DOC AIRBUS | AMM A320FGENERAL - POWER PLANT - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
1. V2500 POWER PLANT
A. General
(1) All the power plant components and connectors are identified by a Functional Item Number referred to as the FIN.
(2) All the connectors are of the rear release type. All the contacts are removed and inserted from the rear of the connector. This allows individual replacement of crimp contacts without damage to the connector.
(3) The connectors have backshells to relieve stress and prevent force on the cable leads at the contact joints. The individual circuit shields (braided layer) connect to the backshell ground interface. The backshells have a grounding ferrule which goes into the body of the backshell and gives a full peripheral ground termination.
(4) The manufacturer requirements of the connectors are more than the military specification. When you order a connector, you must order by the connector part number and vendor code only. Do not order by the military specification number.
(5) Unless specified differently, all square flange-mounted receptacles must be installed with the main polarizing keyway forward on horizontal surfaces, and upward on vertical surfaces.
NOTE: This data does not apply to vendor accessory-mounted receptacles.
(6) All harness connectors must be visually examined to make sure that they are clean and have no pin or contact damage, before they are connected to their related receptacles.
(7) When engaged with their related receptacles, the coupling nuts of all the connectors must be continuously tightened by hand until the visual indicator color bands cannot be seen and the coupling nuts are fully tightened.
NOTE: This condition can be examined if you try to carefully shake and tighten the connector body at the same time.
(8) Make sure that the connectors are fully tightened. Where access to the connectors is not easy, soft jaw pliers or a mini strap wrench can be used.
NOTE: Because of the different standards of connector specifications used on the engine, it will be necessary to obey the recommended torque values, for the related shell dimensions, from the connector specifications.
(9) The ratchet-type lock mechanism, on all connectors and back-clamps, must operate correctly, which will be felt when they are tightened.
(10) Connectors, shells and back-clamps which are wire-locked, must be locked together they are sorted by ATA Chapter 70-40-11.
(11) You must inspect each cable assembly before you disassemble the assembly.
(a) Examine each cable assembly for the conditions that follow:
1 Cable for chafed insulation or worn braid
2 Cable for damaged sleeves
3 Broken thermocouple terminals or lugs
4 Connectors for bent, broken or recessed contacts
5 Connectors for worn or stripped threads
6 Backshells for broken, worn or stripped threads.
(b) Replace all the detail parts that show too much damage. (Refer to the applicable removal, installation or test procedure in Chapter 70-71-20.).
(12) All the connectors are not the same. Carefully examine the connectors for the correct FIN, part number, and connection location to prevent possible cross-connection of the connectors.
(13) A sharp bend, twist or pull can cause damage to the wires and wire bundles. This type of force can cause damage to the conductor.
(14) Good standard shop practices and safety precautions should be followed at all times. This prevents injury to persons and damage to the equipment.
(15) You must replace a wire or cable with the same type of wire. To get the correct data on the wire type and wire length, you must refer to the AWL. Refer to the applicable installation and test procedure in Chapter 70-71-20.
(16) Wire Identification. All the wires are identified with a label on each wire. The identification of the wire label number is shown below.
Example of a wire identification code is 5A001W20
Example of a wire identification code is 5A001W20
| 5 A 001 W 20 |
| - - --- - -- |
| 5 - Manufacturer |
| __ |
| 5 = JAEC |
| 8 = SHORTS |
| 9 = ROHR |
| A - Individual loom |
| - |
| A thru W |
| 001 - Wire number |
| --- |
| W - Wire color code |
| -- |
| B - Blue |
| F - Orange |
| R - Red |
| W - White |
| Y - Yellow |
| A - Alumel (Green) |
| C - Chromel (White) |
| 20 - Wire gage number |
| -- |
(17) Clip / Clamp Data:
All clips must hold the harness in bundles, to make sure it cannot move through the clips.
Always make sure that the wires and clip protection materials are not trapped when the clips are closed.
Also the clips must not hold the bundles too tightly, because this causes damage to the clip bundles.
When two or more harness bundles go through the same clip, the bundles must be parallel to each other, through the clip, to form one harness bundle.
