What affect does high ambient temperature have on the operation?
MCBs have thermal/magnetic characteristics. As the current is increased, the heat generated increases to the point where the current and subsequent heat is greater than the calibrated setting – the MCB trips. When placed in high ambient temperatures the calibrated point is lowered, i.e. the rating of the MCB is de-rated. Refer to the table below when installing MCBs in ambient temperatures other than 30C.
