
116 SEBU8088-06
Maintenance Section
Space Heater - Check
a. Placetheredte
st lead on the negative “-”
terminal. Place the black test lead on the
following rectifier terminals: “AC1”(3), “AC2”(4),
and “AC3”(5).
All readings on the meter should
be between 0.4 and 1.0.
b. Place the bla
ck test lead on the negative
“-” terminal. Place the red test lead on the
following rectifier terminals: “AC1”(3), “AC2”(4),
and “AC3”(5)
. In all cases, the meter should
read “OL” (overload).
3. To test the po
sitive rectifier block, follow these
steps:
a. Place the red
test lead on the positive “+”
rectifier terminal. Place the black test lead
on the following rectifier terminals: “AC1”(3),
“AC2”(4), a
nd “AC3”(5). In all cases, the meter
should read “OL” (overload).
b. Place the b
lack test lead on the positive “+”
rectifier terminal. Place the red test lead on the
following rectifier terminals: “AC1”(3), “AC2”(4),
and “AC3”(
5). All readings on the meter should
be between 0.4 and 1.0.
Note: Asho
rted diode can cause damage to the
exciter rotor. If a diode is shorted, check the exciter
rotor. Refer to the Testing and Adjusting, “Winding -
Test ” and
Testing and Adjusting, “Insulation - Test”.
Perform these tests.
Note: Thi
srectifier block also contains varistor “CR7”.
“CR7” can be checked by measuring the resistance
between the positive “+” rectifier terminal and the
negativ
e“-”rectifier terminal. The resistance should
be a minimum of 15000.
i02985289
Space Heater - Check
SMCS Cod
e: 4450-535-HTR
The space heater is attached to the rear bearing
bracket
. The space heater is located in the
generator’s exciter end.
g00610396
Illustration 72
Space Heater Connec tion Diagram
An SR5 generator can operate in high humidity
conditions without problems. The humidity can be as
high as 100% non-condensing humidity. However,
problems can occur when the generator is idle and
the surrounding air is warmer than the generator.
Moisture can form on the windings. Moisture will
result in poor performance or even damage to the
windings. Whenever the generator is not active, the
optional space heaters should be operated.
An external source is required to operate the space
heaters. Both of the sources must be a single phase.
This source can be either 115 vac or 230 vac. When
the external source is 50 hertz, 200 vac must be
used. Refer to Illustration 72.
See your Caterpillar dealer for information on
checking your Caterpillar generator.
i0262754
7
Speed Sen so r - Clean/Inspect
SMCS Code: 1907-040; 1907-070
The C32 Ge
nerator Set has three different speed
sensors.