ARMY TM 9-4120-380-14
AIR FORCE TO 35E9-136-21
ELECTRICAL HEATERS (HR1 AND HR2). This task covers inspection, testing, removal and installation.
Tool kit, service, refrigeration unit (Item 1, Appendix B)
Disconnect input power to the air conditioner before performing any miternal
maintenance. Voltages used can KILL. Shutting the umt off at the control panel does
not disconnect unit power
(1) Disconnect air conditioner input power at source; and
a. Remove two screws (1), lockwashers (2), flat washer (3), and plastic cover (11) (see fig 442).
b. Check heater elements for deformation, damaged terminals, damaged threads, cracked or broken parts.
Replace if damaged.
Disconnect one lead to heater
b. Using multimeter, check for continuity between two terminal studs of each element Replace element if no
Use two wrenches to ensure that the terminal stud does not turn, to prevent ceramic
a. Tag leads.
b. Remove nut (4), lockwasher (5), two flat washers (6) and wire leads (7) from heater element (8).
c. Remove nut (9) securing heater element (8) to plate (10).
d. Remove heater element (8) from plate (10).