TM 5-4520-253-13
CONTROL BOX ASSEMBLY PROCEDURES INDEX
PROCEDURE
PAGE
Inspect/Remove/Install Control Box
Inspect/Remove/Install Room Thermostat Receptacle
Inspect/Test/Remove/lnstall Circuit Breaker
Inspect/Test/Remove/lnstall RESET Circuit Breaker
Inspect Control Box Wiring Harness
Repair Control Box Harness Plug
Repair Wire Terminals
Replace Control Box Harness Wires
Inspect/Test/Remove/Install HEATER-OFF-FAN Switch
Remove/Install HEAT and FAULT Lights
Inspect/Remove/Install Power Receptacle and External Fuel Pump Receptacle
Inspect Printed Circuit (PC) Board Assembly
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l N S P E C T / R E M O V E / l N S T A L L C O N T R O L B OX
TOOLS: Tool kit, service, refrigeration unit
NSN 5180-00-596-1474
REFERENCES: Table 3-2 for cleaning procedure for control box.
GENERAL SAFETY INSTRUCTIONS:
Power off.
Heater cool.
INSPECTION :
Death or serious injury could occur if precautions are not
taken when maintaining this equipment. Position HEATER-
OFF-FAN switch to OFF, remove power cable plug from
POWER RECEPTACLE, and ground capacitors C1 and C2
prior to gaining access to heater compartments. Terminals
of capacitors are accessible at end cover of combustion
blower. Always disconnect power cable before making con-
tinuity tests or before repairing heater. Always have
another person standing by who is trained in electric shock
first aid.
Allow sufficient time for heater to cool to room tempera-
ture before gaining access to heater compartments.
1. Release stud (1) in control box cover and open control box as shown. Check RESET circuit breaker
(2), circuit breaker (3), FAULT light (4), HEAT light (5), HEATER-OFF-FAN switch (6}, and
room thermostat receptacle (7) for security.
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