Product Overview

3RT1 contactors/3RH1 control relays
SIRIUS System Manual
3-104 GWA 4NEB 430 0999-02 DS 01
Diode
Fig. 3-66: Circuit with a diode (AC/DC operation)
This is what happens when a coil is de-energized that is connected to a
diode:
Advantages: No overvoltage occurs during de-energization. The diode block
becomes effective at 0.6 V.
Disadvantage: The diode can only be used for DC operation.
The opening time of the contactor is considerably increased and amounts to
6 to 9 times the normal opening time.
This increased break time can be used, if necessary, for control purposes,
such as for bridging brief interruptions in voltage.
Zener diodes (diode combinations) are available for shorter opening times.
The opening time then amounts to 2 to 6 times the normal opening time.
Surge suppressors The following surge suppressors are available for the 3RT1 contactors:
Circuit with diode
(DC operation)
0
200
20
U
Sp
[V]
0
t [μs]
U
Sp
= 0,6 V = U
SP
of the Diode
^
Surge suppressor
With
LED
Without LED
for S00 for S00 for S0 for S2, S3 for S6 to S12
Suppression diode
xx—— —
Diode combination:
suppression diode and
Zener diode
—xx x —
Varistor
x x x x integrated
RC element
—xx x x
Table 3-40: Surge suppressor