Electrical System Flashcards
What bus bars are powered during the electrical emergency?
In an electrical emergency the top 4 busbars are powered.
What else does the left GCU do?
The left GCU samples ground power
Where are the busbars located?
Within the PDU’s
When are the bus bars powered?
When both generators are online all Bus Bars are powered
If ground power is online both busbars are powered
What happens if I lose one generator?
The shed bus is unpowered.
What happens if you lose both generators?
In flight when you lose both generators only the top four bus bars would be powered by the batteries. Embraer calls that the Electrical Emergency.
What are the generators restricted to in Flight and on the Ground?
In flight 300A
On the Ground 250A
Above 34,000 ft 250A due to air density
What does the GPU need to be?
24.5 V DC to 29 V DC, (800/1000) A
the electrical control panel GPU switch will show a white AVAIL indication when these parameters are met.
How many busbars and how are they composed?
2 × Main Bus - connected by Central Bus
2 × Hot Battery Bus
1 × Emergency Bus
1 × Shed Bus
EBC2 only closes during the Electrical Emergency
When should the batteries be green?
Between 27V to 29V
What must the ground power be to charge the batteries?
27V and above
What is the name of the Phenoms Electrical System?
Electrical Power Generation Distribution System (EPGDS)
What is the purpose of the EPGDS?
To provide the DC power to the aircraft systems and power for automatic and manual controls to the flight crew.
How is the EPGDS separated?
The EPGDS is separated into power generating systems and power distribution systems.
These systems can be divided into main and emergency power generation and primary and secondary power distribution. Normal operation of the electrical system is automatic.
What is the main power generating system?
The main power generating system is composed of two engine driven 325A (Capped at 300A for us) starter/generators and one external power unit connection, controlled by two Generator Control Units (GCUs).
What is the purpose of the Starter/Generator?
The starter/generators are used as a primary source of the DC electrical system supplying power to their respective DC BUS.
What is the secondary system composed of?
The secondary power distribution system is composed of two main Circuit Breaker (CB) panels, two secondary circuit breaker panels and two relay panels.
What happens in the event of a power generating source failure?
Bus ties automatically connect between the networks with no significant operational degradation or additional workload.
What are the EPGDS components?
Battery 1/Battery 2
Generator Control Units (GCUs)
Starter/Generators
Power Distribution Units
Emergency Power Distribution Unit (EPDU)
Circuit Breakers
Where is battery 1 located?
Battery 1 is located in the forward compartment, which is a non-controlled environment, and can be accessed by removing the access panel in the forward baggage compartment. Its vent valves require the installation of ventilation tubes to avoid unsafe hydrogen accumulation inside the aircraft fuselage
Where is Battery 2 Located?
Battery 2 is located in the aft compartment and can be accessed by opening battery compartment access door. Its vent valves do not require the installation of ventilation tubes, but its compartment requires ventilation overboard to avoid unsafe hydrogen accumulation inside the aircraft fuselage
What are the purpose of the Generator Control Units (GCU’s)?
Operate the primary power distribution system contactors
Regulate, control, and provide protection functions for:
Electrical generating system
Perform power-up
Continuous BIT testing
Eliminate system disturbances (voltage dips and surges associated with start, cross-start assist and start-terminate)
Isolate faults
Provide system fault indication
How do the Starter/Generators operate?
Each engine has a 28 V DC, 325 A SG monitored and controlled by a dedicated GCU. When an engine is successfully started, the SG will automatically come on line, powering the respective DC BUS. If the previous power source was a GPU, then the SG does not come on line until the GPU is disconnected from the CENTRAL BUS.