Condenser Fan Motor (B2)

TM 5-4120-393-14

4-60. Condenser Fan Motor (B2)

This task covers:

a. Removal

c. Testing

b. Inspection

d. Installation

Initial setup.

Tools:

Tool kit, ser vice, refrigeration unit NSN 5180-00-596-1474

Personnel: 2

Equipment condition:

1. Turn unit power off at power source. If there is a chance that it will be turned on, also disconnect power cable

to air conditioner.

2. Remove condenser fans. See para 4-59.

General Safety Instructions:

WARNING

Disconnect input power to the air conditioner before performing any internal

maintenance. Voltages used can KILL. Shutting the unit off at the control panel

does not disconnect unit power.

INSPECTION/TESTING (INSTALLED)

Check motor for rotational freedom by spinning fans. If there is any stiffness or binding, contact Intermediate Direct

Support Maintenance.

Check motor bearings for lateral or end play. If the re is excessive lateral or end play, contact Intermediate Direct

Support Maintenance.

Electrically test motor at connector J2 as follows.

Disconnect motor cable connector P2.

Use a multimeter set on lowest OHMS scale to check continuity between pins A and B, A and C, and B and C in

the connector. If there is no continuity between any pair of pins, the motor winding is open. Replace motor.

Use a multimeter set on lowest OHMS scale to check for continuity between each pin in connector (A, B, and C)

and the motor housing. If there is continuity between any pin and motor housing, the motor winding is shorted.

Replace motor.

Use a multimeter set on high OHMS scale to test stator insulation by checking between each pin in connector (A,

B, and C) and the motor housing. A reading of less than 500,000 ohms indicates insulation failure. Replace

motor.

Check continuity between pins D and E. If there is no continuity, this indicates an open thermostat. Contact

Intermediate Direct Support Maintenance.

4-137