WIKA PGS23.160 - Manual (Page 13)

WIKA operating instructions pressure gauge model PGS with reed contacts 13
GB
14000322.01 03/2011 GB/D/F/E
7. Contact protection measures
7.1. 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
Contact
Diode
Contact
Contact
7.2. Inductive load with AC voltage
With AC voltage two protection measures are possible:
Example:
Contact protec-
tion measure with
voltage-depend-
ent resistor VDR
Example:
Contact protection
measure with RC
element