DOC AIRBUS | AMM A320FWIRE HARNESS LACING PROCEDURE - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
1. General
** ON A/C NOT FOR ALL - This chapter gives the procedure to lace the wire harness after the replacement of an individual wire bundle or damaged lacing.
- Consumable materials can be replaced with equivalent items.
2. Standard Equipment
** ON A/C NOT FOR ALL - None
3. Consumable Material
** ON A/C NOT FOR ALL | !-------------!------------------!-------------------------------------------! |
| ! Part No. ! Supplier Code ! Designation ! |
| !-------------!------------------!-------------------------------------------! |
| ! 18DR ! 82110 ! Tape, Lacing (black) ! |
| ! 718G ! 82110 ! Tape, Lacing (white) ! |
| ! TTL20A ! S5217 ! Thermotite No. 200 (black) ! |
| ! V07-084 ! K7750 ! Silicone Varnish ! |
| ! ! K6835 ! ! |
| ! V02-148 ! 76381 ! Adhesive Tape (Electrical) ! |
| ! ! 94960 ! ! |
| ! ! K0993 ! ! |
| ! ! K6835 ! ! |
| !-------------!------------------!-------------------------------------------! |
4. Standard Practices for Wire Harness Lacing
A. Procedure
(1) Use the PN 718G Lacing Tape (white) for general lacing of the wire harness. Use the PN 18DR Lacing Tape (black) on the wire harness to show the clamp positions on the harness.
NOTE: Do not use lacing tape on any wire harness that does not have lacing tape installed before you repaired the harness, such as wire harnesses with all wire braid or tape wrap.
(2) Lace the wire bundles in a neat arrangement and the lacing must not be loose.
(3) The distance between the individual laces on the wire bundles is 50.8 mm (2 in.) maximum.
Wire Bundle(4) Use a clove hitch knot to lace the wire bundles and then tie a square knot to hold the lacing.
(5) A bundle of two or more wires must be laced together.
(6) The wire harness must be laced two times at the same position when the harness is more than 38.1 mm (1.50 in.) in diameter.
(7) All wire bundle breakouts must be in the same plane as the bundle center line and go along the same direction of the breakout.
(a) All wire bundle breakouts must make smooth curves, from their primary bundle, and go to the parts to which they will be connected or attached to with clips.
(b) To prevent too much force on the breakout tie, the bundle breakout must be in the same plane as the primary bundle. If this is not correct, during the harness installation, the primary bundle must be locally twisted to get the necessary position.
(c) The bundle breakout must not touch other wires or parts, after its exit from the primary bundle.
(d) If the bundle breakout and primary bundle do touch, the bundle breakout must be attached to the primary bundle to prevent movement between the two bundles, at the points where they touch
All the wire bundles must be laced as shown on the figure.
All the wire bundles must be laced as shown on the figure.
(8) The wires in the harness groups must be put as straight as possible, with a minimum of twists before you lace the harness.
(9) Cut the lacing tape ends to a minimum of 8 mm (0.31 in.) from the knot.
5. General Lacing
Lace the wire harness by doing steps 1 thru 8. Use PN 718G Lacing Tape. Lace the wire harness two times at the same position when the harness is more than 38.1 mm (1.50 in.) in diameter by doing step 9.
Lace the wire harness by doing steps 1 thru 8. Use PN 718G Lacing Tape. Lace the wire harness two times at the same position when the harness is more than 38.1 mm (1.50 in.) in diameter by doing step 9.
A. Parallel and Across Bundles
(1) When harnesses are parallel to or go across each other near a contact exit, they must be attached together, to prevent movement in relation to each other.
(2) When necessary, apply adhesive tape (electrical) (Material No. V02-148) on one of the harnesses, at the points where they touch and rub.
NOTE: The bundles must not be forced together. Before they are attached together, apply a light thumb pressure to make sure they are free to touch each other.
(3) When necessary, release the harnesses from each other. Loosen the adjacent clips, adjust the harnesses, then tighten the clips again.
B. Bird Caging
(1) Bird caging is the separation of bundle wires, between general tie positions on the harness, which can cause bulges and gaps in the bundle.
(2) If, during harness installation, because of the routing and position of the harness, bulges and gaps are found in the harness bundle between ties which are more than the average wire diameter, a tie must be made at that point.
(3) If bulges and gaps are found on a radius bundle, it can be removed by local twists or ties.
