120V more house fires
240V more electrocutions
120V more house fires
240V more electrocutions
Pretty much yeah.
240V shocks aren't super lethal, you'll find lots of people on here who have been shocked with 240V 5-10 times in their life and are still alive.
So there's not really much point worrying about the lethality of 240V over 110V.
we’ve had 240v in residential use since the being of electrification of the US? Or, perhaps I’m having trouble with comprehension these days, more and more content is starting to feel like it is AI generated,Sorry but I am not an AI, in the North American codes like the NEC for example has a section:
210.6 (A) Occupancy Limitation.
In dwelling units and guest rooms or guest suites of hotels, motels, and similar occupancies, the
voltage shall not exceed 120 volts, nominal, between conductors
that supply the terminals of the following:
(1) Luminaires
(2) Cord-and-plug-connected loads 1440 volt-amperes, nominal, or less or less than 1⁄4 hp
210.6 (A) Occupancy Limitation.
In dwelling units and guest rooms or guest suites of hotels, motels, and similar occupancies, the
voltage shall not exceed120 volts, nominal, between conductors150 volts to ground that
supply the terminals of the following:
(1) Luminaires
(2) Cord- and plug-connected loads 1440 volt-amperes, nominal, or less or less than 1⁄4 hp
120V more house fires
240V more electrocutions
Pretty much yeah.
240V shocks aren't super lethal, you'll find lots of people on here who have been shocked with 240V 5-10 times in their life and are still alive.
So there's not really much point worrying about the lethality of 240V over 110V.
yeh, here a population of 6mill there is occasionally one death in a year from electrocution, and it is pretty much always an electrician or similar
I don’t have the NEC handy, but 240 V outlets (120-0-120) have been common for my long lifetime in the US for stoves and window-mount air conditioners in single-family houses.You can view the NEC for free various places online, since its a model code not a US federal law states adopt it at the state level, so there are different variations by state, but if you look at any of them under section 210.6(A) it restricts 240v receptacles to loads over 1440W in residences, so they are allowed for large appliances that dont move easily, they are not allowed for say your kitchen tea kettle or lights;
it restricts 240v receptacles to loads over 1440W in residences, so they are allowed for large appliances that dont move easily, they are not allowed for say your kitchen tea kettle or lights
Lifetime odds of death for selected causes, United States, 2024
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120V requires more current, which is why it presents a higher fire risk than 240V.
Typical service fuse in UK or AU is 100A or 63A, vs US 200A. Yes, the US might typically have many smaller breakers for end loads but the panel entry and higher currents are present.120V requires more current, which is why it presents a higher fire risk than 240V.Although, the maximum appliance current in the UK is 13 A, while in the USA it is 12 A. All that happens is that appliances in the USA have a lower maximum power.
A 15 A circuit in the USA has a maximum permitted load of 12 A (e.g. a 120 V/1500 W kettle or toaster oven). There are 20 A circuits with a special 20 A plug (max load 16 A), but very few such appliances exist. They can't easily sell appliances with 20 A plugs on them because the average consumer would be confused why it won' t plug into a normal outlet.
240 causes more electrocutions? Must be electricians as most people never come into contact with240V AC is substantially more dangerous than 110/120V AC:
240(no pun intended). Most people are fearful of 240, for no real reason.
240V shocks aren't super lethal, you'll find lots of people on here who have been shocked with 240V 5-10 times in their life and are still alive.
You can view the NEC for free various places online, since its a model code not a US federal law states adopt it at the state level, so there are different variations by state, but if you look at any of them under section 210.6(A) it restricts 240v receptacles to loads over 1440W in residences, so they are allowed for large appliances that dont move easily, they are not allowed for say your kitchen tea kettle or lights;How is it considered when dealing with high efficiency appliances that are drop in replacements for old 240V ones? For example, a heat pump water heater or heat pump clothes dryer. While those can often be sufficiently low enough power to run from 120V, there are 240V versions in order to not require rewiring to install where only a 240V outlet is available.
