TH-1H Electrical [Systems]

What is the voltage for the primary DC electrical system?

28 VDC

What are the 4 main sources for DC power?

Main generator

Standby generator

Battery

Ground power receptacle

What are the ratings on the external power (GPU)

7.5kW, 600 amps minimum

What is the caution associated with the GPU?

CAUTION: If external power voltage exceeds 29.5 volts turn off external power immediately, adjust the GPU to provide lower voltage. Damage to the aircraft electrical system could occur at voltages above 29.5 volts.

Where is the battery located?

Top of the lower nose shelf

What type of battery is in the TH-1H?

Lead acid non-spillable, 24 volt, 42A

Minimum voltage passing through 10% Ng

16V

Starter/Standby generator is driven by the _____ gearbox.

Ng gearbox

The starter/standby generator is rated at....

30V/300A

The generator is located where?

Forward side of the main transmission

The voltage regulator controls output in what range?

27-28.5VDC

The DC voltmeter on the center MFD has what readouts?

BAT

MAIN GEN

STBY GEN

ESS BUS

NON-ESS BUS

What is the readout range of the DC voltmeter?

0 to 33VDC

The yellow band of the dial range is...

0-22VDC

The green band of the dial range is...

22-30VDC

What is the readout range of the ammeters?

0-330A

What is the readout accuracy of the ammeter?

1A

When does the DC Gen light illuminate?

When the main generator goes off line.

What does the main DC bus bar do?

Connects all DC power sources into the aircraft's DC system

When does the overvoltage relay trip?

When the generator exceeds 31-33 volts

What does the bus control relay do?

It determines which generator will supply power

What does the AC electrical system do?

Provides 26VAC 400Hz power to the fuel pressure transmitter and EDCU

Where is the AC power supplied from?

EDCU

What indication will result with an overheated battery?

Rotten egg smell, mist or vapors from the nose compartment, abnormally high main/standby load meter indication

The battery is good for _____ minutes without the generator.

30 minutes

Overvoltage relay trips field relay when the generator exceeds...

31-33V

What does the standby generator not have?

Overvoltage protection

If the main generator fails, the bus control relay de-energizes to do 4 things...

Illuminate DC GEN caution light

Open circuit to nonessential bus relay

De-energize nonessential bus relay

Connect standby gen to main DC bus