TM 11-6125-220-20
to the top of the stator housing of the inverter. The top
543C/A, and PU-543D/A four dc brushes are located
of the regulator box is a cover which can be removed,
internally within the dc endbell. In the PU-543B/A, the
for inspection of the regulator, by loosening the screw
four dc brushes are installed at the dc end of the inver-
fasteners. The power input and output are connected
ter and are externally accessible for maintenance. The
to the inverter through either of two power connectors
PU-543D/A (fig. l-3) also contains a Total Time Indica-
located on the front and on the side of the regulator
tor (MS17322-10) which indicates total running time
box. (Refer to the applicable aircraft technical manual.)
of the inverter in HOURS.
Also provided on the front of the regulator housing are
c. Additional Equipment Required. A 28-volt dc
two test point jacks for checking the ac output.
power source is required to supply the input power to
the inverter
NOTE
The two inverter power connectors are used to
1-9. Tabulated Data
make the inverter compatible with any aircraft
Voltage input . . . . . . . . . . . . . . . . . . . . . . . 28 volts dc.
configuration which uses a 250 volt-ampere
Current input . . . . . . . . . . . . . . . . . . . . . . . 24 amperes dc.
Voltage output, three phase . . . . . . . . . . . 115/208 volts ac 6.
(va) inverter. Only one of the power connec-
Voltage output, single phase . . . . . . . . . . . 115 volts ac 6.
tors is used in an installation. When either
Power output . . . . . . . . . . . . . . . . . . . . . . . 250volt-amperes.
power connector is used, the other power con-
Frequency output . . . . . . . . . . . . . . . . . . . . 400 Hz 10.
nector is disconnected from the inverter power
Power factor . . . . . . . . . . . . . . . . . . . . . . . . 0.8 lag to 0.9 lead.
circuits (para 2-3).
Operating speed . . . . . . . . . . . . . . . . . . . . . 12,000 revolutions per minute.
Altitude range . . . . . . . . . . . . . . . . . . . . . . . 0 to 65,000 feet.
Phase rotation:
b. Rotating Section. The rotating section of the
Wye output (4-pin connector) . . . . . . . . . . A,B,C.
inverter is contained in a heavy metal frame which is
Delta output (4-pin connector) . . . . . . . . . A,B,C.
the stator housing. The inverter mounting plate is a fixed
Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.8 lb (PU-543B/A).
part of the bottom of the stator housing, and it has
13.8 lb (all others).
holes for attaching the inverter to the aircraft mounting.
Size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.25 in. high, 9.25 in. deep,
4.75 in. wide.
An endbell on each end of the inverter gives access for
inspection of the rotating parts. Both endbells are slotted
1-10. Items Comprising An Operable Equip-
to provide an airflow through the rotating section for
ment
cooling. The airflow intake is through the dc endbell,
The inverter in itself comprises an operable equipment.
and the airflow exhaust, through the ac endbell. In the
PU-543/A, (modified), PU-543A/A (modified), PU-
1-2