It's atrocious the amount of electricians that die. Usually doing a domestic. Whether it's not wanting to disrupt the household by isolating, or just not paying attention. That's before we get into untrained insulation installers stapling conductive insulation into live wires.
120V more house fires
240V more electrocutions
Pretty much yeah.
240V shocks aren't super lethal, you'll find lots of people on here who have been shocked with 240V 5-10 times in their life and are still alive.
So there's not really much point worrying about the lethality of 240V over 110V.
The data is out there that house fires caused by electricity are more prevalent in the US
Just the voltage? Difference in regulations? Over to you.
Exactly, thats one of the reasons the proponents have for lifting the ban.You can view the NEC for free various places online, since its a model code not a US federal law states adopt it at the state level, so there are different variations by state, but if you look at any of them under section 210.6(A) it restricts 240v receptacles to loads over 1440W in residences, so they are allowed for large appliances that dont move easily, they are not allowed for say your kitchen tea kettle or lights;How is it considered when dealing with high efficiency appliances that are drop in replacements for old 240V ones? For example, a heat pump water heater or heat pump clothes dryer. While those can often be sufficiently low enough power to run from 120V, there are 240V versions in order to not require rewiring to install where only a 240V outlet is available.
Any data on EV automotive technicians? 400 and 800 VDC is really lethally dangerous!It's atrocious the amount of electricians that die. Usually doing a domestic. Whether it's not wanting to disrupt the household by isolating, or just not paying attention. That's before we get into untrained insulation installers stapling conductive insulation into live wires.
A lot of the deaths are from becoming complacent or operating on automatic, which is pretty common when its a job you do every day.
When doing something new you are usually paying a lot more attention.
Now that we all understand both 120V and 240V receptacles are both allowed in the US for decades by code, maybe the better question would be "what load less than 1440VA is better served by 240V?"
120V has performed just fine. 240V can also perform just fine. Why the critical need for a change when the current state is working well? Standards are there for a reason, and we have a standard in place.
90.1 Purpose.
(A) Practical Safeguarding. The purpose of this Code is the
practical safeguarding of persons and property from hazards arising
from the use of electricity. This Code is not intended as a design
specification or an instruction manual for untrained persons.
(B) Adequacy. This Code contains provisions that are con-
sidered necessary for safety. Compliance therewith and proper
maintenance result in an installation that is essentially free from
hazard but not necessarily efficient, convenient, or adequate for
good service or future expansion of electrical use.
(C) Relation to Other International Standards. The require-
ments in this Code address the fundamental principles of pro-
tection for safety contained in Section 131 of International
Electrotechnical Commission Standard 60364-1, Electrical
Installations of Buildings.
It's not about "dangerous", because it manifestly isn't more dangerous.The reasoning behind the NEC opposition to changing section in question is indeed about "dangerous" again the US code is a minimum safety standard not a design manual, and that minimum standard currently prohibits the use of 240V receptacles and lighting for general purpose use in a residence, like appliances less than 1440VA and any lighting in a residence.
../..
It's more about convention and convenience. ../..
So this whole situation is a non-argument.
The question they are debating now is should they continue to prohibit it for safety reasons?
Based on available statistics, the odds of dying from electrocution are so far down the list compared to other dangers it is not really something worth worrying about.Those statistics don't take age into account.
