(c)
Continue to observe the meter value as you slowly install power supply A. 1) When the meter value is less than 2 ohms, the power supply
connector is in the correct position. 2) If the meter value is not less than 2 ohms, adjust the power supply mating bracket.
S 424-033
(2) Install the MAWEA power supply B:
(a)
Connect one terminal of the meter to the electrostatic jack located at the bottom right corner of the MAWEA chassis.
(b)
Connect the other terminal of the meter to the "B" GND test point on the MAWEA POWER SUPPLY monitor panel located at the top center of the MAWEA chassis. 1) Make sure the meter value is greater than 10 megaohms.
(c)
Continue to observe the meter value as you slowly install power supply B.
(d)
When the meter value is less than 2 ohms, the power supply connector is in the correct position.
(e)
If the meter value is not less than 2 ohms, adjust the power supply mating bracket.
S 864-021
(3)
Remove the DO-NOT-CLOSE tags and close these circuit breakers:
(a) P7, Overhead Circuit Breaker Panel
1) 7A01, MAWEA PWR A
2) 7B01, MAWEA PWR B
(4)
Supply electrical power (AMM 24-22-00/201).
S 714-017
(5)
Do a test of the new MAWEA power supply as follows (preferred):
(a)
Make sure the applicable PS-A or PS-B light on the MAWEA monitor panel is not on.
(b)
Make sure the EICAS Status messages, MAWEA PWR SUPPLY and MAWEA SCID CARD, do not show on the bottom display.
S 864-016
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747-400 MAINTENANCE MANUAL
(c) If one of these EICAS messages does show, do these steps: 1) Open the applicable MAWEA power supply circuit breaker. 2) Reseat the MAWEA power supply. 3) Close the applicable MAWEA power supply circuit breaker. 4) Make sure again that the EICAS Status messages, MAWEA PWR
SUPPLY and MAWEA SCID CARD, do not show on the bottom display.
NOTE: If an EICAS message still shows, do the
____ removal/installation procedure again. When the power supply is removed, push at the side of the "floating" chassis receptacle laterally to align the receptacle approximately at the center line of the connector cutout.
S 714-018
(6) Do a test of the new MAWEA power supply as follows (alternate):
(a)
Make sure the applicable PS-A or PS-B light on the MAWEA monitor panel is not on.
(b)
Use a voltmeter at the jacks on the MAWEA monitor panel to do a check of the applicable power supply output voltages. 1) Make sure that +5.7 volts, -12.7 volts, and +12.7 volts are
present at the three jacks.
(c)
If the output voltages are not present, do these steps: 1) Open the applicable MAWEA power supply circuit breaker. 2) Reseat the MAWEA power supply. 3) Close the applicable MAWEA power supply circuit breaker. 4) Do a check again for the applicable power supply output
voltages.
NOTE: If the output voltages are still not present, do the
____ removal/installation procedure again. When the power supply is removed, push at the side of the "floating" chassis receptacle laterally to align the receptacle approximately at the center line of the connector cutout.
S 434-028
(7)
Tighten the screw in the center of the power supply.
S 434-029
(8)
Tighten the wedge clamps to 5 inch-pounds on each side of the power supply unit.
(9)
Put the access door over the power supply.
(10)
Tighten the four screws that hold the access door in position.
S 414-030
S 414-031
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本文链接地址：747-400 AMM 飞机维护手册 指示/记录系统 2(11)
