Why Are RC Filter Kits Recommended for Mechanical Relays?
During the activation and deactivation of mechanical relays, a spark can be generated on the surface of the
relay contacts, which over a period of time melts the surface of the contacts and prevents the contacts from
making a physical connection. RC Filter Kits will prevent these sparks from occuring and will extend the life
of the mechanical relays used in Signet products. If a RC Filters are used, relay specifications do not
change and must not be violated. The placement of these filters based on the load and power used in
the circuit. The RC filter kit part number 3-8050.396 (159 000 617) comes with two RC filter assemblies.
See the figures below:
Figure A: Mechanical relays create a spark when switching inductive loads such as motors or solenoids.
Figure B: Suitable for AC and DC applications.
Figure C: Also suitable for AC and DC applications however, if this configuration is used with an AC
power source, verify that the impedance of the load is smaller than the impedance of
the RC Filter; current leak through the filter may occur and cause the device to be
constantly on.
