It's worth mentioning it's always better to use the hard-wired CT connections if possible. There's a lag with harvi since it's not sending a continuous datastream, meaning you'll import/export more energy.
Not always. Especially on longer length distances. The inaccuracies over long data cabling with CT application is a known issue. Some manufacturers will prohibit them beyond a certain length. The harvi will work beautifully in this instance and is ideal for the application shown. We have systems installed (dozens) both with harvi and direct ct cabling. The export/import differences are negligible. All that said we do have data cabling into the loft space now for other purposes so could attach a wired ct. Sounds like an experiment to be honest! But to installers out there be careful with the wired CT approach we have had huge issues with Zappi installations based on this approach and harvi was the only way. In this application its more of a problem because the lag can allow time for a service fuse to operate rather than a small inconvenience of perhaps 10p a month in import/export. I know professional installers will know all this. But for the DIY and enthusiastic experts it's good info to share.
@@electrician247 The issue with the harvi, and why it makes a system non-G100 compliant is the data intervals can be 30 seconds, but also it's classed as an unreliable link - if a packet is missed, or something else is transmitting on the 868 MHz band there's no bi-directional comms to request another packet. Noise on a CT extended with twisted pair should be negligible unless it's installed wrong - we're modulating current on the secondary, not voltage.
Exactly and the inaccuracies with harvi are more evident at lower power full levels. The CT extension on a Zappi are limited in MI to 100m which is beyond spec on many commercial EV applications. Again this is nothing new to professional installers but appreciate can be of interest to enthusiastic experts. The CT extensions on some solar inverters for example are 5m. It really does depend on the quality of the CT in use and its rating/anticipated current flows. They are less accurate at smaller current flow. We know this due to access to hundreds of installations with measured usage via smart metering, CT data and equipment data. No easy answers but even when installed perfectly they are not 100% fool proof and all the systems rely on electronic management be that with a harvi or hardwired to a Zappi/Eddi. Which is why DNOs will not allow either method for a long term connection to limit electrical consumption. Devil as always is in the detail.
@@electrician247 I wish they allowed you to directly connect the Harvi to the Eddi / Zappi via RS485, that would resolve both issues. The other option would be for the Eddi / Zappi to support meters which have modbus / meter-bus outputs.
What cylinder temperature will you be targeting with this? Will the plumbers be increasing the immersion heater's limit to say 80C and installing a tempering valve on the output? Assuming a 210l cylinder, a boiler setpoint of 60C for Legionella and a solar cutoff of 80C, that will be equivalent to nearly 5kWh of storage. As a side note (I know you like technicalities), if the Harvi is drawing power from the CT and you've installed the CT before the meter - That's technically stealing energy, even though it's probably too little for the meter to even register. :)
Haha yes I know mate with the CT. It was there while we moved the tails doing the main house CU but good spot! The system will still have conventional gas system for main daily heating cycles etc. The immersion just supplements that. It's 2 x 120L tanks I believe.
@@electrician247 Ah okay in that case heating 240l of water by 20C will take around 5.5kWh of energy then. The only issue with just having a boiler heat the water to the same temperature is that you can only really take advantage of the excess solar as the hot water is used. Another option without the need for higher temperatures and a tempering valve would be to dedicate one cylinder to solar pre-heating (Increasing 120l of water from 20C to 65C will allow you to store 6.3kWh) and feeding the second cylinder from that. The second cylinder would then be the only one heated by the boiler. This has a couple of advantages: - You always have 120l of hot water via the boiler, ready to go - There water should spend plenty of time within the second cylinder for any Legionella to be destroyed - You have an entire 120l cylinder to absorb the excess solar energy - No extra costs for tempering valves Essentially it's an alternative to a Mixergy setup. I guess it's all up to the plumber and customer at the end of the day.
@@yngndrw. you are so right I find it very hard to explain this to my customer's that they get all the energy from solar into the first cylinder and then it feeds the second cylinder which is heated from main source. I know some people don't have the space.
