Voltage spikes on opposing legs

[Dropandpull]

This question was brought to me from a former employee. A service is getting 120 on each leg and 240 across both. Under a load one leg gets 140 and the other 80. But it will randomly switch voltages between legs? PPL changed bugs at house and on flying tap, 5 houses are on same transformer, (no problems reported from other customers), main was changed, and all connections are clean and tight. Any ideas?

 

[gar]

120925-1034 EDT

A high resistance in neutral.

You indicate 120-0-120, and 240 measurements, but then indicate 140 and 80 which sums to 220. You need to specify the load currents when the voltage measurements are made.

If under load the voltage drops from 240 to 220, then you have a large load relative to the source impedance, or for that load the the source impedance is too high.

All of these could mean some bad connections.

The switching of the unbalanced voltages is a result of changes in the relative loading of the two phases.

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