ASTM D3145-13

5.1 This test method is used to determine the effect of exposure to elevated temperatures on the bond strength of combinations of magnet wire insulations and electrical insulating varnishes. The results are used as a guide for the comparison and selection of varnishes and combinations of varnishes and magnet wire insulation for specific applications. Test Methods D1932 and D3251describe additional tests for determining the thermal endurance of insulating varnishes. A comprehensive evaluation of thermal characteristics includes a comparison of the thermal endurance determined in these different ways.

5.2 This test method is useful for research and product qualifications purposes.

1.1 This test method covers the determination of the thermal endurance of electrical insulating varnishes alone or in combinations with magnet wire insulation. Changes in the helical coil bond strength are used as the test criteria. The coils are made from bare aluminum or copper wire, or from film- or fiber-insulated magnet wire.

1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.