to do that


----------



## 480sparky (Feb 1, 2009)

RedHeadElectric said:


> If I remember right, there is something in the code about switching the hot and grounded conductor at the same time on a switch or disconnect for gas pumps...but that's about the only time I would know that would want to do that



That's required.

FWIW, the things you get gasoline from are _dispensers_. The _pumps_ are underground in the tanks. Yeah, I know. We all call 'em pumps. But if you ever wire a gas station, you'll need to know the correct terms.


----------

