User Manual

Configuration
11.6 Calculating the permissible switching frequency
SIRIUS 3RW30 / 3RW40
90 Manual, 10/2010, 535199502000 DS 03
MLFB a (mm) a (in) b (mm) b (in) c (mm) c (in)
3RW30 1./3RW30 2. 15 0.59 60 2.36 40 1.56
3RW30 3./3RW30 4 30 1.18 60 2.36 40 1.56
3RW40 2. 15 0.59 60 2.36 40 1.56
3RW40 3./3RW40 4. 30 1.18 60 2.36 40 1.56
1
1
3
5
2
4
6
a
a
E
F
Clearances from other devices
3RW40 5./3RW40 7. 5 0.2 100 4 75 3
11.6.2 Calculating the switching frequency (example)
Problem
The maximum permissible switching frequency of a 5.5 kW (12.5 A) 3RW4024 soft starter
must be determined. The requirements are side-by-side assembly and vertical mounting. A
ramp-up time of approx. 3 s at an ambient temperature of 40 °C is specified as a
supplementary condition (e.g. a pump motor with CLASS 10 starting). The soft starter must
be connected to a 3RV2021 motor starter protector by means of cables. (Clearance between
3RV and 3RW >= 40 mm)