Siemens sirius System Manual page 188

3RT1/3RH1 contactors
Mode of operation
Variants
Installation
RC circuit
Varistor circuit
3-80
The EMV suppression module reduces through 3 phases the radio-fre-
quency parts and the voltage peaks. The advantages of this are as follows:
• Longer service life of the contact pieces
• Higher operational reliability and high system availability
A fine grading within the performance class is not required because smaller
motors have greater inductance due to their construction, and one EMC sup-
pression module is thus sufficient for all non-stabilized drives up to 5.5 kW.
Two electrical variants are available:
• RC circuit
• Varistor switching
2
3RT1916-1P..
Figure 3-62: EMC suppression module
The RC circuit is suitable:
• For reducing the rate of rise
• In RF damping
Effective suppression can be achieved for a wide range of applications.
A varistor circuit can absorb a high level of energy and can be used for fre-
quencies from 10 to 400 Hz (stabilized drives). There is no limit below the
buckling stress.
The EMC suppression module is
attached to the underside of the
contactor. To do this, hook the
EMC suppression module with
both hooks onto the contactor,
and push it upward until the con-
1
nection pins of the EMC module
are firmly in place in the terminal
openings of the contactor.
SIRIUS System Manual
GWA 4NEB 430 0999-02b