Operation Of The Cm On Grounded/Ungrounded Power Supply - Siemens SIMATIC RF185C Operating Instructions Manual

Connection

5.2 Operation of the CM on grounded/ungrounded power supply

You will find additional information on setting up an MRP ring topology in the STEP 7 online
help and in the "SIMATIC PROFINET system description
(https://support.industry.siemens.com/cs/ww/en/view/19292127)".
5.2 Operation of the CM on grounded/ungrounded power supply
Below, you can find information on the overall configuration of an RF18xC/RF18xCI
communication module on a grounded power supply (TN-S network). The specific subjects
discussed here are:
• Supply voltages of the communication module
• Disconnecting devices, short-circuit and overload protection according to IEC 60364
(corresponds to DIN VDE 0100) and IEC 60204 (corresponds to DIN VDE 0113)
• Load voltage supplies and load circuits
Grounded power supply
For grounded power supplies, the neutral conductor of the supply system is grounded. A
short-circuit to ground of a live conductor, or of a grounded part of the system, trips the
protective devices.
Supply voltages
Two supply voltages are available for the communication module:
• 1L+: Power supply
• 2L+: Load voltage
Note that the power supply (1L+) supplies the communication module and the readers with
power. The load voltage (2L+) has no direct effect on the RF18xC communication modules.
For RF18xCI, the actuators and connected IO-Link devices (connectors with Class B
assignment) are supplied with power over the load voltage (2L+). If the load voltage (2L+) is
not connected, the channel fault LED (IO-L1) is continuously lit in red. This voltage is looped
through to further consumers via the L-coded plug-in connectors.
Safe electrical isolation (SELV/PELV according to IEC 61140)
Power supply units/power supply modules with safe electrical isolation are required for
operation of the communication module. This protection is referred to as SELV (Safety Extra
Low Voltage) / PELV (Protective Extra Low Voltage) according to IEC 61140.
Setting up RF18xC/RF18xCI with grounded reference potential
When the communication module is set up with grounded reference potential, any
interference currents that occur are diverted to functional ground. The connections must be
connected externally (connection between 1M and FE).
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SIMATIC RF185C, RF186C, RF188C, RF186CI, RF188CI
Operating Instructions, 03/2022, C79000-G8976-C512-04