Siemens SIMATIC ET 200AL System Manual page 34

Connecting
5.1 Rules and regulations for operation
External fuses/switches
External fuses and switches must be installed so that they meet the standards for cable and
device protection applicable to your application.
Line voltage of the SELV/PELV power supply
The following section describes what you need to pay attention to with respect to the line
voltage (you will find additional information in the section Information on insulation,
protection class, degree of protection, and rated voltage (Page 108)):
• For stationary plants or systems without an all-pole line disconnector, there must be a
disconnector unit (all-pole) fitted in the building installation.
• For load current supplies, the configured rated voltage range must correspond to the local
line voltage.
• For all power circuits of the ET 200AL distributed I/O system, the fluctuation/deviation of
the line voltage from the rated value must be within the permitted tolerance.
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Distributed I/O system
System Manual, 08/2021, A5E31861578-AJ