In the event of a power cut?

Hi All,
We recently had a power cut ( our first in 2 years) and discovered that, although our batteries were full, we didn't have any working electrical sockets.
We specified this option with our installer who have generally been very good but on this issue I'm getting stonewalled.
We have an Eddi and Harvi and a new sub board to accommodate the solar panels.
Could anyone please advise what I'm missing and/or what I need to do? And if you have any idea of cost (however approximate) that would be really helpful too.
Many thanks in advance
Roberto

You dont say what inverter you have.

You need something connected to the EPS output (sockets or small consumer unit)
Make sure you do not try to power big electrical loads via EPS such as dishwasher etc. or you may overload it - depends what inverter you have.
I have small consumer unit to feed boiler and boiler controls, lounge sockets (TV, sky box, laptop etc.), router socket, lounge lights, fridge and freezer - it was relatively easy for me to modify my wiring to do that, but might be difficult because of house layout.
If we lose power we can sit in the lounge, watch TV with the heating on and make a cup of tea with a pan on the gas cooker OR drink cold gin from the fridge

https://kb.givenergy.cloud/article.php?id=12&oid=1

SteveCook I have much the same, due to the way our house was extended with a new fusebox in the extension my original fusebox only has house lighting and a few of the ring mains on it. All the high load stuff like the kitchen is separately powered.

I had my inverter feed the house fusebox to give me EPS for TV, internet, etc.

It sounds like @Rob24 your installer didn't do this work. They would also have had to put a new earth spike in outside and feed that to the new fusebox, probably with a changeover switch as well

geoffreycoan

Geoffrey, thank you for the very prompt and helpful reply. I do remember being told about the need to fit a new earth spike outside and then one was never fitted.... with patio slabs all around it wouldn't have been that easy so I think he just decided to forget that part of the job.

SteveCook

Hi Steve, thank you too for your very helpful reply.
Our inverter is a Giv-Energy GIV-HY3.6
Hopefully we can do the same as you... which is what I thought we were getting.
I wouldn't bother with the tea though.
Cheers
Rob

My setup is an AIO 13kWh battery and a Gateway. The inverter is rated a 6kW so when the system was installed, I had the cooker circuit excluded and also the circuit to my wife's studio (it has a heat pump). I figured that these two circuits alone could get me close to 6kW.

With this setup, unless we are using the dishwasher, tumble dryer and microwave simultaneously we should keep below 6kW. Our background use is 500-600w so 5.5kW should be enough.

The downside is loss of the ovens (we have a gas hob) and the studio

Weasel The heat pump quite possibly, but I'm not so sure about the kitchen. We have an AIO 6kW and that happily services the kitchen. With the electric oven on, a hob ring and microwave, we don't get close to drawing 6kW at anyone time. Don't forget the oven switches on and off once at temperature, as does the microwave or air fryer. Our electric shower tho....!

Rob24 I also have an HY3.6 (gen1) and the good news is that it supports EPS.
It has a an EPS terminal which can be wired to a separate consumer unit to provide limited power off grid in the event of a power cut. There is a GE document showing possible options.

https://givenergy.co.uk/wp-content/uploads/UK-End-User-Mangement-Connect-EPS-guide-2023.pdf

Note that a TT earth is required for the EPS side. If your property doesn't have TT earth then one will need to be installed. Once you have the EPS side installed, your GE system will need to be recommissioned to include the EPS (even though it will work, it also needs to be setup properly). I had a TT earth point and a double socket added to my inverter which cost £500 for local electrician to do. They also took the GE course so they could work on the inverter without voiding the warranty. Then £120 for the GE supplier to recommision the system.

Regarding an earth and a patio, it should be possible to simply drill a hole through any paving until you reach earth then insert a spike before ensuring you have a proper earth.

CW Yeah, agreed. Electric ovens generally have less kW draw than a kettle these days - good idea to have the whole-house covered by the AIO and have options, even if it can't cover all items on simultaneously - that's what we went for, the whole house (induction hob, elec oven, etc) consumer unit is powered after/by the GE Gateway, which in-turn has inputs from the grid, solar and AIO.

