Like a lot of people I was frustrated by the CT Clamp on my Growatt SPH5000TL BL-UP hybrid inverter, and the fact it didn't appear to control my grid input/output with much accuracy. I would constantly draw between 50w and 100w from the grid, which also meant the totals each day on the ShinePhone app never really matched the equivalent numbers from the Octopus App. I therefore set upon replacing the CT clamp with the electric meter using information gathered from forums and facebook groups. The install is now complete, was it worth it?
Well I'm pleased to confirm it has completely fixed the phantom draw from the grid. My grid usage is now pretty much non existent when Solar or Battery is available, and my readings are almost identical to the Octopus app.
There seems to be a few myths about using a non Growatt electric meter so below is a guide that hopefully answers most of the questions. Please note this worked perfectly on my UK Growatt SPH5000TL BL-UP. I can't vouch for other SPH TL BL-UP models, but I'd be surprised if it didn't work.
To install an electric meter you'll need;
First thing to do is make up the comms cable. Growatt supply this with their meter but there's nothing special about it, it's just a standard Ethernet cable. I bought the Cable Matters one from Amazon which was CAT6, but any CAT5e or above should be fine.
To make up the cable simply cut off the plug on one end (doesn't matter which). Strip back the outer sleeve about an inch or so. Cut all cables back to the outer sleeve apart from White/Orange and White/Blue. This will be pin 1 and pin 5 on the plug the other end. To make things neat you could add some heat shrink tubing and some ferrules which is what Growatt do but it's not essential.
See below the cable I made up, and how this will fit to the meter. Blue/White connects to terminal 5 on the meter, White/Orange connects to terminal 6 on the meter.
Next get an electrician to install the meter. This is a must as the meter should go on the main tails after the house Smart Meter and may need the main fuse to be pulled. Never do this yourself unless your qualified!!!!! I took the opportunity to ask for a 100 amp isolator to be fitted also meaning I could isolate the supply to the new meter at any time.
Below is the install once complete. Nice job from my sparky and took less than an hour. Note on the comms cable I added some extra heat shrink tubing (leaving the colour of the cables visible), and we also covered the bottom mains terminals with some white tape just to be extra safe.
Now to connect the other end of the comms cable from the new meter to the Inverter. IMPORTANT : You MUST change the Power Harvester setting on the inverter from 'CT Clamp' to 'Meter' or it will not work. This can only be done via the web version of the Growatt Solar Dashboard; https://server.growatt.com/index. The same option doesn't appear in the App.
Go to Settings in the bottom right corner of the dashboard. Scroll down to the bottom of the settings page. Change Power Harvester to 'Meter'. The password is growattyyyymmdd. yyyymmdd being year month and day eg; for 18th Aug 2024 the password would be 'growatt20240818'. Make sure you are careful to just change the power harvester setting. The rest leave alone.
At this point you will most likely get an error on the inverter which is expected because you now have the CT Clamp connected with the power harvester set to 'Meter'.
At this point I isolated the mains supply and shut down the inverter in order to unplug the CT Clamp and plug in the new meter. Not sure shutting every down was really necessary but better to be safe than sorry in my view.
The CT Clamp is plugged into the port labelled 'CT/Meter'. Simply unplug the CT Clamp, and plug your new meter into the same port.
The install is now complete. Turn everything back on and let the inverter go through its initiation. I found the error cleared immediately and the inverter connected to the meter.
The telephone symbol on the meter shows it's connected to the inverter. Check your readings on the app and it should all look as normal (but more accurate). I found my load went up slightly. This is because the inverter is now seeing the missing 50w-100w.
If it's not working and the install is correct, there may be some settings to look out for and change if necessary.
For me the v2 meter was set to channel 1, with a baud rate of 9600 by default. This is crucial or again it won't work. My inverter was already on channel 1 so everything worked immediately. I didn't have to change a thing.
To check the channel your inverter is on, there's a good video below:
It's easier to change the channel on the inverter rather than the meter, if need be. Once set to the same channel you should be fine.
A couple of nice extra's I didn't notice until after is you'll see the new meter in your device list on the ShinePhone app, and also the web dashboard, where you can pull new graphs based on its readings. You could never do this with the CT Clamp.
Now my view on some of the points that I saw coming up many times on the forums.
Well I'm pleased to confirm it has completely fixed the phantom draw from the grid. My grid usage is now pretty much non existent when Solar or Battery is available, and my readings are almost identical to the Octopus app.
There seems to be a few myths about using a non Growatt electric meter so below is a guide that hopefully answers most of the questions. Please note this worked perfectly on my UK Growatt SPH5000TL BL-UP. I can't vouch for other SPH TL BL-UP models, but I'd be surprised if it didn't work.
To install an electric meter you'll need;
- EASTRON SDM230 Modbus MID V2 Electricity Meter. I bought mine from Amazon here : https://www.amazon.co.uk/gp/product/B08XJS1SBC. Mine was the one for £55 dispatched by Amazon, sold by NRG Instruments Ltd.
