Electricity: what trips, and why

It is nine at night and half the house has gone dark. The kettle had just boiled, or the washing machine had just started its spin, or nothing at all seemed to be happening. Somewhere in a cupboard a switch has dropped. That switch is doing one of two things. It may be telling you the circuit had more asked of it than it could safely carry, which is a nuisance you can usually clear. Or it may be telling you something is faulty: a short, in a US utility's word, or current going somewhere it shouldn't, perhaps through a faulty appliance, perhaps through the wiring in a wall. That is a fault reporting itself. Telling those apart, and knowing what the sources let you do about each, is this lesson.

One clause in that box is what the rest of the page unpacks: "if a breaker, RCD or GFCI keeps tripping, leave it off and call an electrician". By the end you'll know what the sources say a device that keeps tripping is telling you, what you may do before you reach that point, and why the line sits where it does.

Where this lesson touches the law, this is general information, not legal advice. The rules differ between England, Wales, Scotland and Northern Ireland, and between US states and cities, and they change.

Two jobs, two kinds of device

Lesson 1, "How a house works, and where it switches off", said the devices in a consumer unit or panel aren't all doing the same job. The difference, properly, is this.

Breakers and fuses look after the wiring

Southern California Edison (SCE), an electric utility, puts the first job in two sentences for its customers: "If a circuit in your home overloads or shorts, the breaker will trip and cut power. This helps prevent fire and possible electrocution."¹ Whichever it was, the breaker's answer is the same: it opens, and the circuit goes dead.

Electrical Safety First (ESF), a UK electrical safety charity, says the same of the smaller fuse inside a British plug: it will "'blow' if an electrical appliance or extension lead draws too much current, either because of an overload or a fault", and "The blown fuse cuts off the electricity, stopping the cable and appliance from overheating and causing a fire."² That is the job: cut the current before the cable overheats. None of the sources this course read goes further into the physics, and this lesson won't either.

The US Consumer Product Safety Commission (CPSC) put the consequence plainly in 1989, and lesson 1 quoted it: breakers and fuses "function primarily to prevent the home wiring system from causing a fire".³ Primarily. The wiring, not the person holding the appliance. Shock is a different job, and it has a different device.

RCDs and GFCIs look after you

The second job belongs to a different device, and the two countries call it by different names: the residual current device (RCD) in the UK, and the ground fault circuit interrupter (GFCI, or sometimes GFI) in the US. ESF says an RCD "protects you from electric shocks if a product is faulty."² In 1989 CPSC said a GFCI "shuts down the power in milliseconds" when current leaks to ground (to earth, in British terms).³

CPSC's GFCI fact sheet gives the mechanism most fully of anything this course read: "A GFCI constantly monitors current flowing through a circuit. If the current flowing into the circuit differs by a very small amount (as little as 0.006 amperes) from the returning current, the GFCI interrupts power faster than a blink of an eye to prevent a lethal dose of electricity."⁴ It is comparing two numbers. Everything that goes out to an appliance should come back. If some does not, it has found another path, and the sheet's example says what that path is: "A bare wire inside an appliance touches its metal case. The case is then charged with electricity. If you touch the appliance with one hand while another part of your body is touching a grounded metal object, such as a water faucet, you will get shocked."⁴ With a GFCI on the circuit, CPSC says, the power goes off before a fatal shock can occur.

What about the British RCD? ESF says it does the same job. The Health and Safety Executive (HSE), Great Britain's workplace safety regulator, describes it in a leaflet written for workplaces as "a device which detects some, but not all, faults in the electrical system and rapidly switches off the supply", and says "RCDs for protecting people have a rated tripping current (sensitivity) of not more than 30 milliamps (mA)."⁵ The page from ESF that explains how an RCD works didn't load when this course's research tried to read it, so the lesson gives you CPSC's account of the GFCI and does not claim a British source said the same about the RCD.

