Secondary Electrical Conditions; Power Supply - Siemens SINUMERIK 840DE sl Manual

Technical data

7.1 Secondary electrical conditions

Note
Information about the climatic and mechanical environmental conditions is contained in the
associated section under:
"General notes and interconnection" → "Operational planning".
7.1 Secondary electrical conditions
7.1.1

Power supply

Requirements for DC power supplies
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, 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
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.)
78
WARNING
(Protective Extra Low Voltage) output voltages acc. to UL 61010 for all connections and
terminals of the electronics modules.
WARNING
Operator panel front: OP 015 black
Manual, 05/2019, A5E35227814B AB