Isolation Procedure for Shutdown and Startup

I'm having some work carried out to add a circuit in our consumer unit.

Can anyone advise the correct sequence of isolation for shutting down, and for restarting afterwards.
We have solar PV with inverter, Battery storage with inverter, and Voltage optimiser.
I'm hoping the system won't completely discharge and recharge itself after startup (recalibration), can you confirm this?
Thanks in advance. I wasn't given this information by the installer and can't find it in any of the (limited) literature I was given.

Here you go. You start from the bottom and work up, to shut down (so battery first, all the way up to the PV), and do the reverse to start up again:

https://ibb.co/0mxRD0N

I don't believe this would trigger a calibration cycle.

The information from GE is poor to start with, and then then most installers do a rubbish job of communicating this important information, to compound the issue.

I don't know where you found that, but thank you very much indeed. Much appreciated.

Yes the documentation has been very poor, as is the way with all things technical these days.
Just a case of research, asking around and hoping, whenever something arises!

Thanks again.

ToothyChris

Like the bottom up approach, easy to remember

Before I commit this to the Wiki I assume the restart is identical but backwards?

In a power cut isn’t the whole lot going to switch off without following a set step by step procedure, and then presumably will restart ok? Certainly our solar has always restarted ok after a powercut, or electricians just throwing the main switch for the house. Just curious as I want to add a CT to the battery for our Eddi and Zappi to see the battery, and was going to just turn off the RCBO in the main CU that feeds the GE mini CU with the monitoring kit in that then goes to the inverter and battery. No EPS on our system so I presume once the RCBO is off the whole lot is off and safe?

Jim It's just the mains ac that trips. The PV and battery are still connected to the inverter. To shutdown the inverter, it will need to be isolated from all sources of power; hence the AC supply; PV supply and battery supply isolators to off.

Jim I want to add a CT to the battery

To enable your solar plant to be visible to the Zappi and myenergi app, an additional CT needs to go on the AC connection between the inverter and the consumer unit. I don't believe myenergi offer battery monitoring per se. The benefit of a CT is that it can be clipped onto the outside of a conductor without interfering with any connections.

Jim once the RCBO is off the whole lot is off and safe?

No, that's not a good assumption to make. As mention earlier, the inverter will still be powered by the PV and/or battery and some internals are likely to be at 240Vac. To fit the CT in the GE mini CU, you need to isolate it from all sources of power. This means opening the connection to the main CU (open the MCB there) and opening any connections to/from any inverter - that's the (usually) red isolator next to each inverter. However, unless you're confident about doing this and are able to test the connections inside the CU with a meter, I strongly recommend you ask a sparkie to sort it for you.

hoggy Hmmm... It looks like the gen 2 inverter doesn't have the external battery isolator between the battery and the integral inverter isolator. That's one way to solve reliability issues with them. Also, the diagram is titled "Shutdown Instructions Batteries", but doesn't suggest what to do if you have more than one battery connected to your inverter.

In answer to your question, I don't think it matters what order things are done in but it would be better if the inverter was quiescent, ie not pumping kWs to/from AC or battery when the relevant isolator was opened. Personally, if feasible I would like to reduce the power output of the inverter via the Remote Control "Inverter Max Output Active Power Percent", then follow the diagram (adding multiple battery scenario and external battery isolator).

And yes, the reverse to start up (not forgetting to set Inverter Max Output Active Power Percent to 100% if adjusted previously.

Tim Thanks Tim. That makes sense to me now. I was hoping if I added the second CT I could then use the extra features MyEnergi offer like “avoid charge” and “avoid drain”. I’ve got Eddi as my master so Zappi is the slave. The existing CT goes to Eddi as I could get an easier route to that. The GE installer kindly added the CT into our CU for the Eddi when they installed the battery.

The GE battery is actually working fine with the Eddi and Zappi so far (3 months). Adjusting the supply grid settings in Eddi to have a threshold and response delay has been making sure the battery always gets in first before Eddi. Maybe I don’t need to bother adding the second CT between the battery and Eddi, at least for now.

Tim I’ll add a bit about sympathetic shutdown on it a bit later (I only had 10mins spares to knock this one together anyway)

In regards to the other post about AC shutting everything by down - sadly not. The inverter will not blink and will carry on quite happily on loss of AC (even using the 4%-0% buffer if it has to under prolonged power cuts)
To fully shut them down it does need all sources severing (battery for AC coupled & Battery + PV for Hybrids)

Jim added the CT into our CU for the Eddi

I think you have all you need for your purposes. We've got a Zappi and hub but no Eddi etc. The CT added to the Eddi by your installer should be good for all myenergi things.

Jim like “avoid charge” and “avoid drain”

This is only applicable to an AC-coupled battery, not a hybrid which it looks like you have. With an AC-coupled, the energy flow is only either battery charge or discharge; for a hybrid energy going in is only battery charge but energy coming out could be PV or battery or both feeding house load. In order to make use of the features the Zappi offers, just set it to ECO+ with a Minimum Green Level of 100% and it will only every charge from diverted export. Obviously, you will only export when there is PV in excess of your house load which will include your Eddi.

Tim Ours is an AC coupled. We added the battery a few after the solar so there is a separate Solis string inverter

Jim Solis string inverter

Adding another CT would be useful for the myenergi system to be able to differentiate between the energy stored in the AC-coupled battery and the PV from the Solis inverter. Assuming your installer wired the Solis to your GE mini CU on one MCB and then added your AC-Coupled to another MCB on the mini CU and that the CT they installed at the time was on the AC-Coupled connection, another CT would go onto the cable from the Solis to your mini CU. Harking back to the post earlier, to isolate the mini CU from all sources of energy, you'd have to isolate each inverter at the inverter red isolator and the mini CU connection to the main CU at the main CU MCB. ie all sources of energy should be isolated at the remote end of the connection to the mini CU. Unless there are any other connections to the mini CU, that should remove all sources of energy. But again, only attempt this if you're confident and can use a meter to check that the board is dead before you start.

It'd be an interesting exercise to set up your system to cater for different priorities for house battery, Eddi and Zappi at different times. Feels like some home automation coming on.