FoxESS Community - Owners & Installers Forum

I'll be having an AC coupled EP12 + H1 installed.
Already have SolarEdge for the PV and Zappi for EV, so yeh, this will be like the United Colours of Benetton!

The Inverter is only supplied with 1 CT Clamp, for the mains cable, to monitor export, but I intend to install 2 CT clamps as per diagram below. The 2nd CT clamp going on the PV cable

Is there even any benefit in having the inverter seeing what is being generated?
I'll likely just be charging battery and EV on Off Peak.

I can see lots of availability of CT clamps from various sellers, mostly the MyEnergi branded ones.
Is there any material difference in CT Clamps that would stop it working with my H1-G2 ?

Presumably they can all be extended with cat 5e cable?

I see various specifications from other brands such as 2000A:1 etc. Not sure on what that actually means and how it compares to the Fox one.

If you want the Fox inverter to provide statistics that make sense you have to install the second CT clamp.

A CT clamp is a current transformer and it has a specific ratio that the monitoring equipment can use to reliably convert what it sees into a credible power value, in the case of the Fox inverter it is a 100A/33.3mA ratio and you must use a CT clamp that conforms to this - you can buy one here https://www.tradesparky.com/solarspark ... aio-ranges

They can be extended with cat5e cable, but if you go beyond 20 metres they will start to get very unreliable.

Dave Foster wrote: ↑Thu May 14, 2026 5:29 pm If you want the Fox inverter to provide statistics that make sense you have to install the second CT clamp.

A CT clamp is a current transformer and it has a specific ratio that the monitoring equipment can use to reliably convert what it sees into a credible power value, in the case of the Fox inverter it is a 100A/33.3mA ratio and you must use a CT clamp that conforms to this - you can buy one here https://www.tradesparky.com/solarspark ... aio-ranges

They can be extended with cat5e cable, but if you go beyond 20 metres they will start to get very unreliable.

Thanks, trade sparky and other sellers seem to be charging quite a fair bit just for postage alone (over £10).

Are there other known compatible brand CT clamps?
Alpha seem to have one that is 100amp input and 30mA output

loofer wrote: ↑Fri May 15, 2026 3:09 pm

Dave Foster wrote: ↑Thu May 14, 2026 5:29 pm If you want the Fox inverter to provide statistics that make sense you have to install the second CT clamp.

A CT clamp is a current transformer and it has a specific ratio that the monitoring equipment can use to reliably convert what it sees into a credible power value, in the case of the Fox inverter it is a 100A/33.3mA ratio and you must use a CT clamp that conforms to this - you can buy one here https://www.tradesparky.com/solarspark ... aio-ranges

They can be extended with cat5e cable, but if you go beyond 20 metres they will start to get very unreliable.

Thanks, trade sparky and other sellers seem to be charging quite a fair bit just for postage alone (over £10).

Are there other known compatible brand CT clamps?
Alpha seem to have one that is 100amp input and 30mA output

I imagine there must be some similar CT clamps, but it must be exactly 100A/33.33mA (not 30mA), be the correct cable diameter and have the same accuracy - in all honesty probably worth having the recommended CT clamp if you ever need to access warranty from Fox support..

Yes looking for official but just seems to cost considerably more than other brands

The one one that came with my inverter is a black and makes no mention of the amp rating

It’s an Electra Mat branded one
120k-T1000c
202544