Derating; Derating Of 3Va5 Molded Case Circuit Breakers - Siemens Sentron 3VA Manual

Technical specifications

6.4 Derating

6.4 Derating
6.4.1

Derating of 3VA5 molded case circuit breakers

The temperature inside the molded case circuit breaker is influenced by the ambient
temperature and the current-dependent power loss generated inside the unit. To prevent
overloading of 3VA5 molded case circuit breakers under difficult thermal conditions, the
maximum rated continuous operational current must be limited as a function of the ambient
temperature.
Note
The values do not apply to all installation situations of the molded case circuit breaker and
may deviate depending upon factors such as cables and busbars, packing density,
ventilation, etc.
The extensive range of accessories of the 3VA5 molded case circuit breaker has no effect
on the thermal response thresholds of the switching devices.
454
3VA molded case circuit breakers with UL and IEC certification
Manual, 01/2019, L1V30435333-01