FoxESS Community - Owners & Installers Forum

Hi, we are due to be carrying out our first hybrid inverter and battery storage installation next week and will be using a Fox H3 5.0 along with a Fox EP5. We have installed solar PV on a number of projects and always wired/connected a CT from the inverter.

The main DB for the property is in a cupboard in the kitchen (our inverter and battery will be located in a detached garage as the garage roof has solar PV located on its roof) and it will be very awkward to install an enclosure and the meter in that area.

Are the meter and CT's required for this system to work? Or can we use CT clamps on their own? We were planning on installing a generation meter in the garage.

Any help would be greatly appreciated, thank you.

Evolve Solar & Energy Storage wrote: ↑Wed Sep 11, 2024 9:46 pm Hi, we are due to be carrying out our first hybrid inverter and battery storage installation next week and will be using a Fox H3 5.0 along with a Fox EP5. We have installed solar PV on a number of projects and always wired/connected a CT from the inverter.

The main DB for the property is in a cupboard in the kitchen (our inverter and battery will be located in a detached garage as the garage roof has solar PV located on its roof) and it will be very awkward to install an enclosure and the meter in that area.

Are the meter and CT's required for this system to work? Or can we use CT clamps on their own? We were planning on installing a generation meter in the garage.

Any help would be greatly appreciated, thank you.

On an H3 you must have a meter installed which connects back to the inverter via RS485 (a single twisted pair) - depending on your installation the meter can be either an in-line measuring device (easiest), or the meter has CT clamps which attach to each of the incoming phases.

In the case of a meter with CT clamps the meter can be located up to 10 meters away - but it is best to be as close as possible to minimise interactions in teh CT clamps.

Hi Dave, thank you very much for your reply.

Are you saying we can use the Chint DTSU666 instead of the generation meter we were planning to install to measure generation? So it doesn’t have to be connected at the incoming in the kitchen

We can still install the CT clamps at the incoming and place the CT clamps under 10 metres away from the meter.

Yes you can use the Chint DTSU666 (-CT) which comes with 3 CT clamps

This for a Solax inverter (essentially the same thing)
Just to double check your point about the generation meter, there is still a (bonkers) requirement to fit an MID/OfGem approved generation meter (Emlite) with older installations that have a FiT element (the DTSU666 does not meet that) - MCS regs follow this requirement i.e. you must fit one if there is an existing FiT install.

But for new installation the code of practice for grid connected PV systems says that there should be a readily accesible device that allows the generation and performance of the system - but this requirement is satisfied because the Inverter display and the app and a 'smart meter' is used for all billing.

This is a useful summary of the requirements https://youtu.be/MZYdMXpVjkU

Thanks for all the information and link to the video, very informative.

It's the location of the meter in wiring diagrams that has been confusing me as it appears it has to be connected at the origin which clearly it doesn't necessarily have to be.

The property is a new build so is not part of FiT fortunately, we also have a ducting which runs from the garage to the house which already has a duct grade CAT 5 in it, this is currently used to hardwire a WiFi extender but we will be installing an external WiFi access point and using the CAT 5 for our CT clamps, we believe the total distance from meter to CT location to be 7-8 metres. We spent 2-3 hours attempting to fish an additional CAT 6 through the ducting but were unable to do so.

Thanks again for all your help Dave

A standard solution (out of the manual) would recommend you fit a Chint meter at the source as you say as it is wired in pass through for all phases - but if you use the Chint meter with CT's you can break that link and fit remotely.

The meter 'hard wired' is more accurate than CT's ( which are typically +/- 2% accurate depending on load power ) but other than that it's a good solution.