Charging help

[SimB]

I have recently starting to use an EV charger instead of the granny cable and while it appears to work fine with others car with the Rav when it charges to approx 37 miles something happens and on occasion causes the RCD on the distribution panel to trip.    The sparky who checked the device and board out cannot find an obvious fault but is keen to know if anything happens with the Rav4 drawing power around 37 miles of charge as this appears to be the level of charge each time it trips.  I cannot find anything obvious written anywhere but thought I’d ask the community for any thoughts or advice.  There are no obvious log data points on the charger either which point to anything 

Charger I am hooking up to is a Zappi V2 

[Ancient Nerd]

I had a similar problem with a zappi v1. The installer had fitted an RCBO, instead of the recommended trip. The included RCD is redundant, as the zappi includes one internally.

It worked fine when taking power from the grid. However, it frequently tripped when power from the solar panels kicked in or out in ECO+ mode. 

The problem was fixed by replacing the RCBO with a trip of the same rating.

MyEnergi support can be quite helpful. It is also worth posting on the myenergi.info site. There are some very knowledgeable, and helpful, people there.

[nlee]

Would seem logical that it was anything to do with the car causing overload as most domestic charging points are 32 amp (approx 7.4kw) whereas the charger on the car is 6.6kw so should be pulling less than 32 amp. Having said that, it seems coincidental that it only happen on the RAV and at around the same point.

Apologies, I don't have a picture because I didn't charge last night but my charge point app shows the profile of the charge and it does fluctuate over the cycle. It starts below the 6.6kw then increases and is more or less flat then tapers towards the end, for the last few % fill. It does seem to have a small peak just before it tapers but nothing excessive and it wouldn't have thought this was around the 38 mile remaining point.

[Ancient Nerd]

Has your installer fitted a standard breaker or an RCBO. You can recognise if it is an RCBO by the presence of a button or similar with 'test' written on it.

MyEnergi recommend the use of a circuit breaker, not an RCBO in their installation guide for the Zappi. In my case, changing from RCBO to  circuit breaker fixed the problem completely.

If you have an RCBO, it may well not be too high a current causing the trip, but a very low level discrepancy between the current flowing in the live and neutral wires.

[SimB]

Many thanks for the advice will check