TM 5-6115-400-35
associate exciter series windings ) with lowest
potential above neutral when the generator is
remove and install the control panel and components
in the 240/416-volt connection.
mounted in cubicle.
b. Repair.
Either the kilowattmeter or the
transducer can be replaced, if defective, without
test wiring harness from control panel to relay box for
replacing the other.
continuity and possible short circuits.
85. Relay Testing
to disassemble and reassemble the control pane] and its
components.
Relay K1 (fig. 130) and relay K6 if 8USpected of being
defective, should be tested and the results compared
83. Frequency Meter and Transducer
with the specifications found in Table 8.
a. General. The frequency meter consists of a
86. Diodes
converter and an indicator. The indicator has a 250
degree scale calibrated in cycles over the range of 48 to
62 cycles, inclusive, and scale divisions of 0.1 cycle.
junction silicon rectifiers operating in connection with
The needle rests on the deft hand edge of the scale
relays K6 and K1.
when the instrument is de-energized.
Alternating
b. Testing. Refer to paragraph 73 (4).
current voltage applied to the converter is transformed
to a direct-current voltage which is proportional to the
87. AC Power Circuit Breaker
frequency of the alternating-current voltage and which is
registered on the "D" Arsonval indicator. The converter
a. General.
is made of static components and is mounted within the
(1) The ac power circuit breaker (fig. 131) is
control cubicle. The converter is connected across
a circuit interrupter (C1) rated at 694
amperes at 240 volts and 347 amperes at
windings associated therewith.
480 volts.
b. Repair. Whenever a defect is found in either
(2) The circuit breaker is mounted above the
the frequency meter or the transducer; both must be
relay box and is connected between the
replaced as a matched set.
voltage reconnection panel and the load
connection terminals.
84. Kilowatt Meter and Transducer
(3) The circuit breaker is electrically operated
from the set 24 volt do system, by circuit
a. General.
breaker switch S3 (fig. 130) on the
control panel.
The AC power circuit
(1) The kilowattmeter measures and indicates
breaker is a three pole, three phase
the power output to an accuracy of 3
device constructed so that the three sets
percent of full scale value at 77 from
F
of main contacts clone and open
set no load to rated load current under the
simultaneously through action of a
following conditions:
common mechanism. It is not possible
for any of these main contacts to remain
(a) Balanced load at any power factor
closed while others are open. Suitable
from unity to 0.80, lagging.
auxiliary contacts are included to prevent
(b) Unbalanced load, where the three
interconnection of governor and voltage
phase voltages, currents, and power
regulator circuits of machines being
factors differ.
operated in parallel, until the circuit
(c) With the output of any one phase
interrupter
equal to zero.
(2) The potential coils of the kilowattmeter are
connected to the generator coils (and
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