Siemens SIRIUS 3RW40 - Page 99

Configuration
12.7 Calculating the permissible switching frequency
SIRIUS 3RW30 / 3RW40
Manual, 10/2018, NEB535199502000/RS-AB/005
99
Calculating the number of starts / hour of a 3RW40 for side-by-side assembly and vertical mounting
Assembly of a 3RV2021 motor starter protector and connection of a 3RW4024 soft starter
with cables and vertical mounting for CLASS 10 starting:
Switching frequency of 3RW40 with standalone assembly:
50 1/h
Switching frequency factor for diagram B without a fan:
0.1
Switching frequency factor for diagram B with a fan
1)
:
1.6
Maximum permissible switching frequency:
Without fan
50 1/h x 0.1 = 5 1/h
With fan
1)
:
50 1/h x 1.6 = 80 1/h
1) Optional fan: 3RW4928-8VB00
Result
The pump could be started five times an hour providing the above assembly conditions are
complied with (side-by-side assembly, vertical mounting). A switching frequency of up to 80
starts per hour can be achieved by equipping the 3RW4026 with the optional 3RW4928-
8VB00 fan.