Siemens SIMATIC ET 200PA SMART Operating Instructions Manual page 23

Line voltage
The following table indicates requirements to be observed for the line voltage.
In the case of ...
Stationary plants or systems without all-
pole line voltage disconnect switch
Load power supplies, power supply mod‐
ules
All power circuits of ET 200PA SMART
24 V DC supply
The following table indicates requirements to be observed for the 24 V supply.
In the case of ...
Buildings
24 V DC supply cables, signal
lines
24 V supply
Protection from external electrical influences
The following table indicates requirements to be observed for protection from electrical
influences or faults.
In the case of ...
All plants or systems in which the
ET 200PA SMART is integrated
Connection, signal and bus lines
Signal and bus lines
ET 200PA SMART
Operating Instructions, 06/2019, A5E34192013-AB
then ...
A line voltage disconnect switch or a fuse must be present
in the building installation system
The rated voltage range setting must correspond to the line
voltage at the site
The fluctuation/deviation of the input/load voltage from the
rated value must lie within the permissible tolerance
(refer to Technical Specifications of the ET 200PA SMART
modules or S7-300 modules)
then ...
External lightning protection
must be ensured
Internal lightning protection
must be ensured
Safety extra-low voltage with safe electrical isolation
then ...
Connection of the plant or system to the protective conductor must
be ensured for discharge of electromagnetic interference.
Correct cabling and installation must be ensured.
It must be ensured that a break of a line or conductor strand does
not result in undefined states of the plant or system.
Assignment planning
2.3 Configuring the electrical structure
Provide lightening protection meas‐
ures
(e.g. lightening protection units)
23