Starting System
Left Starter/Generator (SG1)

Location - The starter/generator is located on the bottom surface of the left engine.  Plug P93 is connected to the receptacle for the starter/generator magnetic pickup.  Remove the lower cowl to access the starter/generator. 

View looking up at left starter/generator

1.  Left Starter/Generator (SG1)
2.  Plug P93
3.  Capacitor (CD003)

Operation - The left starter/generator is rated at 30 VDC and 300 amps. The starter/generator voltage output is controlled by the Left Generator Control Unit (BT001).  The generator control unit regulates the starter/generator output at 28.5 ±0.1 VDC.  Starter/generator cooling is accomplished by utilizing fan bypass air ducted to the forward end of the starter/generator.

NOTE: The measured resistance between pins A and B on the receptacle for the starter/generator magnetic pickup is approximately 30 ±10 ohms.

Terminals

Functions

A

Field excitation for the starter/generator.  Connected to pin AA on the generator control unit (GCU).  The GCU applies a variable voltage to the field windings during engine start to control the starter/generator torque output.
B

28 VDC input from the Left Start Relay (KZ007) during start
D

Starter/generator interpole winding voltage reference.  Connected to pin W on the GCU.  The GCU monitors the voltage on the interpole windings to control field excitation
E

Airframe Ground GT001