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DPU1U SERIES
INSTALLATION & OPERATING MANUAL
P O W E R I N G T E C H N O L O G Y
Document Number: DPU1U-MAN Rev. 4
dpu1u-man-rev1-0719.indd
12.0 SETUP AND TESTING
It is not necessary to have the combination panel mounted in a rack for initial testing.This can be
done on a bench. It is also not necessary to have loads connected to the panel for this testing.
12.1
Distribution Sections
12.1.1
With the input power source off, connect the input wires to the A side of the
combination panel. Connect ground to the chassis ground terminal. Insert all fuses into
fuse holders or set all circuit breakers to on.
12.1.2
Turn on the input power source. The A side LED should be green. If it is red, one of
the fuses is blown or a circuit breaker is tripped. If the LED is off, there is no input power
to the unit. Check the output voltage at each set of output terminals with a digital voltmeter.
12.1.3
With the A side LED green, use an ohmmeter to check the Form C relay contact
outputs. Measure the resistance between C and N.C. This should read “open”. Measure
the resistance between C and N.O. This should read “short”.
12.1.4
On the A side insert a blown fuse into fuse no. 1 position or trip circuit breaker no.
1. The A side LED should turn red. On the side A alarm terminals, measure the resistance
between C and N.O. This which should read “open”. Measure the resistance between C
and N.C. This should read “short”. Replace the blown fuse with a good one or reset the
circuit breaker.
12.1.5
On the A side check each succeeding fuse by replacing it with a blown fuse, or
breaker by tripping it, and verify that the LED turns red. It is not necessary to recheck the
Form C relay contacts.
12.1.6
Repeat the same tests of Sections 12.1.1 through 12.1.5 on the B side of the
combination panel when another distribution section is fitted. Refer to table 5.
12.2
LVD Section
12.2.1
Set an unconnected bench-type DC power supply with digital voltage display to
48VDC if a 48V LVD is being set up or to 24VDC if a 24V LVD is being set up. Turn the
power supply off.
12.2.2
Connect the power supply the input bus bars on the back of the LVD section. Connect
the minus output to REC and the plus output to RTN. It is not necessary to make connection
to the Battery or Load bus bars terminals for this test. Make sure the battery circuit breaker
is “on”. If there is a bypass switch make sure it is “off”.
12.2.3
Turn the power supply on. The LED for side B (right one) should be off. Reduce the
power supply output voltage slowly while observing the output voltage. At approximately
42.5V for the 48V version or 21.5V for the 24V version the red LED should turn on. With
an ohmmeter, measure the resistance between side B alarm terminals N.O. and C. It should
measure a short.
