Section Il. REMOVAL AND INSTALLATION OF COMPONENTS

tion of condensation on the inside walls of the

HEAT position, the remaining heaters are ener-

tubing. Plug or cap all openings as a part is re-

g i z e d , providing maximum heating capacity

moved to minimize the entry of dirt and moisture.

(12,000 BTUH).

c. Use a silver solder on all soldered connections.

5-3. Repair Procedures

Easy-Flo silver solder (or equivalent) with a 50

percent silver capacity and a melting point of ap-

a. If the system must be opened for repair or

proximately 1160F. is recommended. Continually

replacement of parts, connect a hose line to the

pass dry nitrogen through the tubing or connec-

suction service valve and purge the refrigerant to

t i o n s being soldered to prevent formation of

an outside area.

harmful copper oxides.

b. After purging the system allow the tubing to

d. No metal to metal contact on capillary tubes

warm to the ambient temperature before opening

is allowable; use tape to prevent such contact.

the system; this delay will help prevent the forma-

Section Il. REMOVAL AND INSTALLATION OF COMPONENTS

c. Disassembly. Refer to figure 5-2, and disas-

5-4. Blower Fan Motor

semble the blower motor.

a. On-Equipment Testing. Before removing the

d. Testing.

motor for replacement, test the motor windings

for opens and grounds:

(1) Overload protector. Disconnect the elec-

(1) Disconnect receptacle connector from

trical leads from the overload protector. Test the

motor junction box.

protector with a multimeter set on OHMS. If con-

(2) Test continuity across each combination

tinuity does not exist, replace the overload pro-

of two motor terminals. Lack of continuity indi-

tector.

cates an open winding.

(2) Motor bench test. Perform the growler

(3) Place one contact of the tester against

tests on the stator as instructed in TM 5764. Re-

motor housing and the other against one of the

place a defective stator.

motor terminals. If a circuit is indicated, the

e. Cleaning, Inspection and Repair.

motor is grounded.

(4) Test the motor stator for insulation resis-

(1) Clean all parts with a cloth dampened in

tance as instructed in TM 5-764. The insulation

approved cleaning solvent.

resistance should measure not less than 0.5 meg-

(2) Inspect the stator housing for cracks,

ohms for the motor on either model.

breaks, or other defects. Replace a damaged or

Note. The resistance measurement should be

defective housing.

used only as a general guide, taking into consideration the

(3) Inspect bearings for pits, scoring, wear,

accuracy of the instrument used, test lead resistance, and

ambient temperature at time of test. If more precise

and out-of-round. Replace worn or defective bear-

measurement is required, an instrument such as a Kelvin

ings.

or Whetstone bridge should be used, or comparative

(4) Inspect the rotor shaft for cracks, wear,

measurement between the suspected component and a like

item known to be good should be utilized. In all cases where

and misalinement. Replace a damaged or defective

a megohmeter is used for testing, make certain that the

rotor. -

unit is thoroughly dry. Wet condemnation tolerances

(5) Inspect the rotor for cracks, breaks, and

should be considered.

damaged laminations. Replace the rotor and stator

(5) Connect the motor leads to a proper

if they are damaged, Replace the stator if it does

source of power. Use a hook-type ammeter and

not meet test standards (d above).

read the amperage flowing in each of the motor

(6) Inspect all threaded parts for damage.

leads. On Model CE20VAL4 the ammeter should

Replace as necessary.

indicate between 1.45 and 2.2 amperes at no load.

The ammeter should indicate between 1.75 and 2,5

f. Reassembly. Refer to figure 5-2, and reas-

amperes at no load on Model CE20VAL6. Start

semble the blower motor.

the unit and check the ammeter reading. If the

g. Installation. Refer to paragraph 3-25, and

readings are not equal, the motor bearings are

install the blower motor.

worn or the stator winding is defective. Follow

the instructions in c below and disassemble the

5-5. Power Receptacle Connector

motor for further testing and repair.

b. Removal. Refer to paragraph 332, and

a. Removal. Refer to figure 53, and remove the

remove blower motor.

power receptacle connector.

AGO 20053A