TM 11-6125-220-20
on fixed terminal board TB2 (closest to the ac endbell)
2-3. Checking Unpacked Equipment
for an output from 11-pin connector J2. Loosen the
a. Inspect the equipment for damage incurred during
seven terminal screws on movable terminal board TB3,
shipment. If the equipment has been damaged, report
reposition the terminal board, and secure the terminal
the damage on DD Form 6 (para 1-3).
leads and seven terminal screws. If a single-phase output
is required (output from four-pin connector J1), movable
b. Check the equipment against the component listing
terminal board TB3 must be positioned on terminal
in the packing slip to see if the shipment is complete.
board TB1 (farthest from ac endbell). The position of the
Report all discrepancies in accordance with paragraph
movable terminal board is externally indicated by the
appearance of a red mark in one of the two sight holes
though a minor assembly or part that does not affect
located on the side of the regulator box.
proper functioning is missing.
c. Check to see whether the equipment has been
543B/A, check the internal linkages for the proper con-
modified. (Equipment which has been modified will have
nections. If the aircraft wiring requires single-phase power
the MWO number on the front panel, near the nomen-
from the four-pin connector, the linkage straps in the
clature plate.) Check also to see whether all current
regulator box must be connected for a delta output
applicable MWO's have been applied. (Current MWO's
(C to H, A to J, and B to E). If a three-phase, four-
applicable to the equipment are listed in DA Pam 310-7.)
wire Wye output (from the 11-pin connector) is required,
2-4. Installation
the linkage straps must be changed (O to H, O to J,
The output and input power of the inverter is routed
and O to E).
through the circuits of the aircraft in which the inverter
is installed. Refer to the applicable aircraft technical
c.
Typical Installation Procedure.
manual for the desired mode of operation, the physical
(1) Make sure that the portion of the aircraft
location within the aircraft, and to the procedures in
mounting that corresponds to the inverter mounting base
a and b below for the proper output connections at the
is free from oil and grease to be sure of good electrical
ac power connector. A typical installation procedure
grounding.
is provided in c below.
(2) Position the inverter on the aircraft mounting
line up the holes in the inverter mounting base with the
WARNING
holes in the aircraft mounting.
Never connect or disconnect the inverters while
(3) Secure the inverter to the aircraft mounting
dc power is present at the connectors.
with the four sets of mounting hardware.
(4) Connect the power cable to the ac power
a. PU-543/A (Modified), PU-543A/A (Modified),
connector of the inverter.
(5) Connect the dc input leads to the terminal board
of the PU-543/A or PU-543A/A was necessary to re-
studs; maintain the proper polarity.
place the automatic switching feature. When modified,
(6) If the inverter is a PU-543D/A, record the in-
the automatic switching feature was replaced by an in-
verter serial number and HOURS total time indicator
ternally mounted, manually operated, terminal block
assembly to make its operation identical with the PU-
d. Removal. To remove the inverter for mainten-
543C/A and PU-543D/A. If a three-phase output is re-
ance or repair, reverse the procedures in a (3) through
quired, the movable terminal board must be positioned
(6) above.
2-4
