TM 9-4110-258-13
4.26 CONTACTOR (POWER RELAY) K2 TESTING AND REPLACEMENT.
This task covers:
a. Testing
b. Removal
c. Installation
INITIAL SETUP
Materials/Parts:
Equipment Conditions:
Lock Washers (4)
Refrigeration unit shut down (para 2.7) and power
6, Appendix G
disconnected.
Marker Tags (8)
Control box cover door raised and latched.
7, Appendix E
General Safety Instructions
WARNING
High voltage and exposed rotating parts are
used in the refrigeration unit. Personal injury
can result if power is connected.
a.
Testing. (See Figure 1-4.)
(1) Be sure power has been disconnected at the source and remove six screws (1). Open control box cover
(2)
(2) Press and hold plunger (3).
(3) Using multimeter set to measure continuity, check each contactor (4) contact continuity between terminals
L1 to T1, L2 to T2, and L3 to T3. Continuity should be indicated.
(4) Release plunger (3).
(5) If no continuity was indicated, replace contactor (4).
(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 (4).
(7) Using multimeter set to measure continuity, check each contactor (4) 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 (2) and install six screws (1).
b.
Removal..
(1) Be sure power has been disconnected at the source and remove six screws (1). Open control box cover
(2).
(2) Tag and disconnect wire leads (5).
(3) Remove four bolts (6), lock washers (7), flat washers (8), and contactor (4). Discard lock washers.
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