https://injuryfacts.nsc.org/all-injuries/preventable-death-overview/odds-of-dying/
Lifetime odds of death for selected causes, United States, 2024
Cause of Death Odds of Dying Heart disease 1 in 6 Cancer 1 in 7 All preventable causes of death 1 in 22 Stroke 1 in 26 Opioid overdose (accidental) 1 in 84 Suicide 1 in 88 Fall 1 in 89 Guns (all intents) 1 in 97 Suicide with gun 1 in 156 Gun assault 1 in 280 Accidental gun discharge 1 in 9,567 Motor-vehicle crash 1 in 101 Pedestrian incident 1 in 492 Motorcyclist 1 in 726 Drowning 1 in 1,025 Fire or smoke 1 in 1,365 Choking on food 1 in 2,367 Bicyclist 1 in 3,093 Sunstroke 1 in 3,740 Cataclysmic storm 1 in 14,115 Electrocution, radiation, extreme temperatures, and pressure 1 in 15,431 Sharp objects 1 in 20,599 Dog attack 1 in 33,899 Hornet, wasp, and bee stings 1 in 42,626 Hot surfaces and substances 1 in 45,318 Lightning Too few deaths in 2024 to calculate odds Railway passenger Too few deaths in 2024 to calculate odds Passenger on an airplane Too few deaths in 2024 to calculate odds
I don't think that I've ever heard of an trained or qualified electrician being electrocuted in the US, usually the people that I hear about being electrocuted are civies working outside that hit the incoming power line with an aluminium ladder or a long handled tree saw or someone putting up an outside antenna and somehow touching the incoming power line.
The primary reason for the restriction dates back to when they added the requirement in the late 1930's almost 100 years ago.
In a dwelling, the NEC assumes a homeowner will be the one changing bulbs; since the old Edison screw-base makes it easy to accidentally contact the shell, keeping that voltage low is critical.
The reasoning behind the NEC opposition to changing section in question is indeed about "dangerous" again the US code is a minimum safety standard not a design manual, and that minimum standard currently prohibits the use of 240V receptacles and lighting for general purpose use in a residence
The primary reason for the restriction dates back to when they added the requirement in the late 1930's almost 100 years ago.
In a dwelling, the NEC assumes a homeowner will be the one changing bulbs; since the old Edison screw-base makes it easy to accidentally contact the shell, keeping that voltage low is critical.
Once again, when touching a live conductor, the electrocution risk is current flowing to ground through the person in contact. And regardless of whether it is a 240 V receptacle or a 120 V receptacle, the voltage is always 120 V.
Once again, when touching a live conductor, the electrocution risk is current flowing to ground through the person in contact. And regardless of whether it is a 240 V receptacle or a 120 V receptacle, the voltage is always 120 V.
Code is 20% personal safety, and 80% fire prevention.
Those statistics don't take age into account.There's another way they're skewed: what do the odds of being struck by a lightning become if you take a parasol and go out for a walk in a field during a thunderstorm?
Does the NEC actually prohibit the use of 240volt outlets in homes in the US? If so what section and what version of the NEC? (I really don't know if it does)
NEC 210.6 (A) Occupancy Limitation.
In dwelling units and guest rooms or guest suites of hotels, motels, and similar occupancies, the
voltage shall not exceed 120 volts, nominal, between conductors
that supply the terminals of the following:
(1) Luminaires
(2) Cord-and-plug-connected loads 1440 volt-amperes, nominal, or less or less than 1⁄4 hp
Does the NEC actually prohibit the use of 240volt outlets in homes in the US? If so what section and what version of the NEC? (I really don't know if it does)
I posted it earlier but here is the exact section as it appears in the 2017 PDF version I have, its unchanged in the current 2026 version:QuoteNEC 210.6 (A) Occupancy Limitation.
In dwelling units and guest rooms or guest suites of hotels, motels, and similar occupancies, the
voltage shall not exceed 120 volts, nominal, between conductors
that supply the terminals of the following:
(1) Luminaires
(2) Cord-and-plug-connected loads 1440 volt-amperes, nominal, or less or less than 1⁄4 hp
Does the NEC actually prohibit the use of 240volt outlets in homes in the US? If so what section and what version of the NEC? (I really don't know if it does)
I posted it earlier but here is the exact section as it appears in the 2017 PDF version I have, its unchanged in the current 2026 version:QuoteNEC 210.6 (A) Occupancy Limitation.
In dwelling units and guest rooms or guest suites of hotels, motels, and similar occupancies, the
voltage shall not exceed 120 volts, nominal, between conductors
that supply the terminals of the following:
(1) Luminaires
(2) Cord-and-plug-connected loads 1440 volt-amperes, nominal, or less or less than 1⁄4 hp
You do realize that this paragraph limits only plugging low power devices into a 220 outlet. This exclusion is ready handled by use of appropriate outlets. In my dwelling unit the garage has a large number of 220 V twist lock outlets.
