WIKA GDM-100 Betriebsanleitung Seite 15

5. Commissioning, operation
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 protective measures are possible:
Example:
Contact protection measure
with voltage-dependent
VDR resistor
Example:
Contact protection
measure with RC element
Capacitive load
With capacitive loads elevated switch-on currents arise. These can be reduced by
series-connecting resistors in the supply line.
Examples: Contact protection measure with current-limiting resistor
U
B
WIKA operating instructions gas density monitor model GDM-100
Contact
Diode
R
1
Load
Load
Load
Load
U
B
R
1
Load
15
EN