Table 5-1. Troubleshooting - TM-5-4120-352-140081

TM 5-4120-352-14

Each trouble symptom or malfunction stated is fol-

5 - 5 . Troubleshooting Chart

lowed by a step-by-step procedure for inspecting and

Troubleshooting procedures for direct and gen-

testing the system to determine the specific cause

eral support maintenance are listed in table 5-1.

of fault or failure. The corrective active recommen-

ded follows the determination of probable cause.

Table 5-1. Troubleshooting

Malfunction

Test or Inspection

Corrective Action

1. COMPRESSOR WILL NOT START

Test for an open-circuit condition in the control circuit by means of a continuity check

Step 1.

Replace component or wire causing open circuit (para 4-12).

Test circuit breaker for defective operation.

Step 2.

RepIace defective circuit breaker (para 4-43).

Step 3.

Check to see if high or low pressure cutout switch is defective

Replace defective switch (para 5-21).

Check to see if compressor motor or thermal protectors are defective.

Step 4.

Replace compressor (para 5-17).

2. COMPRESSOR STARTS BUT IMMEDIATELY STOPS

Check to see if thermal protector or circuit breaker is tripped.

Step 1.

Reset circuit breaker, or allow thermal protector to cool and reset. If condition repeats, replace

compressor (para 5-17).

3. LITTLE OR NO HEATING CAPACITY.

Check for loose electrical connections or faculty wiring.

Step 1.

Repair or replace wiring as necessary (para 4-33).

Test mode selector switch and temperature selector for faulty closure in heat control circuit

Step 2.

Replace defective switch (para 4-42).

Test heater relay for faulty contact closure

Step 3.

Replace defective relay (para 4-43).

Step 4.

Test for defective operation of heater high temperature cutout.

Replace defective thermostatic switch (para 4-34).

Step 5.

Test heater for open-circuited element.

Replace defective heaters (para 4-35).

5-3