SIPLUS PSU (6DL3500-8BA)
SIPLUS PSU Power Supply Unit
A5E00854207E
12 of 30
Copyright (C) Siemens AG 2018
V 8.00 released
2018-05-03
For electronic switching off there are two possible reasons:
-
Overload
At overload condition the transistor/Smart-FET switches off thermally. After a short cooling
time the transistor switches on automatically again. This process recurs until there is no more
overload condition or the fuse is blown.
-
Low impedance short circuit
The short circuit supervision responds and a clocked current limitation is realized. When the
short circuit is eliminated it is automatically switched on.
If a power supply output channel LED signals a red continuous light in the “OFF” state, then there is
an internal fault. The supply channel is faulty and must not be switched on any more. In addition at
the signaling outputs MELD (active HIGH) and MELD_N (active LOW) a collective message is output.
When a monitoring circuit is activated the supply output concerned goes into the operating state
"FAULT". Fault treatment and reset conditions are described in the chapter 8 “Maintenance and Di-
agnosis”.
The operating states are described in the chapter 4.7 “Signaling Scheme” in tabular form.
4.6 Signaling Outputs
When a monitoring facility in a supply output is activated a collective message is output. The signal is
provided at two signaling outputs via the plug connector X21. The signaling output MELD provides a
HIGH active signal DC 24 V/0.5 A. The signaling output MELD_N provides a LOW active signal
DC 24 V/0.5 A.
The signaling outputs are short-circuit-proof and overload-proof against M and DC 24 V. After remov-
al of the short-circuit or overload condition, the outputs resume their function automatically. By means
of suppressor diodes they are protected against positive and negative overvoltage.
Note:
In order to connect the signaling outputs in wired-or with other digital DC outputs, both
outputs are high-impedance in the inactive condition. Therefore the MELD output must
be charged with a pull-down resistor against M and the MELD_N output must be
charged with a pull-up resistor to DC 24 V
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To match the specified signal levels in the inactive state, the pull resistors must not exceed 100 kΩ.
At wired-or connection with other digital DC outputs the pull resistors have to be more low-impedance
according to the specification of these outputs. Example: Wired-or connection with a second digital
DC output. The second output requires a pull resistor of 39 kΩ. The pull resistor is the parallel con-
nection of 39 kΩ and 100 kΩ and results in 28 kΩ.
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or with current drawing digital DC inputs (MELD) and current sourcing digital DC inputs (MELD_N) respectively
