Limb in service creating high voltage?? 1

[gobblerhuntr]

Got a call from a customer whose house burnt a year ago and said rebuilt and has been living there several months. He noticed smoke the other day and called and electrician. The electrician found high voltage and thought the source was a tree that had grown up into the service between the transformer and weatherhead. Could that have been the case?? I was trying to relate this situation to the same circumstances and a loose neutral which can make the voltage do some strange things. How high could the voltage get on a 120/240 volt transformer in an abnormal state on the low side??? As far as I know the low side of the transformer was not damaged, there was just a tree grown up in the service.

 

[magoo2]

If I understand the situation, your electrician measured the voltage at the house. I assume the 240 V level was OK, but the high voltage was on one of the 120 V connections.

If you had an open neutral, you'd get 240 V delivered to the home and, without a neutral reference, the load balance between the 2 120 V legs would determine how high the voltage gets.

How high? You would approach 240 V on one leg.

With a tree in the service line, you can get abrasion that gets accelerated by the wind. This could cause the neutral to break.

 

[waross]

magoo2 said it better than I could. I agree completely.
respectfully