Protection
Figure 001
20-54-20 Page 2
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CLEANING - DESCRIPTION AND OPERATION
_______
1.
General This chapter gives the procedures related to the cleaning of electrical components that have contamination.
________________________
2.
Structure of the chapter
A. General Cleaning (Ref. 20-55-10).
B. Cleaning of Wires (Ref. 20-55-20).
C. Cleaning of Conduits (Ref. 20-55-30).
D. Cleaning of Standard Electrical Items (Ref. 20-55-50).
E. Cleaning of Bundle Attachments (Ref. 20-55-40).
20-55-00 Page 1
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GENERAL CLEANING - DESCRIPTION AND OPERATION
_______
1. General
R This chapter gives the general instructions related to the cleaning of electrical components that have contamination. The contamination can be:
-natural: the contamination agent is an identified material used in the aircraft systems (hydraulic fluid, fuel, ect.),
-accidental: the contamination agent comes from an external source (cleaning agent, etc.),
-the effect of ageing: the contamination agent is dust.
________________2. Safety Practices
_______
WARNING : BEFORE YOU USE A MATERIAL REFERRED TO IN THIS PUBLICATION, YOU MUST KNOW ALL OF THE APPLICABLE PRECAUTIONS. THESE PRECAUTIONS TELL YOU HOW TO:
-USE THE MATERIAL SAFELY,
-KEEP THE MATERIAL SAFELY,
READ THE SAFETY DATA SHEETS FROM THE MANUFACTURER OR THE SUPPLIER
OF THE MATERIAL TO LEARN THE RECOMMENDED PRECAUTIONS. OBEY YOUR
LOCAL REGULATIONS.
_______
WARNING : USE SOLVENTS/CLEANING AGENTS, SEALANTS AND OTHER SPECIAL MATERIALS ONLY WITH A GOOD FLOW OF AIR THROUGH THE WORK AREA. THESE MATERIALS ARE POISONOUS AND FLAMMABLE AND SKIN IRRITANTS. OBEY THE MANUFACTURERS INSTRUCTIONS. PUT ON PROTECTIVE CLOTHING. DO NOT GET THEM IN YOUR MOUTH. DO NOT SMOKE. DO NOT BREATHE THE GAS. GET MEDICAL HELP IF YOUR SKIN OR EYES BECOME IRRITATED.
_________3. Procedure
A. Sequence of Actions
In relation to the type of contamination, do these steps:
-stop the contamination source.
-keep the area that has contamination to a minimum.
-find the applicable cleaning procedure.
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B. Type of Contamination
(1)
Liquid contamination:
-stop the contamination source.
-make a sealed barrier, usually with cloth, to stop the liquid and prevent contamination of the adjacent areas.
-remove the contamination with cloth or a vacuum cleaner for liquids.
(2)
Powder, granular or dust contamination:
-make sure that there are no draughts.
-remove the contamination with a vacuum cleaner.
C. Analysis of Accidental Contamination If the contamination is accidental, find the characteristics of the contamination agent (Refer to the material manufacturer's documentation). You must make an estimate of the risk of deterioration of the electrical items. Some contamination agents can cause damage to the polymers used in the electrical items. There can be a change in the electrical performance (insulation resistance, dielectric strength. ). Refer to the table to know if:
-
you can clean the items.
-
you must replace the items.
(1) Visually examine the area that has contamination Examine the electrical items that have contamination for traces of damage.
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| Type of Damage | Procedure |
|--------------------------------|-----------------------------------|
|- Discoloration (connectors, | Replace the electrical item. |
| terminal blocks, modules, | |
| bases, etc.). | |
|- Cracks. | |
|--------------------------------|-----------------------------------|
|- Expansion of the sealing | Replace the electrical item. |
| grommets (module, connectors, | |
| etc.). | |
|--------------------------------|-----------------------------------|
|- Supplier marks erased. | Replace the electrical item. |
|--------------------------------|-----------------------------------|
|- Loss of label adhesion. | Replace the electrical item. |
|--------------------------------|-----------------------------------|
|- Functional Item Number erased | Replace the electrical item |
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