Siemens 3VA1 100 A Manual page 159

Shunt trips left STL
Shunt trips of type STL can be fitted in the left-hand accessories compartment as an
alternative to an undervoltage release. The units are available with five rated voltages in the
following range:
● 24 to 600 V AC 50/60 Hz
● 12 to 250 V DC
They have a maximum power consumption of 58 VA which is significantly lower than the
power consumption of the flexible shunt trip versions.
Switches (permanent signal) or buttons (minimum signal duration 40 ms) can be used to
control shunt trips.
Shunt trips flexible STF
Shunt trips of type STF can be fitted in the left-hand and the right-hand (3VA2 only)
accessories compartment. They are therefore suitable for combining different auxiliary
releases in one switch.
The units are available with six rated voltages in the following range:
● 24 to 600 V AC 50/60 Hz
Due to their design, their power consumption ranges up to maximum 750 VA and is therefore
higher than the power consumption of STL versions.
Undervoltage releases UVR
Undervoltage releases trip the molded case circuit breaker in the event that the rated voltage
fails or drops to between 70 % and 35 % of its normal value (in compliance with the relevant
standard).
The main contacts of the basic breaker cannot be reclosed until the rated voltage of the UVR
reaches 85 % of its normal value. The breaker main contacts cannot close until the UVR
rated voltage reaches this level.
The units are available with rated voltages in the following range:
● 24 to 480 V AC 50/60 Hz
● 12 to 250 V DC
3VA molded case circuit breakers
Manual, 04/2015, A5E03603177010-02
Accessories
4.2 Internal accessories
159