Siemens SENTRON 3VA2 - Derating and Temperature Compensation; Derating of 3 VA1 Molded Case Circuit Breakers

Technical specifications
6.4 Derating and temperature compensation
3VA molded case circuit breakers with IEC certificate
628 Manual, 03/2019, A5E03603177010-03
6.4
Derating and temperature compensation
6.4.1
Derating of 3VA1 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 3VA1 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 were calculated for molded case circuit breakers without accessories. They 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.
Please observe the applicable overriding guidelines (e.g. IEC 61439).
1)
For TM120M only (starter protection circuit breaker)
No derating up to the rated operational current I
n
of the molded case circuit breaker