Speak EV - Electric Car Forums banner

1 - 16 of 16 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter · #1 ·
I’ve got the impression that Harvi, which is presented by Myenergi as optional, is pressed as a concomitant sale to Zappi. Suppose I want to simplify my EV home charging installation (meaning one without Harvi and any other wireless gadgets) and that I can hard-wire two CT sensors (one for the grid and the other for solar PV) using a data cable (two pairs of twisted cables). Where, within Zappi, should I connect the CT solar PV, knowing that the CT grid goes to CT1 (and CT2 and CT3 for a 3-phase grid supply)? Zappi’s latest brochure (operation & installation manual dated Jan 2021) is still non-explicit on this and my installer can only ‘recommend’ adding a Harvi, which I don’t want.
 

·
Registered
Joined
·
1,256 Posts
I’ve got the impression that Harvi, which is presented by Myenergi as optional, is pressed as a concomitant sale to Zappi. Suppose I want to simplify my EV home charging installation (meaning one without Harvi and any other wireless gadgets) and that I can hard-wire two CT sensors (one for the grid and the other for solar PV) using a data cable (two pairs of twisted cables). Where, within Zappi, should I connect the CT solar PV, knowing that the CT grid goes to CT1 (and CT2 and CT3 for a 3-phase grid supply)? Zappi’s latest brochure (operation & installation manual dated Jan 2021) is still non-explicit on this and my installer can only ‘recommend’ adding a Harvi, which I don’t want.
On my single phase, 1st gen Zappi, which only has two CT inputs, you set what each CT does in the advanced menu. You can select between grid, solar generation and battery.

Edit, forgot to add I don't have a harvi. The two CT's in my Zappi are both in use, recording grid import/export and PV generation.
 

·
Registered
Joined
·
2,060 Posts
Harvi is optional. I just have a Zappi with no extraneous bits with CT clamps on Solar and Grid. I think the OLEV grant needs the Harvi . hub so it can be monitored / turned off remotely, mine was fitted without the grant.
 

·
Registered
Joined
·
429 Posts
My guess (without checking, because I'm lazy and I have a Zappi 1) is that, for a three phase Zappi, you don't have enough CT ports to monitor all three phases and the solar generation without a Harvi. Most people don't have three phase so it's not a common situation.
 

·
Registered
Joined
·
1,256 Posts
Harvi is optional. I just have a Zappi with no extraneous bits with CT clamps on Solar and Grid. I think the OLEV grant needs the Harvi . hub so it can be monitored / turned off remotely, mine was fitted without the grant.
Hub is required for OLEV grant, not harvi. Harvi is only needed (in a single phase install) if the Zappi is too far from the consumer unit to be able to hard-wire the CT's.
 

·
Registered
Joined
·
1,256 Posts
My guess (without checking, because I'm lazy and I have a Zappi 1) is that, for a three phase Zappi, you don't have enough CT ports to monitor all three phases and the solar generation without a Harvi. Most people don't have three phase so it's not a common situation.
Good point. I've edited my earlier post to confirm my knowledge is for single-phase only
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #7 ·
Let’s assume, for the sake of argument, a 3-phase supply. In this case, three CTs grid are needed and will input into CT1, CT2 and CT3 within Zappi. Where, then, will the CT Solar PV go? There’s no CT4!
 

·
Registered
Joined
·
1,256 Posts
Let’s assume, for the sake of argument, a 3-phase supply. In this case, three CTs grid are needed and will input into CT1, CT2 and CT3 within Zappi. Where, then, will the CT Solar PV go? There’s no CT4!
Either hard-wired into an Eddi (if one is installed), or a Harvi.

There's a similar issue with the first gen single phase Zappi, which has only two CT inputs. If you have PV and a home battery there aren't enough inputs, so a Harvi is needed. Unless you have an Eddi as well. I would guess this is why there are three CT inputs on the second gen Zappi, to cover off this exact scenario without having buy a Harvi.
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #9 ·
Many thanks Roger for keeping this thread going. My point is that Myenergi has explicitly stated that Harvi is optional, which means that it is available to be chosen but not obligatory. What troubles me is that, contrary to the CT grid, there is no explicit guidance, in any of their successive manuals, on how to hard-wire the CT Solar PV into the Zappi. Has this been an oversight (repeatedly!), or has it been on purpose, in order to make a market for what appears to me to be a rather superfluous gadget? Any advice from Myenergi’s network of professional installers?
 

·
Registered
Joined
·
429 Posts
Many thanks Roger for keeping this thread going. My point is that Myenergi has explicitly stated that Harvi is optional, which means that it is available to be chosen but not obligatory. What troubles me is that, contrary to the CT grid, there is no explicit guidance, in any of their successive manuals, on how to hard-wire the CT Solar PV into the Zappi. Has this been an oversight (repeatedly!), or has it been on purpose, in order to make a market for what appears to me to be a rather superfluous gadget? Any advice from Myenergi’s network of professional installers?
Monitoring the solar generation is optional. The Zappi only needs to monitor the export to function, which it does by monitoring the three phases. The solar monitor is just to give you more information, but it isn't necessary for the Zappi to do its job.
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #12 ·
Monitoring the solar generation is optional. The Zappi only needs to monitor the export to function, which it does by monitoring the three phases. The solar monitor is just to give you more information, but it isn't necessary for the Zappi to do its job.
Sure, but compared to other competitors’ chargers, the raison d’être of Zappi is to work in harmony with the grid, Solar PV, wind generation, and battery storage whenever the latter three exist. Furthermore, all CT sensors are presented with two options to choose from: wired and wireless. I’m only interested in the wired one and how to wire any additional CT properly.
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #13 ·
Look at page 28 of the installation manual, connect to CT2.


Unfortunately, there are many updates of the manual. I have referred to the latest (Jan 2021) and cannot see anything of the sort on page 28. I'll read again the relevant pages, but I'm afraid I will just fall again on the same ambiguities.
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #14 ·
Please, try and read the discussion starter before commenting. It does focus the mind and concentrate on the relevant suggestions we're expecting from each other. Thank you all for your time and kind help.
 

·
Registered
Renault Zoe 50
Joined
·
20,780 Posts
On page 5 of the Zappi manual, the diagram shows the Solar PV CT should be installed between the Consumer Unit and the FIT meter (or inverter) from the solar supply.

It's not clear, but if you look at the Eddi manual diagram that should give you a better idea.

Do you have single or three phase installation?
 

·
Registered
Joined
·
1,343 Posts
Try connecting the T to CT2 as that is the historic place, and see if it registers your Solar PV. Ask myenergi.com otherwise.
 
1 - 16 of 16 Posts
Top