Two cautions. CPSC's 0.006 amperes (6 milliamps) is how small a difference a GFCI can detect, on a US agency's fact sheet. HSE's 30 mA is the most a people-protecting RCD's rated tripping current may be, in a British workplace leaflet. They measure different things, from different sources, and this course read nothing that compares them. And notice HSE's "some, but not all": an RCD is a backstop. HSE's own list starts "an RCD is a valuable safety device, never bypass it".⁵

AFCIs: a third job, fire from arcing

CPSC describes a third device, the arc fault circuit interrupter (AFCI), and its leaflet on it is careful to say what it is for. "Typical household fuses and circuit breakers do not respond to early arcing and sparking conditions in home wiring." And: "By the time a fuse or circuit breaker opens a circuit to defuse these conditions, a fire may already have begun."⁶ CPSC describes the problem only as arcing and sparking in home wiring, and this course read nothing that goes further, so the point to take is CPSC's: an ordinary breaker does not catch it early.

CPSC keeps the two apart in one line: "AFCIs are intended to address fire hazards; GFCIs address shock hazards."⁶ It says older homes with ordinary breakers "especially may benefit" from AFCI protection, and says to have a qualified electrician install them, because the work is inside a panel. So an AFCI is something to ask an electrician about, not something you fit. This course read no UK source on arc fault devices, and says nothing about them for British homes.

What is in your box

In the UK

ESF: "Modern consumer units have a main switch and fuses and/or circuit breakers." To find out whether yours has an RCD, "look for the ‘Test’ or ‘T’ button."⁷ Pressing it, ESF says, "will switch off the power to the areas of the home it protects".⁷ Notice "the areas": an RCD may not cover the whole house, and your unit's labels or an electrician can tell you which parts it does.

If there is no test button, you're not alone and you're not necessarily in danger. ESF: "Older units may not have an RCD or circuit breakers, but this does not necessarily mean they are unsafe or require upgrading." It goes straight on: "An EICR will tell you if yours is still safe or not."⁷ An EICR, an Electrical Installation Condition Report, is an inspection a registered electrician carries out. ESF's FAQ adds that upgrading a fusebox without RCD protection "would be recommended", "but it is not urgent".¹³ ESF also gives a way to get the protection without touching the unit: "If you don’t have RCD protection, use an RCD plug on the socket where the product is plugged in."² HSE says the same for workplaces, that where an RCD can't be built into the board or the socket, "a plug incorporating an RCD or a plug-in RCD adaptor can also provide additional safety".⁵ A plug-in RCD is Yours: you buy it and plug it in, and nothing is opened.

In the US

The panel holds a main breaker and a row of branch breakers, and SCE's news site notes that "Some homes may have multiple electrical panels located outside or within the home."⁸ Worth knowing before the night you need one. A tripped breaker, SCE says, sits at "off" or in a middle position between on and off, and "Most tripped breakers show an orange flag when a breaker is in the tripped position."¹

GFCIs come in more than one form. CPSC describes GFCI circuit breakers, which sit in the panel; GFCI receptacles, which replace an ordinary outlet and have their own test and reset buttons; and portable GFCIs that plug in like any other device. A GFCI receptacle, CPSC says, protects whatever is plugged into it and other outlets further along the same circuit.⁴ One consequence is this course's reading of that sentence, not a line from the sheet: an ordinary-looking outlet that has gone dead may be downstream of a GFCI receptacle somewhere else, perhaps in another room, that has tripped. Check the GFCI receptacles before you decide a breaker is to blame.

This paragraph touches US law. This is general information, not legal advice. Where GFCIs are required is set by the model electrical code, and only where a state, county or city has adopted it. CPSC's sheet lists when that code started requiring them: outdoors from 1973, bathrooms from 1975, garages from 1978, kitchens from 1987, crawl spaces and unfinished basements from 1990, wet bar sinks from 1993, laundry and utility sinks from 2005. Read that list as history. It stops at 2005, and CPSC's own sheet adds, "The NEC typically only applies to new construction/major renovations."⁴ It does not tell you what is required in your house today; your local building department can.

