TM 9-6115-669-13&P
k. Remove two nuts (21). two serrated washers (22) and resistor R21 (20).
NOTE
This procedure is the same for all resistors R21 to R32 (Example R21)
and transformers T1 to T12 (Example T1).
a. Test resistor R21 (20):
(1) Remove screw (14), lock washer (15), cable clamp (16) and cable.
(2) Use a multimeter to check resistor R21 (20). Resistance must be 1.5 Ohm.
NOTE
The current transformer, installed on a conductor, transforms the
present value of current in this conductor in a defined linear ratio of
150:1.
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=
1A X 1 x [A] X 1.5 Ohm
= 1 A X 50 A X 1.5 Ohm
= 1 x 50 A x 1.5 Ohm
75V
150A
150A
150
=
150
= 0.5 V
b. Test transformer T1 (13):
(1) Ensure good contact for cables of resistor R21 (20).
(2) Connect a multimeter at terminals of R21 (20) to measure AC voltage.
(3) Slide a suitable conductor through opening in transformer T1 (13) and connect to a
suitable AC power supply.
(4) Switch on power supply, set a current of 50 A and read the indicated AC voltage on
multimeter.
a.
When replacing current transformer T1 (13), install two screws (25), two serrated lock
washers (24) on current transformer and screw on nuts (23).
b.
Place resistor R21 (20) with plate on current transformer T1 (13).
c.
Install two serrated lock washers (22) and screw on two nuts (21). Tighten nuts (21).
d
Install current transformer T1 (13) and resistor R21 (20), screws (17), serrated lock washers
(18), and washers (19).
e.
Insert cable 79 end (11) through center of current transformer T1 (13).
f.
Install cables to current transformer T1 (13), using two screws (14), two serrated lock washers
(15), and two cable clamps (16).
g.
Install cable 79 end (11), washer (10), serrated lock washer (9) and screw (8) on bus bar (12).
h. Install cable 79 end (11) to contactor K3. Refer to paragraph 5.10.
i.
Install protective cover (7) and secure with screw (4), serrated lock washer (5) and washer (6).
j. Remove stanchion.
k. Stow prop (3), close access door (2) and secure.
l.
Install stanchion by PDU (1).
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