Hope this helps when you have bought and your thinking my Inverter or Generator Inverter is going great you may want to think again. When I received a Gentrax Generator Inverter I always test the outputs wilt a Electrical Usage Meter (About $25) . Guess what faulty from new and I'm glad I checked it. It could happen with any brand, some more than others granted.

There are lots of reasons these problems can occur. Such like a faulty part or just bad quality control issue like, part left out because they ran out but voltage OK, built incorrectly, lower manufacturing price for profit, mislabelled and sent to wrong country etc.

When you buy your fuel for your Generator or you moving you solar panels around think:

If your Inverter output has one or more of these issues this is what happens

60Hz not 50Hz - 20% inefficiency or buy 5Litres and throw away 1 Litre.

Best Power Factor range is 1.0 to .93 so if say PF .67 = 33% inefficiency or buy 3Litres and throw away 1 Litre.

Modified Sine Pure instead of Pure Sine Wave up to 30% inefficiency. You work it out.

Also harder on appliances that run on it and the may fail earlier in there life.

Talk to others about how much fuel you use in relation to the size of your air-con is a good indicator if something is wrong also.