An EPS wall socket is a single 13A socket wired from the inverter's EPS terminals — it powers one or two appliances during an outage. A dedicated EPS circuit is a separate sub-board protecting multiple circuits (lights, sockets, freezer, boiler). A full-house manual changeover switch lets you switch your entire consumer unit to battery power by turning a rotary isolator. A full-house automatic changeover switch does this automatically within milliseconds when the grid fails. Each option increases in coverage, complexity, and cost.
System upgrade · Backup power
EPS installation — backup power from your solar battery
EPS (Emergency Power Supply) lets your battery keep your home running during a grid outage — automatically, silently, and without fuel. From a single backup socket to full-house automatic changeover, there are four ways to configure EPS depending on how much coverage you need.
- Switches over in <20ms
- Dedicated circuit from £795
- Most hybrid inverters supported
EPS not working during a power cut?
If your inverter is EPS-capable but your circuits go dark in an outage, the problem is usually a missing neutral-earth bond or the EPS circuit not being correctly wired. We diagnose and fix EPS configuration issues as part of our fault diagnosis service.
Book EPS diagnosis / installationRemote EPS fault diagnosis 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
What is EPS and how does it work?
EPS is a feature built into most modern hybrid solar inverters. When the grid supply fails, the inverter automatically disconnects from the grid and switches its output to protected circuits — powered entirely by your battery. This happens in under 20 milliseconds, fast enough that computers and clocks typically keep running without rebooting.
How much of your home gets protected depends on which EPS configuration you choose. A simple wall socket keeps one or two appliances alive. A full-house automatic changeover switch protects every circuit in the building — seamlessly and without any manual intervention.
What EPS does
✓ Keeps selected (or all) circuits running during a grid outage
✓ Switches over automatically — no action needed
✓ Charges from solar during daytime outages
✓ Silent, no emissions, no fuel required
✓ Automatically reconnects when the grid returns
What EPS cannot do
✗ Work without a charged battery
✗ Sustain high-draw loads indefinitely (showers, cookers, heat pumps)
✗ Operate on a string inverter (hybrid required)
✗ Work correctly without proper wiring and neutral-earth bond
✗ Replace a generator for multi-day outages with small batteries
Important: Enabling EPS mode in your inverter portal alone is not sufficient. You must have physical EPS wiring — whether that is a dedicated socket, a sub-board, or a changeover switch. Without the electrical work, enabling EPS mode has no practical effect and the inverter will still shut down your circuits when the grid fails.
Four types of EPS configuration
EPS is not one-size-fits-all. There are four distinct ways to wire EPS backup power, each offering a different level of coverage, complexity, and cost. The right choice depends on how many circuits you want to protect and whether you need automatic or manual switchover.
Type 1
Basic
EPS wall socket
A single 13A socket wired directly from the inverter's EPS output terminals. During a power cut, this socket stays live while the rest of the house goes dark. You plug in whatever you need most — a phone charger, broadband router, or extension lead to a fridge-freezer.
Grid outage — EPS socket active
✓ Simplest and cheapest installation
✓ No sub-board or changeover switch needed
→ Only one or two appliances at a time
→ No lighting circuits protected
Typical use: Keep the broadband router and a phone charger running during short outages. Suited to households that rarely experience power cuts but want basic resilience.
Type 2 · Most popular
Dedicated EPS circuit
From £795
A separate EPS consumer unit (sub-board) wired from the inverter's EPS output terminals. Selected circuits are moved onto this sub-board — typically lighting, essential sockets, boiler, freezer, and broadband router. During a power cut, only these protected circuits stay live. The rest of the house remains off until the grid returns.
Grid outage — protected circuits active
✓ Multiple circuits protected (lights, sockets, boiler, freezer)
✓ Automatic switchover — no manual action needed
✓ Best balance of coverage, cost, and battery life
→ Requires rewiring selected circuits to the EPS sub-board
Typical use: The standard recommendation for most homes. Protects 3–8 essential circuits. Battery lasts longer because high-draw circuits (cooker, shower) stay off.
