Testing. - TM-5-4320-234-340056

TM 5-4320-234-34

(11) Inspect the slip rings for cracks, wear

fumes and prolonged exposure of skin to

grooves, damaged or loose lead connections, or other

cleaning-solvent.

Wash exposed skin

damage. You can restore a smooth surface to the slip

thoroughly.

Dry cleaning solvent (fed.

rings with fine crocus cloth. Wipe all residue from slip

spec. P-D-680) used to clean parts is

rings. Replace the slip rings if they are too worn to be

potentially dangerous to personnel and

reused.

property. Do not use near open flame or

excessive heat. Flash point of solvent is

(12) Inspect the rotor bearings for wear,

100 to 138 F (38 to 59 C).

catching or binding operation, or missing or damaged

seals. Replace the bearings if defective. While the

(2) Use a cloth dampened with cleaning

bearings are off the rotor shaft, you should inspect the

solvent (fed. spec. P-D-680) to clean the diode

shaft bearing surfaces for wear.

assemblies, stator, and rotor. Wipe dry.

(13) Inspect the rotor shaft and body for

(3) Wipe the bearings with a cloth, taking

stripped threads, worn key slot, cracked or marred pole

care that you do not disturb the bearing seals.

fingers and shaft. Replace a damaged rotor.

(4) Clean all remaining parts with cleaning

(14) Inspect all other parts for cracks,

solvent; dry thoroughly.

distortion, or damaged threads. Replace all damaged

parts.

(5) Inspect and test the brush assembly as

directed in sub-paragraph b above.

Testing.

(6) Inspect the pulley for cracks, groove

NOTE

wear, and damage to the keyway. Replace a damaged

pulley.

Use only rosin core solder to solder diodes

to the stator leads. If you use acid core

(7) Check the fan for bent or missing fins

solder, the connection will corrode,

and mounting hole wear. Replace if damaged.

resulting in an open circuit and damage to

the components.

(8) Inspect all insulating sleeves and

washers for cracks, separations and other damage.

(1) Test the diodes with a diode tester

Replace as necessary.

according to the instructions of the equipment

manufacturer. To test, it will be necessary for you to

(9) Inspect the front and rear housings for

unsolder the leads from the stems of the positive and

cracks, bearing bore wear, distortion, damaged threads,

negative diode assemblies for individual testing. When

and other obvious damage. You should remove any

you solder and unsolder leads from the diodes, use long

burrs with a fine stone or file. Replace either housing if

nose pliers to grasp the diode stem between the diode

not reparable.

and the stator lead to be removed. This will give better

heat dissipation and protect the diode from damage.

(10) Inspect the stator for gouged or

You should make note of the diode to stator lead

discolored windings.

Discoloration of the winding

connections to facilitate reassembly. If one diode is

insulation is an indication of an overheated stator that

bad, you must replace the entire diode assembly. The

may result in shorted or grounded windings.

positive diode assembly has red printing on the diode

body; the negative diode assembly has black printing.

Refer to figure 3-9.

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