General Measures Of Radio Interference Suppression For Relays, Contactors, Switches, Chokes And Inductive Loads - Bosch Rexroth IndraDrive Mi Instruction Manual

DOK-INDRV*-KSM02*UL***-IN01-EN-P
Rexroth IndraDrive Mi Distributed Servo Drive KSM02
6.5 General Measures of Radio Interference Suppression for Re‐
lays, Contactors, Switches, Chokes and Inductive Loads
If, in conjunction with electronic devices and components, inductive loads,
such as chokes, contactors, relays are switched by contacts or semiconduc‐
tors, appropriate interference suppression has to be provided for them:
● By arranging free-wheeling diodes in the case of d.c. operation
● In the case of a.c. operation, by arranging usual RC interference sup‐
pression elements depending on the contactor type, immediately at the
inductance
Only the interference suppression element arranged immediately at the in‐
ductance does serve this purpose. Otherwise, the emitted noise level is too
high which can affect the function of the electronic system and of the drive.
If possible, mechanical switches and contacts should only be realized as
snap contacts. Contact pressure and contact material must be suited for the
corresponding switching currents.
Slow-action contacts should be replaced by snap switches or by solid-state
switches, because slow-action contacts strongly bounce and are in an unde‐
fined switching status for a long time which emits electromagnetic waves in
the case of inductive loads. These waves are an especially critical aspect in
the case of manometric or temperature switches.
Bosch Rexroth AG
EMC Measures for Design and Installation
67/81