The part you leave shut

Two facts from lesson 1 come back every time electricity does, and they apply to both boxes. CPSC says panel boxes "are usually electrically live, even with the main circuit breakers turned off".⁶ And HSE's guidance for people who work on electrical systems does not recommend "non-contact devices such as 'volt sticks'" for proving anything dead.⁹ So the front of the box is yours: the door in front of the switches if it has one, the main switch, each breaker's switch, the test buttons, the labels. Anything held on with screws, and everything behind it, is somebody else's. That is this course's line, and lesson 1's.

Testing the button

The test button is the check both countries' sources hand a householder for these devices.

In the UK, HSE's leaflet says an RCD "has a test button to check that its mechanism is free and functioning" and that "you should use this regularly".⁵ It does not say how often, and the leaflet is workplace guidance that describes itself as "not compulsory". You may have read that an RCD should be tested every three months. This course saw that figure only in a search summary and couldn't find it on a page it could read, so it does not give it. The instructions from the unit's maker say how often. Pressing the button should make the RCD trip, and ESF says that "will switch off the power to the areas of the home it protects".⁷ You then switch it back on. If it doesn't trip, ESF's FAQ says to "get a registered electrician to investigate".¹³

In the US, CPSC's sheet says to test every GFCI "At least once a month", "After a power failure", and according to the maker's instructions.⁴ The Electrical Safety Foundation International (ESFi), a US safety body, also says every month.¹⁰ CPSC gives a routine for when you don't have the instructions: plug a lamp into the outlet and switch it on, press the test button and watch the lamp go out, then press the reset button and watch it come back. If the lamp does not go out, CPSC says the GFCI "is not working or has not been correctly installed", and to contact a qualified electrician to correct the wiring or replace the GFCI. If it won't come back on, the sheet says to replace the GFCI.⁴

That last step needs a label. CPSC says breaker and receptacle GFCIs may be fitted by a qualified electrician, and receptacle GFCIs also by consumers "with adequate knowledge and skills", which the sheet ties to following proper wiring practice and the device's instructions.⁴ Replacing an outlet is wiring, and this course teaches no wiring, so for you, here, a GFCI that fails its test is Call someone. That is the course's scope decision, explained at the end of this lesson. It is not a claim that CPSC is wrong.

So pressing the test button and resetting it is Yours, in both countries. The one condition is practical: know what goes off. A test switches off everything on that device. That may be the freezer, the fridge, a computer mid-save, a clock or a router, or equipment someone depends on for their health. Check before you press, not after.

When something trips: the reset, in the sources' own order

First: is it you, or the network?

Before you touch your own box, the two UK network operators this course read say to find out whether the problem is yours at all. National Grid Electricity Distribution, one of Britain's electricity distribution networks, says: "First, check to see if it's a power cut or a problem with your fuses. Speak to your neighbours, or during the night, check the street lights."¹¹ SSEN, another network, adds a check of its own: see if any switches are off, and "check if your meter has a display, if it does, this means power is coming into your property."¹²

If the whole street is dark, the fault is likely to be the network's, and both networks give 105 as the number for a power cut.¹¹¹² If only your house is dark, start with your own box. SSEN's meter check tells you whether power is reaching the house at all, and both networks say to call them if a reset doesn't bring it back. This course read no US utility's page on telling the two apart.

Resetting: the UK network operators

National Grid gives the steps in one paragraph: "Find your fuse box and check that the trip switch is set to 'On' (It's the biggest switch and is usually red). If it's in the 'Off' position, turn off anything plugged into the sockets (or pull out the plugs) and turn the switch to 'On'. If the power doesn't come back on, you can call our Contact Centre".¹¹ Its description of the switch is one network's shorthand, not a standard: in your box the switch that has dropped may be an RCD, which you'd know by its test button, or a single breaker.

