MWBC & neutral current

[sw_ross]

I deal with this stuff a lot after hurricanes. Have a lot of boxes in the ground with a mixture of 277 and 480 (single phase) lighting loads. I find it is worth the price to add fuse holders at each fixture. IIRC I use littlefuse LEB series. Just don't put them in backwards

I find a megger invaluable.

These fixtures do have fuses at each fixture. Apparently the only time a fuse has blown is when the ballast corroded in the base of the pole (from moisture) to the point of shorting out.

My assumption is that if there was an issue within any of the poles would trip the fuse, therefore the issue must be in the ground between the poles, or where the DB wire comes into the pole base.

I would like to see the problem become more consistent to give more incentive for the mayor to deal with the issue (money wise!).

 

[kwired]

These fixtures do have fuses at each fixture. Apparently the only time a fuse has blown is when the ballast corroded in the base of the pole (from moisture) to the point of shorting out.

My assumption is that if there was an issue within any of the poles would trip the fuse, therefore the issue must be in the ground between the poles, or where the DB wire comes into the pole base.

I would like to see the problem become more consistent to give more incentive for the mayor to deal with the issue (money wise!).

Had an intermittent problem with some pole lights (only 10 foot poles) once tripping the branch circuit breaker. These were not fuses individually at poles, which probably would have isolated the fixture with a problem immediately, but what I did was put a temporary fuse in the base of about the middle pole in the run. I don't remember details of troubleshooting that one anymore but it helped narrow down which half of the circuit to be looking at, and when I know that can at very least halve it again by moving the fuse to a different pole. I do remember when I discovered the problem it was because of a retrofitted CFL in what used to be a mercury vapor fixture, and when the pole shook in the wind the socket couldn't handle the stress of that heavier CFL shaking in there and that was causing problems.