Konzept
Grounding and Power for Systems with RP-C-16A Controller
This section provides grounding and power recommendations for system configurations with the RP-C controller model RP-C-16A, which is a model that supports 230 VAC input power.
Use the following recommendations to design a good working system:
Select any of terminals 4 or 5 to be used as G0 (Power Ground/Common).
G0 (terminal 4 or 5) can be connected to RET. Avoid this if not necessary.
G0 and/or RET can be connected to protective earth ground (PE). Avoiding this connection is preferable, as it can cause circulating ground currents.
Do not connect RET to terminal 3 as the creepage distance must be at least 5.5 mm from mains voltage to RET.
The fuse (circuit breaker) F11 must be rated 3 A or higher.
Signal Ground Rail (SGR) is not needed.
When interconnecting several RP-C-16A controllers:
Avoid interconnection of local grounds (G0/RET) for different RP-Cs 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.
If the local grounds (G0/RET) of different RP-Cs are interconnected, every RP-C with local ground connection to another device must be grounded to PE.
It is necessary to connect RET to PE because the RP-C is supplied from mains voltage and a small touch current (<0.2 mA) is generated by the RP-C's internal AC/DC converter. If several RP-Cs are interconnected, the sum of all touch currents can be high, making it dangerous to touch parts such as the antenna or other parts connected to the internal ground.
Warnung
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HAZARD OF ELECTRIC SHOCK Do not connect signal ground (RET terminals, USB shield, Ethernet network shield, or antenna shield) between RP-C controllers without connecting at least one of the RET terminals to protective earth ground. Failure to follow these instructions can result in death, serious injury, or equipment damage. |
It is important to know that several nodes are internally interconnected to the common signal ground. This is important for safety reasons and to help avoid ground loops and incorrect supply of G0. The following nodes are all interconnected:
All RET terminals (20, 23, 26, and 29)
Antenna connector
USB connector shields
Ethernet network connector shields
RS-485 (Room bus and Sensor bus) ground reference
I/O Wiring
Grounding and Power
RP-Cs
Grounding and Power for Systems with RP-C-12A, -12B, or -12C Controllers