240v double pole switch

[TNGuy81]

Hey I just picked up a switch for a air compressor (240v 20a) and the supply house gave me a 208/120/277v double pole switch. Is this switch not for just single phase/leg use?? Will 240v be ok to use on this switch?? THanks

 

[tallgirl]

Hey I just picked up a switch for a air compressor (240v 20a) and the supply house gave me a 208/120/277v double pole switch. Is this switch not for just single phase/leg use?? Will 240v be ok to use on this switch?? THanks

Is there a reason you don't want to disconnect both L1 and L2 with that switch? Or is it 240 volts to neutral / ground?

 

[TNGuy81]

Yes from leg to leg its 240. 120A/ 120B. I just wanted to make sure the switch was the right one and safe to install. I am thinking its ok its been awhile though sense I have done this type of application. For some reason im thinking the switch should be rated 240v because its got A leg and B. 277 and 120 are single. I maybe over thinking this but its worth asking.
Thanks

 

[Ken In NJ]

If its a 2 pole switch rated for 277, then its fine to use for 240 as far as I know.

BUT if its used for a compressor motor with no starter, I'm pretty sure it has to be a "Motor Rated Switch"

We have a crap load of 30 amp 2 pole 120/277 volt toggle switches, but cant use them for motors, because they are NOT motor rated. Got shot down for using one a few months back

 

[kwired]

If its a 2 pole switch rated for 277, then its fine to use for 240 as far as I know.

BUT if its used for a compressor motor with no starter, I'm pretty sure it has to be a "Motor Rated Switch"

We have a crap load of 30 amp 2 pole 120/277 volt toggle switches, but cant use them for motors, because they are NOT motor rated. Got shot down for using one a few months back

You should shoot this back at the inspector, unless you did not meet either of the requirements mentioned or had more than 2hp less than 300 volts.

430.83 Ratings.

....

(C) Stationary Motors of 2 Horsepower or Less. For stationary motors rated at 2 hp or less and 300 volts or less, the controller shall be permitted to be either of the following:
(1) A general-use switch having an ampere rating not less than twice the full-load current rating of the motor
(2) On ac circuits, a general-use snap switch suitable only for use on ac (not general-use ac?dc snap switches) where the motor full-load current rating is not more than 80 percent of the ampere rating of the switch

430.109 Type.

...

(C) Stationary Motors of 2 Horsepower or Less. For stationary motors rated at 2 hp or less and 300 volts or less, the disconnecting means shall be permitted to be one of the devices specified in (1), (2), or (3):
(1) A general-use switch having an ampere rating not less than twice the full-load current rating of the motor
(2) On ac circuits, a general-use snap switch suitable only for use on ac (not general-use ac?dc snap switches) where the motor full-load current rating is not more than 80 percent of the ampere rating of the switch

 

[TNGuy81]

thanks for the feedback. Its got a starter on it and its a 3 hrspwr. thanks again

 

[kwired]

thanks for the feedback. Its got a starter on it and its a 3 hrspwr. thanks again

If there is a starter then the switch in question is not the motor controller so 430.83(C) does not apply.

If it is the motor disconnecting means then 430.109(C) does not apply because it is more than 2hp. The rest of 430.109 (B thru G) does not apply also. That means 430.109(A) applies. Your switch must meet one of the following:

(A) General.

(1) Motor Circuit Switch. A listed motor-circuit switch rated in horsepower.
(2) Molded Case Circuit Breaker. A listed molded case circuit breaker.
(3) Molded Case Switch. A listed molded case switch.
(4) Instantaneous Trip Circuit Breaker. An instantaneous trip circuit breaker that is part of a listed combination motor controller.
(5) Self-Protected Combination Controller. Listed self-protected combination controller.
(6) Manual Motor Controller. Listed manual motor controllers additionally marked ?Suitable as Motor Disconnect? shall be permitted as a disconnecting means where installed between the final motor branch-circuit short-circuit protective device and the motor. Listed manual motor controllers additionally marked ?Suitable as Motor Disconnect? shall be permitted as disconnecting means on the line side of the fuses permitted in 430.52(C)(5). In this case, the fuses permitted in 430.52(C)(5) shall be considered supplementary fuses, and suitable branch-circuit short-circuit and ground-fault protective devices shall be installed on the line side of the manual motor controller additionally marked ?Suitable as Motor Disconnect.?
(7) System Isolation Equipment. System isolation equipment shall be listed for disconnection purposes. System isolation equipment shall be installed on the load side of the overcurrent protection and its disconnecting means. The disconnecting means shall be one of the types permitted by 430.109(A)(1) through (A)(3)

Unless your switch is marked for 3hp or more you probably can't use it.

 

[TNGuy81]

hum... Its got a "pressure switch"? already on it which is staying that turns the thing off when its full of air. Its corded he wants a switch installed vrs the 3 prong plug that he has to plug in and unplug every time he wants to use it. The guy told me at the supply house the switch was fine for this..http://www.hardwareandtools.com/Pas...remium-Double-Pole-Toggle-Switch-u172726.html Its not getting inspected its for a friend and we are on a budget. I just want to make sure it will work and its safe is all. Thanks

 

[jumper]

I would use one of those pull out disconnects. They are like $15.00 or so.

 

[TNGuy81]

ok i have already purchased the switch. Is it subpar, or will it suffice. Many thanks.

 

[kwired]

hum... Its got a "pressure switch"? already on it which is staying that turns the thing off when its full of air. Its corded he wants a switch installed vrs the 3 prong plug that he has to plug in and unplug every time he wants to use it. The guy told me at the supply house the switch was fine for this..http://www.hardwareandtools.com/Pas...remium-Double-Pole-Toggle-Switch-u172726.html Its not getting inspected its for a friend and we are on a budget. I just want to make sure it will work and its safe is all. Thanks

The pressure switch is the motor controller or drives the controller that you said it has (starter).

The switch you are wanting to install is a disconnecting means and must follow rules for disconnecing means already mentioned.

No inspections or tight budgets do not make the codes change.

 

[TNGuy81]

Granted the code does not change i am well aware. So I need a motor control rated switch then?