A-101
Appendices
NJ-series CPU Unit Hardware User’s Manual (W500)
A-5 EMC Directive Measures for Relay Outputs
A
When switching a load with a high inrush current such as an incandescent lamp, suppress the inrush
current as shown below.
Yes Yes The varistor method prevents the
imposition of high voltage between
the contacts by using the constant
voltage characteristic of the varis-
tor. There is a delay in the resetting
time.
If the supply voltage is 24 or 48 V,
insert the varistor in parallel with
the load. If the supply voltage is
100 to 200 V, insert the varistor
between the contacts.
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Circuit
Current
Characteristic Required element
AC DC
Power
supply
Varistor method
Inductive
load
OUT
COM
R
Countermeasure 1
Providing a dark current of
approx. one-third of the rated
value through an incandescent
lamp
OUT
COM
R
Countermeasure 2
Providing a limiting resistor