Pathetic (non-existent) Technical Support

I have a GivEnergy system, installed by one of your approved installers (see Existing.jpg), but they neglected to install the changeover switch to allow the system to provide backup EPS power. They now tell me that is cannot be connected as directed in your installation manuals (Method 4.jpg) because the inverters will not work in tandem (as they do when powered by mains electricity), but cannot explain why this is.
Your FAQ brochure (FAQ.jpg) clearly states that it will work and does not mention any limitations about multiple inverters / batteries.
The upshot of this is that they say I have to have separate changeover switches for each inverter, but only for two inverters.
As an Electrical Engineer, I am at a loss to understand why two inverters would work in tandem (i.e. connected to the same single phase power distribution system), yet three inverters will not.
If this IS the case, there is a serious design fault with the GivEnergy offering, and this misrepresentation means I have spent over £20,000 on something that will not provide the service for which it was intended.
I require someone who actually knows what to do about this to visit the installation and at least provide an explanation for the failings of the system.
I have now spent over 2 hours on hold attempting to contact technical support today, and two yesterday. I have also filed a report on the website, but if it is anything like the ones before it, it will just disappear. This is the worst tech support I have ever experienced and not what I would have expected from a company purporting to be the best of British.
David Powell
rating: 0 stars

Try using the email address provided in the contact section on the web site. Also try being a little less needy.

No one likes a whiner.

As far as I can see the FAQ only mentions an AC plant system on a single phase supply with up to 3 AC-Coupled inverters connected in parallel on the grid connections.

There are no examples of multiple EPS connections in parallel, in fact the EPS document describes it as 'Island Mode' which would indicate it is a separate circuit from anything else, and also requires it's own dedicated earth rod.

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

In 'Island Mode' each inverter has to generate it's own 50 Hz supply, so will not be attempting to synchronise the waveform with any other live supply, such as from another inverter.

DavidPowell2021 The EPS outputs of multiple inverters cannot be connected together as they have independent frequency and voltage references - they are asynchronous and would fight against each other. The main power connection works in tandem as all inverters will synchronise perfectly to the incoming mains using a PLL.

As I understood the original post it is Qty x 1 EPS and Qty 3 x inverters. With that in mind I fail to see where the problem is.
1) Power fails
2) EPS power fail switch is manually switched over
3) EPS supply presented to the inverters (as apparently indicated by the FAQ)
4) Inverters restart as they would if it were an ordinary power interruption, if not why not?, they wouldn't know the difference would they?

I would guess that the OP's setup ensures that each inverter has enough battery storage to cover an outage so where is the problem?... other than the fact that the OP also cannot get someone to talk sensibly to him about the problem.

If I'd just spent £20k based on the documented setup and couldn't actually speak to someone I'd be pretty hacked off as well.

Is the configuration such that only inverter 1 has a direct connection to the grid, then inverters 2 and 3 have their grid feed from downstream of the changeover switch which switches between the grid feed and inverter 1 EPS output?

The Method 4 page also includes the statement:-

Note - With method 4 the AC supply to the GivEnergy inverter, and any other grid tied generation must be supplied from the grid side of the auto changeover switch.

Understandable that the OP is upset the system is not as per expectations, but not sure what specific documentation is stating the required feature is actually possible.
In the first instance the installer needs to be accountable for the scope of works signed up to, and if the system was too complex for them then they should have obtained clarification from GivEnergy before installation.

It does sound like you probably need to take this up with the installer as legally that's where your first, and strongest, port of call is.

That said, I totally sympathise with the lack of GivEnergy responsiveness. My system's been faulty since it was installed a year ago (see threads about battery problems) but GE take weeks of chasing to send replies which usually just amount to "We're aware of the problem and we'll get back to you." When I do manage to speak to someone in person they tell me how the business has exploded and how they're recruiting as fast as they can, but it doesn't allay a suspicion that they're inclined to just ignore the more difficult requests.

My own system suffered a borked BMS following a firmware update last week. I contacted them by email as the phone line was uberbusy. It took them four days to get back to me with a "we'll get back to you" email.

