Connection
4.1 General rules and regulations for operating the ET 200pro
ET 200pro distributed I/O system
68
Operating Instructions, 03/2013, A5E00335544-08
24 V DC power supply
The following table identifies requirements you must observe for the 24 V DC supply.
With ...
you must ensure ...
buildings
external lightning
protection
Install lightning protection
(e.g. lightning protection
elements).
24 V DC power supply cables, signal cables internal lightning
protection
24 V DC power supply
Safe (electrical) isolation of safety extra-low voltage
(SELV)
Looping-through of the supply voltage
Voltage drop at looping-through
Protection against external electrical interference
The table below shows how you must protect your system against electrical interference or
faults.
With ...
make sure that ...
all plants or systems in which the ET 200pro
is integrated
the plant or system must be grounded observing EMC
in order to dissipate electromagnetic interferences.
supply/signal/bus cables
the cable routing and installation is correct.
signal and bus cables
a cable/conductor break does not cause undefined
plant or system states.
See also
Commissioning ET 200pro (Page 155)