Why Insulation Is Used?
All insulating material used in the manufacture of electrical motors perform one or more the folllowing functions:-
1. Act as a dielectric medium to prevent occurrences of an electrical breakdown.
2. To protect the conducting parts from moisture, abrasion, corrosion, etc.
3. To provide mechanical support to conducting parts.
4. To withstand heat which is present at their point of use during operation of the motor. It is essential that the insulating properties of the materials used remain unaffected at the operating temperature.
Where To Insulate?
Listed below are four principal areas where a potential difference occurs and where, therefore, insulation must be aplly;
1) Between turns in a coil (turn-to-turn)
2) Between coils of the same phase (coil-to-coil)
3) Between coils of different phases (phase-to-phase)
2) Between coils and ground (phase-to-ground)