Solar PV vs Grid usage

[Andy1733]

Btw. The directional arrow is sometimes on the inside of the clamp. Where the cable fits

 

[Neil1976]

I’ve not changed anything but asked the installer to check that it is correct although they haven’t responded to my voicemail yet

 

[Ronski]

Was this a one off problem or ongoing?

Apparently the Givenergy battery will do a full discharge/charge cycle when first commissioned.

 

[Neil1976]

It’s been ongoing since it was installed on the 18th January, figures don’t match up between Octopus and GivEnergy app and looks like my usage according to Octopus hasn’t changed. In fact, it’s probably gone up. They both keep claiming their figures are accurate so back with the installers to check what’s going on

 

[johnb2713]

This is how I understand a CT
Clamp works. I'm sure of I'm wrong someone will be along correct me..
The CT clamp works by reading the current flowing in the direction the arrow is facing. So if the CT clamp is pointing towards the meter and you have the back to grid feed turned off/disabled. You will get the zero figure like you stated in the op.
If the arrow on the CT clamp is facing towards the CU and you have used 9kwh of power like octopus have stated, then you should get 9kwh readings from the CT clamp.
I read somewhere when I was installing mine that if the live and neutral feed to the meter are reversed (by mistake) this can give the meter a wrong reading.

The device is a transformer with a single winding on the primary. It will give a voltage whenever there is current flow. Installing it the wrong way round may result in the following - assume a small amount of export is taking place, the inverter sees a small amount of import. To stop the import it increases its output voltage. This causes more export which the inverter sees as more import and it will continue to ramp up its voltage until it reaches maximum voltage where it will stay.

 

[Neil1976]

The arrow on the top CT clamp is on the inside and is pointing up towards the fuse box. Still no response from the installer after trying to contact them a few times.

 

[MHarv]

Needs to point to Grid, reposition check values on app do a kettle test. Battery should supply up to 3000w for standard kettle if no readings from battery it is incorrect reposition as before wait for installer.

 

[Andy1733]

Neil. I'm not sure if you have sorted this but whilst I was skipping through my inverter installation manual I came across a setting that relates to the meter. It's listed as meter placment.
My inverter has 3 settings.
Grid
Load
Grid +PV
Could this be set wrong on your setup?

 

[Neil1976]

Hi Andy, still not fixed but the installer is at least looking at the issue now and they change some settings, not sure what they were but yesterday’s usage was only about 1kWh difference. I have a GivEnergy battery and I can’t find any settings similar to this. I’m hoping since they’ve made changes it might match today’s usage and so far it’s says I’ve pulled nothing from the grid but Octopus doesn’t give real time data on their app so may have to wait until tomorrow

 

[Neil1976]

Hi Andy, still not fixed but the installer is at least looking at the issue now and they change some settings, not sure what they were but yesterday’s usage was only about 1kWh difference. I have a GivEnergy battery and I can’t find any settings similar to this. I’m hoping since they’ve made changes it might match today’s usage and so far it’s says I’ve pulled nothing from the grid but Octopus doesn’t give real time data on their app so may have to wait until tomorrow

Checked my smart meter and has me using 3.93kWh today so doesn’t look like it’s working

 

[Neil1976]

So latest from the installer is they have 3 customers with the same issue and they think it’s a software issue (part circled on the attached photo) and I have the wrong version. They are in the process of updating the software for another customer and if that works they’ll do the same for me….after 4 weeks we might get a resolution but I’ll wait and see

 

[Neil1976]

My installer has been out after 5 weeks from install and believe it’s fixed now but will monitor it for the next few days. Turns out that they believe it was a cross wire in the fuse box that was causing the incorrect readings. Hopefully the next few days will confirm they have actually fixed it

 

[Andy1733]

.
I read somewhere when I was installing mine that if the live and neutral feed to the meter are reversed (by mistake) this can give the meter a wrong reading.

Could have been this. Maybe?

 

[Mrjmegson]

Neil, do you know why you have a DIN meter and a CT? They would be reading the same thing.

My system has one or the other.

 

[Neil1976]

I have no idea, that’s what was installed and I have no idea if it’s been done correctly or not but trusted that as they’re MCS registered they should know what they’re doing, maybe I should ask more questions

 

[Mrjmegson]

You have been able to see where the bottom one of your CT clamps goes, you said the EV charger, are you able to see where the top one is going? There will be a very thin coms wire coming out of that DIN meter, can you (safely) trace that back and see where it goes?

Id say that's your issue if they both go to the inverter.

 

[Neil1976]

My issue was fixed, there was a cross wire in the fuse box. I say it’s fixed, the usage on the GivEnergy app is on average about 0.4kWh difference each day and have asked my installer if that is a tolerance that is usually seen and within an acceptable range.

 

[Mrjmegson]

Ah ok, I read your message as "it might be fixed", but it definitely sounds like it is.

Yeh, if you watch solar stuff on YouTube, anyone with several devices that have their own apps, will always say they all report different values.

Did he tell you where the crossed wire was?

I'm still very interested in why you have a meter and a CT.