5. Commissioning, operation
5.2.2 Contact protection measures
Mechanical contacts must not exceed the specified electrical values for switching
current, switching voltage and switching power independent of each other, not even for
a short time only.
For capacitive or inductive loads we recommend one of the following protective circuits:
Inductive load with DC voltage
With DC voltage the contact protection can be achieved via a free-wheeling diode,
connected in parallel to the load. The polarity of the diode must be arranged so that it
closes when the operating voltage is on.
Example:
Contact protection
measure with free-
wheeling diode
Inductive load with AC voltage
With AC voltage two protection measures are possible:
Example:
Contact protection
measure with
voltage-dependent
resistor VDR
Example:
Contact protection
measure with RC
element
WIKA operating instructions, models GDM-100-TI, GDM-100-TA
Contact
Diode
Load
Load
Load
EN
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