Problem diagnosis · SolaX Power

SolaX Grid Disconnection Fault — G99 Overvoltage Fix UK

Your SolaX inverter has disconnected from the grid. It may be showing an E012 voltage fault, a PLL Lost error, or simply dropping offline every sunny afternoon. In most cases this is not an inverter defect — the grid voltage at your property is exceeding the 253V safe limit, and the inverter is disconnecting because UK grid code requires it.

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Inverter tripping every sunny afternoon?

Grid overvoltage is the most common cause of repeated SolaX disconnections in the UK. We review your SolaX Cloud voltage data, identify the pattern, and recommend the right fix — export limitation, DNO report, or reactive power adjustment.

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13 Trustpilot reviews

Trustpilot Google

I have a GivEnergy system consisting of two batteries, two inverters and a controlling EMS (Energy Management System) which has not worked since Nov 2025. After six months I discovered Solar Tech Support, reached out to them and Ron phoned me back – how often do you get that service? Could not be more helpful – worked directly with me over the phone, outside what I would call normal working hours. Lucid explanations and we were able to discuss the issues and history using camera and email history. As this was a very rare setup, Ron was able to access an EMS expert in the field to confirm the solution. One sunny day in, I am now only paying for standing charge and a few pence for spikes in grid consumption while battery catches up with house demand.

Ian · May 2026 Trustpilot

When my GivEnergy system had an issue, I was completely left without support and had honestly lost all hope. Thankfully, I searched online and found Ron, which completely turned things around. After sending him a message, he responded incredibly fast and called me to assure me that he would get the problem fixed. I really admire his dedicated, supportive nature and his determination to find a solution. With this kind of outstanding attitude and customer service, he has absolutely secured a future customer in me.

Sree · May 2026 Trustpilot

Ron want out of is way to help, nothing was to much. He was very thorough in what he did Very knowledgeable I would highly recommend Ron and his company He did a fantastic job for me. if you have any problems, he'll do his best to help you out and resolve your problem. I wouldn't hesitate to recommend them

Dennis Brown · May 2026 Trustpilot

Ron took me through a diagnostic to confirm my GivEnergy Inverter had a fault. A common one as it turns out with the AC Inverter. As GivEnergy is defunct there is no immediate fix, aside from sourcing 2nd hand replacement. It may be that a fix becomes available over the summer which would make a lot of GivEnergy customers happy (Again)

Tony Deacon · May 2026 Trustpilot

Contacted Ron with a problem and he sorted it out quickly with no problems at all. Very knowledgeable on anything solar/ batteries. I would recommend him to anyone

Phill · May 2026 Trustpilot

I've spoken to Ron a couple of times with issues with my Givenergy installation. Such a friendly knowledge guy very highly recommended. Thank you very much for resolving my issues

michael fairhurst · May 2026 Trustpilot

Contacted Solar Tech Support in desperation. After explaining the issues I had with my system a diagnosis was made and a solution proposed. Fantastic service, even contacted a manufacturer to arrange replacement parts for me. Great communications, explained all they were doing and what I had to do, clearly and precisly. Followed up to confirm all was ok. Excellent service.

Mr Machin · May 2026 Trustpilot

After GivEnergy went into liquidation, just my luck, my battery started playing up (internal board crashed). Contacted my installer - not interested! Found Solar tech support on a Google search. Sooo glad I found this company! Ron is extremely helpful and has plenty of experience. He soon confirmed what the fault was, and helped me to get my system up and running again. Now moved my GivEnergy account to Solar tech support, and will definitely use again if I have more issues. Unusual to find such a helpful company in these times, no morons reading scripts, just direct contact with the engineer.

Keith Ballard · Apr 2026 Trustpilot

Contacted Solar Tech Support when trying to understand what my Givenergy inverter problem might be and what might be my options. Received good/honest advise which backed up my thoughts.

Hugh Speirs · Apr 2026 Trustpilot

Ron is a super star. Two months ago my GivEnergy battery failed a firmware upgrade leaving it a brick. My installer couldn't/wouldn't fix it. GivEnergy couldn't/wouldn't fix it. Then they went into administration and all hope was lost. A flurry of emails later and Ron had diagnosed the fault (failed USB flash drive, something I'd suspected) and talked me through resolving it. Two months of nothing resolved in about 3 hours. It's great to work with someone who pays attention to the details, knows that they're doing (not just following a script) and gets stuff sorted without a fuss or up-charging.

