Configuration - Siemens SIRIUS 3RT Manual

Accessories
9.4 Surge suppressor
9.4.2

Configuration

Selection aid
The table below compares the effects of the different surge suppressors and specifies the
applications to which they are most suited.
Table 9- 19 Mode of operation and preferred applications of surge suppressors
Surge suppressor Suitable
for
Control
voltage
Noise DC
suppression
/freewheel
diode
Diode DC
combination
: Noise
suppression
and Zener
diode
Varistor AC/DC
300
Overvoltage Effect
is limited ...
To 0.7 V
OFF-delay
•
becomes
considerably
longer (6 to
10 times)
With
•
contactors of
size S0 or
larger,
"2-stage
drop-out"
cannot be
excluded
To Zener
OFF-delay
•
voltage
becomes
longer (2 to 6
times)
A 2-stage
•
drop-out no
longer occurs
To varistor
OFF-delay
•
voltage
becomes only
slightly longer
(2 to 5 ms)
Advantages/disadvantages
Advantages
•
•
•
•
Disadvantages
•
1)
•
Advantages
•
Disadvantages
•
Advantages
•
•
•
Disadvantages
•
SIRIUS - SIRIUS 3RT Contactors/Contactor assemblies
Manual, 09/2017, A5E03656507120A/RS-AE/006
Preferred
application
Instable control
Simple
commands/con
implementation
trol supply
Reliable
voltage
Non-critical
dimensioning
Low induction
voltage
Long drop-out
delay
Only suitable for
size S00
EMC-critical
Non-critical
components in
dimensioning
the vicinity
Attenuation only
above U (10 V)
ZD
Suitable for
Energy
most standard
absorption
applications,
Non-critical
e.g. in the
dimensioning
SIMATIC
environment
Simple
implementation
Attenuation only
above U
VDR