Omron SYSMAC CVM1 Series Operation Manual page 18

Conformance to EC Directives 6
Precautions Regarding Relay Output Switching:
Noise generated by the switching of relay outputs may exceed the standards of
the Common Emission Standard (EN50081-2). In this case, take the necessary
countermeasures to reduce the emissions, such as connecting a surge sup-
pressor or shielding the PC. Some methods of reducing emissions are shown
below.
Countermeasures are required when the load switching frequency of the overall
PC exceeds 5 times/minute. Refer to 3-8 Compliance with EC Directives in the
CVM1D Installation Guide for examples of circuits that can be used to reduce
noise generated by switching.
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