- Standard Ethernet Cable. I bought mine from Amazon here : https://www.amazon.co.uk/gp/product/B00G9BN9KW, but any CAT5e or above ethernet cable should work.
First thing to do is make up the comms cable. Growatt supply this with their meter but there's nothing special about it, it's just a standard Ethernet cable. I bought the Cable Matters one from Amazon which was CAT6, but any CAT5e or above should be fine.
To make up the cable simply cut off the plug on one end (doesn't matter which). Strip back the outer sleeve about an inch or so. Cut all cables back to the outer sleeve apart from White/Orange and White/Blue. This will be pin 1 and pin 5 on the plug the other end. To make things neat you could add some heat shrink tubing and some ferrules which is what Growatt do but it's not essential.
See below the cable I made up, and how this will fit to the meter. Blue/White connects to terminal 5 on the meter, White/Orange connects to terminal 6 on the meter.
Next get an electrician to install the meter. This is a must as the meter should go on the main tails after the house Smart Meter and may need the main fuse to be pulled. Never do this yourself unless your qualified!!!!! I took the opportunity to ask for a 100 amp isolator to be fitted also meaning I could isolate the supply to the new meter at any time.
Below is the install once complete. Nice job from my sparky and took less than an hour. Note on the comms cable I added some extra heat shrink tubing (leaving the colour of the cables visible), and we also covered the bottom mains terminals with some white tape just to be extra safe.
Now to connect the other end of the comms cable from the new meter to the Inverter. IMPORTANT : You MUST change the Power Harvester setting on the inverter from 'CT Clamp' to 'Meter' or it will not work. This can only be done via the web version of the Growatt Solar Dashboard; https://server.growatt.com/index. The same option doesn't appear in the App.
Go to Settings in the bottom right corner of the dashboard. Scroll down to the bottom of the settings page. Change Power Harvester to 'Meter'. The password is growattyyyymmdd. yyyymmdd being year month and day eg; for 18th Aug 2024 the password would be 'growatt20240818'. Make sure you are careful to just change the power harvester setting. The rest leave alone.
At this point you will most likely get an error on the inverter which is expected because you now have the CT Clamp connected with the power harvester set to 'Meter'.
At this point I isolated the mains supply and shut down the inverter in order to unplug the CT Clamp and plug in the new meter. Not sure shutting every down was really necessary but better to be safe than sorry in my view.
The CT Clamp is plugged into the port labelled 'CT/Meter'. Simply unplug the CT Clamp, and plug your new meter into the same port.
The install is now complete. Turn everything back on and let the inverter go through its initiation. I found the error cleared immediately and the inverter connected to the meter.
The telephone symbol on the meter shows it's connected to the inverter. Check your readings on the app and it should all look as normal (but more accurate). I found my load went up slightly. This is because the inverter is now seeing the missing 50w-100w.
If it's not working and the install is correct, there may be some settings to look out for and change if necessary.
For me the v2 meter was set to channel 1, with a baud rate of 9600 by default. This is crucial or again it won't work. My inverter was already on channel 1 so everything worked immediately. I didn't have to change a thing.
To check the channel your inverter is on, there's a good video below:
It's easier to change the channel on the inverter rather than the meter, if need be. Once set to the same channel you should be fine.
A couple of nice extra's I didn't notice until after is you'll see the new meter in your device list on the ShinePhone app, and also the web dashboard, where you can pull new graphs based on its readings. You could never do this with the CT Clamp.
Now my view on some of the points that I saw coming up many times on the forums.
- Growatt load their own firmware and a non Growatt meter will not work
- Not true on my SPH model. The App and Web Dashboard identifies the meter and shows the status as 'normal' so there can't be anything else it's expecting
- The cable Growatt supplies is specific to the meter
- This isn't the case. It's just a normal ethernet cable. As long as it's a standard cable with the pins as in the picture above, the only wires you need is Blue/White to connect to terminal 5 on the meter, and White/Orange to connect to terminal 6 on the meter. Just follow the pics.
- You need to change the channel and baud rate
- Not the case for me. The channel and baud rate on the Eastron V2 defaults to the correct settings of Channel 1 and Baud rate of 9600. My inverter was already set to this also out the box. If anything I suspect the channel is the one people may need to change. Hopefully the video above helps with this.
- Which pins connect to which terminal on the meter.
- I saw so many different answers to this. I simply downloaded the Growatt meter install guide, which clearly says which colours to use. The Eastron v2 I used has identical ports to the Growatt Eastron v1, so just follow the original Growatt user guide; https://www.alternergy.co.uk/media/...pm-e_smart_meter_quick_guide_-_17_12_2019.pdf
- Why not just buy the Growatt meter, surely it's easier
- This may be true if you can source one, however the Growatt package is much more expensive, and you'll be given the v1 Eastron. Personally I like to have the latest model, and the Live and Neutral connections on the V2 suited my install much better.
