Technical data
8
8.1
Supplementary electrical conditions
8.1.1
Power supply
Requirements for DC power supplies
WARNING
Electric shock due to connection of an unsuitable power supply
When equipment is connected to an unsuitable power supply and/or insufficiently grounded or
rear cover (Page 31), exposed components may carry a hazardous voltage that might result in
serious injury or death.
• Only use power supplies that provide SELV (Safety Extra Low Voltage) or PELV (Protective
Extra Low Voltage) output voltages acc. to UL 61010 for all connections and terminals of the
electronics modules.
WARNING
Inadequately fused supply cables can be life-threatening
In the case of supply lines >30 m, protectors must be installed at the device input to protect
against lightning (surge).
The DC power supply must be connected to the ground/shield of the NC for EMC and/or
functional reasons. For EMC reasons, this connection should only be made at one point. As a
rule, the connection is provided as standard in the S7-300 I/Os. In exceptional circumstances
when this is not the case, the ground connection should be made on the grounding rail of the
NC cabinet (also refer to /EMC/EMC Installation Guide.)
ONE MCP Part 1: MCP xxxx
Equipment Manual, 07/2020, A5E50324729B AA
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