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w_tom
 
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Modified sine wave means what? Nothing useful because it is
not nor describes a number. One critical number is THD. Does
that inverter even provide a THD number?

Many computer UPSes output modified sine waves. That means
they are 'computer grade'. Another term used to confuse.
'Computer grade' may mean it is only good for computers
because inverter may damage small electric motors. Myths
forget to mention that computers can be more robust than other
appliances. A modified sine wave is not destructive to a
computer but could be destructive to something less robust
such as a furnace.

But again, what is the THD number? It's not which is more
demanding. It's about which is more robust. But then I have
told you little that is useful since I provided a subjective
word (robust) and did not provide numbers.

Toller wrote:
Harbor Freight has an 800w inverter on sale for $45. It claims to
have surge capacity of 1800w. My refrigerator draws 13 amps for a
second when starting, and then less than 2 amps. So, will the
inverter be able to start my refrigerator? Is it safe to run a
refrigerator on modified sine wave? When they installed my
furnace last year they told me the msw inverters will fry the
furnace, but refrigerators seem less demanding.

I don't plan on using it, but for $45, back up to my generator
would be nice; but not if it will trash a $1,000 refrigerator.

And since I am on the subject, what would happen if I tried to
start it with inadequate current? Would it burn out, or is there
a safety feature? I tried to get an answer from the manufacturer,
but they wouldn't tell me.