If you need wiring disconnected, panels removed, or are unsure about any part of the shutdown procedure, book an engineer.
Book an engineerEmergency repairGivEnergy owners: the DC isolator in step 3 is the one on the bottom of your inverter (on Gen 2 and Gen 3 it is the switch GivEnergy's own guide calls the toggle switch), and AC-coupled inverters have none, so skip step 3. Where your battery DC MCB is, and the full order: the GivEnergy restart page.
Excellent support. He is extremely knowledgeable and his experience is second to none. I have GivEnergy equipment and he sorted out my solar problems remotely. He was understanding and patient and excellent to deal with. Would highly recommend. Thank you
Sts does a extremely great job. Thank you.
Ron dealt with a battery issue within an hour on a weekend remotely. Very clear instructions to fix the issue worked first time. Excellent service.
Wow!!! I have a Givenergy system. The battery stopped charging and depleted fully. Obviously Givenergy went into administration, so I was working with the reseller / installer to get it fixed. They told me they couldn't resolve it and the best they could do was offer me a replAcement at cost, so basically having to buy a new system. I happened to come across STS when searching for how to fix it myself. Ronald has been a god send, within 2 days all is working perfectly and set up correctly. When it comes to experts. He truly is the expert. If you have issues with your Givenergy system and don't know where to go for good help, give him call. 07944 877329. Thanks Ronald, regards Neil W
Unfortunately, only weeks after Givenergy went into receivership, our system failed. Our installers were unhelpful in the extreme but Solar Tech Support were able to diagnose a terminal problem with our Gen 1 AC3 inverter. They advised regarding the available options and (having decided to buy a replacement Givenergy inverter as the simplest solution) they were able to get us up and running. They made themselves readily available to talk through the process and manage any faults. I would have no problem recommending them.
Diligent and reliable service.
Most solar systems run continuously without any need for manual shutdown. There are only a handful of situations where you need to isolate the system, and the correct approach depends on which one applies to you.
An electrician is working on your consumer unit, replacing a battery module, servicing the inverter, or performing an annual health check. Standard shutdown procedure — no urgency.
Roofers need to work near the panels — re-tiling, repairing flashing, scaffold erection, or chimney work. The system should be shut down and the roofers informed that DC cables remain live.
Your inverter is showing a fault code that does not clear after a soft reset, or the system is behaving erratically. Shutting down prevents further damage while you wait for an engineer.
You smell burning, see smoke, hear arcing, or notice water near electrical components. Shut down immediately using the emergency procedure below and call your installer or an emergency electrician.
This is the standard shutdown sequence for all UK residential solar systems. The order matters: battery off first at its power button, then AC, then DC, and the battery DC breaker last. This applies to GivEnergy, SolarEdge, Growatt, Sunsynk, Solis, Huawei, Fox ESS, Fronius, and all other grid-tied and hybrid inverters.
If a battery is fitted, it goes off first: before the AC isolator and before the DC isolator. That is the same on every brand. If your battery app offers a soft shutdown, use it first so the battery management system can settle into standby.
Then press or hold the power button on the battery until it powers down. Where several modules are stacked, shut each module down. If your system has no battery, start at step 2.
The AC isolator is usually a red rotary switch mounted on the wall next to or directly below the inverter. Some installations have it inside the consumer unit area instead. Turn the switch to the OFF position.
The inverter display will go dark or show a "no grid" or "waiting" message within a few seconds. On some models a brief alarm beep may sound. That is normal and indicates the inverter has detected grid disconnection.
The DC isolator disconnects the solar panels from the inverter. Its location varies by installation: on string inverters it is typically a rotary switch on the underside or side of the inverter itself. On SolarEdge systems, the DC isolator is on the inverter with a yellow safety label. Some installations have an additional DC isolator near the panels on the roof.
Turn the DC isolator to the OFF position. The inverter is now disconnected from both the grid and the panels.
Open your consumer unit (fuse board) and switch off the MCB or RCBO that feeds the solar circuit. This is typically a dedicated breaker labelled "Solar", "PV", or "Inverter". It provides a further point of isolation and is required if anyone will be working on the AC wiring between the consumer unit and inverter.
If you are unsure which breaker is for the solar circuit, check the circuit chart on the inside of the consumer unit door. If there is no label, do not guess — contact your installer or an electrician.
Only now, with the battery already powered down and both isolators open, turn off the battery DC breaker or isolation switch. Opening it last means it is opened with no current flowing through it. Where several modules are stacked, open each one.
If the breaker will not stay off, or it feels warm, stop and call an engineer rather than forcing it.
Confirm the inverter display is completely off, with no LEDs and no screen illumination. Check the monitoring app: it should show the system as offline with zero generation. If the inverter still shows any activity, recheck that both the AC and DC isolators are in the OFF position.
Wait at least 30 seconds after the final isolator is switched off before anyone touches the inverter or its connections. Internal capacitors need time to discharge.
If your system includes a battery (GivEnergy, Pylontech, Dyness, BYD, Sofar, or any other), the battery bookends the whole sequence. It is a separate energy source from the panels: it goes off first at its power button, and its DC breaker is the very last thing you open. The order below is the same on every brand.
