b. On the unit, place the load feed breakers to the
7-10. Troubleshooting the Power Pallet
Troubleshooting the power pallet is accomplished by
c. On the bottom of the unit, loosen the 16 captive
screws and remove the unit.
d. Replace the unit by performing steps a, b, and c
in reverse order.
Voltages dangerous to life exist in the
power switch box. Exercise extreme
Removal and Replacement of Power
care if voltage checks must be
appropriate component as shown in the following step.
main power input cables from the
Then replace the switchbox in the reverse order of
generator 1 and 2 connectors.
a. The MONITOR meter located on the power
a. Switch S1.
distribution panel in the shelter may be used to perform
(1) On the front panel remove the knob from
the fault isolation techniques contained in steps b
through h below. Verify that no fault is present in the
(2) Remove the 30 screws, washers,
power distribution panel or EMI filter assembly by
lockwashers and nuts securing the bottom cover plate to
b. Apply power to the shelter by using the two 50 ft
Retain the hardware.
interconnecting cables from the switch box.
(3) Remove the shaft seal from the switch.
c. Place one of the two redundant 30 kW
(4) Remove the four screws, washers,
generators ON-LINE at the switch box. Using the
lockwashers, nuts and sealing washers securing the
transfer switch and the LOAD FEED circuit breaker.
switch to the front panel.
d. Use the MONITOR meter to verify the presence
(5) Slide the switch back from the front panel
of line to neutral voltage on each phase for MAIN-1 and
and rotate to allow removal of the hardware securing the
MAIN-2. The circuit breakers for MAIN-1 and MAIN-2
wires to the switch terminals.
must be ON. All other breakers are OFF.
e. If only one MAIN breaker trips, at least one of
the phases is missing or out of tolerance. Interchange
terminal. Remove and tag the wires.
the connections at the power entry panel. If the other
(7) Replace the switch by performing steps (1)
MAIN breaker trips the problem is in the external cabling.
through (6) above in reverse order.
Circuit check the cables between the switchbox and
shelter. Replace any defective cable.
b. Circuit Breakers CB1, CB2 and Switch S2.
f. If both mains trip, circuit switch-over to the other
(1) Remove the switch as described in a
generator. If this eliminates the problem check the
generator and the cable between the faulty generator
(2) If replacing switch S2, remove the bar.
hookup and switchbox. Replace any defective cables. If
(3) Remove the nine screws and lockwashers
both main switches trip, the problem is in the switchbox.
securing the part to the front panel. Note the orientation
Circuit check the switchbox using the schematic wiring
of the part.
diagram in figure FO-5. Repair or replace the defective
(4) Remove and tag the wires from the circuit
components or wires.
breaker terminals using a nut driver. Tag each wire after
g. If a load feed breaker trips, check for shorts in
it is removed.
the external cable or in the switchbox. Replace the
(5) Remove the part from the switchbox.
breaker if no fault is found.
(6) Replace the part by performing steps (1)
h. Replace the parallel connect switch S2 if
through (5) above in reverse order.
difficulty is encountered in paralleling the two generators
c. Connectors J1, J2, J3 and J4.
(1) Remove the 30 screws, washers,
lockwashers, and nuts securing the bottom cover plate to
Use instructions on plate provided
(2) Remove protective cover from the
synchronizing instrument cable.
(3) Remove the jam nut that secures the
Removal and Replacement of Power
connector to the chassis.
power cables from the generators and to the shelter.
Remove the ground cable.