KLM MD-11 - Electrical Power Control Unit (EPCU)

MD-11 Flight Crew Operations Manual
k
Electrical -
Description and Operation
Elec.10.4
The respective GCU (1, 2, 3, and APU) regulates the following:
• IDG and APU generator voltage.
• IDG frequency and current limit.
• IDG load control.
Each GCU (1, 2, 3, and APU) protects its respective generator from electrical
faults.
The respective GCU (1, 2, 3, and APU) provides automatic operation of:
• IDG reset due to generator protective trips.
• ac generator bus 1, 2, and 3 fault reset.
• Maintaining IDG oil temperature and pressure indication for IDG fault
indicating.
Electrical Power Control Unit (EPCU)
The EPCU controls the following:
•EPR.
•BTR-EP.
• Ground Service Relay (GSR) - external power position.
• Auxiliary Power Relay (APR) 1, 2, and 3.
• Load shedding.
• APU N2 speed for APU NBPT operation.
• NBPT from external power to APU generator.
• NBPT from IDG to external power across BTR-EP.
• NBPT from IDG to APU generator.
• DUAL LAND mode electrical system configuration.
• Electrical Power System (EPS) operating mode.
• EPS parameter transmission to EIS.
• EPS fault transmission to the CFDS.
• Frequency reference for GCU 1, 2, and 3.
• Galley Transfer Relay (GTR) 1, 2, and 3.
The EPCU provides protection for the following:
• Main external power phase sequence.
• Main external power over/under voltage.
• Main external power over/under frequency.
• Main external power feeder fault.
• ac tie bus fault.
• If galleys are installed, galley external power voltage, frequency and
phase sequence.
The EPCU provides automatic operation of the following:
• APU generator reset for incorrect voltage, frequency or feeder faults.
October 02, 2006