Type 3
Full-house manual changeover
£795
A manual changeover switch (typically a rotary isolator) is installed between the grid supply and your main consumer unit. When the power goes out, you physically turn the switch to transfer the entire consumer unit from grid supply to inverter EPS output. Every circuit in the house is then powered by the battery. When the grid returns, you switch it back.
Grid outage — manual switch engaged — whole house on battery
✓ Every circuit in the house protected
✓ No need to choose which circuits to move
✓ Simpler wiring than a dedicated sub-board
→ Requires manual intervention to switch over
→ Everything stays off until you turn the switch
→ Battery drains faster with full house load — manage usage carefully
Typical use: Households that want full-house coverage without the cost of automatic changeover. You need to be home (or have someone home) to operate the switch when the grid fails.
Type 4 · Premium
Full-house automatic changeover
From £1,295
An automatic changeover switch (ATS) monitors the grid supply continuously. The moment the grid fails, the ATS transfers the entire consumer unit to inverter EPS output — automatically and without any manual intervention. When the grid returns, it switches back. The whole house stays powered throughout, with a brief interruption of under 20 milliseconds during switchover.
Grid outage — auto changeover — whole house on battery
✓ Every circuit in the house protected automatically
✓ No manual action — works even when you are away
✓ Seamless transition — most devices do not notice
→ Highest cost option
→ Battery drains faster with full house load — manage usage carefully
→ Larger battery bank recommended (10 kWh+)
Typical use: Households that want complete seamless protection. Ideal when people are often away, when there are vulnerable occupants, or where any interruption to power is unacceptable (medical equipment, home office, security systems).
Quick comparison
| Feature | Wall socket | Dedicated circuit | Manual changeover | Auto changeover |
|---|---|---|---|---|
| Circuits protected | 1 socket | 3–8 selected | All | All |
| Automatic switchover | Yes | Yes | No (manual) | Yes |
| Battery efficiency | Best | Good | Load dependent | Load dependent |
| Works when away | Yes | Yes | No | Yes |
| Starting price | £795 | £795 | £795 | £1,295 |
Which inverters support EPS?
EPS capability is standard on hybrid inverters but absent from string inverters. All four configuration types above require a hybrid inverter with EPS output terminals.
EPS-capable inverters (most common)
GivEnergy: AIO 2.0, AIO 2.6, AIO 5.0, All-in-One Gen2
Sunsynk: Sunsynk Hybrid 3.6, 5.5, 8.0 kW
Growatt: SPH 3000–6000TL3, SPA series
SolaX: X1 Hybrid G4, X3 Hybrid G4
Fox ESS: H1, H3, AIO series
Lux Power: SNA / LXP hybrid series
Sigenergy: SigenStor series
Alpha ESS: SMILE5, STORION series
No native EPS — string inverters
SMA Sunny Boy: (standard, non-Storage series)
Fronius Symo: (non-hybrid series)
SolarEdge: (single-phase without backup interface)
Solis string: (non-hybrid models)
Huawei SUN2000: (without backup LUNA unit)
Most pre-2018 string inverters
Not sure about your model? Check your inverter's user manual or search the manufacturer's portal settings. If there is no EPS, backup, or island mode setting, your inverter does not support EPS. The alternative is inverter replacement with an EPS-capable hybrid model.
Why the neutral-earth bond matters
The neutral-earth bond is the single most common reason EPS fails during an actual power cut — and it applies to all four configuration types. Understanding why it is needed prevents the most frequent EPS installation fault.
When the grid is live, your home's earth reference comes from the electricity network. When the grid drops and EPS activates, the inverter output becomes an isolated island supply — the earth reference from the grid disappears. Without a replacement earth reference, RCDs on the EPS circuits cannot function and will trip immediately.
The fix is a neutral-earth bond — a simple connection at the EPS sub-board or changeover point that establishes a local earth reference. This allows RCDs to operate correctly during island mode. Every EPS installation we carry out includes this bond as standard.
