Siemens SENTRON 3VA1 - Page 635

Technical specifications
6.4 Derating and temperature compensation
3VA molded case circuit breakers with IEC certificate
Manual, 03/2019, A5E03603177010-03
633
Using the two calculated values, it is possible to determine the temperature compensation
TK and finally the setting value for the trip unit I
r(TU)
:
TK(T
U
) Temperature compensation for molded case circuit breaker with service tempera-
ture T
U
K Correction factor
T
u
Service temperature of molded case circuit breaker
Trip unit setting value:
I
r(TU)
= I
n
· EF(50 °C) · TK
I
r(TU)
Trip unit setting value with service temperature T
u
The operational current must never exceed the maximum rated operational current I
n
of the
molded case circuit breaker. If the current calculated for the operating conditions is higher
than the rated operational current of the unit, a molded case circuit breaker with the
appropriate rated operational current must be deployed.