In the last few months, there has been interest in the PVPowered brand of grid tie inverters, specifically, questions asked about configurations and performance. I have been in Contact with PV Powred but at this point they have NOT agreeded to monitor the solar-guppy site for questions relating to their products.

I have also been testing the PVP 2800 model inverter in the next few weeks will be updating this site to have my performance data , notes and comments on this inverters

Mr Guppy,

I am curious about the PV Powered inverters. I am looking to set a up 3kw grid tie in Apache Junction AZ and the PV power inverters speak sheet on the Northern AZ wind & Sun site speak very highly of themselves. (key word themselves) The 10 year warranty is a big plus for my wife as well.

1) Does it have an internal disconnect? (I assume so as most of the grid tie inverters now have them), I did not see it listed.

2) Can you connect 2 or 3 strings to it or do you need a serperate junction box/breaker isolator? And, do you reccomend an isolater for safety sake (300 or so volts on the roof could be pretty serious)?

3) I am leaning toward 18 of the BP sx-170's in 2 strings. From what I have read you can/should rate the inverter at 80% of the array capacity (3060W) , is this true?

Also...

4) A kindy person on the other forum mentioned that in the winter with the cool arrays and the bright sunlight I may have a peak V over the rated V. Would a string of 9 (peak v of 318) and a Peak V on the inverter of 500 give me enough margin for error.

Also...

5) The inverter efficiencies on many of them are greatest at the 50 - 70% capicity. Should I over rate the inverter to gain efficiency and to possibly add panels int he future? or simply size it properly (? see question 3) I ask this because I'm trying to take advantage of the one shot max 3KW rebate Az offers.

Thanks for your time and putting up with this long post.

Mikey

No, you have to have external AC and DC diconnects, figure 200-250 for this. Most folks use the HU-351 SquareD disconnect for the DC side



NEC would limit to two strings, some inverter manufactures have connections for more, but its limited by the amp rating of the panels. More than 2 should have fuses for each string



I wouldn't, you will almost never get your rated DC, thats a thing called Standard Test Conditions, which is at full sunlight and the panels at 25C, my panels typically run about 70C so the power is lower. Also, this is the DC input, PVPowered is 2900 watts (or 3200 depending on the model) AC side rated




This is a negative for the PVPowered inverters and a real concern. The Xantrex and SMA inverters have wider input ranges (600V).



If you read thru the posts, you will see I recommed the Xantrex GT3.0 (they now have a GT3.3). It has best in class efficiency, wide 190-600V operational range, included communications and PC software and bulit in disconnects.

The PVPowered folks were also less than honest about the product when released 2 years ago, they were boasting about 97.6% efficiency when my tests were showing closer to 93%. The unit I tested had some other quirks but It would seem they have improved the product and may have resolved issues I documented in my testing.

As for the 10 year, well thats only good if there around to honor the warrenty, Xantrex, for a small fee has an extended warrenty and even with the extra cost is still lower cost with all the features included, no nickle and dime stuff that adds up with other inverters

http://www.beyondoilsolar.com/inverters.htm has the GT3.0 for 1822.00, its a good honest place to buy equipment from

This is what I documented from last summer
http://www.solar-guppy.com/reports/PVPowered_report.htm

Thanks for the great info. I'm definately going ot look into the Xantrex. My only other question is concerning the margin for error with the DC input V.




A 318 V Peak array and a 500V max inverter yields about a 36% margin of error for bright sunny cold days that might exceed the rated max V of the array. Your reply indicates that this might not be enough. What should I be shooting for?

A good free sizing tool

http://www.xantrex.com/support/gtsizing/index.asp#calculator

I looked up your typical highs and lows and it does look like the 500V limit will be OK using the above sizing tool, sorry, I was to lazy to look this up before . Using 9 modules , it showes 253 for a low VMP and 441 for a high VOC so you'll be OK, though the PVPower is listed as 450 as a maximum operational voltage, you could be close on a cold winter morning

For any inverter, the GT,PVP,SB they all run better at lower input voltages