SSEN gives a fuller version: "Complete a full reset of your fuse box by turning OFF the main larger switches and then all your smaller switches. Repeat the process by turning ON the larger switches first, then turn the smaller switches on one by one. This reset can help identify if there is an internal issue."¹²

Resetting: a US utility

SCE numbers five steps. Here are the first four, in order; the fifth, for a breaker that trips again, is in the next section.¹

1. "Turn off light switches and unplug appliances in all rooms that have lost power."
2. Find the breaker box and "open the cover". SCE says no more. This course reads it as the door in front of the switches, which you open by hand, and never anything screwed on. The breakers inside "may be labeled" by room.
3. Find the tripped breaker, at "off" or in the middle position.
4. Push it all the way to "off", then back to "on". "This should clear any overload and return power to the room."

SCE adds two habits of its own: "When resetting a breaker, use only one hand. Stand to the side to avoid electrical arcing if the breaker should malfunction."¹ Neither UK page this course read says that, and neither says anything against it. The course has no source for why only SCE gives it, so it does not offer a reason.

What the two countries agree on

Read side by side, National Grid and SCE share a shape: take the load off first, by switching off or unplugging what is on the dead circuit, then put the switch back to on (SCE's step 4 says all the way off first). SSEN's full reset is a different route: every switch off, then the big ones on and the small ones one by one. None of the three says to keep trying.

The label for this is Yours: resetting a tripped device from the front of the box, with the load off. The sources that give it are UK network operators and a US utility, writing advice for their own customers. Nothing this course read makes it a legal duty, either way.

When it trips again

The two network pages say nothing about what to do if a switch trips again. Three of the sources this course read do speak to it, and they point the same way, towards the rule the box at the top of the lesson carries.

ESF's FAQ, about the British RCD: "If the RCD in your fusebox keeps tripping, there is likely to be a fault that needs investigating", "either with a particular appliance or the wiring itself", and "You should get a registered electrician to investigate".¹³ HSE, in its workplace leaflet: "if it trips, it is a sign there is a fault", and it adds that the system is checked "before using it again". Its next item: "if it trips frequently and no fault can be found in the system, consult the manufacturer of the RCD".⁵ SCE, about the US breaker: "If a breaker trips repeatedly, reset it only when you've corrected the problem. You can also call an electrician."¹ Its news site puts the next step plainly: "Hire a qualified, licensed electrical contractor to troubleshoot the issue and perform repairs."⁸

What does SCE think the problem might be? Its step 5 says a breaker that trips again "could be" tripping for any of several reasons, and the list is worth reading closely: "too many lamps and appliances plugged in; a damaged cord or plug; a short-circuit in a receptacle, switch, or fixture; or faulty wiring."¹ Then it says, "Be sure to identify and fix problems." Look at where that list splits. The first two causes are things you can see and take out of use without opening anything: plug less into the circuit, and stop using an appliance whose cord or plug is damaged. ESF's advice when a plug shows burn marks or feels hot is "Unplug and contact the retailer, manufacturer, or a qualified repair technician."² The last two causes are inside the walls and the fittings, and fixing those is wiring. So this course draws its line through the middle of SCE's list. The first two are Yours. The last two are Call someone, and so is any trip you can't pin on the first two. SCE's news site does not split the list at all: its version ends "faulty wiring or circuit breakers", so the breaker itself can be the cause, and it sends a breaker that trips again to "a qualified, licensed electrical contractor".⁸

Some things appear in no source's advice, in either country: holding a breaker or an RCD on, taping or wedging it, or resetting it over and over to see whether it sticks. HSE's list says of an RCD, "never bypass it", and ESF says a plug fuse is replaced "only with another of the same rating", never a bigger one.²⁵ The box at the top puts the rule in one line: leave it off and call an electrician.

