170 Electrical

• 2 independent networks

• Redundancy and fault isolation

Bus ties automatically connect to provide no system degradation

• • 2 Integrated Drive Generators (IDG)
• • Auxiliary Power Unit (APU)
• • Inverter
• • Ram Air Turbine (RAT)
• • AC GPU receptacle

• • 2 NiCad batteries
• • 3 Transformer Rectifier Units (TRU)
• • DC GPU receptacle

A Constant Speed Drive (CSD) attaches the IDG to the AGB (Accessory Gear Box)

Each has a Generator Control Unit (GCU)

yes

• • High oil temperature
• • Low oil pressure

No. This is a maintenance function

• • To power the AC BUSSES and AC ESS BUS which…
• • Power the 3 Transformer Rectifier Units (TRU) 1, 2, and ESS

To convert 115 VAC to 28 VDC

yes

• • Onside (IDG)
• • Inside (APU)
• • Outside (GPU)
• • Cross-Side (Other IDG)
• Note: The airplane uses an onboard AC power source before an external AC source

• GPU button displays AVAIL and the GPU icon is presented on the electrical synoptic page

• Once the GPU button is pushed in, the button will display IN USE provided another AC power source is notavailable

• • Ground service bus is in use
• • Cockpit GPU button will display AVAIL even though the ground service bus is in use

Deselect the GPU button before the next GPU connection

Any AC Power Source

10 minutes

• For APU start when batteries < 22.5 VDC, or

• If battery temp is < -20°C

-20°C

18 volts

• BATT 2 powers the APU Start Bus

• BATT 1 powers the FADEC & EICAS for monitoring

Converts 28 VDC from the batteries to 115 VAC to power the AC STANDBY BUS when an AC source is notavailable

Engine exciters 1A and 2A

Airflow turns the RAT propeller which spins the turbine inside

• Automatically deploys if AC BUSSES are not powered

• Manually by pilot

8 seconds

No. Batteries supply power to the DC ESS BUSSES and AC STANDBY BUS

ESS BUSSES

• 130 kts

• Load shedding occurs below this speed

When the RAT is deployed

• 4 Integrated Control Centers (ICC)

• 2 Secondary Power Distribution Assemblies (SPDA)

An electrical control device, which provides power distribution and protection for electrical loads

An electrical load-management unit (powered by the ICC’s) that distributes electrical loads to aircraft systems according to distribution logic

• ICC CB’s can only be reset by maintenance on the ground

• SPDA CB’s can be reset via the MCDU

Battery 1

Courtesy / service lights fwd

DC ceiling lights

Engine 1 oil level ind

Engine 1A fire extinguish

Engine 2A fire extinguish

Engine fuel shutoff valve 1

Hydr sys sov 1

Battery 2

CMC

Engine 1B fire extunguish

Engine 2 oil level indication

Engine 2B fire extinguish

Engine fuel shutoff valve 2

Hydr sys sov 2

Panel refuel 3

Water and waste system controller pwr 3

AC fuel pump 2A

Hydr motor pump 3A

SF-Ace 1 flap channel 1 ac feed

SF-ace 2 slat channel 2 ac feed

Engine 1 exciter 1A

Engine 2 exciter 2A

Integrated control center - collect and confirm the power is safe and then sends it to the SPDA

Provides power distribution and protection for the airplane electrical loads

Line replaceable units which is plug and play like a computer's motherboard

Secondary power distribution assembly

Receives power from the ICCs and distributes the power to the airplane systems

The SPDA works as a circuit breaker or relay interfacing the electrical buses with the airplane systems and components.

Modular avionics assembly

The airplane systems that require a complex logic for the normal operation are connected to the MAUs which have the ability to process various inputs and define either on/off or open/close status for a specific system

Monitors aircraft systems

• Auto Pilot
• Air Data Application
• Auto Throttle
• Data Aquistion
• Display Control Functions
• Flight Director
• Flight Management System
• GPS
• Monitor/Warning System
• Stall Protection/Warning
• Windshear Guidance

• MAU 1 and 2
• SPDA 1
• EICC
• Battery 1
• 2 P-ACE
• 1 S-ACE

• MAU 3
• LICC
• RICC
• SPDA 2
• 2 SF-ACE
• 2 S-ACE

AICC