SIPLUS PSU (6DL3500-8BA)
SIPLUS PSU Power Supply Unit
A5E00854207E
25 of 30
Copyright (C) Siemens AG 2018
V 8.00 released
2018-05-03
8.3 Checking of the Feeder Diodes
For the check of the feeder diodes a power supply unit is required for the auxiliary supply of the DC
24 V supply voltage. At the auxiliary supply unit an output voltage of 30 V and a current limitation of
60 A must be adjustable.
Repair of faulty feeding diodes is not provided. In that case the SIPLUS PSU must be replaced by a
new unit (see chapter 8.5 “Replace of an Equipment”).
Step 1: Checking of the feeder diodes for short circuit
Measure the voltage drops of the feeder diodes between L1 and L1/L2 and between L2 and L1/L2
(see figure 19). The voltages UL1 and UL2 can be tapped at the screw heads of the feeder clamps.
The voltage drops UL1 and UL2 must be in the range of 0.3 V to 1.0 V (valid for voltage at L1 = volt-
age at L2 and feeding current I ≥ 1 A). At voltage drops under 0.3 V one or both feeder diodes are in
a short circuit condition.
L1 L2
M
M
M
M
L1 L2
L1/L2
SIPLUS PSU
U
Einspeisekabel
Zum Nachbarschrank
UL1
UL2
Figure 19: Checking of the feeder diodes for short circuit
Step 2: Connecting the Auxiliary Supply
Disconnect one of the feeding cables from M (see figure 20). Adjust at the PELV auxiliary power sup-
ply an output voltage of 30 V and a current limitation of 60 A.
NOTICE
Danger of property damage!
The SIPLUS PSU as well as post-connected equipments may be damaged in
case of false polarity. The auxiliary supply may be damaged in case of feeding
back.
Please observe the correct polarity before connecting the auxiliary supply. The
used power supply must be re-feeding protected.
Supply cable
To neighbor cabinet
