Delta RMC70 - Manual (Page 46)

RMC70 Startup Guide
44 Delta Computer Systems, Inc.
Appendix C: Agency Compliance
CE
For CE compliance and to minimize electrical interference:

Use twisted pairs for all wiring where possible.

Use shielded cables for all wiring.

Keep RMC wiring separate from AC mains or conductors carrying
high currents, especially high frequency switching power such as
conductors between servo drives and motors or amplifiers and
proportional valves.
UL and CUL
For UL and CUL compliance:

Power supply must be Class 2.

All RMC inputs and outputs must be connected to Class 2 circuits
only.