Table 2-2. Generator Set Troubleshooting (Cont)
Malfunction
Probable cause
Corrective action
27.
Generator runs at 130
a.
Defective overload
a.
Replace K14 (para 8-6
—
percent or more
relay (K14).
and 8-7).
rated current for
longer than 10 minutes,
b.
Defective re-
b.
Replace resistor R23, R24 or
CB2 does not open and
sisters R23, R24
R25, if ohmmeter test indi-
overload indicator does
or R25.
cates defect (fig. 8-2 and 8-3).
not light.
c.
Defective current
c.
Replace defective current’
transformer CT1,
transformer CT1, CT2 or
CT2 or CT3.
CT3 (para 6-7 thru 6-8).
28.
Generator runs at
Defective overvoltage
Replace overvoltage relay (para 8-6
overvoltage (130
relay K2.
and 8-7).
percent. Set does
not shut down and
overvoltage indi-
cator does not light.
29.
Generator runs
Defective undervoltage
Replace undervoltage relay K11
under voltage (85 percent
relay Kilo
(para 8-6 and 8-7).
of rated voltage or less).
CB2 does not open and
undervoltage indicator
does not light
(Class I only)
30.
Percent power meter
Reverse power relay
Measure dc voltage at K15 terminals
reads down scale with
(K15) defective.
3 and 4. It should be 24 volts
2 or more sets paral-
(positive on terminal 3). Check
leled.
for Vdc at pins 1 and 2. If 2 or
more Vdc are present with 1 positive
replace reverse power relay (para
8-6 and 8-7).
31.
Set starts but will not
a.
System fault as
a.
Correct indicated fault.
—
run unless protection
indicated by
bypass switch (S7)
fault indicator
is closed.
panel.
b.
If no lamp is il-
b.
Replace any defective lamps.
luminated, press
fault indicator
test switch to
ensure that all
lamps are working.
NOTE
If the corrective action in a and b above does not correct
the malfunction, proceed to determine if one of the fol-
lowing components are defective by placing jumpers
across their contacts as follows:
c.
Overvoltage
c.
Terminals 3 and 4 of K2.
relay K2.
d.
Low oil pressure
d.
Terminal 3 of K2 and 4 of AS.
switch OP and high
coolant temperature
switch WT.
Change 5
2-17
