21-58-07
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BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400 MAINTENANCE MANUAL
S 864-011
(2)
Make sure the EQUIP COOLING selector, on the overhead panel, P5, is in the NORM position.
S 864-012
(3)
Supply electrical power (Ref 24-22-00/201).
S 714-013
(4)
Make sure the overboard exhaust valve moves to the open position.
S 864-014
(5)
Remove the electrical power, if it is not necessary
(Ref 24-22-00/201).
F. Do the Installation Test for the Switch
NOTE: Do this test when the ambient temperature is less
____
than 45°F (7°C).
S 824-015
(1)
From the outer side of the airplane, turn the manual drive collar of the overboard exhaust valve until the valve is open (Ref 21-58-12/401).
S 864-016
(2)
Make sure the EQUIP COOLING selector, on the overhead panel, P5, is in the NORM position.
(3)
Supply electrical power (Ref 24-22-00/201).
(4)
Make sure the overboard exhaust valve moves to the closed position.
S 864-019
(5)
Remove the electrical power, if it is not necessary
(Ref 24-22-00/201).
S 864-017
S 714-018
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21-58-07
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BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400 MAINTENANCE MANUAL
EQUIPMENT COOLING OVERHEAT SWITCH - MAINTENANCE PRACTICES
_________________________________________________________
1. General_______
A. This procedure has instructions to do the tasks that follow:
(1)
Equipment Cooling Overheat Switch Cleaning
(2)
Equipment Cooling Overheat Switch Removal
(3)
Equipment Cooling Overheat Switch Installation
B. The overheat switch for the equipment cooling system is installed in the duct in the left sidewall of the forward cargo compartment.
TASK 21-58-08-102-023
2. Equipment Cooling Overheat Switch Cleaning (Fig. 201)__________________________________________
A. References
(1)
21-58-08/201, Equipment Cooling Overheat Switch
(2)
IPC 21-58-08 Fig. 1
(3)
WDM 21-58-19
(4)
SSM 21-58-02
B. Access
(1) Location Zone 121 Forward Cargo Compartment Forward Half, LH
C. Clean the Switch
S 022-019
(1) Do the Equipment Cooling Overheat Switch Removal (Ref 21-58-08/201).
S 162-020
CAUTION:_______BE VERY CAREFUL WHEN YOU HOLD THE SWITCH. YOU CAN EASILY CAUSE DAMAGE TO THE SWITCH IF YOU DO NOT HOLD IT CAREFULLY.
(2)
Remove the lint and the dirt from the switch.
(3)
Use a wet cloth to clean the probe of the switch.
S 162-021
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21-58-08
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BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400 MAINTENANCE MANUAL
S 422-022
(4) Do the Equipment Cooling Overheat Switch Installation (Ref 21-58-08/201).
TASK 21-58-08-002-001
3. Equipment Cooling Overheat Switch Removal (Fig. 201)_________________________________________
A. References
(1)
24-22-00/201, Manual Control
(2)
25-52-01/401, Containerized Cargo Compartment Ceiling and Sidewall Panels
(3)
IPC 21-58-08 Fig. 1
(4)
WDM 21-58-19
