Siemens X-400 - Manual (Page 90)

Installation and Commissioning
Operating Instructions for SCALANCE X-400 Industrial Ethernet Switches
90 C79000-G8976-C186-03
6.6 Ports
6.6.1 Power Supply Connectors (X1)
Polarity Reversal Protection X1, X2
The two 4-pin male connectors (X1, X2) for the power supply and the signaling
contact have no polarity reversal protection. If the connectors are accidentally
swapped over, this does not cause damage or destroy circuits. Normal functionality
is, however, not available while the connectors are swapped over.
The redundant power supply is connected over a 4-pin connector at the front ter-
minal block on the power module.
X 2
X 1
L 2 M 2 M 1 L 1
Figure 6-9 Pin assignment of connector X1
Conn. 1 L1+ + 24 V power supply 1
M1 Ground
M2 Ground
L2+ + 24 V power supply 2