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Problem diagnosis · Sigenergy

Sigenergy Grid Protection Trip — G98/G99 Voltage & Frequency Fault Diagnosis

Your SigenStor keeps disconnecting from the grid with a protection alarm. It's not the inverter failing — it's protecting the network. Grid overvoltage, frequency excursion, or isolation fault — each has a different cause and fix. This guide walks through how to identify which one you're dealing with.
  • G98/G99 voltage and frequency limits
  • Safety protection, not system failure
  • SigenCloud event log diagnosis
Frequent grid trips?

We review your SigenCloud event log, check grid code configuration, and determine whether the trips are caused by grid quality, system settings, or an isolation fault.

Book your free remote diagnosticBack to Sigenergy hub

Independent — not affiliated with Sigenergy Technology.

5.0
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

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

⚡ Safety Warning

Do not open your inverter or interfere with DC cabling. Solar panels produce live DC voltage whenever exposed to light. Always use your DC isolator switch and contact a qualified solar engineer for hands-on fault diagnosis.

ℹ️

Important: A grid protection trip is a safety function, not a system failure. Your SigenStor is doing exactly what it should — disconnecting to protect the grid when voltage or frequency exceeds safe limits. The system reconnects automatically when conditions normalise. Understanding the cause helps reduce trip frequency.

Diagnostics

5-step grid protection trip diagnosis

Grid protection trips fall into two categories: grid quality issues (voltage/frequency — external) and isolation faults (DC insulation — internal). The SigenCloud event log tells you which one you're dealing with.

1

Check SigenCloud event log for the trip details

Log into SigenCloud and navigate to the alarm or event log. Find the grid protection trip and note:

Fault type — overvoltage, undervoltage, overfrequency, underfrequency, or isolation fault
AC voltage reading at the time of disconnect
Grid frequency at the time of disconnect
Time of day — midday trips suggest solar export pushing voltage up
Grid protection thresholds (G98)
Over voltage: Above 253V for more than 200ms → automatic disconnect
Under voltage: Below 207V for more than 200ms → automatic disconnect
Over frequency: Above 52Hz for more than 200ms → automatic disconnect
Under frequency: Below 47.5Hz for more than 200ms → automatic disconnect

The fault type determines which diagnostic path to follow. Voltage and frequency trips are grid quality issues. Isolation faults are internal to your system.

2

Confirm the correct G98 or G99 grid code is configured

In SigenCloud, check the grid code configuration for your SigenStor:

G98: For installations up to 3.68kW per phase. Can connect without prior DNO approval. Standard voltage and frequency protection limits.
G99: For larger systems. Requires formal DNO application and acceptance. Additional requirements for reactive power support and frequency response.

If the wrong grid code is configured — for example, a factory default from another country, or G99 set on a system that should be G98 — the protection limits may be wrong, causing unnecessary trips. Grid code settings typically require installer-level access in SigenCloud.

If you have a G99 system, check your DNO acceptance letter for the specific export and protection settings that were agreed.

3

Determine if the trip is transient or persistent

After a grid protection trip, observe the reconnection behaviour:

Transient (reconnects in 5–10 min)

A brief grid voltage spike or frequency excursion. Common in areas with high solar density at midday. The system recovers automatically. Accept as normal grid behaviour or consider export limiting to reduce frequency.

Persistent (stays disconnected 30+ min)

Grid voltage or frequency remains outside limits for an extended period. This is a local grid infrastructure issue. Export limiting may help, but the DNO should be notified if it happens regularly.

Monitor over 3–5 sunny days to establish a pattern. Note the time, voltage, and whether the system reconnects automatically.

4

Check for isolation faults on the DC side

If the grid protection alarm includes an isolation fault code, the issue is on the DC side of the system — not the AC grid. An isolation fault means the insulation resistance between DC circuits and earth has fallen below the safety threshold:

MC4 connector water ingress — moisture inside panel connectors reduces insulation resistance
Damaged DC cable insulation — UV degradation, rodent damage, or mechanical abrasion
Battery module fault — internal insulation breakdown within a module (see battery module fault guide)
Junction box fault — cracked or water-damaged panel junction boxes

Isolation faults require on-site testing with an insulation resistance (IR) meter to locate the affected circuit. Do not attempt to inspect DC wiring yourself — solar panels produce voltage whenever light hits them.

