Thanks Mike. I had held off on trying the saw bench but eventually needed it, so bit the bullet. Would have liked to watch the startup current but can't be in two places at once.

Thanks for the heads up that the shunt pcb can be purchased seperately. Mine was faulty from the start and I was surprised and relieved that the seller was happy to send a replacement after a couple emails back and forth where he asked a heap of questions. He sent a new shunt board not a complete replacement  ...  but it now works fine.

I might just purchase a spare at that price anyway.

We chose to fly under the radar and not bother with any grid connect  ...  so I can't claw back any losses by exporting to the grid. Is working well so far and haven't used much of theirs this cycle.   Fortunately the inverter seems strong enough to cope with the whole house and workshop  ...  and of course the additional GTI takes a fair bit of load off at least during the day.

We've had some brilliant weather lately so I'm always running around looking for stuff to turn on. Along with all the heating, I pulled out a 15 litre water boiler  ...  the type used for dispensing water for tea and coffee  ...  and started boiling batches to do some weed killing.

Davo99 used to talk about doing that  ...  and while I was testing out the Warpverter I boiled heaps of water as a load test  ...  then poured it on the weeds around the fenceline near the workshop. It killed them promptly and virtually none have grown back in two months  ...  so I'm going to keep doing it.

I have it strapped to a sacktruck and hook it to the hose and the power  ...  wait 90 mins  ...  then dribble it over the weeds. Did 45 litres today. I will also concentrate on the area near my ground mounted panels as I don't want to have to use a whipper snipper or ride-on too close.

Had to laugh this morning, my wife said the heater in her mum's room wasn't working. Turned out it got too hot so she'd turned it off at the power point.    Of course I had to reset the mechanical timer to start it up again.

And I came in tonight to see my wife had turned off the air heater  ...  said the dog couldn't handle the heat and was panting. HAhaha!

I understand the bit about having a peek every morning and find myself wandering in many times a day to check things out. Fascinating.

  rogerdw said  

We chose to fly under the radar and not bother with any grid connect  ...  so I can't claw back any losses by exporting to the grid. Is working well so far and haven't used much of theirs this cycle.   Fortunately the inverter seems strong enough to cope with the whole house and workshop  ...  and of course the additional GTI takes a fair bit of load off at least during the day.

I understand the bit about having a peek every morning and find myself wandering in many times a day to check things out. Fascinating.

I chose to keep my grid connect since it costs me nothing. By now I have about one grand of credit with the power company, thanks to the government assistance grant, which will pay my connection fees for many years to come. Especially if our generous government keeps adding to that credit .

An Inverter working well is a good thing to have when living off grid but it may be wise to have a spare on standby. I find building these things a challenge and fun all mixed together, so much so that by now I have several "spares" .

I also keep a daily routine to check my home power station every morning .

Hi Roger & Klaus, yes great idea having a spare. I have a couple of the China boards that are beasts in their own right, I posted one on my original build that I simply could not kill. But - a right pain to repair if it failed, and of course here we are today with the latest designs by Wiseguy and utilizing Poidas SPWM Code module, and all of it simple to repair if a part fails for any reason.

And of course Rogers older designed and brilliant build of the very different Warpinverter proving it can still kick arse big time.  

Klaus has his own innovations, design and variations and is in a similar situation as myself with spares and parts, and we share a love of everything DIY and building stuff.

My second WG inverter unit is almost ready to go as another backup - it's nice to be able to build your own Solar controllers and repair you own inverters, especially in these times of uncertainty and possible parts shortages - Moto - Have spares can fix.  

Roger, that inverter is running sweetly, congratulations again on building such an impressive off-grid system. I'm still jealous of the Land and sheds.

Klaus, my thought process was the same as yours with the feed in.  


Edited 2024-05-08 08:28 by KeepIS

  Murphy's friend said  

I chose to keep my grid connect since it costs me nothing. By now I have about one grand of credit with the power company, thanks to the government assistance grant, which will pay my connection fees for many years to come. Especially if our generous government keeps adding to that credit .

I didn't word that too well. We have still got the grid available here but I didn't go down the path of grid tie to try and get a feed-in tarrif  ...  because we are such latecomers the rate is only a few cents  ...  and I figured if the power providers give us a hard time, I will disconnect altogether.

At the moment it is very convenient to have the grid as backup in case my inverter fails or when I need to shut it down to make any mods. I just flick off the AC-out on the Warpverter and the ATS in the meterbox just swaps over to mains without any interruption. Then when I am ready to go, just turn on the AC-out again and the ATS reverses.

  Quote  

An Inverter working well is a good thing to have when living off grid but it may be wise to have a spare on standby. I find building these things a challenge and fun all mixed together, so much so that by now I have several "spares" .

I also keep a daily routine to check my home power station every morning .

Yes agreed, I've been watching Wiseguy's build with great interest and figure one of them would make a great backup. As soon as he asks for orders I'll put my hand up.  

It's a bit of a trap  ...  my workbench is only in the next room so it's always tempting to go see what's happening  ...  but always good to see it doing what it's supposed to.

Thanks for the kind words Mike and the support from both you and Klaus. As above I certainly would like a backup in case there's any trouble.

