AC COUPLING, OFF GRID & MINI GRID & back charging batteries.

[Scruff]

I just realised I built a bang-bang lead I can interface with a 12v signal over the inverter-combi relay.
For instance: closed when battery can accept charge, open when full to 20% discharged....



There's allsorts of things wrong with this solution but 

I built it for genset simulation testing but if I install it on the inverter output instead of the input then it does GTIs too...as long as you put a plug on the GTI as all mine have.
...this is a handy thing allova sudden, I was debating whether it'd keep it around or not.
I heart anti-islanding, it's useful in all sorts of ways they never expected.

You can also use the GTI side of the anti-islanding relay as a photocell trigger.

[clockmanFRA]

METHOD B.

To shut down the GTI as the battery starts to get to much DC voltage, then a DC voltage Comparator circuit can be used.

These are on Fleebay and ALLIexpress.    DVB01. Voltage Comparator.  The relays are reasonable quality.



And to set them properly and for hysteresis times for the battery to settle, you will probably need this Setting Flow chart.    My grateful thanks to 'Klaus' for doing this chart.



Each GTI installation will require not just the main Mini Grid AC cable, but also a separate data cable with the battery bank DC voltage.   This is especially important if the Installation is some distance away from the batteries and OzInverter.

Here is my little enclosure, Data cable feed is separate and here it is coming down to the enclosure  with the comparator circuit and relay that shuts off/on the GTI.

[Scruff]

I've another take on this.

I'm using the programmable relay contact on my inverter combi. Most of the high-end inverters have these. Except ApprenticeVolt is called an alarm contact and is directly tied to the inverter/charger shutdown parameters. I gave out to them about this and they said that if I gave them ludicrous amounts of more money for an external module then the problem they engineered could be circumvented (after having paid ~€120 for an interface to plug a computer into the device to find out that being able to do that wouldn't help me any).

Anyways the bang banger lead I made is 12v triggered because my genset triggers are 12v because the gensets I intend to use them with are 12v triggered.
And my powerplant is 24v.

I tailed off the 24v battery into an el cheapo variable buck reg.



I gave the output a flyback diode to protect it from the relay coil.



Bang banger - genstart interface online.


 

[Scruff]

Titans. I've never been able to kill one

I lost an Xtender last night. 

I had her back feeding 300W to the house with a GTI on standby to reload in the morning.
Checked this morning. The mains was in through and the DC was dead.
Cause of death unknown, no system oddities to report.


This is the thing about AC coupling...when it goes wrong it's terminal.