(2)
Make sure that the contacts are correctly locked in the cavities by lighthy pulling the cable rearwards. No significant movement must be felt.
(3)
Make sure the connector backshell is correctly installed by lightly pulling the locking wire (if installed) No significant movement must be felt.
20-52-12 Page 920-52-13 Page 1
____________________________________________CHECK FOR AGEING - DESCRIPTION AND OPERATION
R _______1. General
This chapter gives general inspections of the electrical installation to find (and repair) possible deterioration because of ageing.
______________2. Bundle Sagging
R A. Description of wire bundle sagging
Bundle sagging is an increase in the length of bundle between two adjacent attachments that causes the bundle to hang down too much. Sagging occurs when the bundle gradually moves from its initial trajectory because of slippage at its attachments. When this movement starts, it usually gets faster with time. Sagging can cause: - Possible loss of segregation, - Wire damage because of chafing between the bundle and the adjacent structure and/or equipment and/or wiring, - Drip loops to become straight, - Too much tension in the bundle between attachments or at connectors.
R B. How to find bundle sagging on the aircraft.
R R ____NOTE : Cable bundles usually hang down a little between adjacent attachments. This is not an incorrect condition and action is
R R R necessary only if the bundle moves from its initial trajectory and hangs down too much between two adjacent attachments.
To find sagging, look for these conditions: - A bundle that hangs down too much between two adjacent attachments (Ref.20-52-12), - No more segregation between bundles (Ref.20-52-12), - Risk of chafing between the bundle and the adjacent structure and/or equipment and/or wiring (Ref.20-52-12), - Missing drip loops/bundle pulled straight. (Ref. Fig. 001)
R R R R R ____NOTE : The increased lenght between the attachments can come from: - Drip loops, - Stowed bundle, - Play in the bundle at other locations.
Check For Ageing - Reduced length or exessive tension example
Figure 001
20-52-13 Page 220-52-13 Page 3
R C. Repair Procedure
R R R _______CAUTION : WHEN YOU REMOVE BUNDLE ATTACHMENTS, TEMPORARILY SUPPORT AND/OR INSTALL PROTECTION FOR THE BUNDLE TO PREVENT DAMAGE TO THE BUNDLE.
R R - Do a check of the bundle installation upstream and downstream of the sagging to find the location(s) where there is too much tension or reduced length. (Ref. Fig. 001)
R
R R R R R R R R - Remove all the bundle attachments between the sagging and the location(s) of reduced length/too much tension. - Re-distribute the sagged length to the location of the excessive tension/reduced length. - Adjust the bundle and do a check for: - Loss of segregation, - Risk of chafing, - Too much tension, - Presence of drip loops, - Adjust the bundle again if necessary, - Install self adhesive tape ASNA5107 (Ref. process described below) at the locations of all removed attachments, - Install the bundle attachments, (Ref. procedure below).
R R ____NOTE : For correct attachment, the internal diameter of the attachment, to be installed must be slightly smaller than the diameter of the bundle with its adhesive tape.
R - Pull lightly on the bundle to make sure that it is correctly attached.
R D. ASNA5107 Self Adhesive Tape Installation Procedure.
_______CAUTION : PULL THE TAPE TIGHT IN THE PROCEDURE THAT FOLLOWS. THIS WILL MAKE SURE THAT YOU ATTACH THE TAPE CORRECTLY AROUND THE BUNDLE.
(1) General Procedure - Remove all cable ties or lacing tape at all securing locations over a lenght of 50 to 60 mm on each side of the attachment. - Insert one end of a piece of self adhesive tape ASNA5107 through the bundle to separate the bundle in 2 equal parts . (Ref. Fig. 002) The tape must come out of the bundle by 10 to 20 mm.
Check for ageing - Installation of Adhesive Tape
Figure 002
20-52-13 Page 420-52-13 Page 5
R R - Pull firmly on the tape and wrap it around the bundle. The first wrap and the last wrap must have a 100% overlap. The other wraps must have a 50% overlap. - Attach the two ends of the tape with cable ties NSA935401. (Ref. Fig. 003) - Install all the removed cable ties.
(2) Procedure for an over-lenght stowage loop (Ref. Fig. 004) - Remove all cable ties or lacing tape on the over-length part of the bundle. - Make a loop to stow the bundle over-length. - At the location where the loop touches the bundle, insert one end of the adhesive tape between the two parts of the bundle. - Install two cable ties NSA935401 at each side of the location of the adhesive tape. - Pull firmly on the tape and wrap it around the bundle.
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：A320 ESPM Electrical Standard Practices Manual 4(65)
