Relative impulse strength of magnet wires at room temperature

This investigation was conducted to determine if shielded magnet wire was really superior to heavy and quad build wire for use in large (up to 900 HP), random wound AC motors under all conditions. Since all motors start cold (at least once), it was determined that testing at room temperature was not unreasonable and that further testing at elevated temperatures could be done, if needed. An attempt to establish a relationship between the AC and impulse breakdowns was made. Five types of magnet wire (heavy build from two manufacturers, shielded wire from the same two manufacturers and quad build from one of these manufacturers) were tested.