3-5
ET 200L Distributed I/O Device
EWA-4NEB 780600902-05
r
The load current power supply feeds input and output circuits (load circuits)
as well as sensors and actuators. The following table lists the characteristics
of load current power supplies that are required in specific applications.
Characteristic of
Load Current
Power Supply
Required for ...
Remarks
Safe (electrical) isola-
tion
Modules that have to be
supplied with voltages
60 VDC or
25 VAC
Power supply PS 307 and Sie-
mens Series 6EP1 load current
power supplies have this charac-
teristic
24 VDC load circuits
Output voltage toler-
ances:
20.4 V to 28.8 V
24 VDC load circuits
If the output tolerances are ex-
ceeded, we recommend that you
install a back-up capacitor. Rat-
ing: 200
m
F per 1 A load current
(with full-wave rectification).
Load circuits should be grounded.
Fault-free operating reliability is ensured by the common reference potential
(ground). Install a detachable connection to the protective conductor on the
external power supply (terminal L or M) or on the isolation transformer (Fig-
ure 3-1,
). This measure makes it simpler for you to locate ground faults in
the power distribution system.
You will find notes on EMC
-
compatible installation and wiring in the manual
for the DP master you are using or for the host system.
Take into account the following notes on EMC-compatible installation of the
ET 200L distributed I/O device:
S
We recommend that you place the cable shield of the PROFIBUS-DP on
both sides of a shield bus.
S
The chassis ground and the ground terminal are interconnected in the
ET 200L distributed I/O device. Connect the ground terminal of the
ET 200L distributed I/O device using a copper cable of at least 2.5 mm
2
to the central grounding point in the installation cabinet.
Characteristics of
Load Current
Power Supplies
Rule: Ground Load
Circuits
EMC
Wiring
