Example circuits
A.1 Main circuit connection
SIRIUS 3RW52 Soft Starter
Equipment Manual, 04/2020, A5E35630451002A/RS-AE/005
217
A.1.3
Feeder assembly, type of coordination 2
Feeder assembly
You must provide protection for all thyristors against short circuits by means of special
semiconductor fuses (e.g. SITOR fuses from Siemens) to achieve type of coordination 2. A
short circuit can occur, for instance, as a result of a defect in the motor windings or in the
motor's power supply cable.
Q1
Motor starter protector
F3
aR partial-range fuse for protection of semiconductors (e.g. SITOR 3NE3/4 or 3NC3)
F3*
gR full-range fuse for protection of semiconductors (e.g. SITOR 3NE1)
Q11 3RW52 soft starter
M1
Motor
PE
Protective conductor