Soft Starter With Contactor Disconnector (Main Contactor) - Siemens SIRIUS 3RW44 User Manual

Installation, Connection and Branch Layout

3.2.4 Soft Starter with Contactor Disconnector (Main Contactor)

3-8
If galvanic decoupling is required, a motor contactor can be installed between
the soft starter and the disconnector, or a fault output relay can be used. (Refer
to Chapter 10.3 "Technical Data" for the contactor assignment)
3/N/PE~ 50 Hz 400 V
L1
L2
L3
PE
Q11
U1 V1 W1
V2
W2 U2
Figure 3-6: Schematic circuit diagram of branch with optional main contactor / contactor
disconnector
Notice
If a main or line contactor is used, this contactor must not be connected
between the soft starter and the motor or in the return line between the motor
and the soft starter. The soft starter would otherwise not recognize the current
circuit version (standard circuit or inside delta circuit) and would output the error
message: "Load phases 1-3 missing".
Notice
With 3RW44 product version *E08* (FW V 1.9.0) the simultaneous and/or prior
switch-off of the main contactor and removal of the on command at the soft
starter may lead to direct on line starting behavior of the motor when restarting.
Include a tripping delay of 1 s for the main conductor or control the main
conductor via an output with parameterized "On-time" function as described in
circuit diagram 9.1.2.
Q1
Q21
K1
G1
M1
U1 V1 W1
V2
W2 U2
SIRIUS 3RW44 manual
GWA 4NEB 535 2195-02 DS 06