79+/-9 deg C 86+/-8.9 deg C
TASK 21-61-07-705-001
2. Zone Duct Overtemperature Switch Test
_____________________________________
A. Special Tools and Equipment
(1)
Tempcal Thermocouple and Thermal Switch Tester - Howell Model H294 or H394.
(2)
Power Cable, Howell Model BH23859-115 or BH23859-230
(3)
Heater Cable, Howell Model BH405
(4)
Heat Probe, Howell Model BH17365.
B. References
(1)
06-09-03/201, Body Section 44 Access Doors and Panels
(2)
21-61-07/401, Zone Duct Overtemperature Switch
(3)
24-22-00/201, Manual Control
(4)
36-00-00/201, Pneumatic System
(5)
IPC 21-28-51 Fig. 2
(6)
IPC 21-61-07 Fig. 1 and 2
(7)
IPC 21-61-64 Fig. 1
(8)
WDM 21-61-93
(9)
SSM 21-61-05
C. Access
(1) Location Zone 123 Forward Cargo Container Compartment Aft Half, LH 133 Air Conditioning Equipment Bay, LH 243 Area Above Ceiling, LH 244 Area Above Ceiling, RH
D. Prepare for the Test
S 865-002
(1) Apply electrical power (Ref 24-22-00/201).
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A
747-400 MAINTENANCE MANUAL
S 865-004
(2)
Release the pressure in the pneumatic system (Ref 36-00-00/201).
S 025-008
(3)
Remove the overtemperature switch (Ref 21-61-07/401).
S 435-009
(4)
Connect the electrical connector to the overtemperature switch.
S 865-010
(5)
Make sure this circuit breaker is closed on the P6 main power distribution panel:
(a) 6F30, MASTER TRIM AIR CONT
S 865-014
(6) Make sure the TRIM AIR switch on the P5 overhead panel is set to ON.
E. Overtemperature Switch Test
S 865-028
(1)
Put the POWER switch to the OFF position on the H294 or H394 Thermal Switch Tester.
S 485-029
(2)
Connect the power cable BH23859-115 or BH23859-230B to the POWER receptacle and to the applicable power source (115 or 230 volts ac, 50-60 Hz).
S 485-030
(3)
Connect the heater cable BH405 to the heat probe BH17365 and to the HEATER receptacle on the Thermal Switch Tester H294 or H394.
NOTE: Test equipment accuracy can be affected by air movement in
____ the area of the Tempcal probe. Always attempt to reduce the amount of air movement near the Tempcal probe.
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747-400 MAINTENANCE MANUAL
S 425-026
(4)
Connect the overtemperature switch to the heat probe BH17365.
S 725-027
(5)
With the H294 TESTER, do the steps that follow:
(a)
Put the POWER switch to the ON position on the thermal switch tester
(b)
Make sure the red light over K in the TEST INPUT display comes on and the red light over C in DEGREES display comes on.
(c)
Make sure the CONTROL TEMP shows 0, and the TEST INPUT and HEATER TEMP show the ambient temperature.
(d)
Push the DSPY TEST button on the keyboard.
(e)
Make sure all lights in TEST INPUT and DEGREES display come on.
(f)
Make sure the TEST INPUT shows 88.88 and the HEATER TEMP and CONTROL TEMP show 8888.
(g)
Push the SET TYPE button on the keyboard.
(h) 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：747-400 AMM 飞机维护手册 空调 AIR CONDITIONING 2(141)
