S 864-019

 (3)  
If you opened these circuit breakers, remove the DO-NOT-CLOSE tags and close these circuit breakers.

 (a)  
On the P180 or P180-1 panel:
 1) C8 or M4, GCU 1
 2) B25, GCU 1 ALT

 (b)  
On the P514 panel:
 1) GCU 1 PHASE C SYNCH BUS

 S 864-022
 (4)  
If you opened these circuit breakers, remove the DO-NOT-CLOSE tags and close these circuit breakers.

 (a)  
On the P180 or P180-1 panel:
 1) C9 or M5, GCU 2
 2) B26, GCU 2 ALT

 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

 24-23-01
 ALL  ú ú 03 Page 405 ú Jun 18/00
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400 MAINTENANCE MANUAL
 (b)  On the P614 panel:
 1) GCU 2 PHASE C SYNCH BUS

 S 864-020
 (5)  
If you opened these circuit breakers, remove the DO-NOT-CLOSE tags and close these circuit breakers.

 (a)  
On the P180 or P180-1 panel:
 1) C10 or M6, GCU 3
 2) B27, GCU 3 ALT

 (b)  
On the P515 panel:
 1) GCU 3 PHASE C SYNCH BUS

 S 864-021
 (6)  
If you opened these circuit breakers, remove the DO-NOT-CLOSE tags and close these circuit breakers.

 (a)  
On the P180 or P180-1 panel:
 1) C11 or M7, GCU 4
 2) B28, GCU 4 ALT

 (b)  
On the P615 panel:
 1) GCU 4 PHASE C SYNCH BUS

 S 864-013
 (7)  Do this task "Ground Test - Generator and Bus Control Units" (AMM 24-23-01/501).
 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

 24-23-01
 ALL  ú ú 02 Page 406 ú Oct 10/95
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400 MAINTENANCE MANUAL
 GENERATOR AND BUS CONTROL UNITS - ADJUSTMENT/TEST
_________________________________________________
 1.  General_______
 A.  This procedure has two tasks. One task is the ground self-test (GST) for the BCUs and the GCUs. The other task is the power-up replacement test (PURT) for the BCUs and the GCUs.
 B.  You use the CMC to start each test.
 TASK 24-23-01-745-006
 2.  Ground Test - Generator and Bus Control Units_____________________________________________
 A.  General
 (1)  
The CMC sends a ground test command to the two BCUs and the four GCUs (through the BCUs) to start a test of all internal circuits and non-volatile memory. If the internal circuit of a unit does not operate correctly, the unit sends a failure indication to the CMC through the EIUs, which causes a CMCS message such as GCU-X FAIL or BCU-X FAIL. The test result is FAIL if one of the above CMCS message occurs, or if a failure related to the electrical power system is active before, during, or immediately after the ground test.

 (2)  
The EPGS (BCU1) ground test looks for faults that are related to BCU-1, GCU-1, and GCU-2. The EPGS (BCU2) ground test looks for faults that are related to BCU-2, GCU-3, and GCU-4.

 B.  
References

 (1)  
AMM 24-22-00/201, Manual Control

 C.  
Access

 (1)  
Location Zone
 221 Control Cabin, LH
 222 Control Cabin, RH

 D.  
Prepare for the Test

 S 865-007
 (1)  
Supply electrical power with external power #1 or APU generator power #1 (AMM 24-22-00/201).

 (2)  
Make sure that all engines are off.

 S 865-020
 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

 24-23-01
 ALL  ú ú 02 Page 501 ú Jun 18/00
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
　
中國航空網 m.k6050.com
航空翻譯 www.aviation.cn
本文鏈接地址：747-400 AMM 飛機維護手冊 ELECTRICAL POWER 電源 2(20)