MCB Temperature Derate
UL489 and UL1077 MCBs are calibrated for a specific ambient temperature.
The UL489 BK63HU is calibrated for
40℃.
The UL1077 BK63H is
calibrated for 25
℃.
The LS MCBs can be installed in an environment from -40 ~70 degrees C.
You must follow the below derating tables when installing at a given ambient temperature.