Electrical Systems Flashcards
Where is the ELEC power panel located?
Overhead Switch Panel
How are the main AC generators cooled and lubricated?
Oil cooled and lubricated by the AFT XSMN Main Oil Lubrication System
The GCUs protect the AC system from what four conditions?
Over Voltage, Under Voltage, Under Frequency, Feeder Fault
Where are the No 1 and No 2 AUX PDPs located?
Left and Right side Cabin (Mid-Point)
How is the APU generator cooled?
Air Cooled by a built-in fan
An indicator on the center instrument panel indicates when the battery voltage drops below _____ Vdc
20
What is the purpose of the AC bus-tie gang bars on each PDP?
Isolate respective system to prevent “bus-tie” from occurring to the other side
With the BATT switch in the OFF position, the battery supplies DC electrical power only to the _____ bus.
Battery Bus
The battery bus can be energized by what two sources of DC electrical power?
Battery
No. 1 DC Bus
What is the order of priority for the DC electrical system from highest to lowest?
Transformer Rectifiers, External DC Power, Battery
True or False? The BATT switch must be in the ON postion in order to recharge or maintain the charge of the battery.
True
What three DC buses are powered by the battery with the BATT switch in the ON position?
Batt Bus, Essential 1 and 2
If the APU is running or external AC power is connected, DC power is supplied by the helicopter _____.
Transformer Rectifier
What is the order of priority of power for the AC electrical system from highest to lowest?
Main AC Generator, APU Generator, External AC Power
What “system” allows either main generator to provide electrical power to both buses should a single generator fail or be taken off-line?
Bus-Tie System
If all three generator switches are placed to the ON position (#1 Main, #2 Main, and APU), which one(s) will provide electrical power to the #1 and #2 AC buses?
Each main AC gen will provide power to its respective bus. APU gen power will not be connected to the bus.
The primary active caution messages to look for in determining whether or not a bus-tie exists are the respective RECT FAIL (OFF), ENG FUEL PRESS LO, and____
AFCS FAIL
Should both generators fail, both rectifiers will be ______.
Disabled
What will be the indications if a bus-tie DOES NOT exist when a RECT1 or RECT2 OFF becomes active?
RECT 1 or 2, AFCS FAIL, ENG FUEL PRESSURE
What indications will you have that a bus-tie DOES exist during a single generator failure?
None besides appropriate GEN caution
Each AC generator produces how much power?
40 kva and 32,000 watts
How do the AC generators produce a current?
How many phases?
By creating a change in magnetic field (spinning magnetic)
Three phase AC power
How much KVA is produced by APU generator?
20 KVA
At max load, what % of load can each EAPS fan consume from the AC generators
16.5% each
What components provide electrical power to the No. 1 and No. 2 DC buses
No.1 and No.2 Transformer Rectifiers
what components measure electrical current as it leaves the generator and again as it enters the electrical bus
current transformers
