Neutral Demand

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Sahib

Senior Member
Location
India
Suppose it is a 3 phase 4 wire supply. Out of 11 nos 8kW ranges, assume 9 nos are equally distributed, 3 nos in parallel in each phase. If the remaining two are also in parallel in any one phase, the neutral current is equal to 2 times the 8kW range rated current. But if the remaining 2 nos are one in each of any two phases. the current in the neutral equal to the 8kW range rated current.
So shall we take the 8kW range rated current as the minimum neutral demand?
 
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Barbqranch

Senior Member
Location
Arcata, CA
Occupation
Plant maintenance electrician Semi-retired
Isn't the neutral current for the ranges 0? The overall apartment neutral current would be determined by facts not in evidence.
 

xformer

Senior Member
Location
Dallas, Tx
Occupation
Master Electrician
Suppose it is a 3 phase 4 wire supply. Out of 11 nos 8kW ranges, assume 9 nos are equally distributed, 3 nos in parallel in each phase. If the remaining two are also in parallel in any one phase, the neutral current is equal to 2 times the 8kW range rated current. But if the remaining 2 nos are one in each of any two phases. the current in the neutral equal to the 8kW range rated current.
So shall we take the 8kW range rated current as the minimum neutral demand?

What does "nos" mean?
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
Isn't the neutral current for the ranges 0? The overall apartment neutral current would be determined by facts not in evidence.

A range may run some elements from line to neutral for low power, although most these days use proportional control instead.
So there may be a neutral load for more than just fan and clock, but it will be less than the full power load current.

Tapatalk!
 

Smart $

Esteemed Member
Location
Ohio
Isn't the neutral current for the ranges 0? The overall apartment neutral current would be determined by facts not in evidence.
Even if a range has 0 neutral current, still have to size the neutral conductor to not less than 70 percent ampacity of the circuit rating. 220.61(B)(1) also permits 70 percent factoring for service and feeder neutral load.

The OP's question asks for minimum neutral demand. Consideration for any other loads would just make the neutral load greater.
 
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