Switch – Light bulb stays on regardless of switch position after breaker flipped

bulbcircuit breakerlightswitch

A light bulb in my office died suddenly. When it happened I heard a loud click. This was the circuit breaker tripping.

I turned off the light switch, went down to the box, and closed the circuit breaker. Back in the room I turned on the light. This caused the circuit breaker to trip again. I repeated with the same outcome.

Came to the conclusion that the bulb was causing a problem. Bought a new one and started to insert it with the light switch turned OFF. To my surprise the light bulb lite up as I was inserting it.

I manually flipped the circuit breaker OFF and inserted the bulb. Then turned the circuit breaker back on. The light turned on in the room with the light switch set to OFF. But this time the circuit breaker did not flip.

I also noticed that the light switch is sensitive. Normally it'd take a firm press to switch between ON and OFF. Now it seems to be hair triggered.

What could cause this?

Best Answer

It sounds like the element in the lamp welded and caused a dead short. With the switch off it worked the first time but the second time the switch welded. It happens. Time to replace the switch