18.1 This test method provides useful engineering information for evaluating the mechanical behavior of rigid electrical insulation at elevated temperature. When the proper exposure and test temperatures are chosen, depending on the material and end-use operating temperature, use the test method as one means of indicating relative thermal degradation of rigid insulating materials.

1.1 These test methods cover procedures for testing rigid electrical insulation normally manufactured in flat sheet or plate form. They are generally used as terminal boards, spacers, voltage barriers, and circuit boards.

1.2 Use Test Methods D619 (withdrawn) or Specification D710 for tests applying to vulcanized fibre.

1.3 Some of the test methods contained in this standard are similar to those contained in IEC 60893-2, which applies to rigid industrial laminated sheets based on thermosetting resins for electrical purposes.

1.4 The test methods appear in the following sections:

Test

Sections

ASTM
 Test
Method

Acetone extractable matter

83 to 84

D494

Arc resistance

47

D495

Ash

56 to 60

...

Bonding strength

49 to 54

...

Burning rate and flame resistance

61 to 75

...

Compressive strength

25

D695

Conditioning

 4

D6054

Dissipation factor

34 to 40

D669

Dielectric strength

28 to 33

D149

Expansion (linear thermal)

76

D696

Flexural properties

12 to 24

D790

Hardness (Rockwell)

55

D785

Insulation resistance and resistivity

41 to 46

D257

Permittivity

34 to 40

D150

Resistance to impact

26

D256

Tensile properties

 7 to 11

D638

Thickness

 5 to 6

D374

Tracking resistance

48

D2132

Warp or twist

77 to 82

...

Water absorption

27

D570

1.5 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.

1.6 This is a fire-test-response standard. See Sections 61 through 75, which are the procedures for burning rate and flame resistance.

1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Specific precautionary statements are given in 31.1 and 1.8.

1.8 This standard measures and describes the response of materials, products, or assemblies to heat and flame under controlled conditions, but does not by itself incorporate all factors required for fire hazard or fire risk assessment of the materials, products, or assemblies under actual fire conditions.

1.9 Fire testing is inherently hazardous. Adequate safeguards for personnel and property shall be employed in conducting these tests.