DIY solar battery storage

[Oldman22]

I think this may be because I don't have the 2nd production CT installed. I can't put this on because the inverter is too far away from the CU and the CT leads are not to be extended according to Solis. In any case, I have not seen anywhere that the production CT HAS to be installed.

If you look on youtube there are instances of extending the CT by up to 40mtr using cat 6 cable. I suggest you keep the length as short as possible and use all pairs.
Pluginsolar even sell the CT with suggestions to extend it.
https://www.pluginsolar.co.uk/?product=solis-ct-clamp-for-export-limitation

 

[Berserkerboy]

Yes. I could do that without too much bother. I'll look into it and let you know the result.

 

[Berserkerboy]

Okay, some good news. When I physically disconnected the data cable between the meter and the inverter, the charge and discharge were reduced to zero. Phew!! I can truthfully fill in the commissioning forms as the failsafe is working..

So other than the odd issue of having to set the meter CT as being on the PV rather than the grid in order to get comms to the inverter, and the lack of battery temperature sensing, all is good.

In fact, thinking about it, the reduced charging to the battery is in fact a good thing:
In the morning charging is limited to 12A for a while. Excess power heats the water via the immersion diverter so we get hot water early on. At 40% SOC the inverter switches to full charging the battery and the immersion switches off. When the battery is full the water gets a heating top-up until the immersion thermostat says enough is enough..

Thanks everybody for your input. I'm hoping this is the end of the saga. BTW still no response from Solis. Appalling customer service.

 

[Badger]

I have to be fair to solis I've emailed tech support 3 times now in the space of the last few weeks and they have responded to me within a couple days each time so I can't say they have been poor customer service at all

 

[Berserkerboy]

I have to be fair to solis I've emailed tech support 3 times now in the space of the last few weeks and they have responded to me within a couple days each time so I can't say they have been poor customer service at all

Still no reply to me.
Have you raised a ticket via web form on each occasion or is there a direct email?
Cheers.

 

[Berserkerboy]

BTW still charging at 12A the other morning despite 58% SOC. Charging at 50A a short while thereafter. So perhaps charging is governed by inverter temperature instead,

 

[Andy1733]

Have you fitted the CT clamp ?
It will never work correctly without the clamp.

 

[Berserkerboy]

Yes. The CT clamp that goes to the Actel meter is on.
The second production CT clamp is not. But this is an optional clamp for if you wish to get production data on the Solis cloud.

 

[Andy1733]

I thought you had a diverter for the hot water? Doesn't this have a CT clamp?

If you put the 2nd CT clamp on then set the inverter from PV back to grid isn't this how Solis recomend the set up?
Just get a cat cable and test the theory n see if it works. I know you don't want to spend money but your going around in circles. Just eliminate everything then if you can't fix it wait for Solis reply.

 

[Berserkerboy]

I thought you had a diverter for the hot water? Doesn't this have a CT clamp?

If you put the 2nd CT clamp on then set the inverter from PV back to grid isn't this how Solis recomend the set up?
Just get a cat cable and test the theory n see if it works. I know you don't want to spend money but your going around in circles. Just eliminate everything then if you can't fix it wait for Solis reply.

Yes. Diverter also has a CT clamp.

There has been no definitive answer about whether the production CT for the Solis has to be connected as well as the consumption one, or whether it's optional.
I have watched a Solis installers video and the instructor said the production clamp is provided if you want to view production data but didn't say it had to be installed.

I will see if your suggestion works regarding the production CT clamp for the inverter. It's a bit tricky for me as I have 2 circuits in the CU that are connected to microinverters from the solar panels. This is because I have a second array of panels that was installed after the first.
Presumably, I will have to see if I can get the CT clamp around both the live feeds from these 2 circuits?

 

[Berserkerboy]

A quick update. I raised a new ticket with Solis which was replied to within a few days. I think the earlier ticket had been 'lost'.
Solis seem to only answer one question at a time. So far, I have been shown that the BMS is limiting the charge rate of the battery. So the inverter is doing what the battery is telling it to do. I guess that the battery is seeing a cool temperature and lowering the charge rate. As the battery warms up it allows a higher charge rate. So that is okay I would say.
Hopefully, they will get around to answering the issue of the meter having to be set to 'on PV' rather than 'on grid' where it actually is, in order for comms with the inverter to be established..

 

[Berserkerboy]

A couple of things to report:
Solis are still dealing with my issues. At least there is an ongoing conversation.
As I have said earlier, the battery temperature problem has largely been resolved although Solis have not specifically said why a low-temperature state exists when it doesn't. The battery software is correctly controlling the charge rate but the actual temperature seems to not be properly recorded on the inverter.
Solis have also not specifically said whether the production CT has to be connected. The meter CT is on the grid live wire where it enters the house. Intuitively, the setup on the inverter should be 'meter on grid' rather than 'meter on PV'. Hopefully, I will get some answers. I'm sure this issue is also being reflected in strange energy flows showing on their app. In the evening power is shown as going to the grid rather than to the house..
Lastly, I have a Solic immersion diverter. This also has a CT on the live grid wire where it enters the property. I was concerned that there might be some competition for solar power. Until yesterday it appeared that the battery was taking power first. This suited me, as with the BMS restricting charging to around 700w in the early morning the rest was going to the immersion so we had hot water as well..
Yesterday, however, I saw that the immersion was taking power from the battery. I guess that the inverter exported a little power as it reacted to house demand which was seen by the diverter and sent to the immersion. There was then a cascading effect until the diverter was sending 3kw to the immersion. Not so good...But not the end of the world..