(b) Visually inspect terminal boards for
(o) Refer to the Operator and Organiza-
cracks, burns, and corroded or damaged terminals.
tional Maintenance Manual and install thermal watt
(c) Inspect relays (Kl and K6) for cracks,
corrosion, and evidence of shorting.
AC Current Meter.
(d) Inspect resistor (R10) for burns, dam-
(1) Refer to the Operator and Organizational
aged leads and insecure mounting.
Maintenance Manual for AC current meter adjust-
ment, removal, cleaning, inspection, and installa-
(e) Inspect silicone rectifier (CRl) for
cracks, burns, and evidence of shorting.
(2) Test AC ammeter as follows:
(f) Inspect printed circuit for cold solder
joints, evidence of component over heating, and dam-
(a) Connect a calibrated test ammeter in
age to the polyreathane coating.
series with the generator set current meter.
(b) Connect a variable load to the gener-
ator set load terminal board.
Prior to coating, deaerate resin by
evacuating at room temperature to 5
(c) Refer to the Operator and Organiza-
to 10 Hg absolute to remove air
tional Maintenance Manual and start the generator
(g) Check all components for illegible
(d) Vary the load while comparing the
indication of the generator set current meter to that
of the calibrated test ammeter.
(h) If any circuit board component must be
replaced or encapsulating coating repaired or re-
(e) Replace generator set current meter
placed, refer to APPendiX A references for detailed
if its indication varies more than 2 percent of full
procedures. Repair/replace encapsulation by applying
scale value from the indication of the test ammeter.
a O. 007 inch (minimum) coating of polyurethane
resin (Scotchcoat 221, Minnesota Mining and Mfg.
Control Cubicle Relay Assembly.
Co. or equal).
(a) Tag and disconnect electrical leads to
Solder joints and components leads shall
not protrude more than O. 094 inch beyond
(b) Remove nut and captive washer as-
surface of printed circuit board.
(i) Solder in accordance with requirement
(4) Assembly. Assemble relay assembly in
(a) Identify any parts removed to facili-
reverse order of removal procedures.
(b) Disassemble relay assembly only as
is necessary to replace damaged or defective parts
(a) Using an ohmmeter or similar device,
by following the ascending sequence of index num-
check relay assembly continuity using figure 4-5 as
Make sure that power supply leads are
Test relay assembly as outlined in sub-
properly connected. Damage to the relay
paragraph d. (5) below prior to disassem-
assembly will result if leads are con-
nected to the wrong terminals.
(3) Cleaning, Inspection, and Repair.
(b) Connect a 120 Vat, 60 Hz power
supply to terminals 4 and 12. Using a suitable volt-
(a) Clean relay assembly with filtered
meter, measure voltage at terminals 6 and 10, Volt -
compressed air and a soft bristled brush.
age shall be 120 Vat. If voltage is not as specified,