Shunt Trip Breaker

[jmellc]

Working on a kitchen hood project. I'm told I will have to shunt a receptacle under the hood that feeds oven fans. I haven't done shunts in ages. For a 20 amp ckt do I have to use #12 wire for the shunt? I am thinking I can go smaller as the shunt is not part of the main ckt. Anyone here done shunts lately?

 

[augie47]

Unless there is a Section of the Code I'm overlooking, the shunt trip conductor would need to be sized by the over-current protection supplying the shunt trip circuit itself (not the breaker being tripped)

 

[kwired]

Take a look at what it says in 725.45(C):

Class 1 circuit conductors 14 AWG and larger that are tapped from the load side of the overcurrent protective device(s) of a controlled light and power circuit shall require only short-circuit and ground-fault protection and shall be permitted to be protected by the branch-circuit overcurrent protective device(s) where the rating of the protective device(s) is not more than 300 percent of the ampacity of the Class 1 circuit conductor.

I think OP can tap 14 AWG control conductors off the 20 amp breaker in his installation.

And since 75C ampacity of 14 AWG is 20 amps could possibly do so with up to a 60 amp OCPD, but at very least should be able to do so up to a 45 amp OCPD.