(b) Loosen the two bolts on the inboard mounting bracket. The bracket is located at the
inboard corner of the panel when you view the rear of the panel from the forward cargo
area.
NOTE: This step is done to get the required flat mounting surface for the power
distribution panel.
(c) Loosely install the four bolts [5] and washers [4] that hold the panel at the corners.
(d) Tighten the four bolts [5] to 82 ±18 in-lb (9 ±2 N·m).
1) Make sure you tighten the bolt located at the same corner as the inboard mounting
bracket last.
(e) Tighten the two bolts on the inboard mounting bracket to 32 ±2 in-lb (4 ±1 N·m).
SUBTASK 24-21-21-420-002
(2) Install the two ground straps on the power distribution panel, do the steps that follow:
(a) Install the straps on the ground stud on the power distribution panel.
(b) Install the two nuts [2] and washers [3] on the ground studs.
(c) Tighten the nuts to 190 ±10 in-lb (21 ±2 N·m).
SUBTASK 24-21-21-420-003
(3) Install the electrical connectors on the power distribution panels.
SUBTASK 24-21-21-420-004
(4) Do these steps to install the cooling duct on the power distribution panel:
(a) Install the gasket [10] on the duct and put the duct in position on the power distribution
panel.
(b) Install the four screws [8] and washers [9] that hold the cooling duct to the power
distribution panel.
(c) Tighten the screws [8].
SUBTASK 24-21-21-420-005
(5) Do these steps to install the power feeders on the power distribution panel:
(a) Use the identification tags to install the power feeders on the correct terminal studs.
(b) Install the nuts [6] and washers [7] on each terminal stud.
(c) Tighten the nuts to 190 ±10 in-lb (21 ±2 N·m).
NOTE: When you install and tighten the power feeders to the rigid bus assembly, there
may be some axial movement of the terminal studs (particularly TB5004 and
TB5008). A small amount of movement is normal and should not affect the
tightening of the nuts to the specified torque.
ILF 401, 406, 409, 410, 412, 416 PRE SB 737-24-1128
SUBTASK 24-21-21-700-001
CAUTION
THESE SCREWS MUST BE RE-TORQUED WHEN THE FEEDER CABLES
HAVE BEEN REMOVED AND RE-INSTALLED. FAILURE TO DO THIS STEP
CAN CAUSE SEVERE DAMAGE TO THE POWER DISTRIBUTION PANELS.
(6) Do a check of the torque on the six screws that hold the terminal studs to the rigid bus:
NOTE: The old rigid bus assemblies should have a decal on the back that reads:
737-600/700/800/900
AIRCRAFT MAINTENANCE MANUAL
24-21-21
Page 415
D633A101-ILF Jun 15/2019
ECCN 9E991 BOEING PROPRIETARY - Copyright © Unpublished Work - See title page for details
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