Planning/Configuring; Selecting Solid-State Switching Devices - Siemens SIRIUS 3RT Series System Manual

3.5

Planning/configuring

3.5.1

Selecting solid-state switching devices

Selecting solid-state contactors
Solid-state contactors are selected on the basis of the line, the load, and the ambient
conditions.
The following procedure is recommended:
● Determine the rated current of the load and the line voltage.
● Select a solid-state contactor with a rated current which is higher than or at least equal to
the load.
● Check the maximum permissible switching frequency based on the characteristic curves.
To do this, you must know the starting current, the start time, and the motorized load
during the operating phase.
● If the permissible switching frequency is below the required switching frequency, it can
only be increased by overdimensioning the motor.
● Alternatively, the correct device size can be determined by entering the line data, the
motor data, the application, and the ambient conditions in the "Selection of solid-state
contactors for switching motors
app/main/index.jsf)" tool on the Internet.
Load feeders
There is no such thing as a typical design for a load feeder with solid-state relays or solid-
state contactors. Rather, the variety of connection systems and control voltages support
universal possible applications. SIRIUS solid-state relays and solid-state contactors can be
installed in either fuseless or fused feeders.
Reference
More information ...
About tested load feeders
About the maximum permissible switching
frequency
SIRIUS Innovations
System Manual, 01/2011, A8E56203870002-03
SIRIUS 3RF34 solid-state switching devices
(https://eb.automation.siemens.com/spicecad/dc-web-
Can be found ...
The configuration guide titled "Configuring
SIRIUS Innovations - Selection data for load
feeders in fuseless and fused designs"
(order no.: 3ZX1012-0RA21-1AC0)
The chapter titled Technical data (Page 350)
3.5 Planning/configuring
329