I note that you have placed the harvi ct clamp between the supply fuse and the electricity meter. I thought the ct clamp was supposed to clamp after the meter but before the consumer unit?
Not how it works. Eddi sees export at the main tail in the CU or meter area. If it would work as a comma method outside standard data. Who knows. Not recommended though in any case from me.
Of course. The immersion should only ever be backup to the main source of heating. This just supplements it and very well indeed it has to be said. Thanks
Life is full of options for different people. That said if you are paying a grand for eddi you got done lol. ATM it’s better to just export your excess generation anyway rather than heat water with it on certain tariffs. I would close by saying consumers will get a much better return on investment by utilising smart abilities in the technology rather than manual function. It’s false economy and over the years you will lose out without it. Especially as tariffs adjust. Consumers would be wise to take a longer term view and understand the best ways to get the best value from all these options.
@@jamesgalloway8835 with the intelligent tariffs, fluctuation in weather and unpredictable energy costs its not so simple no. With the eddi for example you can send 200W to the element when you have that in export rather than dump 2-3kW at it because a battery is fullish. Way better ways to maximise return.
❤ My Eddi your Matty installed, so pleased i got your Company to install it, best thing about my PV & Battery install 💕
Thank you Ian. Hope you are keeping well!
@@electrician247 how much does is cost to supply and install ?
@@helenalovelock1030 it depends on existing wiring but £600-£800 ish
Nice one Mark you need a hoover attachment for your sds don’t want to breathe the silica and brick dust in
We have several 🤣. Dust mask while drilling on this one as I was slumming it with an old sds
@@electrician247 haha Mattie and Nate pinched all the good stuff dad can slum it with the old stuff 😂😂😂
It's worth mentioning it's always better to use the hard-wired CT connections if possible. There's a lag with harvi since it's not sending a continuous datastream, meaning you'll import/export more energy.
Not always. Especially on longer length distances. The inaccuracies over long data cabling with CT application is a known issue. Some manufacturers will prohibit them beyond a certain length.
The harvi will work beautifully in this instance and is ideal for the application shown.
We have systems installed (dozens) both with harvi and direct ct cabling. The export/import differences are negligible.
All that said we do have data cabling into the loft space now for other purposes so could attach a wired ct.
Sounds like an experiment to be honest!
But to installers out there be careful with the wired CT approach we have had huge issues with Zappi installations based on this approach and harvi was the only way. In this application its more of a problem because the lag can allow time for a service fuse to operate rather than a small inconvenience of perhaps 10p a month in import/export.
I know professional installers will know all this. But for the DIY and enthusiastic experts it's good info to share.
@@electrician247 The issue with the harvi, and why it makes a system non-G100 compliant is the data intervals can be 30 seconds, but also it's classed as an unreliable link - if a packet is missed, or something else is transmitting on the 868 MHz band there's no bi-directional comms to request another packet. Noise on a CT extended with twisted pair should be negligible unless it's installed wrong - we're modulating current on the secondary, not voltage.
Exactly and the inaccuracies with harvi are more evident at lower power full levels.
The CT extension on a Zappi are limited in MI to 100m which is beyond spec on many commercial EV applications. Again this is nothing new to professional installers but appreciate can be of interest to enthusiastic experts.
The CT extensions on some solar inverters for example are 5m. It really does depend on the quality of the CT in use and its rating/anticipated current flows. They are less accurate at smaller current flow.
We know this due to access to hundreds of installations with measured usage via smart metering, CT data and equipment data.
No easy answers but even when installed perfectly they are not 100% fool proof and all the systems rely on electronic management be that with a harvi or hardwired to a Zappi/Eddi. Which is why DNOs will not allow either method for a long term connection to limit electrical consumption.
Devil as always is in the detail.
@@electrician247 I wish they allowed you to directly connect the Harvi to the Eddi / Zappi via RS485, that would resolve both issues. The other option would be for the Eddi / Zappi to support meters which have modbus / meter-bus outputs.
