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DC DISTRIBUTION -GROUND HANDLING TRU

General
The ground handling TRU is in the P320 ground service/ handling power panel. It converts ac power into 28v dc power. These are typical loads for the ground handling 28v dc power:
*
Cargo handling

*
Refuel valves

*
Refuel quantity control/indication

*
Service interphone

*
Powered door opening system (engine cowls).

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777 AIRCRAFT MAINTENANCE MANUAL

DC DISTRIBUTION -GROUND HANDLING TRU

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DC DISTRIBUTION -FUNCTIONAL DESCRIPTION -POWER DISTRIBUTION

General
The dc distribution divides the electrical power dc buses into sections. The primary buses are in the ELMS power management panels P110, P210, and P310. These are the primary buses of the electrical power dc system:
*
Hot battery

*
Left dc

*
Right dc

*
Captain’s flight instrument

*
First officer’s flight instrument.

The ground handling bus is in the P320 ground service/handling power panel. The APU battery bus is in the P49 APU panel.
Hot Battery Bus
The hot battery bus divides into these:
*
Tow dc bus

*
P11 supply

*
Hot battery distribution bus.

Left and Right DC Buses
The left and right dc buses do not divide. They do supply power to P11.
Captain’s Flight Instrument Bus
The captain’s flight instrument bus divides into these buses:
*
Battery bus

*
P11 supply

*
Captain’s flight instrument distribution bus

*
Battery #2 bus.

The battery bus further divides into these:
*
P11 supply

*
Battery distribution bus.

First Officer’s Flight Instrument Bus
The first officer’s flight instrument bus does not divide. It does supply power to the P11.
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DC DISTRIBUTION -FUNCTIONAL DESCRIPTION -POWER DISTRIBUTION

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