This is a real weird one !!!!
This is a farm. The power for the whole farm is from one pole and goes overhead to several different locations, except for the house which has the wire underground and is only 10ft. from the main pole. There are THREE overhead lines, one is the main from the transformer to the main pole. One is the one to the barn and several sheds, the third is to the garage.
The house power is fine, (underground feed). The second overhead goes to the barn, and that is fine. The third overhead to the garage is where there must be a problem.
Here is what I got, and this is very weird. I should mention that I have done wiring for years, and this one has me puzzled. This is not the first time this has happened. It happened twice during the summer, and each time I pulled the main 100A garage breaker and cleaned the contacts. The first time, just the main, the second time I thoroughly wire brushed every breaker and the contacts in the box.
Tonite it is real cold, and I go to the garage to cut a few furring strips for a project in the house. I start the circular saw, and the lights in the garage got real dim. The saw was so slow it barely cut the 1x2. That's when I first said "what the f--k". I stop the saw and the lights stay dim. I start the saw again, and it barely hums, and half the lights go out completely, while others are very dim, and yet a few look normal. I pull the cover off the panel and jiggle the main breaker and all the others. No change. I pull the main, clean the contacts and put it back, no change. I get my meter. I read 120V from neutral to one side of the line and ZERO V to the other side of the line. Yet I read 120V across both mains (that should be 240V). OK, I shut off the main 100A breaker and read 240V across the line. I flip the breaker back on and read 120V across the mains. I leave meter across the mains and as I flip off the small breakers, one by one, the voltage climbs, and gets to 240V when all of them are turned off. (Thats when I slapped myself in the face and yelled "WHAT THE F--K").
OK, I got to thinking that maybe the main breaker is bad, so I took out the main wires and screwed them into my 50A Welder breaker, totally bypassing the main breaker and using the 50A breaker as the main. I turn the power back on, and get the same readings across the mains. 240V with all the small breakers off, 120V with them on, and from neutral (or ground), I get ZERO V one one side, and 120V on the other.
Now, here is the real freak. I came in the house to use the toilet, and flushed it, not thinking that my 240V water pump is connected to the garage. As soon as the pump kicked in, the garage lights came back on, but some are still dim. The pump alwo worked. (How in the heck it works when there does not appear to be 240V in there is beyond me). So I go back to the garage, and just for the heck of it, I plug in my electric drill (just a small one). I start the drill, some lights get brighter, others get dimmer (all lights are on the same 15A breaker). I plug in my circular saw, and all the lights go completely out. OK, I turn on some water, the pump kicks in, and the lights come back on, but some are still dim.
I must admit, that in all my years of doing wiring, this is just plain bizarre, and makes no sense at all. I have a good ground rod on that garage, and I did bypass the ground to the neutral, which made no change. That tells me that the neutral overhead wire should be ok. I eliminated the main breaker, and still have the problem, so it's not the main breaker. All the contacts inside the box are one piece of thick copper, and all are clean. That eliminates the box entirely.
This leads me to believe that one of the hot leads is not intact in the overhead triplex, probably at a connection on one or the other end of the cable. However, I took a long board and made the wires sway, and nothing changed. However, at the same time, if either hot lead is not making a good connection, then how is the water pump working? And why are some lights dim and others bright, when they are all on the same 15A breaker.
I'm totally lost !!!! . . . . . HELP !!!!
Can anyone make sense of this?
All help appreciated !!!
- ASAP * I got livestock and their electric fence is now off too....
Mark
PS. I have one idea, and I wonder if anyone has ever tried something like this. The run from the garage to the pole is about 100Ft. I happen to have at least 100Ft of 12-3 romes. I'm thinking of stringing it across the ground from the main pull out fuse panel on the main pole, and stringing it over to the garage, and one by one, starting with the neutral, using that cable to see which wire brings things back to normal. As long as my welder and air compressor are off, I probably never exceed 20A in there anyhow.