S 434-060

 (7)  
Install the two clamps on both ends of the fan.

 S 434-045

 (8)  
Install the electrical connector, DB8270, on the fan.

 S 864-046

 (9)  
Remove the DO-NOT-CLOSE identifiers and close these circuit
 breakers:

 (a)  
Right Power Distribution Center, P415
 1) 415H35, VENT FAN PWR LWR AFT CARGO

 (b)  
Overhead Circuit Breaker Panel, P180
 1) 180E11, CARGO VENT AFT CONT

 D. Do the Installation Test of the Fan
 S 864-047
 (1)  
Supply electrical power (AMM 24-22-00/201).

 (2)  
Make sure the aft or the bulk cargo door is fully open.

 S 864-049

 (3)  
Make sure the cargo air conditioning flow control switch on the overhead P461 panel is set to OFF.

 S 864-048
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747-400 MAINTENANCE MANUAL
 (4)  S 864-061Open, then close this circuit breaker on the main power distribution panel, P6: (a) E34, A/C CONT CARGO - PCA
 (5)  S 864-050Put the AFT CARGO VENT switch just forward of the cargo door to ON.
 (6)  S 714-051Make sure the fan operates. (a) Make sure air comes from the ceiling outlets.
 (7)  S 794-054Examine the fan to duct connections for air leaks. (a) Light leakage is permitted. (b) If the leakage is strong, align the joints and tighten the clamps.
 (8)  S 864-062Put the AFT CARGO VENT switch to OFF.
 (9)  S 414-055Install the cargo compartment sidewall lining (AMM 25-52-01/401 or AMM 25-55-02/401).
 S 864-056

 (10)
 Close the aft or the bulk cargo door. S 864-057

 (11)
 Remove electrical power if it is not necessary (AMM 24-22-00/201).

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747-400 MAINTENANCE MANUAL
 FORWARD OVERBOARD VALVE - REMOVAL/INSTALLATION
______________________________________________
 1.  General_______
 A.  There are two tasks in this procedure, one for removal and one for installation of the forward overboard valve.
 B.  To get access to the forward overboard valve you must go through the main equipment center.
 TASK 21-26-15-004-001
 2.  Forward Overboard Valve Removal (Fig. 401)_______________________________
 A.  References
 (1)  
IPC 21-26-15 Fig. 1

 (2)  
WDM 21-23-11

 (3)  
SSM 21-23-01

 B.  Access
 (1)  Location Zone 115 Area Between Nose Gear Well and Fuselage, LH
 C.  Procedure
 S 864-002
 (1)  Open circuit breakers as follows for removal of the forward overboard valve:
 (a)  
P6 Main Power Distribution Panel
 1) 6J32 FWD OVBD VLV CONT
 2) 6J33 ESC MISC PC ASSY

 (b)  
P180 DC Power Distribution Panel
 1) 180J20 FWD OVBD VALVE POWER

 S 014-003
 (2)  
Get access to the valve in the space adjacent to the left side of nose gear wheel well.

 (3)  
Remove the electrical connector DV462 from the valve.

 (4)  
Loosen the clamps from each end of the valve.

 (5)  
Remove the valve.

 S 034-004
 S 034-005
 S 024-006
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