Good video buddy.
Just getting my head round it all atm.
Sound like you're East Yorkshire.
Yes we are lol
What cylinder temperature will you be targeting with this? Will the plumbers be increasing the immersion heater's limit to say 80C and installing a tempering valve on the output? Assuming a 210l cylinder, a boiler setpoint of 60C for Legionella and a solar cutoff of 80C, that will be equivalent to nearly 5kWh of storage.
As a side note (I know you like technicalities), if the Harvi is drawing power from the CT and you've installed the CT before the meter - That's technically stealing energy, even though it's probably too little for the meter to even register. :)
Haha yes I know mate with the CT. It was there while we moved the tails doing the main house CU but good spot!
The system will still have conventional gas system for main daily heating cycles etc. The immersion just supplements that. It's 2 x 120L tanks I believe.
@@electrician247 Ah okay in that case heating 240l of water by 20C will take around 5.5kWh of energy then. The only issue with just having a boiler heat the water to the same temperature is that you can only really take advantage of the excess solar as the hot water is used. Another option without the need for higher temperatures and a tempering valve would be to dedicate one cylinder to solar pre-heating (Increasing 120l of water from 20C to 65C will allow you to store 6.3kWh) and feeding the second cylinder from that. The second cylinder would then be the only one heated by the boiler. This has a couple of advantages:
- You always have 120l of hot water via the boiler, ready to go
- There water should spend plenty of time within the second cylinder for any Legionella to be destroyed
- You have an entire 120l cylinder to absorb the excess solar energy
- No extra costs for tempering valves
Essentially it's an alternative to a Mixergy setup. I guess it's all up to the plumber and customer at the end of the day.
@@yngndrw. you are so right I find it very hard to explain this to my customer's that they get all the energy from solar into the first cylinder and then it feeds the second cylinder which is heated from main source. I know some people don't have the space.
I note that you have placed the harvi ct clamp between the supply fuse and the electricity meter. I thought the ct clamp was supposed to clamp after the meter but before the consumer unit?
Makes no difference so long as in the line conductor
Hi Mark, can it be connected to a heatpump hot water system ?
great vid cheers. how will these work when the customer already has a zapi using a libbi plz
sorry zapi using a harvey for monitoring
They link into the system and take in the CT data to work. Details in the myenergi manuals. Pretty simple though once you get your head around it
QUESTION:
Could you use a TP link that sends data through mains cables.
One at the Eddi and the other at the hybrid inverter ?
Not how it works. Eddi sees export at the main tail in the CU or meter area.
If it would work as a comma method outside standard data. Who knows. Not recommended though in any case from me.
What happens if there isn’t enough solar to heat the tank? Can it then switch to gas to heat the rest ?
Of course. The immersion should only ever be backup to the main source of heating. This just supplements it and very well indeed it has to be said. Thanks
I would install a fire alarm above an Eddi.
Already one in the loft for the boiler and tank controls. Done and done
If you have a decent sized battery just use the immersion heater on a timer … save £1K …
Life is full of options for different people. That said if you are paying a grand for eddi you got done lol.
ATM it’s better to just export your excess generation anyway rather than heat water with it on certain tariffs.
I would close by saying consumers will get a much better return on investment by utilising smart abilities in the technology rather than manual function. It’s false economy and over the years you will lose out without it. Especially as tariffs adjust. Consumers would be wise to take a longer term view and understand the best ways to get the best value from all these options.
@@electrician247 … but isn’t it just the same electricity? I know my battery is fullest at about 14:00 o’clock so I just set the timer for then?
@@jamesgalloway8835 with the intelligent tariffs, fluctuation in weather and unpredictable energy costs its not so simple no. With the eddi for example you can send 200W to the element when you have that in export rather than dump 2-3kW at it because a battery is fullish. Way better ways to maximise return.
You're setting off my autism hurting my brain.
It's not a "ba-tree".
It is a "ba-TTerY"
Please don't do that.
Accent and how people talk is unique to them. I won't be changing