Inverter problem

[Fostfreez]

Hi all, great time at the Desert Rat non-official Rally. On the last day there I turned on the inverter to watch tv and noticed that that meter I have plugged into a kitchen receptical was showing 136 volts. Is my inverter bad or is something else causing this?

Thanks,
John Foster
'04 34'

[vsheetz]

Could be meter not indicating correctly for an inverter.
PSW or MSW inverter?
Have you used the meter with this inverter previously and if so what did it indicate?

[Algoma]

If you have a modified sine wave inverter your meter probably won't show the correct RMS voltage.

[BFlinn181]

I agree with the above. If your inverter is not a pure sine wave, it will make most meters read incorrect voltages. Square wave or Modified Sine wave are more common inverter types. If your TV didn't smoke or blow up, you still might be O.K. Just be cautious plugging phone or computer chargers, electric blankets, etc. in these type of inverters. This video show meter types can effect voltage readings, but they offer no explanation. In addition, they show a LOWER reading rather than higher.

How To: Get the AC voltage reading on an inverter - Tripp Lite tutorial - YouTube

[Koop]

Modified sine wave inverters will show voltage either low or high. The only way to get an accurate reading is with a true RMS volt meter.

[Algoma]

I don't know about those cheap plugin meters. I have a Fluke Clamp meter which gives true RMS readings. Expensive, but they last forever.