Current spikes and tripping fuses

Afternoon, we've had our system (Hybrid 5.0 Gen 2 inverter and 2x9.5 bats) for about 20 months now and all in all it's run pretty much trouble free.

Recently though, the system has gone off line several times due to the fuse tripping out. I didn't realise what had happened at first as none of the kit actually turns off! but then you realise you've been running off the grid for several hours and the app data is gibberish.

Fix is easy enough, flip the fuse and all comes back online as normal. I've spoken with GE about it and they say the fuse needs changing - currently a Crabtree B32 32amp fuse, GE have said to change it to a C32 32amp as this will allow for higher current spikes without tripping, which we will do.

My concern is that this seems to be more of a work around, than addressing why the current spikes have increased to the point it's tripping fuses when there has been no issue before. The house was rewired a couple of years before the install and a new sub-board in the garage back to the main board by a 10mm cable, in preparation for adding solar and batteries.

Can anyone suggest a reason as to why we would be seeing an increase in current spikes? both in terms of size and frequency? It's happened when exporting from the batteries, charging the batteries and just in the day during normal use, just meeting background house load. Any thoughts welcome.

A large motor may have a large current surge on startup and then drop off when running (bit like 1st push on pedal when moving off on a bike), but the cable and MCB does not really want to be sized/rated at that for continuous use as it will be oversized. The MCB allows a short time surge without (nuisance) tripping.

I think GivEnergy now say fit C type and I guess your installer originally used a B, prior to their latest guidance

Ae you sure it is a fuse. I think you mean MCB?
Is it an MCB or are you getting nuisance RCD trips

Arron hmm... Just yesterday, out of the blue, the RCD in my 16-month old system tripped 3 times. It had happened exactly once previously, a few months ago. Not quite sure whether to worry about it yet.

There was some thunder/lightning yesterday, but I don't think it was very close.

DD Water getting somewhere?.
Our old house was 150 years old and solid 10" walls.
The ground floor wall sockets used to "sweat" in winter and would cause the power ring RCD to trip.
Power off, a good wipe out with kitchen roll and some WD40 would fix things

SteveCook yes, did wonder if it was the generally damp conditions.

DD
but is it mcb or rcd
mcb is overload protection
rcd is for earth faults and will trip if damp causes earth leakage

SteveCook Mine was definitely the RCD

SteveCook thanks for the reply, sorry they're all fuses to me!?! I've googled the labeling on it and it would appear to be 32A 30mA RCBO - Crabtree Starbreaker.

I could be completely wrong but I seem to remember an issue with the starbreaker, possibly something about premature tripping.

We had to put a C type on our lighting circuit when we blitzed out our kitchen/diner with LED lighting many years ago. All the transformers took an initial surge to get going just like motors.
USB wall warts, sockets and extension leads can all be a source of extra earth leakage too so that's something else to consider that might have changed over time to influence the behaviour. Having an all in one I have spent a long time chasing trips 🙁

Now with me, we had the AIO trip when cutting over to Island Mode - I think this was due to wiring becoming loose over time, as once the engineer had tightened up the connections the fault went away - may be something to get checked on the wires going into/out off that breaker

Arron
RCBO is mix of RCD (earth fault) and MCB (overload).
It may be you are getting some damp in things, if it was all good for a number of years and has now started tripping in this wet weather