question

The CT because there is less software involved in the signal path, or so I have read here.

Thanks for the reply, actually makes sense as it cuts out the middle man, so to speak

We have a parallel AC coupled ESS system with AC grid tied Solar.

We started with the 20m CT clamp and it was snappy in its reaction to the AC loads, however we wanted to be able to expand the system in the future by adding a second inverter and this isn't possible using a CT clamp so we swapped to the ET112. Its fair to say that the reaction time has a noticeable delay however this has not fed through to the billing as nothing changed between the 2 systems - all I can think of is either the delay manifests itself in the VRM dashboard and / or the initial draw from the Grid is offset by the over run feedback ?

This is confirmed by our Octopus Go energy bills which are published daily and show no spikes of draw or grid feed as per the VRM dashboard.

In addition the accuracy of the ET112 actually improves the situation so our 'real world' bills have reduced.

Finally the dashboard is now more representative of the actual situation as apposed to the CT clamp which showed all loads passing through the MultiPlus instead of being in parallel with the Grid.

Food for Thought ?

Oh Yeah - we now have a 20m CT current clamp (hardly used) for sale !

Thanks for your reply, I’m currently running on a ET112 at the moment but have also just ordered a 100a/50ma CT. I will carry out some tests once the clamp arrives.

Ok just some additional information after completing basic test with the ET112 and 1m CT clamp. Switching on a 3kW load and measuring the dc current with a clip in ammeter. The ET112 took around 10s to slowly ramp up to 60A after switching the 3kW load on and a further 10s to ramp down after switching off ie exporting to grid. The CT clamp reacted in less than 0.5s both switching on and off. The system appears to react much faster with CT clamp and must therefore be more efficient.