Back when I worked for a living, I was the hardware guy and my partner was the software guy. Tom and I would get together and spec out a new product. I would design and build the circuit board, then hand it off to him to program in the features. Knowing each other well, it worked well.
Back when I was doing field service, I did not intimately know the hardware that someone else designed and neither did the programmers. There was always the tendency of one side to blame the other when something peculiar was happening. Oh, smoking circuit board or howling hard drive was clearly mine and a lot of flashing lights and blank screens after a software update was pretty much a ball in the programmer’s court. Then there is the tricky stuff and suspicion builds.
Today, pretty much everything from your microwave oven to your inverter has a microprocessor in it and things like this have a variation of programming in there called firmware. Some are not as firm as others as you’ll find keypads and SD cards or Bluetooth so you can go in and change the program. One of my inverters is dumb as a rock, as far as being programmable goes. It has a couple of jumper for things like choosing 50 Hz or 60 Hz. Other than that it just turns 48 vdc into 240 vac. Nothing more. Simple. The microprocessor just sits there making sine waves.
My pair of 6048 Sunny Island inverters goes the opposite direction. It is programmable up one side and down the other. Flexible. Handy, I guess, but it scares me to death. There are ominous warnings about not pulling out the SD cards. I have changed the programming a bit, but it is doing what I need it to do, so I generally leave it alone.
Cory’s Outback GS8048a pair is another that is highly programmable and it needed programming when we revived it from retirement. We wanted it to work with the grid when we needed it, run on battery and sunshine when we had it and never, ever sell back to the grid, which would bring the white bucket trucks to his driveway.
This involved dire measures…I had to read the book. There was a bundle of stuff in a plastic sleeve on top of the inverter, but it became apparent that something was missing. We got the inverter running for a while, but were not really satisfied with the available operating modes. The full manuals that we downloaded from Outback (no excuses, you can have the manual on your phone) were frustrating in that they described modes and menus that his inverter did not have. This was an older machine, so I reluctantly decided to do a firmware update.
My innate distrust of software people and experience with clunky and unreliable procedures made me hesitant, but I proceeded with caution. First off, I went online to Outback’s Support page and it was a breeze to download the files. The only tricky bit was the Mate3 programming interface. Was it a Mate3 or a Mate3S? Judging from the photo, I thought it was a Mate3S, which proudly displays its programming wheel. The Mate3 does not. Well, it does not unless somebody took off the plastic cover and left it off. I remembered the plastic cover on a shelf and chose Mate3.
The support page recommended updating the Mate3 before updating the inverter. What’s the Mate3? The Outback system has one or more inverters that will invert, if left alone. It also has a communication block so that other Outback goodies, like FlexMax charge controllers, can coordinate their activities. The Mate3 is the master control panel. It is used to set parameters, load update and save backups of the settings.
This one did not have a card, so Cory’s job was to find one. A small one. 2GB cards are hard to find, so I think he ended up with 32GB. I went through a pro photographer stage early in the digital revolution and have lots of smaller cards from the older cameras. Some of the huge cards reportedly won’t work. I copied the downloaded files to two 2GB SD cards, one for the mate and one for the GS8048a. Files go in the root of the card, not in the folder that was downloaded. That was easy enough, but then I worried about whether the inverters were GS8048 or GS8048a. The two models are not the same and not “close enough”. There is no label on the outside. At Cory’s, we popped off the front cover to view the ID plate and it was indeed the “A” variant.
No more excuses. Show time.
To program the Mate3 first, the SD card is plugged into the slot on the side of the Mate3. The top of the card faces away from you. I punched the LOCK button, dialled up the password, and scrolled through menus to an item that was clearly meant to update the Mate3. Punch the GO button in the middle of the dial and it’s off to the races. While it was programming, a small girl in a swim suit came by, carrying a large chicken. The chicken was perfectly content with the free ride. Life as usual, out in the country. It took a little longer than expected, but it was obvious when programming was finished.
Mate card out and inverter card in. Find the inverter update in the menu and press GO. It happens…and then it happens again. There are two inverters stacked in this system and they are programmed sequentially. It happens and the fans all come on as the beast resets itself. Gee, that wasn’t so scary after all!
Now, into the menus to set the parameters. You never know what will be remembered and what will be forgotten. We got red fault lights. Apparently it forgot it could and needed to handle 50 amps of AC input and settled in on 1.7amps. Yeah, like you can do much with that. More button pushing and we had no more flashing lights and lots of amps. Now, to see if the menus included modes in the new manual. They did…and more. There was an even newer version of the manual, which I had not yet read.
We selected the MiniGrid mode, which lets you run on solar and battery when available and switch over at night when our punky battery gives out. Intriguing, was the GridZero mode. I decided to let that one alone until I read up on it.
The big surprise was the huge power draw we observed when the inverters came on line. We don’t have the house connected. The lights in the hangar were on the inverter and so was the camper out back. Some friends have been staying in a camper while hunting for a new house. This has gone on for a while and the power bills have been high. Really high. FPL high. Last visit, before it started getting really warm, I’d see maybe 2500-3500 watts being burned, but today it was between 3500 and 7500. Wow. I have to have the central air and the clothes dryer going for my house to hit 7500 watts. We decided to hold off on switching power to the house, too. All I know is that when the friends get their new house and Cory’s solar is running full time, he is going to see a heckuva drop in his power bill. If he can come up with another 1000ah of battery capacity, the bill will be trivial.
So, back to the manual and this GridZero mode. Did you ever get excited over a firmware update? Me neither, until now. As I read it, in GZ mode, the AC grid power is never disconnected, like it is in the MiniGrid mode and it never switches on when the battery is low. The grid stays connected, but just kind of rides along with the the inverter, stepping in to help, only when needed. What that means is, when the battery is a little low on a cloudy day, if the air conditioner kicks on with its big starting surge, the inverter will not drop out in favor of the grid. The grid just makes up the difference in what the battery can’t do until that surge is past and you get to continue using the stored sunshine power. Furthermore, there is no little blink that you get when the inverter switches power sources in other modes. How cool is that?
In essence, Outback has built in Zero Export Grid Tie and off grid in one package! ZEGT is one of the best tools available for combating the anti-solar policies we see coming from more and more power companies. With GZ mode, you can stay running off grid after a storm, but maximize the available capacity of your batteries.
I LIKE IT! Maybe the software guys aren’t so bad, after all.
–Neal