TM 9-4110-258-13
4.41 ELECTRIC HEATERS HR1. HR2. AND HR3 TESTING AND REPLACEMENT.
This task covers:
a. Testing
b. Removal
c. Installation
INITIAL SETUP
Materials/Parts:
Equipment Conditions:
Self Locking Nuts (12)
Refrigeration unit shut down (para 2.7) and power 14,
disconnected.
Self Locking Nuts (4)
General Safety Instructions:
8, Appendix G
Marker Tags (6)
WARNING
7, Appendix E
High voltage and exposed rotating parts are
used in the refrigeration unit. Personal injury
can result if power is connected.
a. Testing. Be sure power has been disconnected at the source and using multimeter set to measure continuity,
check each electric heater (1) continuity between terminal ends A and B. Continuity should be indicated. If no
continuity was indicated, replace electric heater.
b. Removal.
(1) Be sure power has been disconnected at the source and remove 12 self locking nuts (2), flat washers (3), bolts
(4), and flat washers (5). Discard self locking nuts.
(2) Carefully remove heater frame (6) as far as wire leads (7) will reach.
(3) Tag and disconnect wire leads (7).
(4) Remove four self locking nuts (8), flat washers (9), bolts (10), flat washers (11), and heater keeper plate (12).
Discard self locking nuts.
(5) Remove three electric heaters (1).
c. Installation.
(1) Install three electric heaters (1).
(2) Install heater keeper plate (12), four flat washers (11), bolts (10), flat washers (9), and new self locking nuts (8).
(3) Using tags and wiring diagram (fig. 1-4), install wire leads (7). Remove tags.
(4) Install heater frame (6) and align mounting holes.
(5) Install 12 flat washers (5), bolts (4), flat washers (3), and new self locking nuts (2).
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