unused contacts in receptacle/plug

[Twoskinsoneman]

Is there a code violation in only using part of the contacts in a receptacle?
Such as using only two ungrounded conductors (240v) in a receptacle designed for 2 ungrounded and 1 grounded (240v/120v)?

 

[charlie b]

I hate to fall back on 110.3(B), but that is all I can think of.

 

[wireguru]

dont know what the code says, but common sense would say a receptacle or extension cord would require every pole wired, while a male plug installed on a piece of utilization equipment could for example, omit use of the neutral if not required by the equipment. You wouldnt want a receptacle which has a neutral installed without the neutral connected. Or a missing phase on a 3 phase receptacle.

 

[Twoskinsoneman]

I guess the same reasoning would apply to any device. Such as using only a single phase of a three phase breaker.

 

[Twoskinsoneman]

dont know what the code says, but common sense would say a receptacle or extension cord would require every pole wired, while a male plug installed on a piece of utilization equipment could for example, omit use of the neutral if not required by the equipment. You wouldnt want a receptacle which has a neutral installed without the neutral connected. Or a missing phase on a 3 phase receptacle.

Certainly common sense... especially for a receptacle they may be used by anyone. But I'm thinking of a situation where it is a dedicated receptacle for a single piece of equipment.

 

[charlie b]

But I'm thinking of a situation where it is a dedicated receptacle for a single piece of equipment.

That would be today's configuration. Tomorrow, they would move that equipment out of the room, and the receptacle would remain. The day after, they would bring in a different piece of equipment, one that needed the 240 volts and the 120 volts, and they would plug it into that receptacle. At a minimum, the new equipment would fail, but the results could be worse than that. Not recommended. Get the receptacle that is designed for the 240 volt, single phase application.

 

[jumper]

I guess the same reasoning would apply to any device. Such as using only a single phase of a three phase breaker.

Not in my opinion. Not properly wiring a receptacle is potentially dangerous, while not utilizing a spare pole on a breaker is not. Two different things.