Specifications

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Table 1.1 TYPICAL MODERN INSULATING MATERIALS FOR ROTATING MACHINES
Component
Low voltage machines High Voltage machines
Class E Class B Class F Class B
Turn-to-turn Insulation
Polyvinyl acetal enamel for both wire and rectangular conductors.
Polyester enamel (wire) or phenolic bonded fiberglass (rectangular)
Estermide enamel (wire) or alkyd bonded fibreglass (rectangular)
Phenolic bonded fibre glass (rectangular)
Coil-to-coil and Inside and phase-to the phase insulation slots
Bakelized fabric strips or Melinex film bonded to press paper
Bakelized fabric strips or Melinex film of suitable thickness
Epoxy fibreglass strips or Nomex sheet of suitable thickness
Shellac or bitumen bonded mica foil or tape on straight portions of the coils
On over- hangs
Melinex film bonded to press board
Alkyd bonded mica glass sheet or Melinex film of suitable thickness
Nomex sheet
Alkyd varnished glass tape on coil ends and alkyd bonded mica sheet between layers
Phase (or coil) to earth insulation
Melinex film bonded to press board
Mica alkyd bonded to glass cloth
Nomex sheet
No extra insulation because the phase-to- phase insulation itself is sufficient
Slot closure (wedge)
Bakelized fabric strip or Epoxy fibre glass strip or Bamboo strip
Bakalized fabric strip or Epoxy fibre glass strip or Bamboo strip
Epoxy fibre glass strip or Bamboo strip
Bakalized fabric strip
Insulation for leads Alkyd varnished terylene or glass tape or sleeving Alkyd varnished glass tape Varnish for impregnation treatment
Alkyd phenolic Alkyd phenolic Estermide or epoxy Alkyd-phenolic
Class F
Alkyd bonded fibre glass (rectangular) Epoxy impregnated mica paper foil or tape on straight portions of the coil. Epoxy varnished glass tape on coil ends and alkyd bonded mica glass sheet between layers
Epoxy fibreglass strip Epoxy