Concept
Grounding and Power for Systems with RP-C-16C-F-230V and External 24 VAC/VDC Power Supply
This section provides grounding and power recommendations for system configurations with the RP-C-16C-F-230V controller model and an external 24 VAC/VDC power supply connected to the EXT Input of the controller.
Use the following recommendations to design a good working system:
It is recommended to use a separate 24 VAC / VDC power supply connected to the EXT Input of each controller to help avoid circulating ground currents (ground loop currents).
The slow blow fuse (or circuit breaker) F11 connected to the Power Input must be rated 3 A or higher.
The fuse F13 connected to the EXT Input should be rated according to the connected external 24 VAC/VDC power supply, but not higher than 8 A.
Avoid interconnection of local grounds (G0/RET) for different RP-C controllers by using non-shielded Ethernet network cables. Avoid shielded Ethernet network cables. Also, do not connect G0/RET from one RP-C with G0/RET of a different RP-C.
It is important to know that several nodes are internally interconnected to the common signal ground. This is important to help avoid ground loops and incorrect supply of G0. The following nodes are all interconnected:
All RET terminals
Antenna connector
USB connector shield
Ethernet network connector shields
RS-485 (Com A, Com B, and Com C) ground reference
The protective earth (PE) ground terminal (
The PE terminal must be connected to the incoming protective earth ground for the controller to meet EMC requirements.
I/O Wiring
Grounding and Power
RP-C Controllers
Grounding and Power for Systems with RP-C 230 V Controller Models
RP-C Models