I am presently in the learning stage of building a "grid-tie" system. At present the inverters of consideration are the (Outback GVFX3524) and (Xantrex SW4024).

My concern for the moment is avoiding "mod-sinewave" issues: front-load washer has variable-speed drive, garage door openers, home theater system components, computer/peripheral components. Just don't want to install a system might cause operational or damage issues with the unknowns.

The Outback appears on the surface to be the closest to true sinewave, right or wrong? When I research the Xantrex site I cannot determine which units are "modified-sinewave", not clearly stated in the docs.

Are the new Xantrex GT series "modified" or regular sinewave units? Sure is hard to tell in the literature for all the models.

TIA,

I will copy my post here from the other forum you posted in... Also, Solar Guppy is one of the designers for the Xantrex GT unit--so his information is the gold standard for that unit...

The Xantrex GT series is a Sinewave, not modified sinewave (really a modified square wave)... You will have no problem with the unit running any of your appliances.

The user manual (PDF link below, page A-2, or page 68 of 82) says that it is a sine wave (technically, it is an stop-wise approximation of a sine wave with harmonics that, IIRC, are less than 5% of the fundamental frequency).

http://www.xantrex.com/web/id/1172/docserve.asp

I have my Xantrex GT 3.0 installed in my garage right next to my garage door opener switch, about 1' from my AM/FM Intercom, and run a wired/wireless network in my home. One computer is on a UPS. I have Fisher & Paykel Washer/Drier which use DC stepper motors instead of the normal induction motors.

A question for you... For example, the Xantrex SW family is an inverter/charger unit. Are you thinking about battery backup for your home?

A Xantrex GT cannot supply any AC power if the utility mains have failed--and I don't believe it would work with a normal home backup generator either. For backup at my home, I currently only use a Honda eu2000i gasoline generator and a manual transfer switch. Near SF CA, I don't have any power failures that last more than a few minutes or an hour. I have the generator prep'ed for earthquake use (fridge/freeze and a few lights). Propane and camping stoves for cooking/heating water.

A properly configured SW (or other system) can supply backup power from batteries with charging/power also supplied by solar panels/windmills/generators... Owning a battery backed system involves more money and servicing time by the owner. But is nice if you have or expect lots of power failures.

-Bill