Complaints of occasional voltage spikes blowing electrical items (computer, ac) in a compound.

A three phase four wire generator is powering a residential building with primarily single phase 230 volt consumers. When loaded with the compound consumers reading at panel shows 230 -218-224 volts phase to neutral.

When disconnected from compound generator readings stablaze.

What is the fault (AVR or building) ? How do I trouble shoot or diagnose?

Thanks for the advise! English is my first language but I'll work on my grammar hahaha.

We will take the load measurements from the compounf and report back ASAP next week.

The generator doesn't work in parallel with the grid power or another genratir. To clarify, when the generator is powering the residence it us reported to occasional have voltage imbalance/spike ( but not all the time). However ehen the change over swith is positioned to neutral ( disconnecting the building from the generator) the observed line to line and line to neutral readings are equal.

Two generator tech companies have made check and said the AVR is okay...but the electrician then blames the genset....

By observing the voltage at load steps do you mean to turn the circuits in the building on one by one to see if/when the spikes occur?

Thanks again and apologies for any incorrect nomenclature.

  • Measure the currents in each phase and report back (in the question). Your post reads as though English is not your first language. If you add this to your user profile we can help you out. – Transistor Dec 23 '17 at 9:49
  • When disconnected from compound generator readings stablaze. Does this mean your generator is synchronous, and both the mains and the generator and mains can be used simultaneously? That requires pretty careful handling. – SomeoneSomewhereSupportsMonica Dec 23 '17 at 10:01
  • Observe the voltage during load steps, this is when surges occur. – Jeroen3 Dec 23 '17 at 12:47

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