Lux ac battery controller

chainreaction

the person I have been talking to at lux has said they dont have a grid ct offset facility which would solve the small import. He has put a request into the software team to see if they can come up with something. I guess if more of us let lux know we have this import issue (the lux grid ct not seeing what the accurate ? smart meter is seeing) and push for a capability to manage the issue, we may get something. 

newbuilder

chainreaction said:

the person I have been talking to at lux has said they dont have a grid ct offset facility which would solve the small import. He has put a request into the software team to see if they can come up with something. I guess if more of us let lux know we have this import issue (the lux grid ct not seeing what the accurate ? smart meter is seeing) and push for a capability to manage the issue, we may get something. 

That’s funny I got told there was!

My reply

Hi

That is the CT error , and also I have tried to reduce the import power , and you can have a check

Kind regards.

Solarchaser

Very funny, as that's what they adjusted to resolve my constant import, and then later when I realised the offset was too much, to resolve my constant export.

Heedtheadvice

 just to add a bit of explanation of the tech issue.

CTs that have a big range (say 100Amps) are not that accurate at low current levels such as under 1Amp. That can be 260watts at mains levels so probably need individual offset tweaks to compensate a bit though that would make an other part of the low current curve a bit I  error too.

chainreaction

Solarchaser said:

Very funny, as that's what they adjusted to resolve my constant import, and then later when I realised the offset was too much, to resolve my constant export.

solarchaser do you have a name at lux and I'll get the person i have been talking to, to speak to them

Solarchaser

Sorry chain reaction, I checked my emails there and they were simply with info@luxpowertek.com

The person never signed off who they were.

This was my wording for last adjustment if that helps. 

"Hi, you adjusted this for 80w compensation for me back in June, however I'm now seeing about 2kw per day of export which says that the 80w isn't right, could you reduce it to 40w please and I'll see how it goes?

Thanks"

As heedtheadvice says ct clamps don't have great resolution at low power draw, but thats why the offset is required. 

newbuilder

Thought I would give you a little background to my situation: 

I was told before that at the rate I am importing to just leave it but every penny counts at the moment. 

So I have a SOLIC and it combats with the battery in thne gybrid Lux inverter. I was basically told my SOLIC to install a timer to stop it happening. I don't know about you but I didn't think, especially in Scotland, that the sun works on timers. 

Anyway after an unsuccessful ask for a refund and Section 75 claim (santander wanted me to get an independent electrician specialist on solar to justify why a timer owuld not work - at my cost) I went to buy a competitor's product and they suggested I try some CT Clamp manipulation. 

So my Lux no longer sees the pull from the SOLIC and the SOLIC no longer sees the LUX. It is a great divorce and everything works fine. I did try to get a new CT clamp for Lux supplier to sort this but they weren't for even sellilng it to me. The reason will become clear when I tell you my set up. 

In a Lux normal setup there is the CT on the tail before the meter - Consumer board side. And the CT clamp for the SOLIC sits beside this. What was happening was that the SOLIC saw a quick export of power (say from the kettle clicking off) and grabbed it- as designed. But as there is no buffer for this on the SOLIC, it kept grabbing it and the battery would kick in and drain. 

Solution was to use a second CT clamp (here is where I wanted another Lux- I did research and got the closest I could do it)- Clamp this to the live at the SOLIC - i.e. the live coming from the distribution board to the immerser, and then double it up on the connections that the LUX clamp was on. 

This as I said earlier means that there is no competition from Lux and SOLIC.  The downfall is there is a bigger error in the importing from grid when the solar is on and the battery charging - about 20-60 watts. (Zero if additional clamp is removed). 

I have already asked for an ajustment and it made no difference. - Could the 2 CT clamps be making a bigger problem?  

Starfrog

How much cost saving per day are we looking at here ? 

chainreaction

Starfrog said:

How much cost saving per day are we looking at here ? 

its not much in the grand scheme of things, 0.5Kw of excess import per day, so 180kw over the year or £60 on my current tariff of £0.29 /Kwh

chainreaction

Thanks newbuilder, I have a SOLIC equivalent called powerdiverter by solar electric (quite big in australia), which diverts power to the immersion when >50w export (or >100w export if the powerdiverter device which looks at export and then tells the diverter to load up etc is run on batteries rather than AC). it has its own ct clamp on the tails just before our smart meter. I have had issues with the powerdiverter doing exactly what your SOLIC was doing when the inverter was under hi load. Ive largely stopped this by having the powerdiverter detecting device sat on a timer which allows the powerdiverter to divert excess electric from 10:30 to 17:00. Anything beforehand will go to the batteries, anything after 5 will largely be nothing, support cooking or recharing the batteries after any cooking we have done. This means the batteries will be fully charged first, then hot water or if i decide EV. I use solcast api for specifc data about the solar irradiance for my system so I can manually decide each evening how much recharge of the batteries i will do via the low rate period. for most of the summer this has been zero other than probably a handful of days. 
Looks like your SOLIC starts to divert as soon as it sees any export - can this be changed in the SOLIC world? A quick read on the internet and SOLIC200 has 2 modes of operation, yours has been installed on mode 2, in mode 1 you set a threshold at which power flows to the immersion. it reads like a "qualified electrician" is required for this. you may be able to use the minimum setting of 100w in this mode and have your ct clamp reversed so that SOLIC will start to divert power if the export is >100w. I may be totally off piste here from my read but may be worth tinkering.