4-38. CONTROL CUBICLE ASSEMBLY.
a. Test, On Equipment (see figure 4-33).
When disconnecting leads from terminals, tape
leads to prevent electrical shorts.
(1) Control Cubical. Perform operational test on con-
trol cubicle, checking for proper operation in each of the
Generator Sets three modes using a voltmeter of known
accuracy. Check that ac output voltage indicated on control
panel matches output voltage at terminal board. Check that
Generator Set does come to an EMERGENCY STOP when
dc control circuit breaker (figure 2-3) is pulled. Test individ-
ual components of the control cubicle as given below. See
figure 4-33 for location of components.
(2) With the generator operating at rated speed or 60
Hz, flash the generator field by placing the master switch on
the control cubicle in the start position. If the generator
voltage fails to build up after flashing, the control cubicle
may be defective.
(3) Voltage Adjust Reheostat (R1). Turn the Amme-
ter Voltmeter transfer switch to its various positions. For
each position of the switch, turn voltage adjust reheostat to
its extreme positions, Voltage readings should be as follows.
Voltage adjust range shall be between 205 and 220V for the
120/208V, 3 phase, 4 wire connection. Between 114 and
126V for the 120V, 1 phase, 2 wire connection. Between 228
and 252V for the 120/240V, 1 phase, 3 wire connection.
(4) Panel Light Assemblies (DS1) and (DS2). With a
good incandescent lamp in place and 24 vdc present at ter-
minals of panel light (panel light switch ON) check that
lamps do not light.
Be certain panel light switch is OFF before
installing or replacing panel light assembly.
(5) Hour Meter (M2). Operate Generator Set. Check
hour meter against a known accurate time source. Replace
meter if necessary.
(6) Battery Charging Indicator (MI), Connect meter
capable of reading at least 35 volts DC from terminal on
battery charging indicator to ground. Operate Generator
Set. With the needle in the yellow area, the meter should read
between 18 and 27.5 volts. With the needle in the green area,
the meter should read between 24.5 and 31.5 volts. NOTE:
The apparent overlap in voltage between the yellow high and
green low is the result of a plus or minus 1.5 voltmeter
(7) DC Control Circuit Breaker (CB2). Operate Gen-
erator Set. Pull circuit breaker (CB2). If generator does not
come to an emergency stop, stop the unit using master switch
and replace breaker.
Disconnect battery cable before making checks,
unless otherwise noted.
(8) Master Switch (S1). Disconnect battery. Tag and
disconnect seven leads to master switch. Using an ohmme-
ter, check for continuity between terminals for each of the
five switch positions as given in table 4-3. If continuity is not
found for each set of terminals listed, replace master switch.
(9) Panel Light Switch (S2). Tag and disconnect two
leads to panel light switch. Using an ohmmeter, test for
continuity between terminals on switch. With the switch in
the OFF position, there should be no
Table 4-3 Master Switch Continuity Check
Check for Continuity
RUN AUX FUEL