Electric Flashcards
The DC electrical system is supplied by:
3 NiCad batteries (24v DC)
2 Engine driven DC Starter-Generators (28.5v DC)
2 Transformer Rectifier Units (28v DC)
1 Auxiliary Power Unit (28v DC)
Name the 7 DC busses.
Battery
Left and Right Essential
Left and Right Main
Left and Right Secondary
The AC electrical system is supplied by:
2 engine driven AC generators that provide 115 volt, three-phase, variable AC power
Automatic reconfiguring of the electrical system is controlled by the…
Electrical Power Control Unit (EPCU).
Where are the batteries located?
Main and Aux - Lower Left section of nose compartment
Standby - Upper Left section of nose compartment
Volts and amp hours of batteries
Main and Aux - 24v, 40 amp hour
Standby - 24v 17 amp hours
Batteries that assist engine start
Main and Aux
How long will batteries supply emergency power?
Approximately 45 minutes
Which battery is connected to the “hot” battery bus
Standby battery
BATTERY MASTER switch
Closes 3 contactors directly connecting all three batteries to the Essential DC buses
How is the EPCU powered?
Indirectly from essential busses, Primarily from standby battery
MAIN/AUX/STBY BATT switch
Directly connects respective battery to its main bus
What busses is the main battery connected to?
Right main DC bus (2 way flow), Right Essential Bus
What busses is the aux battery connected to?
Left Main DC bus (2 way flow), Left Essential Bus
What busses is the standby battery connected to?
Left Main DC bus (1 way flow for charging), Right Essential Bus
Battery temperature range
Amber - 50C to 65C
Red - greater than 65C
What bus is external DC power is received by?
Left Main DC Bus
When will the EPCU automatically disconnect from the external power source?
External DC voltage exceeds 31 volts or drops below 22 volts