I know that Trace/Xantrex was the North American distributor of the 100 watt synchronous inverter and that it originated from OKE in Europe. Does anyone know if it is still available and or if there are other products similar to that.. say in the 100 to 300 watt range?

Due to limited income, but high determination to get more energy independant, I can't exactly fork out a couple thousand (Canadian) for some of the larger units, although one day that may happen but not for many years. I have a hard enough time scrounging (and i'm a master scrounger heheh) up enough cash to buy a 75 watt panel each year to add to my system.

The Trace Microsine aka OK4U was never UL1741 listed and is not legal for grid-intertie in the US.

I also believe the parent comapny in the netherlands no longer produces the unit.

The reason for NO inverter in the power range you desire is economic , the engineering and testing requirements to meet UL1741 (your talking 10's of thouands of dollars) could never be recouped in sales of units measured in the 10's of units

Your best bet is a Sunite on eBay , now about 400-500 dollars

Ok, thanks for the info! I have been asking around but haven't located any surplus units that anyone wanted to part with. I have also been hearing some growing complaints that they were prone to failure as well. One store here in Canada wanted $400 for the last one they had on the shelf. A little rich for my tastes. And the sales guy there told me that they have sold three of them to date to experimenters, and that one of them failed after only a couple of months. Then I read in some Home Power magazines about some guerilla solar (man, I love those articles) activists in Europe who were using them.

It had my interest piqued so I thought I would ask around.

Thanks again for the info.

I think there was a very small number of units from Trace that actually had UL1741. I will have to check the ones that I have in my garage to be sure.

The ones labled OK4U not Trace absolutly were not UL1741.

I know for a fact NONE of the Trace units ever had 1741 certification

I just dug out 2 of my MicroSine inverters. I don't know what standard they were tested at but they are both marked UL Listed 17DM. They were made in 1999.

They are cute little buggers. I have one of them set up as a little demo system with a couple of very old 40 watt panels and a single phase 120volt watt meter.

I have an OK4U-100 and OK485 data interface. The inverter, from 3rd quarter of 2000, only lists 'UL Listed 17DM'. The comm module lists it's identification but no standards info.

Does anyone need a spare? I have an orphan AE GC-1000 to play with now.

From what I have been able to find out, the MicroSine inverters were tested and UL listed to the version of UL1741 that was current at the time of their manufacture. Changes in the standard made it un-economical to continue production to the newer standard. Some OK4U inverters were marked with a UL listing but they really did not have the legal authorization to mark that Trace had. There are minor differences between the MicroSine and the OK4U in both microcode and in testing.

Per NEC, the MicroSine is legal for grid tie but it may not be accepted by the utility. The MicroSine is just as legal as an SW of the same time period.

There are a batch of MS100s on eBay now - looks like six units.