DOC AIRBUS | AMM A320FGENERAL - POWER PLANT - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
1. CFM56-5A POWER PLANT
A. General
(1) The engine harnesses interconnect the airframe with the electrical components mounted on the engine. These harnesses provide electrical power to the various components. They also provide circuits for the transmission of signals for engine control and engine monitoring functions.
(2) Some of the harnesses are named for engine functions and others are named for the area of the engine or thrust reverser to which they apply.
(3) The harnesses have been constructed in different ways. In some instances there may be more than one version of a particular harness. Earlier versions of some harnesses were designed to be routed around the engine using P-clamps. Later versions of these harnesses were designed to be routed around the engine using fairlead clamps. Some harnesses have been improved by the addition of tubing to prevent wear and seal out moisture.
See next table for a list of engine harnesses.
See next table for a list of engine harnesses.
CFM56-5A Engine Harness Construction(1) Open bundle type harness:
(a) Some of the engine harnesses were designed using the concept of "open bundle" construction this is a very simple construction technique. The "open bundle" type of harness is constructed by tying individual wires or families of wires together by the use of tie string and then wrapping tape around the wires to bind them together. This type of harness is very easy to repair.
(b) The "open bundle" type wire harnesses are equipped with connector backshells. The backshell, when combined with the braided shield of the individual wires or cables, resist penetration of EMI/RFI into the system.
(2) Woven metal overbraid type harness:
(a) Some of the engine harnesses have been constructed using a woven metal-overbraid. These harnesses have a protective sleeve over the wires and a woven metal shield for lightning strike protection.
(b) These harnesses do not have a connector backshell. This type of harness is equipped with a connector adapter. The metal overbraid is attached directly to the connector adapter by the use of a lock ring.
(3) Woven metal overbraid and moisture-sealed harnesses:
(a) Some of the engine harnesses have been improved by the addition of tubing to prevent wear and to seal out moisture. These harnesses have a protective sleeve over the wires, a woven metal overbraid for lightning strike protection, and protective tubing to prevent wear and moisture contamination.
(b) The connectors on these harnesses are equipped with boots which are sealed to prevent moisture. All branches on this type of harness have transition fittings and tubes which are moisture sealed.
| ------------------------------------------------------------------------- |
| ! PART NUMBER ! HARNESS CONSTRUCTION ! AIRLINE EFFECTIVITY ! |
| !--------------!-------------------------------!------------------------! |
| ! 238W0903-503 ! Open Bundle Construction ! ALL ! |
| ! 238W0903-507 ! Open Bundle Construction ! ALL ! |
| ! ! ! ! |
| ! 238W0904-509 ! Woven Metal Overbraid ! AAA, AFR, BAW, ITF ! |
| ! 238W0904-519 ! Metal Overbraid/Moisture Seal ! ALL EXCEPT AAA and BAW ! |
| ! 238W0904-523 ! Metal Overbraid/Moisture Seal ! AAA, AFR, BAW, ITF ! |
| ! ! ! ! |
| ! 238W0904-511 ! Woven Metal Overbraid ! AAA, AFR, BAW, ITF ! |
| ! 238W0904-521 ! Metal Overbraid/Moisture Seal ! ALL EXCEPT AAA and BAW ! |
| ! 238W0904-525 ! Metal Overbraid/Moisture Seal ! AAA, AFR, BAW, ITF ! |
| ! ! ! ! |
| ! 238W0904-513 ! Open Bundle Construction ! AAA, AFR, BAW, ITF ! |
| ! 238W0904-515 ! Open Bundle Construction ! ALL EXCEPT AAA and BAW ! |
| ! 238W0904-517 ! Open Bundle Construction ! AAA, AFR, BAW, ITF ! |
| ! ! ! ! |
| ! 238W0905-507 ! Open Bundle Construction ! ALL ! |
| ! ! ! ! |
| ! 238W0907-505 ! Open Bundle Construction ! ALL ! |
| ! ! ! ! |
| ! 238W0908-511 ! Woven Metal Overbraid ! AAA, AFR, BAW, ITF ! |
| ! 238W0908-513 ! Metal Overbraid/Moisture Seal ! ALL EXCEPT AAA and BAW ! |
| ! 238W0908-515 ! Metal Overbraid/Moisture Seal ! AAA, AFR, BAW, ITF ! |
| ! ! ! ! |
| !321-404-701-()! Shielded and Sealed ! ALL ! |
| !321-404-801-()! Shielded and Sealed ! ALL ! |
| ! ! ! ! |
| ! 238D0912-501 ! Open Bundle Construction ! ALL ! |
| ! 238D0913-501 ! Open Bundle Construction ! ALL ! |
| ------------------------------------------------------------------------- |
C. Component Identification:
(1) All of the engine harness components and connectors are identified by a Functional Identification Number (FIN).
(2) The Equipment List, Section 92 of the AWL, lists all engine harness components by their Functional Identification Number.
(3) All connectors are not the same. Carefully examine the connectors for the correct FIN, part number, and connector location to prevent possible cross-connection of the connectors.
(4) Wire Identification
(a) You must replace a wire or cable with the same type of wire. Refer to the AWL for the correct wire type, wire length, and wire terminations.
(b) All engine harness wires are identified with either a number stamped on the wire or a number stamped on a sleeve which is on the wire. A typical Rohr engine harness wire number is 903001-20B-73-25. The breakdown of the wire number is shown below.
| 903 - 001 - 20 - B - 73-25 |
| 903 - The last three digits of the Rohr Harness Number |
| 903 = 238W0903 |
| 904 = 238W0904 |
| 905 = 238W0905 |
| 907 = 238W0907 |
| 908 = 238W0908 |
| 001 - The wire number |
| 001 through 999 |
| 20 - The wire size |
| 16 AWG |
| 18 AWG |
| 20 AWG |
| B - The wire color, if applicable |
| B = Blue |
| R = Red |
| Y = Yellow |
| G = Green |
| 73-25 - ATA reference for wire function |
(5) Before disassembly the engine harness should be inspected to determine the condition of the harness.
(a) Examine each harness and the branches of the harness for the following conditions:
1 Examine tape wrapping, lightening strike shielding or moisture seal tubing for wear or damage.
2 Examine sleeves, boots, transition fittings and tubing for cracks.
3 Examine connectors for bent, broken or recessed contacts.
4 Examine connectors for corrosion, worn or stripped threads.
5 Examine connectors and backshells for proper installation of safety wire.
6 Examine harnesses with woven lightning strike shielding to ensure proper trim and termination at the connector.
7 Examine backshells for broken, worn of stripped threads.
8 Examine connector backshells to ensure enough tape has been installed to provide a firm clamping action on the cable.
9 Examine shielded wire for proper trim of shields and jumper wires.
10 Examine shielded wire for proper trim of shield termination sleeve installations.
11 Examine wire for broken strands where insulated wire conductors are terminated on the connnector contacts.
12 On insulated wire, examine for broken shield strands where the insulated wire conductor is extracted from the shield (a maximum of 3 broken strands is allowed).
(b) Replace any component parts that show too much damage. Refer to the removal, installation and test procedures for additional information.