| 318 / | HD | ELECTRICITY: MOTIVE POWER SYSTEMS |
| 700 | DF | SYNCHRONOUS MOTOR SYSTEMS {7} |
| 705 | DF | .~ Synchronization systems {4} |
| 706 | DF | .~.~ With armature power removal upon failure to synchronize or loss of synchronism {2} |
| 708 | ![]() | .~.~.~ Responsive to thermal electrical element in system |