Motor load without neutral

m sleem

Senior Member
Can i supply 3 core cable without neutral to a 3 phase Y motor load? this is a client request,

I think no as Per 250.24(C), am i correct?
 

winnie

Senior Member
All motors that I've encountered do not require a neutral connection to function. The motor might be internally connected in 'wye' but is supplied with only the three phase conductors, no neutral conductor.

If the _load_ requires a neutral for whatever reason, then you must provide that neutral conductor. But I would be very surprised if a 'motor load' actually requires the neutral.

Article 250 is about grounding, and 250.24 is about bonding the grounded conductor; relevant for the service but not for supplying an individual load. In addition to the 3 phase conductors, your motor load will require and EGC.

-Jon
 
Last edited:

ActionDave

Moderator
Staff member
Can i supply 3 core cable without neutral to a 3 phase Y motor load? this is a client request,

I think no as Per 250.24(C), am i correct?
The answer is yes. That is the only way to do it. A wye or star motor just describes the way the motor is wired internally or configured in the make up box, it has nothing to do with the circuit powering it.
 

augie47

Moderator
Staff member
250.24(C) refers to bringing the neutral to the service. There is no requirement to bring neutrals to individual pieces of utilization equipment such as motors unless required by the equipment.
 

StarCat

Senior Member
Although they are not very common, I have worked on Fan Powered Boxes that have 277V Single phase PSC motors.
 

Besoeker3

Senior Member
All motors that I've encountered do not require a neutral connection to function. The motor might be internally connected in 'wye' but is supplied with only the three phase conductors, no neutral conductor.

If the _load_ requires a neutral for whatever reason, then you must provide that neutral conductor. But I would be very surprised if a 'motor load' actually requires the neutral.

Article 250 is about grounding, and 250.24 is about bonding the grounded conductor; relevant for the service but not for supplying an individual load. In addition to the 3 phase conductors, your motor load will require and EGC.

-Jon
I have noted that ground and neutral are sometimes confused with each other.
 
Top