I understand they're snowed under due to an explosion in demand for product, but a simple "try rolling back to this version of firmware" with a link to download it from their site would have been simple to do.

The company that installed it is not the company who supplied it, though the installer is GE certified. The supplier is technically me, as I ordered it from the distributor I deal with for offgrid DC kit.

DavidPowell2021 I can't see the jpgs you mentioned. Fundamentally, the EPS does not have the capability to synchronise to another supply. Each inverter EPS is limited to 2.5/3.6kW (G1/G2) and feeds a separate consumer unit which can be used for general lighting/small power loads. It can't supply the whole house. The EPS operates in "island" mode although if the inverter does have a grid connection on the other terminals, the the EPS is synchronised by the inverter to that supply. For this reason, each inverter EPS has to supply separate consumer units as they cannot synchronise to each other to parallel up the supply capability.

I think the only way round the issue (in the event of a power disruption) would be to install a separate generator which is capable of being a synchronisation source for the inverters to follow (ie one designed to be the lead generator for other supplies to synchronise to). Of course, the whole property would have to be isolated from the grid to enable the additional generator to become the lead. Once a 50Hz 240V supply was available for the inverters to synchronise to, they could in theory be restarted in their normal mode. This sounds simple but the supply would be much more likely to become unstable as loads were switched on and off. The separate generator would have to pick up load instantaneously when a kettle was switched on while the inverters ramped up, and sink surplus energy when it boiled (electrical generators really aren't designed for this). Power systems are more stable when load changes are small compared to the overall system. eg When the cup final gets to half time, the National Grid are ready to meet the national increase in demand by holding back some "flexible" generators at say 85% output until people start switching on kettles. When the frequency and/or voltage starts to drop, these generators respond to keep these parameters steady at their despatched values.

As an Electrical Engineer you will understand these synchronisation issues and the fact that the separate EPS supply can work synchronised with the inverter connected to the grid supply but has to be islanded when there is no grid frequency to synchronise to. The fact that Givenergy's sales blurb doesn't clarify this, particularly in respect of multiple inverter installations, reflects the fact that it would go over the heads of most of their customers, or they wouldn't care anyway (IMO).

I'm guessing the OP is trying to follow the configuration on page 4 or 5 of:

https://kb.givenergy.cloud/assets/EPS%20Configuration%20v2.pdf#viewer.action=download

(I'm surprised there isn't an interlock between the changeover switch and the "New 'Grid' Consumer Unit" noted, especially on the automatic one)

The OP made reference to 'Method 4' which is on page 5 of that document.

There is talk of an external control box for multi inverters, as they have for commercial scaled systems. Maybe this is what is needed to sync the inverters together in EPS mode?

But so far logic says that each inverter has its own free funning 50hz reference, so outputs in island mode could never be connected, without some form of synchronization going on.
When I have seen generators bonded together in such a way, there is a sync cable between them, then maintains their outputs in phase

The EPS document only allows for a single inverter to be used at a time for EPS supply, all inverters should be connected together on the mains/non-EPS inputs for normal operation. This isn't to say that one couldn't use multiple, segregated, EPS loads on different inverters. All the methods in the document show this, even though the diagrams are pretty atrocious.

What hasn't been documented is whether one could use one inverter in EPS mode as the master synchronisation source, with one or more other inverters on their normal mains inputs as 'grid' tied slaves. It might need a sine wave filter or an idler motor to clean up the waveform and give some stability (I use a sine wave filter on the output of the inverter that supplies 3phase electric to my workshop). Having said that, with a stated 3% total harmonic distortion, I assume that the inverters have already got filtration on the outputs. It probably would need some thought as to the positioning of metering/current transformers to avoid wild load oscillations between the inverters.

I guess that cooperation between multiple inverters for EPS is still in the development pipeline, since there is still work to be done on cooperation when in normal grid tied operation.

mrand31 How many of us would rush out and buy more kit because the EPS outputs can be paralleled? Looks like a dubious business case to me!

stevelewis There is the curious case of what happens for EPS if you have three inverters in a three phase setup???

mrand31 All three phases would be supplied independently - three single phases, not synchronous 3-phase. 27M homes in the UK is a big market, those wanting to parallel up inverters or run true 3-phase are only a small subset of the market and other suppliers already operate there.

