Inputs and outputs
Based on the example of the 6ES5 955-3LF41 power supply unit, the
following figure shows the arrangement of inputs and outputs on the
front plate of the power supply units:
The following table provides an overview of the labelling and purpose
of the inputs and outputs:
ID Label
Element
Purpose
A
AC 120V 4.5A
AC 230V 2.6A
Screw terminals
1, 2, 3
AC connection and
protective conductor
B
EN
Screw terminal 4 Enable Power Supply
Control input for power
supply
C
U
H
Screw terminal 5 Supply for EN
D
Input
DC 24V Ext.
Screw terminals
6 and 7
Voltage Monitor
Monitors 24 V load voltage
for > 16 V
E
Fan Warning
max. 250V/3A
Screw terminals
8, 9, 10 (relay)
Indicates failure of a fan
F
Fan Alarm
max. 250V/3A
Screw terminals
11, 12, 13
(relay)
Indicates failure of at least
two fans and inadequate air
flow; if jumper set
accordingly, output enable
is the second signal source
G
Battery
Warning
max. 250V/3A
Screw terminals
14, 15, 16
(relay)
Indicates that lithium bty or
rechargeable bty has
dropped below limit
H
3V = 40A
2 test sockets
Current measurement
sockets for test purposes
only; no continuous
operation; linearity range
0.5 V/6.6 A to 3 V/40 A
I
Output
DC 24V 2.8A
Screw terminals
17, 18
Enable voltage for I/O
modules
J
Ext.Batt.
4.5V DC
2 input sockets
Input for an external 4.5 V
backup voltage
6ES5955-3LF41
L1 N
1
2
3
4
1
1
1
2
2
2
3
3
3
5
6
7
8
9 10
11
14
12
15
13
16
17 18
+
+
+
-
-
-
AC 120V 4,5A
AC 230V 2,6A
CAUTION!
Disconnect
before
removing
power supply!
Voltage
selector
Unlock
fan
Unlock
fan
Unlock
fan
Input
DC 24V Ext.
Output
DC 24V 2,8A
AC line 50/60 Hz
Enable
Power supply
Voltage Monitor
Fan
Battery
DC 5/15/24V
Internal
Ext.Batt.
DC 4,5V
Fault
Fan Warning
Fan Alarm
Warning
max.AC 250V/3A
max. AC 250V/3A
V
o
ltage
low
Fa
n
1
MB
low
3V=40A
Fa
n
2
RB
low
5V
o.k
.
Fa
n
3
15V
o.k
.
24V
o.k
.
Batt.
+
F
an
Re
se
t
Al
arm
EN UH
Power
I O
1
2
3
4
5
6
7
8
9
1
0
Batt. 3,6V/5Ah
Replace by
trained personnel
only!
SIEMENS
A
B C
E
D
G
I
H
J
F
Power Supply Units
System Manual
4 - 24
C79000-B8576-C199-03