Security Gate Voltage Drop

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KKraync

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I am working on a security gate installation. The electrical cabinet at the gate has 10 amps max loading (120V single phase). It is feed by a 20 amp circuit breaker. Do I have to size the feeder wire to the panel for a voltage drop at 20 amps or can I use the 10 amp loading since it is a dedicated circuit. What code section do I use to justify it with the inspector.
 

Dennis Alwon

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KKraync said:
I am working on a security gate installation. The electrical cabinet at the gate has 10 amps max loading (120V single phase). It is feed by a 20 amp circuit breaker. Do I have to size the feeder wire to the panel for a voltage drop at 20 amps or can I use the 10 amp loading since it is a dedicated circuit. What code section do I use to justify it with the inspector.

The NEC is quiet on voltage drop in that scenario. There is FPN about VD in note 4 to art 210.19(A)(1). It is a good idea to figure VD regardless.

I would use the 10 amps for calculation purposes
 

tryinghard

Senior Member
Location
California
Size the branch circuit conductor supplying the gate with the gates actual 10A load. With NEC I?d start in Definitions: ?Branch Circuit, Individual?, then 210-19, then 210-21(B)(1), & 210-23.

In this light you can supply the individual load and respect 3% VD, so VD=2x12.9xIxD/CM (Table 8), of course the 3% of 120 V would be 3.6 volts loss.
 
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