2 pole switch use

Status
Not open for further replies.
stickboy1375

stickboy1375

Senior Member
Location
Litchfield, CT
I installed a 2 pole switch to operate two separate switch legs, then I got thinking (after hanging out at this site long enough I doubt the switch was listed for the application :roll: ) so, is this legal or not.
 
So yes if the switch legs were from different circuits and on a dp breaker. Otherwise it wouldn't matter.

Edit to delete the redundancy
 
Last edited:
look at 404.8(c) (2008)

not sure if this is relevant to your question, but could be:-?
 
I don't think it is relevant to a standard DP switch. Here is the art.

(C) Multipole Snap Switches. A multipole, general-use snap switch shall not be permitted to be fed from more than a single circuit unless it is listed and marked as a two-circuit or three-circuit switch, or unless its voltage rating is not less than the nominal line-to-line voltage of the system supplying the circuits.
Click to expand...
 
This to me is one of those stupid listing issues.

However.... If you look at a standard two pole switch it is labled "Single Circuit Only" so to use it for two circuits is in fact a violtion.

9-92 Log #3406 NEC-P09 Final Action: Accept
(404.8(C) (New) )

Submitter: Frederic P. Hartwell, Hartwell Electrical Services, Inc.

Recommendation: Insert a new 404.8(C) as follows:
(C) Multipole Snap Switches. A multipole, general use snap switch shall
not be permitted to be fed from more than a single circuit unless it is listed
and marked as a two-circuit or three-circuit switch, or unless its voltage rating
is not less than the nominal line-to-line voltage of the system supplying the
circuits.

Substantiation: The device industry still shows no inclination to mark twopole
switches ?2-circuit?, and thereby allow their use on two circuits with a
total voltage spread within the switch rating. Representatives generally declare
their willingness to act promptly if there were market demand. Unfortunately,
the submitter strongly suspects the lack of demand is a result of lack of
knowledge, and not any lack of applications. In other words, installers are
routinely installing these switches and inspectors are accepting them for want
of any observable hazard. A routinely available 277-volt rated two-pole snap
switch used to control two 120-volt circuits within the ampere rating of the
switch to control related equipment, such as two oil burners, is a completely
reasonable application. It can be frustrated, usually only on paper, by the UL
Guide Card restriction. If this proposal is accepted, UL will have to revisit the
Guide Card information, and the problem will disappear. Note that under the
terms of this proposal, as soon as the potential line-to-line voltage exceeded
that of the switch, the enhanced marking provisions would still apply.


Panel Meeting Action: Accept

Number Eligible to Vote: 11

Ballot Results: Affirmative: 10

Ballot Not Returned: 1 de Vega, H.
Click to expand...
 
The change in the 2008 code puts the code in conflict with the UL listing rules as the code permits the switch to be used on two circuits as long a the voltage rating of the switch is equal to or greater than the line to line voltage of the circuit. The UL listing always required that a two pole switch be marked as suitable for two circuit when used with two circuits. Also don't forget about 210.7(B) which will require a common means of disconnect for the circuits that supply a two pole switch.
 
stickboy1375 said:
I installed a 2 pole switch to operate two separate switch legs, then I got thinking (after hanging out at this site long enough I doubt the switch was listed for the application :roll: ) so, is this legal or not.
Click to expand...

Now there's your problem. Quit thinking and you will never make a mistake again. :D
 
Clarification: is a 2-pole circuit, such as for, say, a 240v air handler, considered one or two circuits for this topic?

After all, if a 2-pole switch isn't suitable for a 2-ungrounded-conductor circuit, what is it useful for at all?
 
LarryFine said:
Clarification: is a 2-pole circuit, such as for, say, a 240v air handler, considered one or two circuits for this topic?

After all, if a 2-pole switch isn't suitable for a 2-ungrounded-conductor circuit, what is it useful for at all?
Click to expand...
I second that thought.
 
LarryFine said:
Clarification: is a 2-pole circuit, such as for, say, a 240v air handler, considered one or two circuits for this topic?
Click to expand...

One.

But say you wanted to control two circuits of 120 volt lighting and they are both supplied with two wire circuits (Not MWBC) then you would have an issue under previous codes.
 
This is a case where if you had two circuits you could abandon one grounded conductor and make the two circuits one MWBC and all is good.

Roger
 
iwire said:
But say you wanted to control two circuits of 120 volt lighting and they are both supplied with two wire circuits (Not MWBC) then you would have an issue under previous codes.
Click to expand...
Based on the listing, I think you still have a problem under the 2008 code. As I said this new rule is in conflict with 110.3(B). UL has a rep on that code panel and I am not sure how this slipped through.

You still have the issue of the requied common means of disconnect on the line side of the switch even where you are using a switch that is listed and marked for use on two circuits.
 
don_resqcapt19 said:
Based on the listing, I think you still have a problem under the 2008 code. As I said this new rule is in conflict with 110.3(B). UL has a rep on that code panel and I am not sure how this slipped through..
Click to expand...

If you read the substantiation I posted it pretty much says that was the entire point of the proposal, to make UL change it's stance. :cool:

If this proposal is accepted, UL will have to revisit the
Guide Card information,
Click to expand...
 
The code doesn't make UL change and UL doesn't make the code change. The use of a two pole switch that is not marked for use with two circuits is a 110.3(B) violation. I don't think that a lot of instructions are 110.3(B) instructions, but if they are in the White Book, they are.

Even if UL would change its rules, I still see an issue with 210.7(B). This rule for a common line side disconnect will limit the use of two pole switches on multiple circuits. If you can use a common disconnect, then in most cases you could use a multiwire branch circuit and there would be no need for a swich to be listed for more than one circuit.
 
LarryFine said:
After all, if a 2-pole switch isn't suitable for a 2-ungrounded-conductor circuit, what is it useful for at all?
Click to expand...

Ever do two restrooms (Mens & Womens), one circuit for both, with a switch in each that both must turn on a single exhaust fan?
 
480sparky said:
Ever do two restrooms (Mens & Womens), one circuit for both, with a switch in each that both must turn on a single exhaust fan?
Click to expand...
Yes, I have, and I did exactly that - 2-poles with the second pole paralleled for the single fan. However, the lights and fan were on the same circuit, so there was one less problem.

Another time, a place had separate fan switches wired as 3-ways. I was amazed someone thought that was a good idea, so I rewired them as above, with paralleled SP switches.
 
Status
Not open for further replies.
Top