| 337 / | HD | ELECTRICITY: ELECTROTHERMALLY OR THERMALLY ACTUATED SWITCHES |
| 14 | DF | ELECTROTHERMALLY ACTUATED SWITCHES {9} |
| 142 | DF | .~ Fusible element actuated {15} |
| 182 | DF | .~.~ With external or auxiliary heating means {2} |
| 183 | ![]() | .~.~.~ Resistive heater {1} |
| 184 | DF | .~.~.~.~> Directly in series with or completing controlled circuit |