C. Tying Instructions
(1) All cables and wires must be made into correct bundles, then attached together with ties. No insulation, cable or wire must be damaged or stressed by ties that are too tight.
(2) Apply silicone varnish (Material No. V07-084) to all tied knots, unless specified differently.
D. Bend Radii
(1) General recommended bend radii:
(a) 10 x wire / bundle outer diameter, unless specified differently.
(b) Sharp bends must be prevented in single and multiplied wire cables at clips, connector backshells, and where cables stop at terminal lugs.
(c) Make sure that all changes in the direction of harness routing use the largest bend radius possible.
6. Lacing with Two Wire Bundles
Lace the wire harness when there are two wire bundles in a harness assembly.
Lace the wire harness when there are two wire bundles in a harness assembly.
A. Procedure
(1) Cut a piece of PN 718G Lacing Tape to lace the wire bundle.
(2) Lace the No. 1 and No. 2 wire bundles together.
(a) Start the lacing tape end B at the top of the No. 1 bundle.
(b) Wind end B of the lacing tape around the No. 1 bundle in a counterclockwise direction one complete turn.
(c) Continue to wind end B around the No. 1 bundle in a counterclockwise direction and put it between the No. 1 and No. 2 bundles.
(d) Wind end B around the No. 2 bundle in a clockwise direction one turn and put it between No. 1 and No. 2 bundles.
(e) Continue to wind end B around No. 1 bundle in a counterclockwise direction one turn and put it between the No. 1 and No. 2 and pull ends A and B tight. The lacing will look like an 8.
(f) Do steps (a) thru (e) until you wind the bundles six times. Refer to step 2.
(g) Wrap end B around the six laces between the No. 1 and No. 2 bundles three turns. Refer to step 3.
(h) Pull tightly on ends A and B and make a square knot.
(i) Cut the tape ends A and B to 8 mm (0.31 in.) minimum from the knot.
7. Lacing with Three Wire Bundles
Lace the wire harness when there are three wire bundles in a harness assembly.
Lace the wire harness when there are three wire bundles in a harness assembly.
A. Procedure
(1) Cut a piece of PN 718G Lacing Tape to lace the wire bundles.
(2) Lace the No. 1, No. 2, and No. 3 wire bundles together.
(a) Start the lacing tape end B at the top of the No. 1 bundle. Refer to step 1.
(b) Wind end B of the lacing tape around the No. 1 bundle in a counterclockwise direction one complete turn.
(c) Continue to wind end B around the No. 1 bundle in a counterclockwise direction and put it between the No. 1 and No. 2 bundles.
(d) Wind end B around the No. 2 bundle in a clockwise direction and between the No. 2 and No. 3 bundles.
(e) Continue to wind end B around the No. 3 bundle in a counterclockwise direction and put it between the No. 2 and No. 3 bundles.
(f) Continue to wind end B around the No. 2 bundle in a clockwise direction and put it between the No. 2 and No. 1 bundle.
(g) Continue to wind end B around the No. 1 bundle in a counterclockwise direction to contact end A. Pull ends A and B tight. The lacing will look like two 8. Refer to step 1.
(h) Do steps (a) thru (g) until you wind the bundles six times. Refer to step 2.
(i) Wind end B around the six laces between the No. 2 and No. 3 bundles three complete turns. Refer to step 3.
(j) Continue to wind end B around the six laces between the No. 1 and No. 2 bundles three complete turns. Refer to step 3.
(k) Pull tightly on ends A and B and make a square knot.
(l) Cut ends A and B to 8 mm (0.31 in.) minimum from the knot.
8. Lacing a Clamp Position on a Harness Assembly.
A. Procedure
(1) Lace the datum clamp position.
(a) Lace the datum clamp lacing positions 8.5 mm (0.33 in.) on each side of the datum clamp position. Use PN 18DR Lacing tape.
(b) Lace the datum clamp lacing positions by doing steps 1 thru 8.
(2) Lace the general clamp positions.
(a) Lace the general clamp position with PN 18DR Lacing Tape.
(b) Lace the general clamp position by steps 1 thru 8.
(c) Lace the general lacing positions with PN 718G Lacing Tape.
(d) Lace the general lacing positions 25.4 mm (1 in.) on each side of the general clamp position by doing steps 1 thru 8.
(e) Coat the general and datum lacing tape knot ends with TTL20A Thermotite or equivalent.
NOTE: Do not coat the knot.