Flashcards in ELECTRICAL Deck (39):
What type of electrical system does the Challenger 350 have?
28 VDC, SPLIT BUS SYSTEM
Although this aircraft is considered DC powered, what items are AC powered?
1. Some passenger convenience items (Inverters)
2. Permanent Magnet Alternator (PMA)
With the batteries connected and Battery switches OFF, what does the LEFT battery power?
What type of batteries are installed?
2, 24 VDC NICAD, 44 amp/hr Batteries
With the batteries connected and Battery switches OFF, what does the RIGHT battery power?
In flight, what busses are powered on battery power (all generators inop)?
How long will the batteries last on essential power only?
What powers the standby instrument normally?
Right Essential Bus.
If power to the right essential bus is lost, what powers the standby instrument?
its own independent 24 VDC battery pack.
How long does the standby instrument battery pack last?
Why do we turn on the standby instrument prior to turning on the batteries?
to ensure the standby instrument battery pack is functioning.
Why is the Right Battery turned ON first?
To prevent an uncommanded APU start.
When the right battery is turned on what are we looking for before turning on the left battery?
1. Check voltage on SUMRY page
2. Verify EICAS messages complete reporting cycle.
3. STAB TRIM position indicator is displayed.
The green AVAIL external power light illuminates when:
Correct voltage and polarity are sensed. External power can now be used by pressing the button.
** also, a white circle and line with Ext Pwr is depicted on the electrical synoptic page in the middle of the bus tie.
Where can individual battery voltages be read?
SUMRY and ELEC synoptic pages.
During ESSENTIAL POWER ONLY operations, the 1 hour of battery life is predicated on the following conditions or items that must be turned off or shed by the pilots:
1. LWSHLD/WINDOW switch- On for no more than 15 minutes
2. No More than 3 APU start attempts
3. Each additional APU start attempt will reduce battery endurance by approximately 2 minutes.
** Additionally Pilots must also load shed the AUX HYD PUMP switch per the ESSENTIAL POWER ONLY Msg QRH checklist.
When External Power is connected and being used, what indications can be seen in the cockpit and in the external power panel?
1. A white ON light in the cockpit.
2. Green Ext. round indication "lollypop" appears in the middle of the bus tie on the synoptic page.
3. An "IN USE" light in the external power receptacle panel on the right side of the airplane.
What are DCMP's?
Hydraulic DC Motor Pumps.
Where does the right DCMP get its power from?
Left Essential Bus
Where does the left DCMP get its power from?
Right main Bus
What happens when you turn on the batteries?
1. Voice recorder starts recording
2. IRS's start to allign
**do not tow or move aircraft until IRS's are alligned.
On the ground if the batteries are the only power source and the battery switches are ON, what busses are powered?
While on External power and the engines are started, when does the power transfer to ships power?
When external power is disconnected even though engine/APU generators are operational and avaialable.
**External power always remains as the power source until disconnected.
What generators are installed in the Challenger 350?
12 kVA @ 28.5 VDC
*** GCU regulates each Generator.
Max Generator load on the ground (more than 1 generator online).
Max generator load in flight (1 generator).
Max transient Generator load in flight (1 Generator).
600 amps for 5 minutes
If both engine driven generators are online and the APU is started, what happens to the APU generator?
The APU generator provides power to RH main bus.
**the APU generator always favors the RH main bus, however if the left generator is lost, the APU generator will switch over to the left side to maintain a split bus condition. If the APU is the only source of power, it will power the RH main bus, the bus tie will close to power the left side.
If operating on a SINGLE generator what are the differences between operating on the ground and in flight?
On the ground all busses will be powered.
In flight, the AUX busses will automatically shed when down to a single generator.
Do the batteries have to be selected ON to accept EXTERNAL power?
The engines/APU generators come online automatically except when:
The external power is powering the ship.
Are the Bus Tie Contactors (BTC's) normally open or closed.
Bus ties are normally open to maintain a split bus system.
Can the bus ties be manually closed and opened?
The bus ties can ONLY be manually opened via the BUS TIE switch (this is usually done via a QRH checklist). You CANNOT manually close the BTC's (prevents you from shorting out the good side if one side has a short or malfunction)
What are DC Power Centers (DCPC's)?
They distribute electrical power loads to the aft of the aircraft and to the Secondary Power Centers (SPC's)
Control automatic load shedding
Isolate faulty buses
Protect the loads from abnormal electrical power
What are Secondary Power Centers?
Distribute electrical power to the loads in the front fuselage of the aircraft.
When the aux buses are shed due to single generator operations in flight, convenience items are lost in the main cabin. What is shed in the cockpit?
Co-Pilot's Right Window Heat. (Right AUX Bus)
Do the batteries have to be ON so they can receive a charge?
It is prohibited to take off if battery temperatures are below: