Sodium Street Light

[woodchopper]

When a street light goes faulty eg. Starts up and cuts out when full intensity has been reached and continuously repeats this cycle what generally is at fault? Lamp or ballast?

[BRIGHT SPARK]

After many hours of repeated use a sox or son lamp will draw more current from the ballast.As the ballast has a finite output the lamp will extinguish.The internal pressure will decrease and after a few minutes will re ignite....the cycle will continue until the lamp eventually fails......so in a nutshell....its the lamp.