CAUTION: IF THE DATA BASE IN THE SYSTEM UNDER TEST HAS
_______ EXPIRED, USE OF A DATE WITHIN THE VALIDITY PERIOD SHOULD BE USED FOR TEST PURPOSES ONLY IN THE FOLLOWING TEST.
(f) Press ENT pushbutton on the CDU. POSITION page is displayed if the entered date is valid, or DATA BASE EXPIRED is displayed if the entered date is invalid.
NOTE: If the data base has expired, turn the INS off, then
____ back on. Enter a date within the validity period for this test.
(2)
Annunciator and Display Tests
(a)
Place mode selector switch on each MSU to STBY.
(b)
Press BRT and DIM pushbuttons on each CDU and verify that display brightens and dims.
(c)
Press STS pushbutton on each CDU; verify that SYS STS/TEST page appears on each CDU display with ALIGN between entry line markers.
(d)
Slew each CDU display up until SYSTEM TEST page appears (on each display) with DISPLAY TEST between entry line markers. Press EXP on each CDU and verify that: 1) Display pattern rotates through each of the five lines on
each CDU display. 2) On each CDU, the WRN, BAT, ALR, and OFS annunciators come on.
(e)
On each MSU, press ALIGN and BATT annunciators; verify that ALIGN annunciator comes on amber and BATT annunciator comes on red.
(f)
To end test, press STS or EXP pushbutton on each CDU.
(3)
If INS is no longer required, restore airplane to normal.
I. On airplanes with Delco INS, test Inertial Navigation Unit Batter Charger
(1)
If required, prepare for test as described in paragraph D.
(2)
Open and secure cover on battery unit associated with navigation unit under test.
(3)
Connect 0 to 3 amp dc ammeter across battery circuit breaker. (See figure 501.)
(a) Connect positive meter terminal to left circuit breaker terminal (viewed from front of battery unit).
EFFECTIVITY
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(b) Connect negative meter terminal to right circuit breaker terminal (viewed from front of battery unit).
CAUTION: USE EXTREME CARE WHEN CONNECTING/DISCONNECTING METER
_______ LEADS TO CIRCUIT BREAKER TERMINALS. IF METER LEAD FALLS OR BRUSHES AGAINST A GROUNDED STRUCTURE A DAMAGING SHORT COULD OCCUR.
(4) Draw power from battery unit using the following steps:
(a)
Check that circuit breaker on front panel of INS battery unit is closed.
(b)
Set mode selector switch on appropriate MSU to STBY position (panel P5).
(c)
Open both PWR-INS circuit breakers on panels P7 (or P126) for appropriate INS system. Observe that BAT light illuminates on appropriate control/display unit.
(d)
After approximately 30 seconds, close both circuit breakers opened in step (c).
NOTE: A warning horn in nose wheel well may actuate during
____ above step. This horn will stop sounding after INS power circuit breakers (opened in step (c)) are closed.
(5)
Open circuit breaker on front of battery unit.
(6)
Observe the battery charging current on the ammeter.
(a)
When the INS is turned on, or when the battery voltage is
24.0 volts or less; the ammeter will indicate between 1.7 to
2.3 amperes. The ammeter will remain at this indication until the battery voltage has increased to 29.0 volts.
(b)
At a battery voltage of 29.0 volts the ammeter will indicate between 15 to 55 milliamperes (40 milliamperes nominal). The ammeter will remain at this indication until the battery voltage has decreased to 24.0 volts. The ammeter will then return to the 1.7 to 2.3 ampere indication.
(7)
After proper indication has been observed, set mode selector switch on appropriate MSU to OFF position.
(8)
Close circuit breaker on front panel of battery unit.
(9)
Disconnect ammeter leads and close and secure battery unit cover.
J. Restore Airplane to Normal
(1) Ensure that all mode selector switches are in OFF position.
CAUTION: FAILURE TO MOVE MODE SELECTOR TO OFF WILL CAUSE INS TO
_______ AUTOMATICALLY SWITCH TO BATTERY POWER AND A WARNING HORN IN THE NOSE WHEEL WELL TO ACTUATE WHEN POWER IS REMOVED FROM THE AIRPLANE.
(2)
Remove electrical power if no longer required (Ref 24-22-00).
(3)
Remove equipment cooling if no longer required (Ref 21-58-00).
EFFECTIVITY
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本文鏈接地址：747飛機維護手冊AMM CHAPTER 34 - NAVIGATION 第34章導航3(65)
