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
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.
Free remote diagnostic · pay only if we fix it — from £75 if remediable remotely
- 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 hubIndependent — not affiliated with Sigenergy Technology.
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
Absolutely wonderful support. I have a GivEnergy system that was installed in 2022, and a firmware update was flagged in the app, so I proceeded to update the software .... and immediately regretted it, as my inverter came up with an error, and was not working at all! With no GivEnergy support available, and my installer saying there was nothing he could do, I googled help, and found Ron. What a stroke of good luck! Submitted an on line enquiry late morning, and received phone call just after 5 pm, and later that evening Ron was able to supply me with old firmware no longer available on the GivEnergy web site. I was then able to update the firmware using a GivEnergy youtube video as reference, and hey presto the system was back up and running. One further slight adjustment by Ron and we are back normal. What a relief. I have no hesitation in recommending Solar Tech Support if you have a problem. Great service! And if you are a GivEnergy system owner, whatever you do, DO NOT UPDATE FIRMWARE!
Neill Ginn · Jul 2026 Google
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
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
Thank you for your diligence. On this occasion the battery was able to be saved but they have given a route to hopefully arrange a repair from the manufacturer.
David Bateman · Jun 2026 Google
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.
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.
Related Sigenergy problems
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Return to the Sigenergy brand hub to explore other common faults and services.
Sigenergy support hubGrid 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.
Book
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.
- No fix, no fee
- Grid code and export limit review
- DNO engagement support if needed
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