Yes this is the problem. While there are people who will tell you
anything to make a sale, how do you know what you are really getting.

One test is the "Modified Square Wave" test.

When you hear these words you know you are dealing either with a shyster
or an ignorant person who should not be selling things he does not
understand.

It is hard, what with a flood of imports at bargain basement prices.

Still, as long as people are willing to believe that a $59 3000W
"modified sine wave" inverter from Walmart, Cost Co, etc, etc has the
same specs as a $900 3000W sine inverter is, at best, fooling themselves.

I buy inverters from known manufacturers who are willing to provide spec
sheets that out line the full parameters of the inverter. You know
things like:

Efficiency curves
Max continuous output
1/2 hour rating
Surge
Standby
Max DC in

Well everything really.

I did build a kit inverter, once, years ago. It had a max rating of
150W, Which it met.

It had a half hour rating of 0W

And a surge of about 300W

Still it did the job it was built to do for many years.

Put your supplier on the spot. Tell them your load and buy on the
condition that what they are selling you will do what they claim or you
get a full refund, no questions asked.

philkryder wrote:
"MSW is a shysters sales pitch which misrepresents the product. "

Are there deterministic tests that tell when a device has a "good
enough" sine wave?
Or is there some sort of accepted "spec"?

I saw in another post where one of the EU2000 hondas had a beautiful
"looking" wave form, but failed to run a furnace.

What can we use to "know for sure" that the wave form of a device is
adequate BEFORE buying it?

Thanks
Phil