Does the NEC actually prohibit the use of 240volt outlets in homes in the US? If so what section and what version of the NEC? (I really don't know if it does)
I posted it earlier but here is the exact section as it appears in the 2017 PDF version I have, its unchanged in the current 2026 version:QuoteNEC 210.6 (A) Occupancy Limitation.
In dwelling units and guest rooms or guest suites of hotels, motels, and similar occupancies, the
voltage shall not exceed 120 volts, nominal, between conductors
that supply the terminals of the following:
(1) Luminaires
(2) Cord-and-plug-connected loads 1440 volt-amperes, nominal, or less or less than 1⁄4 hp
You do realize that this paragraph limits only plugging low power devices into a 220 outlet. This exclusion is ready handled by use of appropriate outlets. In my dwelling unit the garage has a large number of 220 V twist lock outlets.
But it effectively prohibits connecting universal input loads to a 240V circuit, where they're typically markedly more efficient.
But if you have a device that can benefit from such a connection it is relatively easy and legal to connect it.
I looked into the statistics of electrocution many years ago. In spite of its ubiquitous presence in our life, it is quite hard to do. (More than 90% of those electrocuted are professionals.
Regulation is indeed a good thing, but it's highly likely we're well past the point of deminishing returns. Perhaps they should not introduce any new regulations, since they're arguably unnecessary.I looked into the statistics of electrocution many years ago. In spite of its ubiquitous presence in our life, it is quite hard to do. (More than 90% of those electrocuted are professionals.
The whole concept of dying from electrocution basically disappeared during 1990's or so, with two simultaneous effects:
* Stricter safety regulations
* The DIY culture of "every Real Man^tm must build his own extension cords and repair and modify everything imaginable" disappeared - I don't mean hobbyists, they were always more careful, just Normal People
Dying from electrocution wasn't among the most relevant ways to die even in Good Old Days, but it was a thing - before it went down by maybe 10-100x so basically totally disappeared from meaningfulness.
People who suggest that regulations are unnecessary because no one dies forget to look at the older statistics, when regulations were not as tight. Quite the oppositely, current level of safety is an excellent proof that regulations worked. It's a nice thing that you don't have to die.
Regulation is indeed a good thing, but it's highly likely we're well past the point of deminishing returns. Perhaps they should not introduce any new regulations, since they're arguably unnecessary.When it comes to human life, there is an argument to be made that all effort is justified, up to the point where further efforts actually make safety worse. (Example of the latter: stronger safety equipment in American football, which has paradoxically led to worse outcomes.)
Regulation is indeed a good thing, but it's highly likely we're well past the point of deminishing returns. Perhaps they should not introduce any new regulations, since they're arguably unnecessary.I looked into the statistics of electrocution many years ago. In spite of its ubiquitous presence in our life, it is quite hard to do. (More than 90% of those electrocuted are professionals.
The whole concept of dying from electrocution basically disappeared during 1990's or so, with two simultaneous effects:
* Stricter safety regulations
* The DIY culture of "every Real Man^tm must build his own extension cords and repair and modify everything imaginable" disappeared - I don't mean hobbyists, they were always more careful, just Normal People
Dying from electrocution wasn't among the most relevant ways to die even in Good Old Days, but it was a thing - before it went down by maybe 10-100x so basically totally disappeared from meaningfulness.
People who suggest that regulations are unnecessary because no one dies forget to look at the older statistics, when regulations were not as tight. Quite the oppositely, current level of safety is an excellent proof that regulations worked. It's a nice thing that you don't have to die.
In a few of the preceding posts it has been asserted that low power loads are more efficient when powered by 240 volts, and specifically mentions PCs and monitors. I am curious and don't understand the physics which would support this.
Is it really that regulations in 240 volt markets demand higher efficiency, thus forcing the design and materials to achieve it?