You'll see a method on plenty of websites for finding the faulty appliance: plug things back one at a time until the trip comes back. This course didn't find it on any official or network operator's page it could read, so it does not give it as a step. What the sources give is enough: take the load off and reset. If it trips again with the load still off, SCE's plug-in causes are ruled out, and that is a fault for an electrician. If it goes on tripping, whatever is plugged in, ESF's "keeps tripping" applies. The one-reset line is this course's reading of those sources, not a sentence any of them contains.

A GFCI in a bathroom

The simple case first. In a 1980s split-level house in New Jersey, the GFCI receptacle by the bathroom basin trips every time the owner's daughter switches on her hair dryer. The lights in the bathroom are still on, and so is everything else in the house.

1. Which device? The GFCI receptacle, which is a shock device: on CPSC's account, it has seen current that didn't come back.
2. The load off. She unplugs the hair dryer, which is SCE's step 1 applied to one outlet.
3. Reset once. She presses the reset button, and the outlet comes back. She plugs in a phone charger, and it holds.
4. What that tells her. With the dryer out, the GFCI holds. On SCE's list, "a damaged cord or plug" is the cause a householder can see, and on CPSC's account a GFCI trips for current going where it shouldn't. So the dryer is the suspect. That is this course's reasoning from the two sources, not a verdict from either of them.
5. What she does. She does not plug the dryer back in to watch it trip again. She takes it out of use. SCE lists "a damaged cord or plug" among its causes and says "Be sure to identify and fix problems", and a dryer she can't inspect inside is fixed by not using it. That is this course's reading of SCE, not a line SCE applies to hair dryers.¹ If the GFCI had tripped again with nothing plugged into it, the job would have become Call someone: SCE's news site says to "Hire a qualified, licensed electrical contractor to troubleshoot the issue and perform repairs."⁸

A kitchen RCD at three in the morning

Now the wrinkle. In a 2000s semi in Herefordshire, the RCD covering the kitchen and the ground floor sockets tripped in the night, around 3 a.m. The household found the fridge-freezer silent and the microwave clock blinking in the morning. Nobody is using anything at that hour. The dishwasher is not on a timer, and nothing is on in the garage.

1. Which device? The switch that dropped has a "T" button, so it is an RCD, the device ESF says protects you from shocks if a product is faulty. A single night trip is a reason to look. ESF's "fault that needs investigating" is for an RCD that keeps tripping.
2. Is it the network? No. The rest of the house has power, and so do the neighbours. National Grid's first check rules the network out.
3. The first reset. They switch off at the wall or unplug what is on those circuits, as National Grid says, and put the RCD back on. It holds, and they plug things back in for the day.

4. Where the sources stop. Could the freezer be the fault? Nobody here can tell. A fault that comes and goes at night is exactly the kind a page can't diagnose, and the sources this course read don't try. ESF sends it to a registered electrician, and so does this course.

Notice that most of what the household did was deciding: which device, whose fault, and when to stop. None of it needed the cover off.

What the law and this course leave shut

This section states law. This is general information, not legal advice.

Everything so far happens at the front of the box. Behind it, the law depends on where you live, and this course draws its own line in any case.

In England, the law lets a householder do some electrical work. Some of it needs building control told before it starts, and the rest needs no notice but still has to meet the regulations.¹⁴ Wales, Scotland, Northern Ireland and each US state and city have rules of their own. Lesson 22, "Who may do what: reserved work, and the argument about licensing", sets the rules out place by place.