If your EPS was installed by someone else and trips during outages: The neutral-earth bond is the first thing to check. It is a quick fix for a qualified electrician and resolves the problem in the majority of cases. See our GivEnergy EPS not working guide for brand-specific troubleshooting.
What EPS installation involves
Regardless of which configuration you choose, the installation follows the same fundamental steps. The complexity and duration increase with more comprehensive configurations.
1
Confirm inverter EPS capability and battery reserve
Before any work begins, we confirm the inverter model supports EPS and that your battery has sufficient usable capacity (minimum 5 kWh recommended for dedicated circuits, 10 kWh+ recommended for full-house changeover). A battery reserve of 20–30% is configured to ensure capacity is always available for EPS use.
2
Choose the right EPS configuration
We assess your property, existing consumer unit layout, inverter location, and which circuits you want protected to recommend the most appropriate of the four configuration types. For most homes, a dedicated EPS circuit (Type 2) gives the best balance of coverage and battery life. If you want full-house protection, we discuss the trade-offs of manual vs. automatic changeover.
3
Install the EPS wiring and switchgear
A Part P certified electrician carries out the physical installation. For a dedicated circuit, this means a new EPS sub-board with selected circuits transferred. For a changeover switch, the switch is installed between the meter and the main consumer unit. All configurations include the critical neutral-earth bond. Work is typically completed in half a day for dedicated circuits, or a full day for changeover switch installations.
4
Enable EPS mode in inverter settings
We log in to your inverter's monitoring portal and enable EPS mode. The exact menu path varies by brand: on GivEnergy it is System Mode Settings → EPS Enable; on Sunsynk it is under Advanced Settings → Off-Grid/EPS; on Growatt, look in System Parameters → Off-grid Settings; on SolaX, it is under Settings → EPS Mode. We also configure the minimum battery reserve for EPS.
5
Load test and verify
With the battery charged, we temporarily disconnect the main AC supply to simulate a grid outage. The EPS circuits should pick up within 20ms. We test with actual loads — lights, appliances — and verify stable voltage and frequency on the inverter display. For changeover switches, we test the full switchover sequence. Grid reconnection is then tested to confirm automatic return to normal operation.
EPS installation pricing
Pricing depends on which configuration type you need. All prices include labour, materials, Part P certification, neutral-earth bond, inverter configuration, load testing, and a written post-installation report.
Socket or dedicated circuit
From £795
EPS wall socket (£795) or dedicated EPS sub-board (£795). Both include cabling from inverter EPS terminals, neutral-earth bond, circuit transfers, configuration, and test.
Types 1 & 2 · Half day
Full house manual switchover
£795
Manual changeover switch between meter and consumer unit, neutral-earth bond, EPS wiring, configuration, and full test sequence.
Type 3 · Full day
Full house auto switchover
From £1,295
Automatic transfer switch (ATS), changeover wiring, neutral-earth bond, EPS configuration, and comprehensive test sequence.
Type 4 · Full day
All costs confirmed in writing before work begins. EPS work is carried out by Part P certified electricians. We include a post-installation report documenting the EPS circuit layout, changeover switch type, configuration settings, and test results. You receive a clear record of what was done and how to use your EPS system.
Inverter does not support EPS? If your current inverter is a string model without EPS capability, the first step is inverter replacement with an EPS-capable hybrid. We can quote the full job — inverter replacement plus EPS installation — as a single package.
How long will my battery last during an outage?
EPS duration depends on battery capacity, protected load, time of day, and battery reserve settings. With a dedicated EPS circuit protecting only essentials, a modest battery can last a full day or more. With full-house changeover, duration drops significantly unless you manage your loads.
If the outage occurs during daylight and your solar panels are generating, the battery recharges continuously — potentially extending EPS duration indefinitely for low loads.
Battery size
Protected load
250W
Lights, router, phone chargers
500W
+ TV, freezer, boiler
1,000W
+ multiple appliances
5 kWh
~18 hrs
~9 hrs
~4.5 hrs
10 kWh
~36 hrs
~18 hrs
~9 hrs
15 kWh
~54 hrs
~27 hrs
~13 hrs
Estimates assume 80% usable capacity with 20% battery reserve. During daytime solar generation, EPS duration extends significantly as panels recharge the battery. Hours shown are approximate and depend on battery health and actual load. Full-house changeover installations should size their load expectations accordingly — see how battery storage works for more detail.
