Therefore, this part uses the CTI
values categorize insulation materials.Insert 165
correlation with the material groups not practical.8.
(see 4.
For the purposes this part, materials are separated into [three] groups
according their CTI values, follows:
Material Group (600 CTI)
Material Group (400 CTI 600)
Material Group III (175 CTI 400)
The CTI values above refer values obtained, accordance with IEC 112.2)
. However, has been
found experience and tests that insulating materials having higher
performance also have approximately the same relative ranking according
to the comparative tracking index (CTI)