This course teaches the procedure for none of it: no socket, switch, light fitting, consumer unit or proving-dead method. That is a scope decision about what a page can teach and check, and it is this course's, not a claim that the work is unlawful where the law allows it. ESF, a charity that campaigns on electrical safety, advises that "Any electrical work should be left to competent professionals."¹⁵ For anything behind the cover, the label is Call someone. That is ESF's advice, and the course's decision rests on its own reason: proving a circuit dead needs a proper tester and the training to use it, as HSE's guidance for electrical workers describes, and a page can't watch you do it.⁹

Why it is worth the trouble

The shock figures this course found are American. CPSC's report of November 2023 gives "an estimated average of 100 electrocution fatalities associated with consumer products per year over the 3-year period from 2018 through 2020", with the caveat that the incidents "were not necessarily caused by the product."¹⁶ An earlier CPSC memo counted an average of 196 a year in homes from 1995 to 1999, put about 47% of them in circumstances a GFCI could address, and reported an Underwriters Laboratories study finding GFCIs 81% to 95% effective at preventing electrocution deaths.¹⁷ ESFi credits GFCIs with a large share of the long fall in US electrocutions.¹⁰ The fall is established; the share owed to GFCIs is an estimate, and the memo presents its figures as estimates.

What people get wrong

"The breaker protects you from a shock." Its job is mainly the wiring: CPSC says breakers and fuses "function primarily to prevent the home wiring system from causing a fire". Shock is the RCD's or GFCI's job.³⁴

"An RCD that trips is being oversensitive." Don't assume it. ESF: if it keeps tripping, there is likely a fault in an appliance or the wiring, for a registered electrician. HSE's workplace leaflet treats a trip as a sign of a fault, and only where frequent trips turn up no fault does it send you to the RCD's maker.⁵¹³

"A GFCI and an AFCI are the same thing." CPSC: AFCIs address fire, GFCIs shock.⁶

"If it won't stay on, hold it on for a moment." Holding, taping or wedging a device on defeats the thing it is there to do. Reset with the load off. If it trips again with nothing plugged in, or keeps tripping, leave it off and call an electrician.¹¹³

"My consumer unit has no RCD, so it has to be replaced." ESF: "not necessarily"; an inspection (an EICR) tells you, and ESF recommends an upgrade without calling it urgent. A plug-in RCD adds protection at the socket meanwhile.²⁷¹³

"Main breaker off, panel dead; volt stick silent, wire dead." Lesson 1 took both apart: CPSC says panels are usually live with the main breakers off, and HSE does not recommend volt sticks for proving dead.⁶⁹

"Test the RCD every three months: it's the law." No law this course read sets a household interval. HSE's workplace leaflet says "regularly"; the maker's instructions give the number.⁵

Practice

For your plan

This lesson adds three things to your home plan. To the calendar: the RCD or GFCI test button, at the interval the maker gives (UK) or monthly (CPSC, US), labelled Yours, and the University of Georgia checklist's line, to "test ground fault interrupters to ensure proper protection".¹⁸ To your map: the drawing of the box, with the RCDs, GFCIs and what each covers. To the stop list: a device that trips again with the load off, or keeps tripping; a device that fails its test; any sign of heat or scorching at the box; and anything behind the cover. Each carries ESF's, CPSC's or SCE's advice as the rule behind it.

Connections

First Aid and CPR lesson 2 taught you to make sure the power is off before touching someone in contact with a supply, and lesson 10 taught that the NHS sends every electrical burn to 999 or A&E (the emergency department). This lesson does not reteach either; it is about the devices that try to stop both being needed. Lesson 1, "How a house works, and where it switches off", found the box and set the rule that its front is yours and its inside is not. Lesson 3, "Taps and toilets", taught isolating the water before opening a tap, and the reset here has the same shape: take the load off first.

Lesson 6, "Plugs, leads and electrical fires", takes the same devices down to the plug in the wall: which fuse goes in a plug, what an extension lead will carry, the warning signs of a circuit in trouble, and what the fire figures do and don't say. Lesson 14, "Before you drill: cables, pipes and what's in the wall", comes back to cables in walls, and lesson 22 sets out who may do which electrical work, place by place.

