CONDENSER FAN AND MOTOR ASSEMBLY. (B-2)

TM 5-4120-369-14

EVAPORATOR FAN AND MOTOR ASSEMBLY (B-3) - Continued

4-32.

Installation.

(1) Assemble the fan and motor assembly as follows:

(a) Install fan housing and secure in place with 4 screws.

(b) Install impeller and secure in place with 1 nut.

(d) Install motor and secure in place with 4 screws.

(e) Slide fan into place and secure with 2 setscrews.

(f) Install 2 clamps and secure in place with screws.

(2) Install evaporator fan and motor assembly as follows:

Slide fan/ motor assembly into place, secure in place with 4 allen head

(a)

mounting screws.

Install 2 set screws holding fan in place.

(b)

Install thermocouple, secure with 2 clamps and screws.

(c)

Reconnect connector.

(d)

(3) Refer to paragraph 4-19 and install the evaporator air inlet louver.

CONDENSER FAN AND MOTOR ASSEMBLY. (B-2)

General. The condenser fan motor is a multispeed motor . The motor operates at 3450

RPM in high and 1725 RPM in low speed. The motor contains separate windings for high or

low speed operation and each winding is thermally protected. Motor speed is automatically y control-

led by an outdoor thermal switch (FO-1). o The motor will operate at low speed until the out-

door ambient temperature rises above 100 F 5F (37.8C 3C).

Before removing condenser fan motor, test mode selector switch and control

Test.

circuit breaker (paragraph 4-28) and the fan motor high/low speed switch (paragraph 4-28) that

control operation of the condenser fan motor. If electrical control components or wiring that

supply power to the motor are not defective and the motor does not operate, remove the conden-

ser fan and motor assembly and make the following tests:

(1) Test the high and low motor winding thermal protectors, using a multimeter, test

for continuity across each terminal connection. If continuity is not indicated, the thermal pro-

tector is defective and motor must be replaced.

(2) With the high and low speed motor winding leads disconnected from the thermal

protectors, test for open or grounded windings as follows:

(a) Using a multimeter, test for continuity across a combination of two leads until

each of the three high speed winding leads is tested. Do the same for the three low speed wind-

ing leads. If continuity is not indicated, the winding is open and the motor should be replaced.

(b) Using a multirneter, test for continuity by placing one test probe against the

motor housing (on bare metal only) and the other probe against each of the motor winding leads.

If continuity is indicated, the winding is grounded and the motor should be replaced.