Related pages
GivEnergy EPS not working
EPS-capable inverter but circuits go dark in a power cut. Neutral-earth bond, EPS configuration, and GivEnergy-specific settings.
Add an extra battery
Extending battery capacity increases EPS runtime. Understand what adding a second module involves and how it improves backup duration.
Inverter replacement
If your current inverter does not support EPS, replacement with a hybrid model may be the only route to backup power.
How battery storage works
Understand how solar batteries charge, discharge, and interact with the grid — essential background for sizing your EPS setup.
EPS installation across Yorkshire & beyond
We install EPS backup systems on-site across a wide coverage area from our Yorkshire base — including Leeds, Bradford, Wakefield, Harrogate, York, Sheffield, Huddersfield, Doncaster, Hull, Barnsley, Scunthorpe, Grimsby, Mansfield, Derby, Nottingham, Manchester, Darlington, and Middlesbrough.
FAQ
EPS installation — frequently asked questions
Most modern hybrid inverters support EPS: GivEnergy AIO, Sunsynk Hybrid, Growatt SPH/SPA, SolaX Hybrid G4, Fox ESS H1/H3, Lux Power, Alpha ESS, and Sigenergy. Standard string inverters do not support EPS — they shut down completely when the grid fails. Check your inverter documentation or the manufacturer's portal for an EPS or backup mode setting.
Almost always a missing neutral-earth bond. When the grid fails and EPS activates, the inverter output becomes an isolated island supply. Without a neutral-earth bond at the EPS sub-board or changeover point, RCDs trip because the earth reference disappears. This is a quick fix for a qualified electrician — adding the bond resolves the problem immediately.
Yes, with a full-house changeover switch (manual or automatic). However, you need to manage your loads carefully — a typical 5 kWh battery will only sustain the whole house for a few hours if high-draw appliances are running. With full-house changeover, you get the flexibility to power everything, but you should avoid running electric showers, cookers, or heat pumps simultaneously to preserve battery life. A 10 kWh+ battery bank is recommended for full-house configurations.
Duration depends on battery size and load. At 500W of protected load: a 5 kWh battery lasts approximately 9 hours, a 10 kWh battery approximately 18 hours. During daylight, solar panels recharge the battery continuously — extending EPS duration significantly. Setting a 20% battery reserve ensures capacity is always available for EPS. See the duration table above for more examples.
An EPS wall socket costs £795. A dedicated EPS circuit starts from £795 including wiring, neutral-earth bond, and configuration. A full-house manual changeover switch starts £795. A full-house automatic changeover switch starts from £1,295. All prices include Part P certification, load testing, and a written post-installation report. Costs are confirmed in writing before work begins.
When the grid fails and EPS activates, the inverter's EPS output becomes an isolated island supply — it is no longer connected to the grid's earth reference. A neutral-earth bond establishes a local earth reference at the EPS sub-board or changeover point so that RCDs can function correctly. Without this bond, RCDs trip immediately and the EPS circuits go dead. This is the single most common reason EPS does not work during a real power cut.
Yes — STS installs EPS on any compatible hybrid inverter regardless of brand. This includes GivEnergy, Sunsynk, Growatt, SolaX, Fox ESS, Lux Power, Alpha ESS, Sigenergy, and others. The installation process is the same in principle: EPS wiring, neutral-earth bond, and portal configuration. Contact us with your inverter model to confirm compatibility before booking.
Book
Ready to add backup power?
Whether you want a single EPS socket, a dedicated circuit protecting your essentials, or full-house changeover for complete coverage — we assess, quote, and install. All work is Part P certified, tested on-site, and documented in writing.
- EPS socket £795 · Dedicated circuit £795 · Manual changeover £795
- Automatic changeover from £1,295 · All Part P certified
- Written report with configuration details and test results
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