Go deeper

• CPSC, GFCIs Fact Sheet. Two pages, free, read here in full. What a GFCI does, the test routine and CPSC's dated list of where the code has required them.
• CPSC, Preventing Home Fires: Arc Fault Circuit Interrupters. One page, read here in full. On the difference between fire and shock devices, and why the installation is an electrician's.
• Southern California Edison, "How do I reset my circuit breakers?". Read here in full. The US reset steps and warnings, from a utility, for its own customers.
• National Grid Electricity Distribution, "What to do during a power cut". Read here in full. Short, and it starts where you should: is it you, or the network?

Sources

1. Southern California Edison, "How do I reset my circuit breakers?", Help Center. Read: full text, 25 September 2026. No date shown. A California utility, writing for its customers.
2. Electrical Safety First, "Plugs and fuses usage and safety". Read: full text, re-read 25 September 2026. A UK electrical safety charity.
3. US Consumer Product Safety Commission, news release 89-031, "Easily Installed Device Protects Family Against Electrocution", 28 May 1989, Internet Archive capture 20260311171701 of cpsc.gov. Read: full text.
4. US Consumer Product Safety Commission, GFCIs Fact Sheet, Document 099. Read: full text, re-read 25 September 2026. The sheet carries the code 092010 in its footer. Its list of code requirements stops at 2005.
5. Health and Safety Executive, Electrical safety and you: A brief guide, INDG231(rev1), first published April 2012, reprinted August 2013. Read: full text, 25 September 2026. Written for workplaces; the leaflet says following it is not compulsory.
6. US Consumer Product Safety Commission, Publication 5133, "Preventing Home Fires: Arc Fault Circuit Interrupters (AFCIs)", dated R042012. Read: full text, re-read 25 September 2026.
7. Electrical Safety First, "RCDs Explained" (the checklist and FAQ that extracted; the page's explanatory body loaded by script and did not come through, and the address now redirects to ESF's page for home buyers). Read: full extracted text.
8. Shulie Tornel, "A Step-by-Step Guide to Safely Resetting Your Breakers", Energized by Edison (Southern California Edison), 8 June 2022. Read: full text, 25 September 2026.
9. Health and Safety Executive, Electricity at work: Safe working practices, HSG85, third edition, 2013. Read: the whole PDF extracted; "Proving dead" paragraphs 53 to 55 read. Workplace guidance, used here only for what it says about non-contact testers.
10. Electrical Safety Foundation International (ESFi), "Ground Fault Circuit Interrupters" and "Ground Fault Circuit Interrupters: Preventing Electrocution Since 1971/1973", read from Internet Archive captures 20250524154705 and 20251123184045 (the live site blocks automated readers). Read: full page text of each capture; the second is an infographic's text.
11. National Grid Electricity Distribution, "What to do during a power cut". Read: full text, 25 September 2026. No date shown. For its own network areas.
12. SSEN, "What to do during a power cut". Read: full text, 25 September 2026. For its own network areas.
13. Electrical Safety First, "FAQ for Electrical Safety", the answers to "If my RCD keeps 'tripping', what action is required?" and "Can an RCD fail?", and the answer on fuseboxes without RCD protection. Read: full text, re-read 25 September 2026.
14. HM Government, Approved Document P, Electrical safety: dwellings, 2013 edition, for use in England. Read: full text. Paragraphs 2.7, 3.8 and 3.13 for the sentence on England.
15. Electrical Safety First, "Advice for DIY-ers". Read: full text. No page date shown.
16. US Consumer Product Safety Commission, Electrocutions Associated With Consumer Products: 2011-2020 (Hanway, Massie and Seebruck, November 2023). Read: the executive summary and Table 5.
17. US Consumer Product Safety Commission, memorandum "Economic Considerations: GFCIs" (Karels, 10 March 2003). Read: full text. The UL study is known only through this memo.
18. P. R. Turner and L. Bailey, Home Maintenance Checklist, Circular 1082, University of Georgia Cooperative Extension, reviewed June 2021. Read: full text.