The three phase case is not really the market they're looking at. The paralleling up of inverters is something that is probably on the list of things that'd be nice when when they've got time.

If you have a fat wallet there's always their PCS systems!

I know nothing about the technical issues but totally agree about the lack of support. I've submitted queries via the website and emailed support - I've received nothing in response. Very bad service.

Hairsy Totally agree with you little help so far with Tech support team on hold now 40 mins, this is not how to handle client experience.

Don't bother phoning. Send an email and be patient.

+1 for email and be patient, though even the emailed responses can be more miss than hit a times too. If they don't have an answer, or they don't like the question, they seem to ignore emails. It's not an acceptable way to handle customers, particularly when the system is designed to be managed remotely rather than by then end user and so requires intervention from GE.

I can't complain about GE support. They have helped me pretty quickly with battery firmware updates twice, and recently I lodged some feedback that they responded to within 48 hrs.

Tim I've been considering doing just this with a generator to replace the grid supply. But, the idea is not to supplement EPS, but purely to charge the batteries from the generator before returning to island mode. We have solar but prolonged winter outages could be a big issue as I've got medical equipment and medication in the fridge.

The choice of generator is obviously crucial, needing to be 50Hz and pure sine wave. The load variability would not be an issue as it would be set to charge the batteries and nothing big turned on in the interim.

My concern is what happens if the system decides to export a little whilst the generator is connected? It sometimes exports just a few Watts here and there.

PhilS The system only exports when a load is disconnected. While the inverters ramp down, the surplus is exported.

PhilS 50Hz and pure sine wave

Pretty much any rotating generator should produce pure sine wave. I don't know anything about modern diesel/petrol generators but I'm assuming they are actually three-phase generators with some electronics on to convert to single phase, so the waveform might be an issue. Obviously a three-phase generator would produce three sinusoidal waveforms but you wouldn't really want to run a three-phase generator with just one phase loaded. If you had three inverters, then with a bit of careful planning and a competent contractor, you could isolate the inverters from the common single-phase consumer unit and connect to a three-phase "off-grid" charging generator. Once charged, the inverters could be switched to disconnect them from the generator and connected back to the single-phase system awaiting grid reconnection.

Given your requirements, I'd contact Givenergy Tech support and speak to them about it. It might be useful for them as an example of how their system could be used. The very least they could do is to advise on how the inverters would cope with a non-perfect ac waveform for charging purposes.

I feed three phase to my workshop from an inverter for all the three phase machines. I've put a sinewave filter on the inverter's output to improve the waveform. One could do that on the output of an inverter generator. it might already have a filtered output.

On the basis of positive feedback as well as negative feedback.

Having tempted fate and told my neighbour who is thinking about solar that my GivEnergy system is working well, a few hours later the battery software 'threw a wobbly' and would show a drop from 100% charge to 3% charge within 30 seconds.

I contacted technical support on Friday at around 4pm and the phone was answered after about 7 minutes. The technician identified a problem of my inverter miscommunicating with the server, and suggested that he update my firmware and then this would run a calibration of the battery.

On Saturday, the firmware had updated but the calibration hadn't. I contacted technical support and again the phone was answered reasonably quickly. The technician then forced a recalibration which started almost immediately. He also asked if I could call on Monday to ask for the power to be turned up as he was reducing the inverter power.

I have just called, the phone was answered almost immediately and the inverter power has now been turned back up.

I am happy with the support given although ideally the calibration would have run on Friday but didn't feel that I was waiting too long. The one improvement I would suggest is that there us some indication of how many people are in the queue ahead of you while you are on hold.

I had to call GivEnergy a couple of weeks ago and the phone was answered pretty quickly. No issues with the support I was given

MY installer originally connected both backup batteries to EPS but kept tripping, as mentioned before it is due to different phases between the inverters.
I have one battery connected to low power board (lighting, essential sockets, router etc) and one connected to a plug socket to be able to run an extension to fridges etc.