I’m hoping someone with a similar setup can tell me how theirs is installed.
TL;DR:If you have a GivEnergy All-in-One with Gateway and PV (using a separate inverter connected via the Gateway), configured to automatically operate in island mode during a mains power cut, does your installation have a local earth rod?
Thanks in advance for any advice.
Steve
Background
I’m not an electrician, so apologies if I’ve misunderstood anything or included irrelevant information.
The system was installed a couple of years ago and has worked perfectly so far.
I only started wondering about the earthing arrangement after seeing it operate during a brief power cut. It made me think: what if the outage was caused by something like a digger ripping through the incoming supply cable? The Gateway would keep my house energised in island mode, but wouldn’t the DNO earth connection be lost as well?
From what I can see, my house earth appears to be connected only to the supplier’s neutral on the DNO side of the cut-out. If the incoming supply cable were disconnected, how would the system remain earthed?
I found the GivEnergy installation manual, and on page 35 it appears to show an earth rod being used. I asked my original installer about this, and they said an earth rod isn’t required.
For reference, the original UKPN application states:
Domestic installation
Single phase
100 A cut-out
Earthing arrangement: TN-C-S (PME)
Not identified as a looped service
So, for anyone with a similar installation:
Do you have a local earth rod?
If not, how is the earthing handled when the system is islanded during a power cut?
I have a similar system to you, an AIO with PV panels connected via micro inverters to my Gateway and it does have an earth rod. Unfortunately it doesn’t reliably enter island mode when there is a power cut even though the installer was advised to upgrade the RCB to 100 Amps. I suspect it does enter island mode when we have short duration power cuts but there is no way that I know of to detect these cuts so I can’t be sure. When a longer power cut occurs, the Gateway fails dismally to switch the house load over to the battery and neither I nor my installer can figure out why, which is particularly galling since that was the main reason why I went for a GivEnergy system. Now that they have gone bust, I will likely never get that feature working. Bummer!
Hi Don. Thanks for the earth rod info.
Originally mine also had problems with switching to Island mode. I wasn’t too bothered (as I’d not chosen the system because of that - I liked the sound of the 12 year unlimited kWh warranty…also bummer!).
Anyway turned out our issue was the comms cable between the AIO and the Gateway. Eventually I found the original comms cable had a fault in wire 1 - despite this the system had worked fine in all other respects except it would trip rather than switch to Island mode.
Replacing it with another T-568B wired cable allowed it to Island but only when the Gateway PV breaker was off - very odd.
So I got a new good quality outdoor Cat6 cable, and wired it using the alternative/custom ‘non-T568B’ wiring from the install guide pg 22 and that seemed to basically fix it! Still in island mode some sudden loads like microwave or heat pump starting up might trip it out but basically it’s functional and more important for me is that now it allows PV to charge the battery even when in Island mode.
Not sure If you’d tried a new comms cable using the alternative wiring??
The main issue is that if your system is supplying power from PV or battery and someone from the electricity network is working on the system upstream of your house they could get a shock. Your system should break all connections to grid on a grid power failure. This means your earth (grid earth) will be lost. This is why you need your own earth (rod). I would ask you installer to confirm in writing why they think an earth rod is not needed and ask for the test certificates when in “island” mode.
Thanks for the replies. So as I read it, 3 of 3 replies have an earthing rod on a similar system and consider it to be essential… ? I’ll try again with the installer then, Cheers all
I agree with your other respondents. Our All In One plus Gateway also had an earth rod installed. The installation manuals I’ve seen are pretty emphatic that it’s essential.
As others have said, an earthing rod is mandatory if the GW is enabled to run in Island mode. If no earth rod then it should not be allowed to run in Island mode (which therefore negates a huge benefit of having a GW in the first place).
Unfortunately your installer sounds clueless / downright dangerous.
Can be lots of problems with RCDs on your main circuit, we had similar issues with our Island mode causing the main RCD to trip due to earth leakage (as in, a bit of earth leakage across each MCB adds up to a total amount of earth leakage that causes the overarching RCD to think there’s a serious problem and trip out).
Eventually fixed it by replacing the RCD with a different spec version, but I’ve readythat moving to RCBO is usually the best / most reliable way to overcome the earth leakage issue.
I have a similar setup but i do have a earth rod installed. My understanding is that when there is a powercut it completely isolates from the mains power so there is no way of injuring any workmen working on a damaged line and hence you need a seperate earth rod otherwise to make the system safe whilst in island mode.
BS7671 - which governs single phase domestic electrical installations requires that every supply MUST be earthed.
Adding shouldn’t be necessary so long installer to existing earth rod. Installed as part of the supply.
My AIO has never worked in island mode and we were told by GE that it was a problem with the Sunny Boy inverters on my old FIT solar install. My installer couldn’t see the connection at the time so I think I’ll try your solution.
Thanks all. I’ve spoken to the installer again following your replies which were v helpful, he seems OK to come back and fit an earthing rod, I’ll post back with an update when that does/doesn’t happen…
Just to close this out, the installer came back this week and fitted an earth rod, connected to the earth bar at the main consumer unit/meter where the supply enters the house.
Given that he did the original installation over a year ago (as part of a “buy the kit + installation” package from a third-party online vendor), it’s been a refreshing change to see his commitment to getting my system set up and working correctly, despite the lack of support from GivEnergy.
Thanks David! And also thanks to those of you who took the time to provide helpful feedback on my question.
