2 Pole Switches

[tom baker]

404.8 (C) Multipole Snap Switches
States a multipole general use snap switch is not permitted to be fed from more than a single circuit unless it is listed and marked as two circuit or three circuit switch.
I had heard that there are no such switches available.
Application is a split HVAC system, with a two pole switch on the inside unit, 208 V single phase. This would require two circuit switch....are there any

 

[LEO2854]

404.8 (C) Multipole Snap Switches
States a multipole general use snap switch is not permitted to be fed from more than a single circuit unless it is listed and marked as two circuit or three circuit switch.
I had heard that there are no such switches available.
Application is a split HVAC system, with a two pole switch on the inside unit, 208 V single phase. This would require two circuit switch....are there any

Yes in fact they're two pole switches.... they are good from 120 volts to 277 volts.

 

[infinity]

A 1?, 2-pole switch serving a 208 volt load would still be a single circuit.

 

[Dennis Alwon]

DP switches are used all the tiome for well pumps, sometimes water heaters (30 amp switch), discos for a multiwire branch circuit to a separate structure etc. As Trevor stated these are considered one circuit. I honestly don't know why you could not have two 120V circuits and use it as a disconnect, seems simply enough but it appears to not be compliant

 

[LEO2854]

DP switches are used all the tiome for well pumps, sometimes water heaters (30 amp switch), discos for a multiwire branch circuit to a separate structure etc. As Trevor stated these are considered one circuit. I honestly don't know why you could not have two 120V circuits and use it as a disconnect, seems simply enough but it appears to not be compliant

I'm not understanding how a two pole switch fed by a two pole circuit breaker is not compliant.:blink:

 

[Dennis Alwon]

I'm not understanding how a two pole switch fed by a two pole circuit breaker is not compliant.:blink:

I didn't say it wasn't-- it is compliant imo. I think what is not compliant, according to Tom Baker, is 2 sp breakers (different circuits) on a dp switch. It does not appear to be compliant but I don't know why.

 

[don_resqcapt19]

I'm not understanding how a two pole switch fed by a two pole circuit breaker is not compliant.:blink:

If the supply side of the switch is connected to a double pole breaker, the switch is only switching a single circuit, even if it switches two different loads and that, in my opinion, is permitted.

If you connect the same switch to the same loads using two single pole breaker, now the switch is switching more than one circuit and it is not listed for that application.

Like Dennis, I don't really see any difference between the two applications, other than one is compliant and the other isn't.

 

[jumper]

That section was added in the 2008 NEC. I looked up the ROP out of curiosity.

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 two-
pole 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

 

[kwired]

A more obvious example of what isn't allowed would be switching a 120 volt load with one pole and a 277 volt load with the other pole.

 

[480sparky]

If the supply side of the switch is connected to a double pole breaker, the switch is only switching a single circuit, even if it switches two different loads and that, in my opinion, is permitted.

If you connect the same switch to the same loads using two single pole breaker, now the switch is switching more than one circuit and it is not listed for that application.

Like Dennis, I don't really see any difference between the two applications, other than one is compliant and the other isn't.

What about two SP breakers with a handle-tie? :?

 

[edlee]

That section was added in the 2008 NEC. I looked up the ROP out of curiosity.

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 two-
pole 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

Fred Hartwell was for many years a wiring inspector locally near where I live. Every inspection was like a code class. Even after being licensed for years he could surprise me with Code or related details I had never been aware of ( for example: "Hey, that Carlon 3" PVC LB you installed isn't UL listed for use in the United States. See those numbers on the inside cover? They mean it's only approved for use in Canada").

 

[GoldDigger]

A more obvious example of what isn't allowed would be switching a 120 volt load with one pole and a 277 volt load with the other pole.

That example would also fall under the "two voltages, one yoke" restriction.

 

[JDB3]

Possibly not for use on 2 single circuits, cause, someone may just test one side, determine it is in the off position, and proceed (not realizing the other side is hot.

I first ran across this application many years ago, with the switch operating a "bunch" of lights.
:?

 

[Strathead]

I'm not sure of the nuance of the discussion. In my opinion, a single phase 240 volt motor fed from phase A and B is one circuit. So you can legally install a 2 pole motor rated switch rated at 120/277 to feed it. Is this in dispute?

 

[Dennis Alwon]

I'm not sure of the nuance of the discussion. In my opinion, a single phase 240 volt motor fed from phase A and B is one circuit. So you can legally install a 2 pole motor rated switch rated at 120/277 to feed it. Is this in dispute?

No this is not in dispute.

 

[Tommy SEA]

2 poles witch

2 poles witch

Helpful HInt:
This was previously explained well in "Two breakers with handle-tie or two pole breaker? " MHF posting 2/07/2011

 

[mopowr steve]

I didn't say it wasn't-- it is compliant imo. I think what is not compliant, according to Tom Baker, is 2 sp breakers (different circuits) on a dp switch. It does not appear to be compliant but I don't know why.

Probably because it relates to multiple circuits landing on the same yoke must be simultaneously disconnected.

 

[kwired]

That example would also fall under the "two voltages, one yoke" restriction.

125/250 volts is on one yoke quite often But is typically a MWBC when it is present.

But I knew someone was going to point something of this nature out.

 

[GoldDigger]

125/250 volts is on one yoke quite often But is typically a MWBC when it is present.

But I knew someone was going to point something of this nature out.

OK, two voltage systems....