Hello Everyone
Just returned from holiday to find Freezers off and defrosted !! My RCD had tripped on fuse board.
With Solar / Battery set up has this occurred with anyone before? Can this happen in heavy Sun?
Trying to establish if it’s a house problem or my installation.
Thanks
Have you asked to confirm no power cuts, however brief?
Also what is the size of your solar inverter vans eating of the breaker that went? Which breaker went and is it on the EPS circuit?
RobRoy594
Does your consumer unit (fuse board) have a single main that feeds all the other circuits?
Trouble with RCDs is that an old style (incandescent) light bulb blowing can cause the RCD to trip and then all power to house is lost.
That is why some consumer units are split so say power circuits on RCD half. Lighting on other half
SteveCook Interesting. I have had the RCD trip in the fuse box on our EPS circuits a couple of times, most recently last week. Is there any way round this, other than having the board rewired so the lighting circuits are not covered by the RCD, is there a replacement for the RCD that doesn’t have this risk?
The (separate) fusebox for our extension has two blocks of RCDs both of which have lights and power circuits intermingled so the electrician can’t have thought this was a risk. The only thing that’s not on the RCD is the smoke alarms.
I think with the advent of single gang RCBOs, the modern trend is to use an RCBO (combined RCD and MCB overload)on every circuit, so if a lightbulb blows, only that circuit trips.
Buy lots of RCBOs
https://hf-group.co.uk/what-is-an-rcbo-and-how-does-it-work/#:~:text=An%20RCBO%20is%20the%20abbreviated,residual%20current%20and%20over%20current.
geoffreycoan Normally put upstairs sockets/downstairs lights on the same RCD and vice versa - there should be some logic in the layout so that some power is available around the house should one RCD trip.
Since I've had my AIO, I've had two mcbs replaced with RCBOs for 'critical' circuits - one with my modem/router/HA pc and the other for the ring main with the fridge and freezer.
FWIW my circuits are all RCBOs on non-lighting circuits. I have an AIO, and if I put it in to Island Mode then all the RCBO circuits flip and will not unflip until grid restoration.
I am waiting to get a replacement Gateway, and am hoping this solves the problem.
On installation I asked my installer to demonstrate Island Mode. He did and we saw the aberrant behaviour. He assured me that it would not happen in a real power cut. It does, as I found out to my cost on my last trip abroad.
Gen1 Hy5.0 with EPS setup.
I kept getting RCD trips when going to island mode.
I finally traced a stray netural - that was shared in normal mode(all OK), but went to the wrong place in island mode because one circuit was essential , and one was non essential.
This was legacy of the original house wiring.
I just had to turn everything off and work slowly though the consumer unit with a meter to find the cross connections. I then had to run some new T&E cable through the loft for correct separation
I have what’s described as ‘mode 3’ EPS on my Gen 1 hybrid https://kb.givenergy.cloud/article.php?id=12&oid=1 - whole house backup with a manual changeover switch.
Its actually not whole house backup because we’ve had an extension and all of the high load appliances (oven, electric showers, etc) are all off the extension fusebox which is fed separately from the meter tails.
So the EPS fusebox only covers the lighting and ring main sockets in the original part of the house, no kitchen, etc. Practically there can’t be any high loads and so the manual changeover switch is set to battery mode all the time.
Per the EPS guide there is a 30mA RCD protecting the EPS fuse box, and its that RCD that has on two occasions tripped. I know it can’t be a stray neutral or anything like that as the fuse box covers the entire original house circuits (minus those circuits that were removed when the extension was built).
But at the moment there are no other RCD’s or RCBO’s in the fuse board, it’s just MCB’s.
Should I get the MCB’s swapped for RCBO’s, perhaps starting with the lighting ones as they could trip first?
I have the same whole house EPS set up. Since install in April 23 it trips when the grid comes back and I turn the big manual switch to grid. Reset the two switches and it’s fine again. Lots of looking at, some shouting, and nothing. Nobody has found a fault of any sort. Installer coming again this week. This is all on the auxiliary box fitted with the solar/battery set up. Main box is all rcbo’s due to a previous issue. It doesn’t trip.
geoffreycoan Per the EPS guide there is a 30mA RCD protecting the EPS fuse box, and its that RCD that has on two occasions tripped. I know it can’t be a stray neutral or anything like that as the fuse box covers the entire original house circuits (minus those circuits that were removed when the extension was built).
sounds like mine, but i had some stray neutrals that did not matter when all the circuits were on the same original CU as all went back to same L&N. it was only when i took the essential live circuits to the new essential CU that the L/N neutral imbalance came to light.
geoffreycoan I think you have to have all MCBs replaced at the same time, and the existing RCD removed. Otherwise you've got two RCDs in series and the main one might still trip before the RCBO.
I expect many sparkies would just recommend an entirely new CU installation. You've likely got no surge protection and an old plastic-body CU.