Removal and Replacement of Power Transformer A7T1

TM 11-5895-1179-13 EE132-EA-OMP-010/E106 KY883 TO 31S1-2GSC-161

Note dressing of leads with respect to keying bracket. Disconnect fan leads at A7TBl-9 and -11 (figure 5-2).

c. Remove the four hex screws and washers which attach the fan assembly A5B1 to the rear panel assembly A5

(figure 5-4). Cut the tiedown straps as necessary and remove the fan assembly.

d. If the fan assembly is to be repaired, replace the defective component.

e. Position the replacement fan assembly against the rear panel so that the leads are at the bottom of the

mounting hole and secure the fan assembly with the four screws and washers removed in step c.

f. Dress the fan leads as noted in step b and connect the fan assembly leads to A7TBl-9 and -11 (figure 5-2).

Use tiedown straps to replace those removed in step S.

g. Install the four plug-in-circuit card assemblies (paragraph 4-7) and the chassis cover (paragraph 5-6). Install

the terminal board cover on A7TB1.

Close and secure the front panel assembly.

i. Ensure that the fan is drawing air through the chassis.

5-11.

Removal and Replacement of Power Transformer A7T1

a. Remove the chassis cover and the four plug-in-circuit card assemblies as described in paragraphs 5-6 and

4-7, respectively.

b. Make certain capacitors A7Cl and A5C1 (figures 5-5 and 5-6) are discharged. Remove the terminal board

cover from A7TB1 and disconnect transformer leads at A7TBl-1, -3, -6, -13, and -15 (figure 5-2).

c. Remove the four nuts and washers which attach tne transformer to the bottom panel assembly (figure 5-5).

Remove the ground lead on the forward inboard mounting stud. Cut the tiedown straps that are associated

with the A7T1 leads. Remove A7T1 by lifting it directly upward from the mounting studs.

d. Set the replacement transformer in place on the mounting studs with the leads correctly oriented and

reconnect the ground lead to the inboard mounting stud. Install the four nuts and washers removed in step c.

e. Connect the replacement transformer leads at the A7TB1 terminals as indicated in figure 5-2. Install the

terminal board cover on A7TB1. Dress leads into A7W1 harness assembly and replace tiedown straps

removed in step g.

f. Install the four plug-in-circuit card assemblies (paragraph 4-7) and the chassis cover (paragraph 5-6).

g. Close and secure the front panel assembly.

5-12.

Removal and Replacement of Clamping Block A6MP2

a. Release the four front panel assembly fasteners (figure 2-1) and lower the front panel assembly. Remove the

two screws, flat washers and lock washers holding the clamping block to the front panel assembly (figure 5-3).

Remove the clamping block.

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