ARMY TM 9-4120-380-14
AIR FORCE TO 35E9-136-21
4.41 TIME DELAY RELAYS (TRI AND TR2). This task covers inspection, testing, removal and installation
Disconnect input power to the air conditioner before performing any internal
maintenance. Voltages used can KILL Shutting the unit off at the control panel dies not
disconnect unit power.
(1) Disconnect air conditioner input power at source; and
(2) Remove control box assembly (paragraph 4 27).
a. Check for loose wire connections (see fig 4-32)
b. Check for cracks, signs of overheating, and other visible damage. Replace if damaged
Check external resistor (3) for signs of overheating Replace if damaged.
Pull relays TRI and TR2 (1) from sockets (2).
b. Using multimeter, measure resistance across external resistor (3). Resistance should be 285-315K for TR1 and
712-788K for TR2.
Terminal A to B'
Terminal 1 to 7:
Terminal 3 to 9
d. Plug relays (1) back into sockets (2).