MattRTB
Electrical
- Jul 7, 2023
- 1
A 500kva threephase padmounted distribution transformer ( loopfeed with 3,8.5kv elbow arresters) primary voltage 13.8kv DELTA and 277/480volt WYE SECONDARY was energized with no load and while single phase switching and upon closing the last cutout one of the MOV elbow arresters failed with a loud bang indicating an overvoltage ..... could a cable fault on the downstream 480volt cable have caused this or does it indicate a damaged primary winding.