| 310 / | HD | ELECTRICAL GENERATOR OR MOTOR STRUCTURE |
| 10 | DF | DYNAMOELECTRIC {5} |
| 40 R | DF | .~ Rotary {28} |
| 219 | DF | .~.~ Current collectors {7} |
| 220 | DF | .~.~.~ Spark-reduction {3} |
| 223 | | .~.~.~.~ Flux compensators {3} |
| 224 | DF | .~.~.~.~.~> Commutating poles or windings |
| 225 | DF | .~.~.~.~.~> Short-circuited coil circuit |
| 226 | DF | .~.~.~.~.~> Field-distortion |