Some battery systems support a soft shutdown from the monitoring app, typically by disabling charge and discharge before anything physical is touched. Doing this first lets the BMS (battery management system) complete any balancing and settle into a safe standby state.
Press or hold the power button on the battery until it powers down. This happens before the AC isolator and before the DC isolator, on every brand. Where several modules are stacked, shut each one down and wait for its LEDs to go out.
With the battery down, work through steps 2 to 4 of the standard procedure above: AC isolator off, then DC isolator off, then the solar circuit breaker at the consumer unit.
Locate the battery DC breaker or isolation switch. On wall-mounted units there is typically a single DC breaker between the battery and the inverter. On rack systems each module has its own breaker, and on some batteries the switch is on the module itself.
Turn it to OFF now, and not earlier. By this point the battery is already down and both isolators are open, so the breaker is opened with no current flowing through it. If you have multiple modules stacked together, isolate each one individually.
After the DC breaker is open, wait at least 2 minutes before working near or on battery components. Battery capacitors and the BMS controller take longer to fully discharge than the inverter. Some manufacturers (Pylontech, BYD) recommend a 5-minute wait. Check the battery LED indicators — they should be off or showing a standby pattern.
If you smell burning, see smoke or sparking, hear arcing or crackling, or notice water near the inverter or battery — use the emergency procedure. The priority is speed: isolate everything as quickly as possible, then get clear.
In an emergency, speed takes priority over the normal battery-first sequence. Switch off whichever isolator you can reach first, then the other. If there is active fire or arcing at the inverter and you cannot safely reach the isolators, go to step 2.
If you cannot safely reach the inverter isolators, go to your consumer unit and switch off the main switch (the large switch at the top). This cuts all power to the property including the solar circuit. It does not disconnect the DC side from the panels, but it removes the AC supply.
If there is fire, smoke, or a chemical smell from a battery, evacuate the room and ventilate by opening windows from the outside if possible. Lithium battery fires produce toxic fumes. Do not attempt to extinguish a lithium battery fire with water.
For fire or smoke: call 999 and inform them the property has a solar panel system and/or lithium battery storage. For electrical faults without fire: call your installer, an emergency electrician, or STS emergency repair. Do not re-enter the area or attempt to restart the system until it has been inspected by a qualified person.
These are the most common mistakes homeowners make when shutting down or working around their solar system. Each one creates a genuine safety risk.
MC4 connectors (the click-together plugs on the DC cables between panels) are not designed to be disconnected while the panels are producing power. Pulling them apart under load causes arcing, which can burn the connector and create a fire risk. MC4 disconnection should only be done by a qualified person, ideally at night or with panels covered.
Turning off the inverter stops generation but does not de-energise the panels or DC cabling. A typical domestic string produces 300–600V DC in daylight. The DC isolator disconnects the panels from the inverter, but the cable from the roof to the isolator remains live. Treat all DC wiring as energised until a qualified person has tested and confirmed otherwise.
Even after full isolation, internal capacitors retain charge for several minutes. Inverter and battery enclosures contain high-voltage DC busbars and terminals. Opening them voids your warranty and exposes you to lethal voltages. Only a qualified engineer should open any equipment enclosure.
Lithium-ion and LiFePO₄ battery fires produce toxic hydrogen fluoride gas and cannot be reliably extinguished with water. If you see smoke, swelling, or smell chemicals from a battery, isolate the system, evacuate, ventilate, and call 999. The fire service has specific protocols for lithium battery incidents.
The restart sequence runs the shutdown in reverse. The AC side comes back first, then the panels, and the battery comes on last: consumer unit breaker, AC isolator, DC isolator, battery DC breaker, then the battery power button.
Switch the MCB or RCBO for the solar circuit back to the ON position. This restores the AC feed to the inverter.
Switch the AC isolator to the ON position. The inverter powers up and begins its startup sequence, which takes between 30 seconds and 5 minutes depending on the brand. During this time it measures grid voltage and frequency for a mandatory monitoring period (typically 60 seconds) before it will begin exporting.
Switch the DC isolator back to the ON position. The inverter picks up the panel voltage and, once its grid monitoring period is complete, begins generating. A brief "waiting" or "initialising" message on the display is normal.
Close the battery DC breaker or isolation switch. Where several modules are stacked, do each one. Nothing should happen yet, because the battery itself is still off.
The battery is the last thing on, exactly as it was the first thing off. Press or hold the power button on each module and wait for the BMS to initialise: the LED indicators should change from off to a normal status pattern. Allow 30 to 60 seconds for the startup checks to complete.
Wait 5 minutes, then check: the inverter display shows normal generation figures, the monitoring app shows the system as online, and battery state-of-charge is reading correctly. If the system was off for more than a few hours, check your charge schedule and export limit settings — some inverters reset these after a prolonged power loss.
If the inverter does not start, shows a persistent fault code, or generation remains at zero, see inverter not turning on or system not producing for diagnosis steps.