Also worth remembering the Gateway can provide the combined power of the AIO plus Solar in the event of a power-cut, so in the height of summer it's 6kW+ (in our case ~ 10kW)

Coincidentally, we have just had our first power outage since installing the AIO and gateway. The lights briefly flickered and we heard the clicking of our UPSs that power our computers etc. I checked on the GE app and sure enough, our connection to the grid was down. By the time I had wandered over to my wife's computer, shut it down and done the same for mine, the power was restored. I know this because the neon light on the cooker socket was lit.

I know I have adopted a belt and braces approach with UPSs supplementing the AIO, but at least I know it works 😃

Weasel and an hour later, the power is off again. This time, it took a second or two for the battery to kick in. I suppose the AIO/EPS is not designed for frequent activation and the 20ms figure is best-case assuming it had not been activated recently beforehand. I had not got round to replacing the old UPS that powers the internet kit (hub, router etc) so was without interwebs for a few mminutes. Once power is restored, job #1 will be install the new UPS that was delivered last week.

Weasel 20ms is probably the time it takes to flip the relays into island mode rather than anything else. It won't be the system/battery response time.

FWIW a friend has a couple of Tesla powerwalls (and gateway) and they take 400-800ms to react to a grid loss (he's measured it)...

Weasel You're lucky - currently when we get a power cut my gateway takes many, many seconds (I've counted up to 20 before now) before the battery kicks in. Long enough for all the smart lights to reset plus any electronic clocks! I'm waiting for the installer to come out and take a look to hopefully get me down to the 20 milliseconds or so

CW You're lucky - currently when we get a power cut my gateway takes many, many seconds

It might be worth getting GivEnergy support to confirm that the 'zero second EPS delay' has been set on your AIO. On my Gen 1 hybrid's (and other older kit) it isn't the default setting and the installer has to change it. Can be done remotely by your installer or GE support

NorfolkMustard
Dont forget, just 'cos the inverter can push out 6kw, that it does not mean the battery can support things indefinitely.
An oven might be 2khw, so it will drain a big battery in circa 4 hr on a dark winter night

3kw AC coupled inverter with an EPS socket here.
I has a power cut for a few hours.
I managed to:

Power Oven for dinner.
Then power kettle for tea.
Then:
Power fridge & freezer & wifi & lights (leds) & tv

I made sure I wasn't drawing too much at one time.

Weasel I have switched to DC-UPS devices to power routers and hubs etc during a power cut. Way cheaper and smaller than a mains AC-UPS and they run for hours on battery backup.

As part of our 3.6 Gen1 installation I had the EPS with a separate protection consumer unit and earth spike with the circuit run in conduit outside the house to a central internal point - where the CH gets its supply. Including recommissioning it was £750. Had our first four hour power cut later that week, and a second the following month, and ran the CH (our only heating) and lighting. I already float the computers and router etc on a small UPS to avoid short outages and lightening strikes.
My main requirement was the heating, but it happily copes with much more.
I cannot find the reference now, but I understood that there was a mandatory 5 second delay between loss of grid and EPS start-up. I was told that at that time only Tesla power wall able to do auto changeover for whole house (and even then I would have some concerns about potential loading) and that was v expensive. Someone may correct me of have a reference.

geoffreycoan I just asked then to check and they have said everything looks fine. The problem is I don't know whether this has always been like this, or whether it is related in some way to a firmware update GE did to try and resolve the AIO breaker tripping when the grid was cut (it was only after that I tried simulating a cut by switching the grid off and noticed the 20-30 second cut-over time)

I used the 240V output feature of my EV6 to stand in for the grid during a recent outage (planned for cable replacement at the substation). I simply removed the input fuse next to the meter and plugged a cable into a 3-pin socket in the house and the other end to the V2L adapter.
Worked a treat.