Ballasts detect end of life
Electronic ballasts include end of life detection circuitry. Units are for 120 or 277-V operation of 36/39-W, 40-W, and 50-W long twin tube, and 55-W FT55/DL/RS lamps. A special circuit removes power from the lamp when it senses a failure, preventing overheating of cathodes and minimizing the possibility of melting and cracking.
Advance Transformer Co.