What is the temperature rating for a breaker termination of 15 to 125A?

medinajuli27 · ‎2023-01-12

The NEC in article 110.14 (C)(1)(a) establishes the provisions for the equipment terminals of circuits with a nominal 100A or less: 1) use conductors with a nominal value of 60oC. Is it possible to use breakers designed to operate at 75oC and be able to use rated conductors at the same temperature? What line of breakers does this specify? Thanks.

RHH · ‎2023-01-12

Dear Medina,

In my experience you take steps of bigger/higher breakers due too (extreme) heat like with the 100% load of solar panels.

So if you have 100A Inom you take 160 or 250 NSX instead. You can check what operating amperage an breaker can handle/operate at what temperatures in the description panflets of your circuit breaker if I am correct.

Hopefully this helps!

Kind regards,

Rick

See Answer In Context

RHH · ‎2023-01-12

Dear Medina,

In my experience you take steps of bigger/higher breakers due too (extreme) heat like with the 100% load of solar panels.

So if you have 100A Inom you take 160 or 250 NSX instead. You can check what operating amperage an breaker can handle/operate at what temperatures in the description panflets of your circuit breaker if I am correct.

Hopefully this helps!

Kind regards,

Rick

Christo.Thomas · ‎2023-01-19

Hello Medina -

Please see the link below, this explains a little more about this. I assume if you are using a breaker lug rated for 75 or 90C and to use on 60C, ampacity is determined based on the 60°C ampacity of the conductor

The NEC Rules - 0110DB9901 Wire Temp Ratings and Terminations (schneider-electric.com)