Section Ill. GENERAL SUPPORT MAINTENANCE OF PU-545/A
and lead connections. Use enough heat to make a well-
a. Clean the inverter according to the instructions in
soldered connection. A poor solder joint that causes
faulty operation is difficult to locate,
b. Generator Section. Repair
of the generator sec-
The fumes of TRICHLOROETHANE are tox-
tion is also a matter of replacement of defective parts.
ic. Provide adequate ventilation whenever it
Procedures for disassembly, including exploded
is used; avoid prolonged or repeated breathing
of vapor. Do not use near an open flame or hot
4-9. Removal of Regulator Section
surface; trichloroethane is nonflammable but
heat converts the fumes into a highly toxic
a. Turn fastener studs (2 and 3) one-quarter turn and
phosgene gas the inhalation of which could
lift regulator housing cover (4) from regulator housing
result in serious injury or death. Prolonged or
(52). Remove grooved pins (1) from fastener stud only if
repeated skin contact with trichloroethane
replacement is required.
can cause skin inflammation. When neces-
b. Remove two machine screws (5) and two lock-
sary, use gloves, sleeves, and aprons which the
washers (6); remove terminal board cover (7), and ac
solvent cannot penetrate.
plug cover (7A).
b. If the generator section is disassembled, wipe the
armature and stator coils with a cloth dampened with
and 12), and two flat washers (10 and 13) to disconnect
trichloroethane, and clean thoroughly with a brush. Do
electrical leads from terminal board TB3 (38). Remove
not soak the assemblies in the trichloroethane. After
one nut (14), lockwasher (15) and flat washer (16) to
cleaning, dry out the armature and stator assemblies
detach electrical lead (17) from terminal board TB3.
by baking them for 2 to 4 hours at 200 F (93 C).
Lift off terminal connecting links (18 and 19).
4-8. General Parts Replacement Tech-
washers (22), and machine screws (23 ) to detach dc
a. Regulator Section. Most repair parts of the
leads from terminal board TB1. Remove one nut (24),
regulator section can be removed and replaced easily.
lockwasher (25), and flat washer (26) to free electrical
Disassemble if necessary, according to instructions in
lead (27) and other ground leads from shouldered stud.
Remove insulation sleeving from shouldered stud
to see that replacement parts are available; observe the
(28A). Unscrew and remove stud, freeing lower
washers (25 and 26).
(1) Disconnect the inverter from the power source
e. Remove machine screw (29), lockwasher (30), flat
before beginning repair.
washer (31 ), and loop clamp (32), from terminal board
(2) Before a part is unsoldered, observe the posi-
TB2 (2, fig. 4-6) freeing circuit card leads.
tion of all leads to that part, and identify each one that
f. Remove four screws (33, fig. 4-3) and four flat
is to be removed with reference to its soldered terminal.
washers (34), and lift out the regulator (38A or 38 B).
Tag each lead, or draw a small sketch of the wiring to
the component and note the color coding and lead
tions for removal of each of the various models
(3) Use a pencil-type soldering iron and a heat-
of the regulator.
sink (such as long-nosed pliers) when soldering and un-
The regulator and base are removed as a unit
soldering leads, to prevent damage to adjacent compo-
and should be disassembled only if repair is
(4) Where defective parts must be replaced, use
identical replacement parts. The new part must be
g. Remove four machine screws (37) and flat
mounted in the same position as the one it replaces.
washers (37A) and lift out terminal board TB
(5) Before soldering, carefully clean the terminals