NEC 440.22 45A or 50A circuit breaker

[Dennis Alwon]

Yes, if the overload protection at the equipment is breaker. I would think we still need to size the OCPD at the panel as 430.52. Did i miss something here?

Unfortunately this rule is a bit strange. I wrote a proposal to change it but it appears they never received it. Why would the same wire that feeds one piece of equipment be a feeder- different rules- or a branch circuit based on whether or not there is ocp at the disco. The entire run should be a branch circuit or there should be an exception to allow the feeder to be sized based on the art.

 

[david]

Unfortunately this rule is a bit strange. I wrote a proposal to change it but it appears they never received it. Why would the same wire that feeds one piece of equipment be a feeder- different rules- or a branch circuit based on whether or not there is ocp at the disco. The entire run should be a branch circuit or there should be an exception to allow the feeder to be sized based on the art.

Yes in principle, and no depends, in this thread yes, since it was stated the intended over-current protection at the panel was going to be 50 amps and the required branch circuit protection needed to be max of 45 amps.

If however the over-current protection near the appliance is of equal or lesser value and is defined as supplementary, (edit: i should through out lesser value)

For example I had a unit that needed 50 amp min circuit ampacity and I ran # 8 awg thhn in conduit 70ft to the appliances protected by the appliances labeled max over-current protection at the panel. I want to transition from the thhn in conduit to #6 awg nm cable at the appliance I needed a disconnect within sight of the unit I have a fusible disconnect can I use it at the appliance in accordance with 240.10 supplementary and not redefine the circuit as a feeder and still define the circuit as a branch circuit.
Or do I need to go out and buy a non-fusible disconnect and through the fusible back in my truck and hope to use it in some other application another day.

The fused disconnect at the appliance is not the required over-current protection for this circuit it should not redefine the branch circuit. It supplements and is not required correct?