21_______
WARNING
DO NOT OPERATE THE APU WITH YES
THE LOWER SHROUD REMOVED IF PERSONS ARE IN OR DIRECTLY BELOW THE APU COMPARTMENT. SEE SHEET 4
YOU MUST BE A MINIMUM OF
(BLOCK 5) 3 FEET AWAY FROM THE OUTER EDGE OF THE APU COMPARTMENT OPENING TO OPERATE THE APU WITH THE LOWER SHROUD REMOVED. AN APU TURBINE WHEEL SEPARATION DURING OPERATION CAN CAUSE INJURY TO PERSONS.
CONNECT THE NEGATIVE LEAD
TO THE STARTER MOTOR. REPLACE THE STARTER MOTOR,
M161 (AMM 49-41-11/401). DOES THE PROBLEM CONTINUE? YES YES
22 EXAMINE THE CIRCUIT FROM TERMINAL X1 TO TERMINAL X2, OF THE START RELAY R5 (WDM 49-31-01).
IS THERE AN OPEN CIRCUIT?
NO NO
23 DO A CHECK FOR 28V DC AT THE START RELAY R5, TERMINAL A1 (WDM 49-31-01).
IS THERE 28V DC AT TERMINAL A1?
YES NO
24 EXAMINE THE CIRCUIT FROM THE START RELAY R5, TERMINAL X1, TO THE APU CONTROL UNIT, M280, CONNECTOR D50B, PIN 30 (WDM 49-31-01).
IS THE CIRCUIT OK?
YES NO
25 EXAMINE THE CIRCUIT FROM THE START RELAY R5, TERMINAL A2, TO THE STARTER MOTOR, M161, POSITIVE TERMINAL (WDM 49-31-01).
IS THE CIRCUIT OK?
YES
SEE SHEET 3 (BLOCK 26)
56 REPAIR THE CIRCUIT FROM THE START RELAY R5, TERMINAL A1, TO THE "AUX POWER UNIT START" CIRCUIT BREAKER, C798 (WDM 49-31-01).
Starter Motor Does Not Turn
Figure 110A (Sheet 2)
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. APU WITH THE ELECTRONIC SPEED SWITCH ú
49-00-00
PART NUMBER 3876259 ú
ú 02 Page 145
ú Jul 12/01
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
L38588
////////////////////////
A / GTCP85-129 SERIES /
737-300/400/500/ ENGINES /MAINTENANCE MANUAL ////////////////////////
FROM SHEET 2 (BLOCK 25)
YES
NO
26 EXAMINE THE CIRCUIT FROM
THE START RELAY R5, TERMINAL
X2, TO GROUND (WDM 49-31-01).
IS THE CIRCUIT OK?
TO THE ELECTRONIC SPEED SWITCH, S634, CONNECTOR D1245, PINS C AND D (WDM 49-31-01).
ARE THE CIRCUITS OK?
YES
NO
29 DO A CONTINUITY CHECK AT
THE ELECTRONIC SPEED SWITCH,
S634, CONNECTOR D1245,
PINS C AND D (WDM 49-31-01).
IS THERE AN OPEN CIRCUIT?
YES
NO
30 EXAMINE THE CIRCUIT FROM
THE APU CONTROL UNIT, M280,
CONNECTOR D50B, PIN 10 TO THE
APU MASTER SWITCH, S248,
CONNECTOR D4218J, PIN 5
(WDM 49-31-01).
IS THE CIRCUIT OK?
REPLACE THE APU CONTROL UNIT M280 (AMM 49-61-11/401).
IF THE PROBLEM CONTINUES, REPLACE THE APU MASTER SWITCH, S248 (WDM 49-31-01).
Starter Motor Does Not Turn
Figure 110A (Sheet 3)
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. APU WITH THE ELECTRONIC SPEED SWITCH ú
49-00-00
PART NUMBER 3876259 ú ú 02 Page 146 ú Jul 12/01
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
L38593
////////////////////////A / GTCP85-129 SERIES /737-300/400/500/ ENGINES /MAINTENANCE MANUAL ////////////////////////
FROM SHEET 2
(BLOCK 4)
YES
YES
5
MOVE THE APU MASTER SWITCH
65 MOVE THE APU MASTER SWITCH TO THE "START" POSITION. TO THE "OFF" POSITION. REPLACE THE STARTER MOTOR,
NOTE: AFTER THE AIR INLET M161 (AMM 49-41-11/401).
DOOR OPENS, THERE WILL
BE 28V DC AT THE
POSITIVE LEAD ON THE
STARTER MOTOR FOR
90 SECONDS.
DO A CHECK FOR 28V DC AT THE POSITIVE LEAD ON THE STARTER MOTOR (WDM 49-31-01).
IS THERE 28V DC AT THE POSITIVE LEAD?
NO YES
6 MOVE THE APU MASTER SWITCH
TO THE "OFF" POSITION.
CONNECT THE NEGATIVE LEAD
TO THE STARTER MOTOR.
EXAMINE THE CIRCUIT FROMTERMINAL X1 TO TERMINAL X2, OF THE START RELAY R5 (WDM 49-31-01).
IS THERE AN OPEN CIRCUIT?
NONO
7 DO A CHECK FOR 28V DC AT
67 REPAIR THE CIRCUIT FROM
THE START RELAY R5, TERMINAL THE START RELAY R5, TERMINAL
A1 (WDM 49-31-01). A1, TO THE "AUX POWER UNIT
IS THERE 28V DC AT START" CIRCUIT BREAKER, C798 TERMINAL A1? (WDM 49-31-01). 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：737-300 400 500 AMM 飞机维护手册 AIRBORNE AUXILIARY POWER 1(27)
