Classify the insulating materials as per operating temperature. Give two examples of each type.
Sr.No.
|
Insulation Classes
|
Maximum permissible temperature (0C)
|
Insulating Material
|
1 |
Class-Y or O
|
900
|
Cotton, silk, paper, press board, wood, cellulose-, PVC, VIR. (Cotton, silk, paper, cellulose, wood etc. Neither impregnated nor immersed in oil comes under this class. )
|
2 |
Class- A
|
1050
|
Cotton, silk and paper suitably impregnated with natural resins or immersed in oil come under this class.
|
3 |
Class- E
|
1200
|
Laminated Cotton, Laminated paper Synthetic resin enamels.
|
4 |
Class- B
|
1300
|
Mica, glass fibers, asbestos with suitable bonding substances comes under this class.
|
5 |
Class- F
|
1550
|
Laminated asbestos, Glass fiber, and asbestos with suitable bonding substances of high thermal stability come under this class.
|
6 |
Class- H
|
1800
|
Mica, glass fibers, asbestos with suitable bonding substances such as silicones come under this class. Or adhesive coating.
|
7 |
Class- C
|
Over 1800
|
Porcelain, ceramics, glass, quartz.
|