Siemens SIRIUS 3RF Series User Manual

SIRIUS 3RT2 contactors/contactor assemblies
2.7 Accessories
SIRIUS Innovations
172 System Manual, 01/2011, A8E56203870002-03
Surge suppressor Suitable for
Control
voltage
Overvoltage
is limited ...
Effect Advantages/disadvantages Preferred
application
Advantag
es
 Energy absorption
 Non-critical
dimensioning
 Simple
implementation
Varistor AC/DC To varistor
voltage
 OFF-delay
becomes only
slightly longer
(2 to 5 ms)
Disadvan
tages
 Attenuation only
above U
VDR
Suitable for
most standard
applications,
e.g. in the
SIMATIC
environment
Advantag
es
 RF attenuation
 Well suited to AC
voltage
 Attenuation
independent of
levels
RC
elements
AC/DC According
to
dimensionin
g
 OFF-delay
remains
unchanged
 Rates of rise of
voltage are
attenuated
Disadvan
tages
 High inrush current
 Sensitive to
harmonics
With critical
operating times
1)
The drop-out speed falls to zero once or twice for a few milliseconds:
● Safe drop-out is always ensured during current-free switching.
● When switching with a current present, the contacts are subjected to a higher thermal
load. This can lead to an overload when switching at the high current limit.

Siemens SIRIUS 3RF Series Specifications

General

Brand	Siemens
Model	SIRIUS 3RF Series
Category	Industrial Equipment
Language	English