Is it ever permissible to downsize a neutral conductor in a typical 120/240 V 3 wire service installation? For instance, can you have two hot legs sized at 2/0 and make the neutral 1/0? I was told by someone recently that this was permissible, but I don't see that in the latest NEC. If it isn't allowed now, was it ever allowed in the past?
Neutral Conductor Sizing
- Thread starter teej
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bphgravity
Senior Member
- Location
- Florida
Re: Neutral Conductor Sizing
Just remember that the service grounded conductor must also serve as the effective fault path of any ground-fault that occurs on the system. Also, this increase in circuit resistance will place more normal operating current on the metal parts and grounding systems.
I don't know why the NEC contradicts itself on this matter.
Just remember that the service grounded conductor must also serve as the effective fault path of any ground-fault that occurs on the system. Also, this increase in circuit resistance will place more normal operating current on the metal parts and grounding systems.
I don't know why the NEC contradicts itself on this matter.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Re: Neutral Conductor Sizing
It probably has to do with the long-term flow of normal current, and the (hopefully) short duration of a ground fault.
It probably has to do with the long-term flow of normal current, and the (hopefully) short duration of a ground fault.
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