Conduit fill continuous non

[Cletis]

Is continuous / non a factor in conduit fill calcs ? If not why not?


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[infinity]

Conduit fill has to do with getting the conductors in without damage.

 

[Cletis]

Conduit fill has to do with getting the conductors in without damage.

I meant are number of circuits in a conduit affected by whether the loads are continuous or non continuous


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[electrofelon]

I meant are number of circuits in a conduit affected by whether the loads are continuous or non continuous


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No. There is no change in derating for number of current carrying conductors based on whether the loads are continuous or not.

 

[JFletcher]

Is continuous / non a factor in conduit fill calcs ? If not why not?


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Not a factor. Derating is based on # of CCC tho, and they are assumed to carry the full load of the circuit(s), even when it's unlikely, like a 480Y system connected to 277V LED lights. If balanced (same number of lights on each phase, all 3 phases + neutral in the conduit), the neutral is not going to carry the same amps as the phase conductors, but must be counted due to the non-linear nature of the load.

Besides, continuous loads are already limited to 80% of the breaker's rating. Non-continuous loads could be sized up to 100% of the circuit ampacity.

Derating would be a nightmare if there were different tables and calcs for continuous and non-continuous loads if both circuits were in the same conduit.

 

[Cletis]

Not a factor. Derating is based on # of CCC tho, and they are assumed to carry the full load of the circuit(s), even when it's unlikely, like a 480Y system connected to 277V LED lights. If balanced (same number of lights on each phase, all 3 phases + neutral in the conduit), the neutral is not going to carry the same amps as the phase conductors, but must be counted due to the non-linear nature of the load.

Besides, continuous loads are already limited to 80% of the breaker's rating. Non-continuous loads could be sized up to 100% of the circuit ampacity.

Derating would be a nightmare if there were different tables and calcs for continuous and non-continuous loads if both circuits were in the same conduit.

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