5

Contact your DNO if grid overvoltage is persistent

If SigenCloud consistently shows AC voltage above 250V at the time of grid protection trips, the problem is grid infrastructure — not your SigenStor:

1. Gather evidence: Screenshot SigenCloud event logs showing voltage readings at each disconnect. Note the pattern — time of day, frequency of trips, and whether it correlates with sunny weather.
2. Contact your DNO: Report persistent high grid voltage. Provide the evidence from SigenCloud. Your DNO is responsible for maintaining voltage within statutory limits.
3. Consider export limiting: While waiting for DNO action, setting an export limit in SigenCloud can reduce peak export power and lower the voltage rise your system contributes.

DNO response times vary. Keep a log of trip events to strengthen your case if the issue persists.

Why grid protection trips happen — and why they're increasing

Grid protection trips are a designed safety function required by UK grid codes. Every grid-connected inverter — regardless of brand — must disconnect when AC voltage or frequency exceeds statutory limits. The SigenStor is not failing when it trips; it is doing exactly what the regulations require. The issue is that the grid infrastructure in many UK residential areas was not designed for the level of distributed solar generation now connected to it.

As solar installations increase — particularly in suburban streets where multiple homes have panels — the cumulative export during peak solar hours pushes local grid voltage above the G98 limit of 253V. This is a voltage rise problem caused by the grid cable resistance and the current flowing back towards the transformer. Every kilowatt exported adds to the voltage rise. When enough systems export simultaneously, the voltage exceeds 253V and all inverters on that circuit disconnect.

Sigenergy SigenStor systems with battery storage have a potential advantage here: excess solar can be stored in the battery rather than exported. If your system is configured for self-consumption priority, it will charge the battery during peak solar periods rather than exporting to the grid — reducing your contribution to local voltage rise. STS can review your SigenCloud settings and recommend a configuration that minimises grid trips while maximising self-consumption and battery utilisation.

Back to

Return to the Sigenergy brand hub to explore other common faults and services.

Sigenergy support hub
FAQ

Grid protection trip — common questions

The SigenStor disconnects when grid voltage exceeds 253V or drops below 207V (G98 limits). In areas with many solar installations, midday export pushes local voltage above the limit. This is a grid quality issue, not an inverter fault. The system reconnects automatically. Export limiting or battery self-consumption mode can reduce trip frequency.
G98 applies to installations up to 3.68kW per phase — no prior DNO approval needed. G99 applies to larger systems and requires formal application. The grid code setting determines voltage and frequency protection limits. Wrong configuration causes unnecessary trips. Check your SigenCloud settings or DNO acceptance letter.
Log into SigenCloud and check the alarm or event log. Grid protection trips show the specific fault type — overvoltage, undervoltage, overfrequency, underfrequency, or isolation fault — along with the voltage and frequency at disconnect. This tells you whether it was a grid quality issue or an internal system fault.
No. Grid protection trips are a designed safety function. The SigenStor disconnects to protect both the system and the grid — no damage occurs. Frequent trips reduce your generation during disconnect periods but do not cause wear or degradation to the inverter or battery.
An isolation fault means the insulation between DC circuits and earth has fallen below the safety threshold. Common causes include water ingress into MC4 connectors, UV-damaged cable insulation, or a fault within a battery module. Unlike grid voltage trips, isolation faults require on-site testing with an insulation resistance meter. Book a diagnostic and we'll confirm the cause.
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SigenStor keeps tripping off the grid?

We review your SigenCloud event log, check grid code configuration, and determine whether the trips are caused by grid voltage, frequency, or an isolation fault. Clear diagnosis, clear next steps.

  • Free remote diagnostic · no fix, no fee
  • Grid code and export limit review
  • DNO engagement support if needed

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