Christopher · Apr 2026 Trustpilot

I can add to the list of customers who had already 'given up' on GivEnergy due to their appalling customer service, and that was before they went into administration (their Trustpilot reviews don't lie!). So you can imagine my desperation when, having changed my ISP and my Inverter, predictably, proving to be the only device that didn't connect automatically to my new network, I found zero prospect of any customer support with GivEnergy having called in the administrators just five days earlier! The salvation came from Solar Tech Support. My IT advisor stumbled across their web site and some very helpful tips for beleaguered GivEnergy customers, as well as an offer to provide direct assistance. Nothing ventured, I decided to drop them an E-Mail, with very low expectations based on my experience of GivEnergy customer support. Within an hour Ron had responded with some pin point advice, and after a few exchanges of E-Mails he had nailed the problem, enabling the combined efforts of my IT advisor and solar installer to resolve it and reconnect my Inverter. Thank you Solar Tech Support, and Ron in particular, for coming to the aid of a deserted and despondent GivEnergy customer. Expert, razor sharp advice and first class customer service, even though I wasn't officially a customer.

customer · Apr 2026 Trustpilot

This company are a rare gem, I had a very unusual problem following a failed firmware upgrade on my GivEnergy kit. I then found out GivEnergy were in administration and had dismissed all their support staff! None of the usual fixes to try and restore my inverter comms would work, and I looked everywhere, forums, GivEnergy youtube support videos - even AI couldn't figure it out. My installer was talking about huge sums for system replacements, and being vague / evasive about if they'd even install replacement GivEnergy inverter. Enter Solar Tech Support, reassuring and knowledgeable from the very start, I've learnt loads about my solar system though the friendly chat while my engineer worked as he diagnosed the problem and figured out a fix procedure that I've not found anywhere else - amazing . If you need solar system repairs - especially if you like me have been left high and dry by GivEnergy, I cannot recommend this company enough. Give them a call.

Andy Thomas · Apr 2026 Trustpilot

I sent a message on their website regarding a problem I have on my Givenergy system. Although not supplied by Ronald, I thought it was worth an email. Within the hour on a Saturday, he phoned and we discussed the problem. He logged in remotely and gave excellent advice. I'm too far away for his on-site help but he did diagnose the problem and was happy also to chat through my thoughts about an upcoming solar/battery install I'm planning. Great bloke.... if only he was nearer!

Philip · Apr 2026 Trustpilot

Ian · May 2026 Trustpilot

Sree · May 2026 Trustpilot

Dennis Brown · May 2026 Trustpilot

Tony Deacon · May 2026 Trustpilot

Contacted Ron with a problem and he sorted it out quickly with no problems at all. Very knowledgeable on anything solar/ batteries. I would recommend him to anyone

Phill · May 2026 Trustpilot

I've spoken to Ron a couple of times with issues with my Givenergy installation. Such a friendly knowledge guy very highly recommended. Thank you very much for resolving my issues

michael fairhurst · May 2026 Trustpilot

Mr Machin · May 2026 Trustpilot

Keith Ballard · Apr 2026 Trustpilot

Contacted Solar Tech Support when trying to understand what my Givenergy inverter problem might be and what might be my options. Received good/honest advise which backed up my thoughts.

Hugh Speirs · Apr 2026 Trustpilot

Christopher · Apr 2026 Trustpilot

customer · Apr 2026 Trustpilot

Andy Thomas · Apr 2026 Trustpilot

Philip · Apr 2026 Trustpilot

SolaX hub ForceTime not working T-BAT BMS fault Grid disconnection Fault codes →

Quick reference — UK grid voltage and frequency limits

Nominal voltage — 230V (UK standard)

Safe range — 216V to 253V

Overvoltage trip — above 253V (inverter must disconnect)

Frequency range — 47.5Hz to 52Hz

Diagnostics

6-step grid disconnection diagnosis

Work through these steps to understand why your SolaX inverter is disconnecting from the grid, whether it is a network issue or a configuration problem, and what to do about it.

