240 volt question

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maxwell_smart007

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Is a switch rated as 120/277 suitable as a DPST shut-off for a 240v circuit?

does the 120/277 mean that it's rated for 'up to 277' volt(s which I assume is three-phase power) and thus safe for 240, or does it need to say '240' on the switch?

just curious - I was looking at these at the store, and was curous!
 
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jttheclockman

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Is a switch rated as 120/277 suitable as a DPST shut-off for a 240v circuit?

does the 120/277 mean that it's rated for 'up to 277' volt(s which I assume is three-phase power) and thus safe for 240, or does it need to say '240' on the switch?

just curious - I was looking at these at the store, and was curous!


Yes but amperage is also a key factor. 240 volt can be 3 phase also:)
 

rej19

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A 120/277 Volt switch is most likely a single pole switch. And therefore is only switching the hot leg. If you are switching a 240V circuit in a residential application you probably want a double pole switch which breaks both hots of the 240volt circuit and that is a different switch. That's my opinion only!

It would be a double pole single throw switch. Usually marked DPST
 
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jttheclockman

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A 120/277 Volt switch is most likely a single pole switch. And therefore is only switching the hot leg. If you are switching a 240V circuit in a residential application you probably want a double pole switch which breaks both hots of the 240volt circuit and that is a different switch. That's my opinion only!

It would be a double pole single throw switch. Usually marked DPST


The way I read it, that is what he was looking at. He just did not see 240volts

You can have single pole switches marked 120/240.

You can have a 120/277 volt double pole switch. There are cases where you break both hot and neutral of 120volt circuit.
 
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maxwell_smart007

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Yes, it's DPST. It was a Leviton 3032-2W - pro grade, according to the box...

thanks for the replies - that helps clear it up! I've often wondered about that!

Looking online, this switch is motor rated for 2hp, so it seems perfect for a 15 amp 240v circuit for a dust collector when I get around to fixing that setup.

I usually hate back-wire setups, but this seems a lot less 'chintzy' than the quickwire terminals - and while I hate Leviton as a rule, it seems well made.
 

jttheclockman

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Yes, it's DPST. It was a Leviton 3032-2W - pro grade, according to the box...

thanks for the replies - that helps clear it up! I've often wondered about that!

Looking online, this switch is motor rated for 2hp, so it seems perfect for a 15 amp 240v circuit for a dust collector when I get around to fixing that setup.

I usually hate back-wire setups, but this seems a lot less 'chintzy' than the quickwire terminals - and while I hate Leviton as a rule, it seems well made.

It will be just fine. Leviton motor grade switches are a step up from general grade. You do not have to back wire it. You can put the wires under the terminal screws.
 
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