M 117/309 Industrial coal Fine coal

High-grade carbons are produced from pre-annealed and solidified carbon material at temperatures above 2500 degrees in a graphitisation furnace, where the carbon is converted into electrographite. The material is largely freed of impurities. The physical data - electrical resistance, density, breaking strength, etc. - are considerably more favourable than those of hard grades.
The high grade carbons have excellent commutation properties, high short-circuit resistance and burn-off resistance.
The vane insulation must be recessed.

Field of application:
DC motors of any power rating, three-phase commutator machines, AC motors, drive motors, reactive power machines, slip rings, welding converters, universal motors, etc.