Check SolaX Cloud for the fault code and voltage reading

Log into SolaX Cloud and check the fault history. The specific code tells you what the inverter detected:

• E012 Grid Voltage Fault — grid voltage was outside the 216V–253V safe range. Check whether the reading was above 253V (overvoltage) or below 216V (under-voltage).

• PLL Lost Fault — the inverter detected unusual grid conditions and could not maintain frequency synchronisation. Often caused by grid instability after storms or outages.

• IE02 Grid Lost Fault — the inverter stopped measuring grid voltage entirely. Check AC connections, breakers, and isolators.

If the voltage reading at disconnection was above 253V, the inverter disconnected because UK grid code requires it — the system is working correctly.

Identify the disconnection pattern from the event log

The pattern tells you the root cause. Check the SolaX Cloud event log covering at least the last 30 days:

• Trips every sunny afternoon — grid overvoltage from high solar export in your area. Multiple homes exporting simultaneously pushes the local voltage above 253V.

• Single trip after a storm or power cut — normal anti-islanding behaviour. The inverter will reconnect automatically once the grid stabilises.

• Random trips regardless of weather — possible weak grid connection, loose AC wiring, or a faulty grid relay inside the inverter.

Export the event log with timestamps — this data is exactly what a diagnostic engineer or your DNO needs to identify the root cause.

Understand the cause — this is usually a grid issue, not an inverter fault

SolaX X-Hybrid inverters comply with G98 and G99 UK grid codes. They are required to disconnect when grid voltage exceeds 253V or when frequency moves outside the safe range. This is a safety mechanism protecting the equipment and the network.

On UK distribution networks where multiple solar systems are connected to the same transformer, simultaneous export during peak generation pushes the local voltage upward. The houses furthest from the transformer see the highest voltage and are the first to trip. This is a network capacity issue — the solution is either export limitation on the inverter side or infrastructure reinforcement by the DNO.

Check if your system needs export limitation configured

If your SolaX system is rated above 3.68kW, it was installed under G99 regulations and may require export limitation. Export limitation restricts how much power the inverter sends to the grid, reducing your contribution to local overvoltage.

On the inverter, navigate to Settings → Advanced Settings → Export Control. If export control is not enabled and your DNO approval letter specifies an export limit, this must be configured. The inverter also needs a CT clamp or meter installed to measure export accurately.

Without correct export control, a G99 system may be non-compliant — the DNO can require disconnection, and you may lose Smart Export Guarantee payments.

Report to your DNO if voltage is persistently above 250V

If SolaX Cloud shows grid voltage regularly exceeding 250V during generation hours, contact your Distribution Network Operator. The DNO is responsible for maintaining voltage within the statutory range. They can adjust the transformer tap setting to lower voltage across the local network, or reinforce the infrastructure if needed.

Find your DNO by entering your postcode on the Energy Networks Association website. When reporting, provide the voltage readings and timestamps from SolaX Cloud. If your neighbours also have solar systems that are tripping, a joint complaint carries more weight with the DNO.

Book a diagnostic for configuration or reactive power adjustments

If grid disconnections continue despite correct export limitation, the inverter's reactive power settings or grid protection parameters may need adjusting within the G99-permitted range. These are installer-level settings that require technical knowledge to configure correctly.

STS can review your SolaX Cloud voltage data remotely, identify whether the issue is a network problem requiring DNO involvement or a configuration issue that can be resolved at the inverter, and recommend the appropriate fix. Remote diagnostic sessions start from £75.

Why grid disconnection faults are increasing on UK SolaX systems

Grid disconnection faults are becoming more frequent across the UK as solar installation density increases. The distribution networks in most residential areas were designed for one-way power delivery — from the transformer to the house. When multiple solar systems on the same network begin exporting simultaneously, power flows in the opposite direction and the voltage at the far end of the network rises. Once it exceeds 253V, every inverter on that section is required to disconnect.

Rural and suburban networks are the most affected. These networks tend to have higher impedance — longer cable runs from the transformer — which means voltage rises more for the same amount of export. A street with five or six solar systems can push the local voltage above the trip threshold on a clear summer afternoon, even if each system is relatively small. The houses furthest from the transformer will trip first and most frequently.

