TM 9-4110-258-13
4.21 HOURMETER M1 TESTING AND REPLACEMENT.
This task covers:
a. Testing
b. Removal
c. Installation
INITIAL SETUP
Materials/Parts:
Equipment Conditions:
Self Locking Nuts (2)
Refrigeration unit shut down (para 2.7) and power
8, Appendix G
disconnected.
Marker Tags (2)
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) Using multimeter set to measure continuity, check hourmeter (4) continuity between terminals 1 and 2
Continuity should be indicate. If no continuity was indicated, replace hourmeter.
(3) 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).
NOTE
Terminal hardware is supplied with hourmeter
(2) Tag wire leads (4) and remove two screws (5), lock washers (6), and wire leads.
(3) Remove two self locking nuts (7), bolts (8), and hourmeter (3). Discard self locking nuts.
c.
Installation..
(1) Install hourmeter (3), two bolts (8), and new self locking nuts (7).
(2) Using tags and wiring diagram (fig. 1-4), install wire leads (4), two lock washers (6), and screws (5).
Remove tags.
(3) Close control box cover (2). Install two screws (1).
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