TM 9-6115-669-13&P
h.
Loosen four nuts (20) and remove PDU electronic N6 (19).
N O T E
The four overcurrent detection boards are identical and interchangeable
with one another.
INSPECTION
Inspect for damage and discoloration due to heat.
TEST
a.
Test PDU electronic assembly N6 (19) with test equipment in accordance to figure 6-38.
b.
Use multimeter to check the following voltages:
(1)
24 VDC operating voltage between (+) and 0 V.
N O T E
Step (2) applies only to operation with commercial power converter.
(2) 24 VDC voltage between +S and 0 V when K12 is excited, i.e. synchronization on.
(Relay K13 must be energized): +24 VDC between Sy and 0 V.
(3)
208 VAC at all times between R’ and S’.
N O T E
The current transformer, installed on a conductor, transforms the
present value of current in this conductor in a defined linear ratio of
150:l.
The voltage drop at the appropriate connected resistor is the equivalent
of the present value of current in the conductor. Following the formula
below a current of 50 A in the conductor will cause a voltage drop of:
U=
1 A x 1x[A] x 1.5 Ohm =
150A
1 A x 50 A x 1.5 Ohm = 1 X 50 A X 1.5 Ohm = 75 V = 0.5 V
150A
150
(4) Adjust voltage at inputs R, S, T and check overload release
Release must occur as follows:
At 1.2 times rated value JL= 156 A, with a delay of < 2.5 seconds.
At 1.8 times rated value JL= 234 A, with a delay of < 1.5 seconds.
When overload release occurs, the following relays are set:
Release at J1: + 24V DC between J1 and AK (relay K16 energized)
Release at J2: + 24V DC between J2 and AK (relay K17 energized)
Release at J3: + 24V DC between J3 and AK (relay K18 energized)
Release at J4: + 24V DC between J4 and AK (relay K19 energized)
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