Siemens SIRIUS 3RH Series, System Manual

Page: 171 / 786

SIRIUS 3RT2 contactors/contactor assemblies
2.7 Accessories
SIRIUS Innovations
System Manual, 01/2011, A8E56203870002-03
171
The following surge suppressors are available for the 3RT2/3RH21 contactors:
Table 2- 28 Overview - Surge suppressors
With LED Without LED Surge suppressor
Size S00 Size S0 Size S00 Size S0
Suppression diode 3RT2916-1L --- 3RT2916-1DG00 ---
Diode combination:
Suppression and
Zener diode
--- 3RT2926-1M 3RT2916-1E 3RT2926-1E
Varistor 3RT2916-1J 3RT2926-1J 3RT2916-1B 3RT2926-1B
RC element --- --- 3RT2916-1C 3RT2926-1C
2.7.3.2 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 2- 29 Mode of operation and preferred applications of surge suppressors
Surge suppressor Suitable for
Control
voltage
Overvoltage
is limited ... Effect Advantages/disadvantages Preferred
application
Advantag
es

Simple
implementation
 Reliable

Non-critical
dimensioning

Low induction
voltage
Noise
suppress
ion/freew
heel
diode
DC To 0.7 V 
OFF-delay
becomes
considerably
longer (6 to 10
times)

With contactors
of size S0 or
larger, "2-stage
drop-out"
1)
cannot be
excluded
Disadvan
tages
 Long drop-out delay
 Only suitable for
size S00
Instable control
commands/con
trol supply
voltage
Advantag
es
 Non-critical
dimensioning
Diode
combi-
nation:
Noise
suppress
ion and
Zener
diode
DC To Zener
voltage
 OFF-delay
becomes
longer (2 to 6
times)
 A 2-stage drop-
out no longer
occurs
Disadvan
tages

Attenuation only
above U
ZD
(10 V)
EMC-critical
components in
the vicinity