120v & 277V Through a 2p switch

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jap

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Electrician
Drawings show two 2p switches.
One in each bathroom.
1-120v circuit paralleled through both switches for a common 120v exhaust fan.
1-277v circuit paralleled through both switches for the 277v Lighting in each bathroom.

Is this code complant?

JAP>
 
I doubt the switches are listed for use with multiple circuits.

Roger
 
I seen a configuration like that for one of the big chain stores. They had a single exhaust fan ( roof unit) for both bath rooms so the 2 pole controlled the exhaust if either bathroom switch was moved to the closed position, but the bathroom lighting was controlled individually. One 2 pole switch in each of the two bathrooms.

The design professional said the switch was rated for 277 volts his position was he met code.

I was an electrician on the job not an inspector.
 
Seems odd there's so much emphasis put on handle ties for MWBC yet nothing about this scenario being fed from 2 different circuits from 2 different panels, High and Low Voltage, unless I'm overlooking a requirement somewhere that wouldn't allow it.


JAP>
 
Look at the switch or the box it comes in.

It will say single circuit use only. At that point NEC 110.3(B) takes over.
 
As mentioned since you have two circuits on one yoke handle ties would be required on the CB's, not really possible when the CB's are in different panels. :roll:
 
jap said:
Seems odd there's so much emphasis put on handle ties for MWBC yet nothing about this scenario being fed from 2 different circuits from 2 different panels, High and Low Voltage, unless I'm overlooking a requirement somewhere that wouldn't allow it.


JAP>
Click to expand...
See 210.7.
 
jap said:
120V Lighting doesn't work out well with 277v designed lighting schemes, and the issue on the table.

JAP>
Click to expand...

Why? We do many jobs where both are present and you already have 120v at the switch location. if it is a problem just use a contactor.

Roger
 
roger said:
Why? We do many jobs where both are present and you already have 120v at the switch location. if it is a problem just use a contactor.

Roger
Click to expand...

I'm not talking about redesigning the Lighting. I was asking about the legality of using 277v and 120v through a 2p switch on the same yoke like the engineers have drawn it on the plans.
It doesn't take a genius to figure out how to switch a 120v exhaust fan from 277v lighting, that's not what the question was.
If I pick up a set of print that shows the circuitry for a certain area being fed off of a circuit out of a 277v panel, it should be that way.
The lighting scheme should not have been changed to 120v just because someone didn't know how to control a 120v exhaust fan from a 277v circuit.

JAP>
 
jap said:
I'm not talking about redesigning the Lighting. I was asking about the legality of using 277v and 120v through a 2p switch on the same yoke like the engineers have drawn it on the plans.
...
JAP>
Click to expand...
There is almost no code compliant way to do that. First very few two pole switches are listed for use with more than one circuit as required by 404.8(C), and second you have to comply with the common disconnect rule found in 210.7. If you can find a wall switch listed for the application you would also have to provide a line side means of common disconnect.
 
don_resqcapt19 said:
There is almost no code compliant way to do that. First very few two pole switches are listed for use with more than one circuit as required by 404.8(C), and second you have to comply with the common disconnect rule found in 210.7. If you can find a wall switch listed for the application you would also have to provide a line side means of common disconnect.
Click to expand...

Thanks,
JAP>
 
jap said:
I'm not talking about redesigning the Lighting. I was asking about the legality of using 277v and 120v through a 2p switch on the same yoke like the engineers have drawn it on the plans.
Click to expand...
And you were given numerous reasons why the engineers design was not code compliant.


jap said:
It doesn't take a genius to figure out how to switch a 120v exhaust fan from 277v lighting, that's not what the question was.
Click to expand...
But you seem to think it's a problem by this statement.
120V Lighting doesn't work out well with 277v designed lighting schemes, and the issue on the table.
Click to expand...
And you didn't answer the question as to why you think that's the case

jap said:
If I pick up a set of print that shows the circuitry for a certain area being fed off of a circuit out of a 277v panel, it should be that way.
Click to expand...
What makes you think designers don't make mistakes?

jap said:
The lighting scheme should not have been changed to 120v just because someone didn't know how to control a 120v exhaust fan from a 277v circuit.
Click to expand...
Which brings us back to the contactor for one solution.

Now, what is your actual question?

JAP>[/QUOTE]
 
roger said:
And you were given numerous reasons why the engineers design was not code compliant.


But you seem to think it's a problem by this statement.
And you didn't answer the question as to why you think that's the case

What makes you think designers don't make mistakes?

Which brings us back to the contactor for one solution.

Now, what is your actual question?

JAP>
Click to expand...
[/QUOTE]

My question now is why are you asking so many questions. :)
My question was answered before you ever chimed in.

Thanks,
JAP>
 
roger said:
And you were given numerous reasons why the engineers design was not code compliant.


But you seem to think it's a problem by this statement.
And you didn't answer the question as to why you think that's the case

What makes you think designers don't make mistakes?

Which brings us back to the contactor for one solution.

Now, what is your actual question?

JAP>
Click to expand...
[/QUOTE]

All I was getting at is that you just cant always simply "change the fixtures to 120v, problem solved".
If you take it upon yourself to change the light fixtures to 120v instead of 277v like it was designed and the plans show, just to be able to run a 120v exhaust fan, then I feel your the one making the mistake not the designer.

Thanks,
JAP>
 
I bet the ballasts are universal voltage and could be added to the exhaust fan circuit.

I would do it in a heartbeat and note it on the as built drawing.
 
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