TM 9-4110-256-14
4-25. CONTACTOR (POWER RELAY) K2 TESTING AND REPLACEMENT.
This task covers:
a. Testing
b. Removal
c. Installation
INITIAL SETUP
Materials/Parts:
Equipment Conditions:
Lock Washers (2)
disconnected.
Lock Washers (4)
Control panel cover open.
Marker tags (9)
General Safety Instructions:
WARNING
High voltage and exposed rotating parts are used in
the refrigeration unit. Personal injury can result if
power is connected.
(1)
Be sure power has been disconnected at the source and remove two bolts (1) and lock washers (2). Open
control box cover (3). Discard lock washers.
(2)
Press and hold plunger (4).
(3)
Using multimeter set to measure continuity, check each contactor (5) contact continuity between terminals
L1 to T1, L2 to T2, and L3 to T3. Continuity should be indicated.
(4)
Release plunger (4).
(5)
If no continuity was indicated, replace contactor (5).
(6)
Using multimeter set to measure continuity, check coil continuity between terminals Al to A2. Continuity
should be indicated. If no continuity was indicated, replace contactor (5).
(7)
Using multimeter set to measure continuity, check each contactor (5) contact continuity between terminals
L1 to T1, L2 to T2, and L3 to T3. No continuity should be indicated. If continuity was indicated, replace
contactor.
(8)
If no failure was indicated, close control box cover (3) and install two new lock washers (2) and bolts (1).
b. Removal.
(1)
Be sure power has been disconnected at the source and remove two bolts (1) and lock washers (2). Open
control box cover (3). Discard lock washers.
(2)
Tag and disconnect wire leads (6).
(3)
Remove four bolts (7), lock washers (8), flat washers (9), and contactor (5). Discard lock washers.
4-50