Because of known differences in the outer diameters of the harness bundles, the specified clips will possibly be too large or too small. It is thus permitted to use clips three clip sizes above or below the usual dimension. This procedure only applies to open wire and closed electrical harnesses.
At general locations the clips must not be installed above the clip centerline tie mark, if available. They must be installed on the correct side of the tie mark in the limits of the clip area.
All clips must hold the harness in bundles, to make sure it cannot move through the clips.
Always make sure that the wires and clip protection materials are not trapped when the clips are closed.
Also the clips must not hold the bundles too tightly, because this causes damage to the clip bundles.
When two or more harness bundles go through the same clip, the bundles must be parallel to each other, through the clip, to form one harness bundle.
Because of known differences in the outer diameters of the harness bundles, the specified clips will possibly be too large or too small. It is thus permitted to use clips three clip sizes above or below the usual dimension. This procedure only applies to open wire and closed electrical harnesses.
NOTE: Only clips from the same part number range must be specified and used.
When the bundle dimension is between the specified clip steps, the larger clip must be used. The bundle diameter can then be increased with tape (Material No. V02-148). At general locations the clips must not be installed above the clip centerline tie mark, if available. They must be installed on the correct side of the tie mark in the limits of the clip area.
(18) Terminal junction block contacts
(a) All the contacts must be correctly and fully attached to their related locations.
(b) All the contact locations that are not used must have the correct blanks installed.
(19) Terminal lugs
(a) Before the wires are connected to the terminal lugs, visually examine all the connection points and terminal lugs for damage.
(b) Make sure that the surfaces of all the electrical ground points are prepared, as specified in the related specification.
(c) The terminals must not be bent, unless specified differently.
(20) Harness routing and clearances
(a) The data that follows gives the minimum clearances necessary, between the harnesses and adjacent parts, when the engine is assembled. The minimum clearance necessary, during a light thumb pressure, is specified as: sufficient pressure to tighten the harness, without movement through the adjacent clips.
(b) The harness bundles must follow, as near as possible, the specified routing, to keep an angle of 90 degrees with the clip.
(c) Where adjustment is necessary, to keep the minimum clearance necessary, the clips must be loosened to tighten the harness, then the clips must be tightened again.
(d) To get better clearances and routing, it is permitted to turn the clips by plus or minus 10 degrees from their specified locations. The minimum clearance is kept and no more force is put on the harness bundles, clip protection materials or connector terminals.
(21) Minimum clearances necessary when assembled
(a) The minimum clearance between a harness and adjacent sharp edges, movable parts, or equipment that transmit flammable fluids is 6.4 mm (0.25 in.).
(b) The minimum clearance between a harness and other adjacent parts is 2.6 mm (0.10 in.).
(c) The minimum clearance between a harness area, with a rub protection and other adjacent parts, is also 2.6 mm (0.10 in.).
(d) Maximum condition clearances must be available for harnesses near high-temperature ducts, which give off heat.
(e) Where harnesses are attached to support trays or brackets with clips, the harness bundle can touch the support smooth surface if the harness is sufficiently held, to prevent related movement between the harness bundle and the support.
(f) Cables or wires which connect to equipment that transmit flammable fluids or gasses, must have routings away from the equipment connections and pipes, unless specified differently.
(g) Harness bundles, cables or single wires, must not be attached to or held by equipment or pipes that transmit fuel, unless specified differently.
(22) Control of tension in wire bundles
(a) The harness must not be too loose when installed, and the instructions that follow must be obeyed:
1 Unless specified differently, the harness must be sufficiently loose to install and remove the connectors or terminal lugs, without the interference of adjacent harness clips.
2 If a connector/receptacle, pin/socket, or terminal lug is damaged, the harness must be sufficiently loose to permit the procedure that follows:
a One more connection at connector positions 6.35 mm (0.25 in.) approximate tension.
b Two more connections at terminal lug positions 10.16 mm (0.40 in.) approximate tension.
3 If the harness bundle is too loose, it must, if possible, be absorbed between the clip positions before it.
4 The above instruction must keep the minimum clearances specified in step (20).
NOTE: The minimum clearance is more important than that specified in step (22) .2 above.
5 If all the above instructions are obeyed and the harness bundle is too loose when examined again, refer to the applicable wire harness lacing procedure in Chapter 70-71-14.