(7) When performing one of the protective
(d) Immediately after contactors trip,
panel trip functions in 60 Hz generating system, actuate
decrease voltage to 120 volts L-N.
control switch to RESET position and hold it there until
reset control trips and remains tripped and ac system
Check under voltage protective device by lowering
becomes de-energized. Remove simulated fault and
voltage to 92 volts for 30 seconds. Readjust to 120
again actuate control. Repeat this procedure for 400 Hz
volts L-N. Decrease to 90 volts L-N. The under voltage
generating system. Reset control shall reset only once
after actuation and shall then trip and remain tripped as
energizes load contactors.
long as the fault exists and control-switch is hold in
(f)
The
40U
Hz
overvoltage
RESET position.
Upon removal of the fault and
protective device shall provide a trip signal on the 400
reactuation of control, the system shall return to normal
Hz generator when three phase average voltage
operation.
increases to 135 volts and remains thus from 0.5 to 10
(8) Low oil pressure shutdown check can
seconds. No trip at 128 volts. The 60 Hz overvoltage
be performed at completion of any test that requires
increases to 135 volts and remains there from 0.5 to 10
operation of turbine engine. Disconnect plug from low
seconds. No trip at 128 volts.
oil pressure switch. Turbine engine shall shut down.
(g) The 400 Hz undervoltage device
Reconnect plug to low oil pressure switch. This test
shall provide a trip signal on 400 Hz generator when
checks continuity of electrical circuit only. This is no
three phase average voltages decrease to 90 volts and
indication of switch setting or operation.
remain there for 4.5 seconds, minimum. The 60 Hz
(9) Check 400 Hz remote output overload
undervoltage device shall provide a trip signal when
sensor by applying a three-phase balanced 95 ampere
lowest leg voltage decreases to 90 volts and remains
load to each of the remote output receptacles. Overload
there for 4.5 seconds minimum. No trip at 92 volts.
sensor shall trip at approximately 190 amperes total
(4) Apply 110 percent or rated three phase
within 10 to 70 seconds at calibrated temperature.
balanced load to 400 Hz generator and 110 percent of
Remote output contactor shall not be reset unless reset
rated single-phase, three-wire, balanced load to 60 Hz
with remote operation switch. Remote trip light shall
generator. Repeat this procedure with 150 percent
glow when remote output contactor trips.
balanced load. Refer to paragraph g, step (7) below.
(10) Check 400 Hz auxiliary output overload
Line contactor shall open at calibrated temperature
sensors by applying a three-phase balanced 225
within the 30 to 120 seconds at 150 percent. Contactor
ampere load to each of the auxiliary output receptacles,
shall not trip at 110 percent (operate for five minutes).
individually. With overload applied, overload sensors
The total air-conditioning system will have to be
shall trip at approximately 225 amperes within 10 to 70
operating and external loads will have to be attached to
seconds, at calibrated temperature, without loss of
power cable through output connector. The 60 Hz
power to the other auxiliary output receptacle. The 400
power can be taken from output receptacle. Obtain
Hz auxiliary trip lights shall glow. Tripped output
meter readings of generator voltage and current.
contactor shall not reset unless reset with 400 Hz
Caution: Do not exceed 45 kw on the external
auxiliary operation switch. Acutation of 400 Hz auxiliary
400 Hz output connector.
switches to OPERATE-RESET shall reset tripped
contactor without loss of power to output receptacle.
Note.
To apply loads required for this
Perform for each output. A delay in resetting of
test for 400 Hz generator, extra leads will have to be
contactor will be required to allow overload sensors to
attached to terminal board on air-conditioning panel.
cool down.
(5) Apply a three-phase balanced 115
(11) Check the transient voltage (motor
ampere load to each of the 400 Hz output power
starting load) as follows.
receptacles. Overload sensor shall trip at approximately
225 amperes within 10 to 70 seconds at calibrated
(a) With 400 Hz generator operating
temperature. The 400 Hz output contactor shall not
at no-load, suddenly apply a 240 volts, two per unit, 0.4
reset unless reset with contactor switch. The 400 Hz
power factor load on 60 Hz generating system or start a
output trip light shall glow when 400 Hz output contactor
120 volts, two horsepower motor. Do not hold two per
trips.
unit load on longer than 15 seconds. Voltage shall not
dip sufficiently low to cause the protective panel to trip
(6) When performing the protective
generator off the line within the limits of undervoltage
devices check herein, observe contactor trip indicator
trip.
lights on unit control panel. Lights shall glow each time
400 Hz main contactor or 60 Hz load contactor trips.
(b) With 60 Hz generator operating
Actuation of corresponding contactor switch to its reset
at no-load and 400 Hz system operating at a steady-
position shall extinguish indicator lamp.
state
2-19
