Adjustable trip CB marked for continuous operation at 80%

Anonymous user · ‎2020-12-03

How does adjusting the trip on a circuit breaker affect the marked 80% continuous operation rating? See CEC C22.1-18 8-104 6). Ie. is the trip adjustment a percentage of the 80% continuous rating?

MathieuGuillot · ‎2020-12-07

Hello,

In Schneider Electric / Square D range of adjustable circuit breaker there is no link between the setting of overload protection "Ir'" and the 80% or 100% rating capability of the circuit-breaker.

Selecting 80% standard rating or 100% rating is more a question of enclosure design due to thermal dissipation for continuous load, rather than a setting question that is linked to the ampacity of the protected circuit.

Masterpact circuit breakers and PowerPact M,P, R frames are designed for continuous operation at 100% of their current rating, and the setting of Ir is given in % of "In" the rated current of the trip unit.

PowerPact B, H,J, L ranges are offering "80% rated" or "100% rated" references. Both will have the same trip units with overload setting in Amps. A 80% rated should be adjusted up to 80% of the rating when used with a continuous load but can be ajdusted up to 100% with non continous load.

Does it answer your question ?

Regards

See Answer In Context

MathieuGuillot · ‎2020-12-07

Hello,

In Schneider Electric / Square D range of adjustable circuit breaker there is no link between the setting of overload protection "Ir'" and the 80% or 100% rating capability of the circuit-breaker.

Selecting 80% standard rating or 100% rating is more a question of enclosure design due to thermal dissipation for continuous load, rather than a setting question that is linked to the ampacity of the protected circuit.

Masterpact circuit breakers and PowerPact M,P, R frames are designed for continuous operation at 100% of their current rating, and the setting of Ir is given in % of "In" the rated current of the trip unit.

PowerPact B, H,J, L ranges are offering "80% rated" or "100% rated" references. Both will have the same trip units with overload setting in Amps. A 80% rated should be adjusted up to 80% of the rating when used with a continuous load but can be ajdusted up to 100% with non continous load.

Does it answer your question ?

Regards

Anonymous user · ‎2020-12-07

Hello Mathieu

Thank you for taking the time to respond to my question. This is crystal clear.

Best regards,

Brian