Given the standards aren't free. I see it as more of a money making effort, than anything to do with safety.Regulation is indeed a good thing, but it's highly likely we're well past the point of deminishing returns. Perhaps they should not introduce any new regulations, since they're arguably unnecessary.When it comes to human life, there is an argument to be made that all effort is justified, up to the point where further efforts actually make safety worse. (Example of the latter: stronger safety equipment in American football, which has paradoxically led to worse outcomes.)
Insurance actuaries may disagree, but loved ones of the deceased probably think you can’t put a price on a life.
When it comes to human life, there is an argument to be made that all effort is justified, up to the point where further efforts actually make safety worse.
When it comes to human life, there is an argument to be made that all effort is justified, up to the point where further efforts actually make safety worse.
No. Unfortunately it does not work that way. Each lobby group has their own eye blinders on. For example, the people who are lobbying for more traffic safety, are vehemently striving for 0 traffic deaths, even if that means nailing all front doors of houses shut. If people then start dying of fat couch potato disease, it's not their problem. They have reached their goal of zero traffic accidents.
That is a bit of an exaggerated example, but the problem is very real. Lots of lobby groups are lobbying for their own thing and laws and rules are getting more complicated because of that. One of the outcomes is the gradual disappearance of small companies. They simply can not afford it to keep up with all the (sometimes contradictory) rules. It is a disproportionate workload for them.
Concerning unification? usa is probably the last country to switch. The're taking their sweet time with fully implementing metrication.
It's one of the (extremely stupid) things that has been used by the "govenment" to divide and conquer their own population.
I should have written “…until further efforts actually cost more lives.” But what I mean is “add safety until doing so makes outcomes worse”, which your example would be an example of. You’re certainly right that people tend to look only at the small picture.When it comes to human life, there is an argument to be made that all effort is justified, up to the point where further efforts actually make safety worse.
No. Unfortunately it does not work that way. Each lobby group has their own eye blinders on. For example, the people who are lobbying for more traffic safety, are vehemently striving for 0 traffic deaths, even if that means nailing all front doors of houses shut. If people then start dying of fat couch potato disease, it's not their problem. They have reached their goal of zero traffic accidents.
I should have written “…until further efforts actually cost more lives.” But what I mean is “add safety until doing so makes outcomes worse”, which your example would be an example of. You’re certainly right that people tend to look only at the small picture.When it comes to human life, there is an argument to be made that all effort is justified, up to the point where further efforts actually make safety worse.
No. Unfortunately it does not work that way. Each lobby group has their own eye blinders on. For example, the people who are lobbying for more traffic safety, are vehemently striving for 0 traffic deaths, even if that means nailing all front doors of houses shut. If people then start dying of fat couch potato disease, it's not their problem. They have reached their goal of zero traffic accidents.
However, in terms of safety from preventable hazards like electric shock… I think the thresholds are somewhat different. Nobody is calling for banning electricity. But safety standards on it absolutely make sense, and I don’t see anything in this domain right now that goes so far as to be counterproductive. On the contrary, a lot of shit is still allowed that shouldn’t be, in particular with regards to old installations, where all sorts of shady stuff is tolerated by being grandfathered in. (For example, in USA old installations without grounds are allowed, and you can still buy ungrounded outlets to repair them with. IMHO, it’s long overdue to say “nope, only grounded installations allowed now” (and requiring inspection to ensure it has been done properly, no fake grounds like people like to do).
why is people so hyped up on earth? here earth in sockets didn't become mandatory until 1994 and only in new installations, so most sockets do not have earth and the number of electrocution is still ~0 a year and when it happens pretty much always an electricianGood question. Is actual earthing actually needed for anything practical? It's still done at the building level in either case (in any relatively modern ones at least), so the point is mostly moot, but let's think of it anyway.
why is people so hyped up on earth? here earth in sockets didn't become mandatory until 1994 and only in new installations, so most sockets do not have earth and the number of electrocution is still ~0 a year and when it happens pretty much always an electricianGood question. Is actual earthing actually needed for anything practical? It's still done at the building level in either case (in any relatively modern ones at least), so the point is mostly moot, but let's think of it anyway.