I do need to finish off a couple of spare modules so I can swap them out quickly if there's any blowups. It actually only takes a couple of minutes to unscrew and remove a module  ...  that part works really well  ...  in fact it probably takes as long to shut it off and discharge the caps as it does to remove one.

I have a reasonable stock of spare components and I can't afford to run out of anything  ...  but hopefully I won't need too much  ...  touch wood.  

My Nick/Poida/Wiseguy based charge controllers are going great and I've got a heap of spares for them too  ...  so like you say it gives a lot of confidence that they can be fixed if anything were to go wrong  ...  plus a great sense of achievement and satisfaction as well.

Have you done any ac-coupling with your inverters Mike? If I do end up using one as a spare I might have to ration my power useage if I can't just hookup my GTI to aid in production.

I've been really hammering mine the last week or so  ...  whenever there's any reasonable sun the Growatt GTI is running at 5kW for 6 or 7 hours a day  ...  and the Warpverter is running up to an additional 6 or 7kW. Any excess power is going into the battery and I've seen up to 170 amps charging at times.

If the mppt's are starting to throttle back because the battery is charged, I just find more loads. Today I boiled 60 litres of water for weedkilling and ventured further afield from the workshop. Hopefully it works as well as the first batches I did.


In the picture, the extra gear on top of the Warpverter is a dozen 47,000uF 63v elctros added in parallel to the main ones to increase overall capacitance. Tony was keen to see me add more to see if that would reduce some of the humming and buzz with the electric blanket and whenever the GTI runs. That makes it a total of 846,000uF!!! Should add a few more to make 1Farad  ...  except I don't have any more.  

Oh, and it hasn't seemed to make any noticeable difference.

And I do need to tidy up the wiring between the Growatt and the Warpverter  ...  just need the next size up cable  ...  plus hide away the DC-In leads.

  rogerdw said  

...

My Nick/Poida/Wiseguy based charge controllers are going great and I've got a heap of spares for them too  ...  so like you say it gives a lot of confidence that they can be fixed if anything were to go wrong  ...  plus a great sense of achievement and satisfaction as well.
....

and that is exactly why I drove this project.

they work
they are cheap
they are easy to build
they are easy to repair

they are all we need: a mppt that does not cost the earth and is easily modifiable
for any application.

  poida said  

and that is exactly why I drove this project.

they work
they are cheap
they are easy to build
they are easy to repair

they are all we need: a mppt that does not cost the earth and is easily modifiable
for any application.

Haha yep. I still remember your first post when you started that mammoth thread and your comments resonated with me way back then and still do now. It did take me forever to get here  ...  but it's better late than never.

Thanks for all the effort you guys have put into this.

Well I had some fun today  ...  I ran the floor heaters for a while then thought I could try out our big ducted air conditioner on heating.

It hasn't worked for quite a while and the last time we tried it was at Christmas time  ...  but it only ran a few minutes then popped the cct breaker.

Took a while to get it to start up today on heat  ...  but same thing, dropped out the cct breaker again.

Spent a little while checking it out and found the start/run?? cap was faulty  ...  only 12uF instead of 50. I found some 15uF 660V caps in the shed and hooked up three and it then ran again.

It was pretty hairy as I had no idea what sort of power was going to be needed  ...  and each time it fired up the lights dimmed for a couple seconds. I saw the Warpverter output up over 10kW a number of times

Hooked on a clamp meter to register the start up current and it came in at 100.4 and later 99.8A. The volts went as low as 215V at the aircon and steady state current between 22 and 26amps. It's a looong way from the Warpverter.

Of course the sun disappeared behind the clouds a few times while all this was happening  ...  so I saw some pretty horrendous current draws from the batteries, with one at 190 amps  ...  though judging from the output, there were probably worse ones.

The heating worked very well and it would be nice to keep using it  ...  but I chickened out after about an hour and shut it down  ...  and went back to the floor heaters.

It's an Airwell aircon and probably close to 20 years old. Prated 7,310 watts and with 14kW of cooling and 16kW of heating. I understand late model aircons are a lot more efficient and less power hungry  ...  but seeing it works, I'm not sure I want to rip it out and spend money on a new one.

Maybe if I can get my new big air heater going soon, that can take up the slack with our heating  ...  and in summer when we might need some cooling  ...  there should be enough sun to have the Growatt GTI provide 5kW and the Warpverter the rest. That way the Warpverter is not being hammered as much carrying the full load.

Anyway, a learning experience  ...  and my nerves are slowly settling down. Phew.  

  rogerdw said  

Hooked on a clamp meter to register the start up current and it came in at 100.4 and later 99.8A. The volts went as low as 215V at the aircon and steady state current between 22 and 26amps. It's a looong way from the Warpverter.

Anyway, a learning experience  ...  and my nerves are slowly settling down. Phew.  

It looks that the time to build your peak Amp meter has come, might be handy to watch during experiments like that above

  Murphy's friend said  

It looks that the time to build your peak Amp meter has come, might be handy to watch during experiments like that above

Haha, yes  ...  though I had the wrong type of hall effect transformer, so am still waiting on the slow boat from China for the correct type. Worst part is that I have two of the incorrect types.