AS 3532-1988

1 - AS 3532-1988 TEST METHODS FOR DETERMINING ELECTROLYTIC CORROSION WITH INSULATING MATERIALS
4 - PREFACE
5 - CONTENTS
6 - 1. Scope
6 - 2. Signi ficance
7 - 3. Visual method
7 - 3.1 Principle of the method
7 - 3.2 Test specimens
7 - 3.2.1 Shape
7 - 3.2.2 Cut surfaces of semi-finished materials (blocks, sheets) or moulded parts (compression mouldings, injection...
7 - 3.2.3 Cut surfaces of films and thin sheets including varnished papers and adhesive tapes
7 - 3.2.4 Sleeving and tubing
7 - 3.2.5 Lacquers and insulating varnishes
8 - 3.2.6 Unmachined surface of semi-finished materials, moulded parts, films and thin sheets
8 - 3.3 Cleanliness of the testing surfaces
8 - 3.4 Number of test specimens
8 - 4. Test apparatus
8 - 4.1 Test devices
9 - 4.2 Test foils
9 - 4.3 Test conditions
10 - 4.4 Power supply
10 - 4.5 Magnifier
10 - 5. Test procedure
10 - 6. Evaluation
11 - 7. Test report
11 - 8. Notes on visual method
12 - 9. Wire tensile strength method
12 - 9.1 Principle of the method
12 - 9.2 Test specimens
12 - 9.2.1 Shape
12 - 9.2.2 Semi-finished materials (blocks, sheets) or moulded parts (compression mouldings, injection mouldings, castings, etc.)
12 - 9.2.3 Films and thin sheets, including varnished papers and adhesive tapes
13 - 9.2.4 Sleeving and tubing
13 - 9.2.5 Lacquers and insulating varnishes
13 - 9.3 Cleanliness of the testing surfaces
13 - 9.4 Number of test specimens
13 - 10. Test apparatus
13 - 10.1 Small apparatus
14 - 10.2 Large apparatus
14 - 10.3 Test wires
14 - 10.4 Cleaning of apparatus and test wires
14 - 10.5 Tensile test equipment
14 - 10.6 Test conditions
15 - 10.7 Power supply
15 - 11. Test procedure
15 - 11.1 Assembly of test specimens
15 - 11.2 Assembly of test wires
15 - 11.3 Voltage and humidity exposure
15 - 11.4 Tensile strength of test wires
16 - 12. Evaluation
16 - 13. Test report
16 - 14. Insul ation resistance method
16 - 14.1 Principle of the method
17 - 14.2 Test specimens
17 - 14.2.1 Shape
17 - 14.2.2 Semi-finished materials (blocks, sheets) or moulded parts (compression mouldings, injection mouldings, castings...
17 - 14.2.3 Films and thin sheets, including varnished papers and adhesive tapes with a thickness less than or equal to 1 mm
17 - 14.2.4 Sleeving and tubing
17 - 14.2.5 Lacquers and insulating varnishes
17 - 14.3 Cleanliness of the testing surfaces
18 - 14.4 Number of test specimens
18 - 15. Electrodes
18 - 15.1 Semi-finished materials or moulded parts (thickness greater than 1 mm)
18 - 15.2 Films and thin sheets, including varnished papers and adhesive tapes (thickness less than or equal to 1 mm)
18 - 15.3 Sleeving and tubing
18 - 15.4 Lacquers and varnishes
18 - 16. Test procedure
18 - 16.1 Test conditions
18 - 16.2 Power supply
19 - 16.3 Voltage and humidity exposure
19 - 17. Evaluation
19 - 18. Test report

Specifies visual semi-quantitative, quantitative, and indirect methods for determining the degree of electrolytic corrosion caused by electrical insulating materials under conditions of high humidity and electric stress.

Electrical insulating materials at high atmospheric humidity and under the influence of electric stress may cause corrosion of metal parts in contact with them. Such electrolytic corrosion is dependent upon the composition of the insulating material and the character of the metal; it is influenced by temperature, relative humidity, nature of the voltage and time of exposure. Direct voltage produces much more rapid and extensive corrosion than alternating voltage. Corrosion is more pronounced at the positive electrode.Not only copper but also most other metals, except the noble metals such as platinum, are subject to electrolytic corrosion. Electrolytic corrosion, however, is usually determined with insulating materials in contact with copper or brass. Other metals may be used when needed for special purposes, but the results may differ from those described in these methods.This recommendation includes:1) A visual semi-quantitative method for determining electrolytic corrosion.2) A quantitative method for determining electrolytic corrosion which involves tensile strength measurements of copper wire.3) An indirect method using a quantitative measurement of insulation resistance.