UPS tests.

I connected the major tech MT250 to the UPs to get an idea of how long the batteries would last with a 50 watt lamp connected.

This is where it got interesting ... I got some really strange reading on the display... take out the good old fluke meter and check... voltage is not a problem - 230 VAC on the fluke display ... however the major tech unit has voltages ranging from 165 - 186 VAC ... checked live to neutral ...neutral to earth ...live to earth ... then i realised it was a modified sine wave UPS.