The procedure above applies to all brands, but some inverters have quirks worth knowing about.
GivEnergy hybrid inverters have a single DC isolator on the underside of the unit; the AC-coupled inverter has none. Gen 2 and Gen 3 batteries each have a built-in DC MCB under the plastic cover; Gen 1 batteries have none of their own and use a separate DC MCB installed between the inverter and the batteries, usually in its own enclosure, with one serving all the Gen 1 batteries. A Gen 1 battery mixed with Gen 2 or Gen 3 can mean an extra DC MCB outside the batteries. After restart, check MyGivEnergy for any "system restart" events in the event log — these confirm the shutdown and restart were detected cleanly. If the inverter shows "waiting" for more than 5 minutes after restart, power-cycle the WiFi dongle. The GivEnergy order step by step is in our GivEnergy restart guide. The physical toggle switch that GivEnergy's own guide lists for Gen 2 and Gen 3 inverters is that same DC isolator on the bottom, not a second switch.
SolarEdge systems have a built-in safety feature: when the DC isolator is turned off, the optimisers reduce panel voltage to a safe level (1V per panel). This makes SolarEdge systems safer for roof work than conventional string inverters. The DC isolator is on the inverter itself, marked with a yellow label. After restart, optimisers take 2–5 minutes to pair and begin reporting — expect a brief delay before generation figures appear in the mySolarEdge portal.
Growatt SPH and MIN series inverters have the DC isolator on the bottom of the unit. After shutdown, the display may flash briefly as residual capacitor charge dissipates — this is normal. On restart, if ShinePhone shows the plant as offline, the ShineLink/WiFi-X dongle may need a manual restart (unplug and replug the USB dongle).
Sunsynk hybrid inverters have a DC isolator on the right-hand side of the unit. The inverter stores settings in non-volatile memory, so charge schedules and system mode survive a shutdown. After restart, Sunsynk typically reconnects to SunsynkConnect within 2–3 minutes. Check the "System Mode" setting (Self Use, Grid Tie, etc.) has not changed.
Our order for a Fox ESS system is the battery's power button first, then the AC isolator, then the inverter's DC isolator, and the battery's DC MCB last if it has one, so the MCB is never switched under load. To turn it back on, go in reverse: battery DC MCB, DC isolator, AC isolator, then the battery's power button.
Huawei SUN2000 inverters have both AC and DC isolators built into the unit. LUNA2000 battery modules have individual power switches on each module — turn them off from top to bottom, and on from bottom to top. After a prolonged shutdown (24+ hours), the FusionSolar app may require you to re-enter the plant and manually refresh the device list.
Two rules are doing the work here. The battery goes off before anything else and its DC breaker comes off last. Between the two isolators, AC comes before DC, because of how grid-tied inverters manage power flow.
Battery first is house policy across every brand we cover, not a quirk of one manufacturer. A battery is an independent energy source: while it is awake it can keep feeding the inverter after both isolators are open. Powering it down at its button before you touch anything else means you remove one live source at a time. Its DC breaker comes off last. The battery DC breaker (MCB) is a protection device, not an on/off switch: opening it while current is flowing is hard on the electronic switches (MOSFETs) inside the battery and inverter. So it only comes off once the battery is powered down and nothing is flowing through it, never while it is carrying load.
A grid-tied solar inverter continuously converts DC power from the panels into AC power synchronised with the grid. The inverter's control loop adjusts its output to match the grid's voltage and frequency in real time. If you remove the DC supply first (panels disconnected) while the AC side is still grid-connected, the inverter briefly loses its power source but remains electrically connected to the grid. This can cause a transient voltage condition as the inverter's protection circuits react — on some models, this results in a hard fault that requires a manual reset.
Disconnecting AC first is cleaner: the inverter detects grid loss, its anti-islanding protection activates within about half a second (the G98/G99 limit is 0.5 s), and it enters a controlled standby state. You then disconnect DC with the inverter already in standby — no transient, no fault, no drama.
Restart runs the other way round. Bring the AC side back first, consumer unit breaker then AC isolator, so the inverter can perform its mandatory grid monitoring period (typically 60 seconds of voltage and frequency measurement). Then the PV isolator, then the battery DC breaker, and the battery power button last of all. The battery is the last thing on, exactly as it was the first thing off.
Understand the role of DC/AC conversion, grid synchronisation, and why isolation sequence matters.
See How Solar Inverters Work →BMS architecture, charge cycles, and why battery isolation is a separate step from inverter shutdown.
See How Battery Storage Works →Settings that can reset after a prolonged shutdown — charge schedules, export limits, and EPS mode.
See Firmware Update Risks →Isolator locations, labelling requirements, and dual-supply warning notices — what should be on your system.
See Installation Day Checklist →If your system won't restart after shutdown — diagnosis steps for all brands.
See Inverter Not Turning On →How emergency power supply works and why it keeps running during a grid outage.
See EPS Backup Installation →If you are unsure about any part of the shutdown procedure, need DC wiring disconnected, or your system won't restart after maintenance — an engineer can attend same day in most cases. Maintenance service from £295.
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