Siemens SIPLUS PSU Operating Instructions Manual page 26

Turn the auxiliary power supply unit off, connect it at the clamp L1/L2 and at the free M clamp and
switch it on again.
The current limitation must not be in action. The output voltage must show a stable value of 30 V.
Otherwise there is a defect of the feeder diodes.
Step 3: Checking of the Feeder Diode at L1 potential in inverse direction
Disconnect the supply cable at L1, strain the clamp L1 with a resistor of 1 kΩ (≥ 1 W) to M and
measure the reverse current of the L1 feeder diode through the load resistor (see figure 20).
The reverse current must not exceed 10 mA.
Connect the supply cable to L1 again.
Note:
The supply cable at L2 must be connected during the whole test step for the supply of
the neighbor cabinet!
Step 4: Checking of the Feeder Diode at L2 potential in Reverse-Biasing
Disconnect the supply cable at L2, strain the clamp L2 with a resistor of 1 kΩ (≥ 1 W) to M and
measure the reverse current of the L2 feeder diode through the load resistor (analog to figure 20).
The reverse current must not exceed 10 mA.
Connect the supply cable to L2 again.
Note:
The supply cable at L1 must be connected during the whole test step for the supply of
the neighbor cabinet!
SIPLUS PSU Power Supply Unit
Copyright (C) Siemens AG 2018
Supply cable
Einspeisekabel
IRL1
I
1k Ohm / 1W
L1 L2 M M
SIPLUS PSU
Figure 20: Checking the feeder diode in reverse-biasing
A5E00854207E
V 8.00 released
To neighbor cabinet
Zum Nachbarschrank
M M L1 L2 L1/L2
SIPLUS PSU (6DL3500-8BA)
30 V / 60 A
26 of 30
2018-05-03