SolaX systems installed under G99 (above 3.68kW) should have export limitation configured to reduce their contribution to voltage rise. But many G99 systems were installed without export control enabled, or the CT clamp was never fitted, or the limit was set incorrectly. Correcting the export control configuration often reduces or eliminates the disconnection events without any network reinforcement needed. For systems where export limitation alone is not enough, the DNO needs to adjust the transformer tap or reinforce the local network.

Reference

SolaX grid disconnection fault codes

E012

Grid Voltage Fault

Grid voltage outside the 216V–253V safe range. Most commonly overvoltage above 253V during peak solar export. Inverter reconnects automatically when voltage drops.

PLL Lost

Phase Lock Loop lost

Inverter lost synchronisation with grid frequency. Often occurs during grid instability after storms, outages, or rapid voltage fluctuations. Usually clears within minutes.

IE02

Grid Lost Fault

Inverter cannot measure grid voltage at all. Check AC isolators, consumer unit breakers, and wiring connections. If the mains supply is present, the AC cable or a relay inside the inverter may be faulty.

Grid Relay

Grid Relay Fault

Internal relay switch malfunction. Can be caused by a poorly connected neutral line or three-phase imbalance on X3-Hybrid systems. May require inverter inspection or replacement.

Grid disconnection faults — common questions

What causes a SolaX grid disconnection fault?

A SolaX grid disconnection fault occurs when the inverter detects grid voltage above 253V, below 216V, or frequency outside the safe range. The inverter disconnects as required by UK grid codes G98 and G99. The most common cause is grid overvoltage — multiple solar systems on the same local network exporting simultaneously during sunny afternoons push the voltage above the threshold. This is a grid capacity issue, not an inverter defect. Other causes include power cuts, storm damage, loose AC connections, and missing export limitation on G99 systems.

Why does my SolaX inverter keep tripping on sunny days?

If your SolaX inverter trips repeatedly on sunny afternoons, the most likely cause is grid overvoltage. When solar systems across your local network export at full power simultaneously, the distribution voltage rises. The houses furthest from the transformer experience the highest voltage and trip first. The inverter is doing exactly what it should — disconnecting when voltage exceeds 253V. Check SolaX Cloud for the voltage reading at disconnection. If it was above 253V, report this to your DNO and consider export limitation configuration to reduce your contribution to the voltage rise.

Can I adjust the voltage trip settings on my SolaX inverter?

The voltage and frequency trip settings are governed by UK grid codes G98 and G99. They can only be adjusted within the ranges permitted by the grid code, and only by a qualified installer with advanced settings access. Raising the overvoltage threshold beyond the permitted range would make the system non-compliant and could result in the DNO requiring disconnection. The correct approach is to configure export limitation to reduce your system's contribution to local voltage rise, and to report the issue to your DNO so they can address the underlying network capacity.

What is the difference between G98 and G99 for SolaX systems?

G98 applies to SolaX systems rated at 3.68kW or below per phase. These are installed under a fit-and-inform process — the installer notifies the DNO within 28 days but no pre-approval is needed. G99 applies to systems above 3.68kW per phase and requires DNO approval before installation. G99 systems often have export limitation conditions attached. If a G99 system is installed without proper approval or without the required export limit configured, the DNO can require disconnection. Both standards define the same voltage and frequency protection thresholds.

How much generation do I lose from grid disconnection trips?

The amount of lost generation depends on how frequently the inverter trips and how long it stays offline each time. A single trip during a brief voltage spike costs very little. An inverter that trips repeatedly throughout every sunny afternoon can lose 20 to 40 percent of its potential generation during those hours. SolaX Cloud records production data alongside fault events, so you can calculate the exact loss by comparing actual versus expected production. If the loss is significant, configuring export limitation or reporting to the DNO is the priority.

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Grid tripping? We identify the cause remotely.

We review your SolaX Cloud voltage data and fault history to determine whether the issue is a network problem requiring DNO action, a missing export limit, or a configuration fix we can resolve remotely.

Not affiliated with SolaX Power
Free remote diagnostic · no fix, no fee
G98 & G99 configuration specialists

Call 07944 877 329 Book free diagnostic