jph320
Member
- Location
- Cinnaminson nj
- Occupation
- Electrician
When does te neutral wire in a service required to be the same size as the condutors? I heard about balanced and unbalanced, when does this occur?
Neutral Sizing
- Thread starter jph320
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Your basic rules would be 220.61 and 230.42(C).
Keeping your minimum allowable size (230.42) in mind, the neutral needs to be sized for the calculated load.
You would need to start with the premises that the neutral needs to be full size and then reduce that by looking at the specific loads.
Keeping your minimum allowable size (230.42) in mind, the neutral needs to be sized for the calculated load.
You would need to start with the premises that the neutral needs to be full size and then reduce that by looking at the specific loads.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Although the neutral is often the same size as the ungrounded conductors for a service it is unusual that it would be required to be. It certainly doesn't need to be in a residence where much of the power supplied can be 240V circuits or even in commercial application where much of the power is used on 3 phased compressors etc.
Unwritten rule of thumb is, for commercial, the neutral is either the same size and sometimes larger than the ungrounded conductors. This would be the case where you have many non linear loads which cause harmonic currents.
For resi. you often see one size smaller( again unwritten rule) but can be considerably smaller if you do a calculation.
Unwritten rule of thumb is, for commercial, the neutral is either the same size and sometimes larger than the ungrounded conductors. This would be the case where you have many non linear loads which cause harmonic currents.
For resi. you often see one size smaller( again unwritten rule) but can be considerably smaller if you do a calculation.
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