My understanding is that we, as end consumers, do not care if any cable is actually buried in the ground anywhere, but what we do need is to have a so-called protective earth conductor, that is, a separate cable which is connected with the neutral at some place before the GFCI unit(s) in the breaker box. This provides all we really care about: a) fire hazard protection; b) electrocution protection. Both being the results of current leaking from live to anything but the neutral.
p.s. yes I've had a nasty personal experience of a fire nearly getting started because of a leakage current from live to earth, the latter by means of a gas pipe. No thanks, no more residential wiring without GFCI for me, period.
GFCI have been mandatory here in all, even old, installations since 2008. I think it is an EU thingYes but that's not what I wrote about. I was talking about the difference in having an actual physically earthed (buried) conductor vs having just a "virtual" PE, which is connected to neutral before the breaker box.
Actually, in the case of metric, it's the population that conquered the government :)
GFCI have been mandatory here in all, even old, installations since 2008. I think it is an EU thingYes but that's not what I wrote about. I was talking about the difference in having an actual physically earthed (buried) conductor vs having just a "virtual" PE, which is connected to neutral before the breaker box.
Does the end consumer care whether there is real earthing or not, and why?
Somehow i have the idea that the copper rod driven into ground near the main installation wallbox helps with safety in case something goes wrong with the mains network outside of the house.
For example if the null conductor gets interrupted during a storm.
I remember measuring the resistance between two copper grounding rods that are about 5 years old and about 3 m apart, getting about 80 to 100 Ohm. So one may assume each of them has a resistance of about 50 Ohm to ground.
Note : this is NOT a ground fault detector ! It is a differential detector as used in europe.
Try pulling 20.1 amp on a 20 amp circuit and it will trip after a few tens of seconds.
The magnetic portion reacts instantaneously on large overloads . Try pulling 30 amps on a 20 amp circuit and the magnetic detector will kick in near instantaneously.
no it's not. Most ground fault interrupters work by sending a signal on the wires. They can detect a short between the neutral and the ground wire. The US system has the neutral and the ground bonded in the breaker box. If a loop is formed (meaning there is a short between neutral and ground ) the GFCI will trip. In europe the neutral is not bonded to the ground. The Us version needs an active circuit (read the LM1851 datasheet, it explains the workings in detail) . The european version is a simple common-mode current transformer. If both currents are equal they cancel each other and no output voltage is produced. if a leakage exists from one of the terminals to ground there will be a current difference. that produces a voltage large enough to activate the retainer winding. A pin retracts and a spring opens a circuit. There is no active electronics involved. It's a simple core with 3 windings. I remember the class-trip to the Legrand Factory in Ghent. They showed us an opened one and explained how it worked. It's extremely simple and nearly fool-proofNote : this is NOT a ground fault detector ! It is a differential detector as used in europe.A 'ground fault circuit interrupter' (GFCI) as used in the US is a differential device just like in Europe.
No, 1.5In is entirely in the thermal operation range, not magnetic. For an EN 60898-1 B curve, 1.5In trip time is measured in minutes, potentially tens of, with ambient temperature having a significant impact. <5s operation for a 20A device is >60A. Most places seem to use C curve, which is 5In for magnetic operation.
In europe the neutral is not bonded to the ground.
The european version is a simple common-mode current transformer. If both currents are equal they cancel each other and no output voltage is produced. if a leakage exists from one of the terminals to ground there will be a current difference. that produces a voltage large enough to activate the retainer winding. A pin retracts and a spring opens a circuit. There is no active electronics involved.
A couple of years ago the transformer at the road got a bad connection of the fuse on the neutral line, and it somehow ended up at 100V WrT ground. I had 140V on half of my power points and 340V on the other half. Nothing tripped.We widely use things like these here. Called a "Voltage relay". Super widespread and reliable. Input voltage goes ouside either boundary (configurable), the device breaks the circuit. Configurable delay on turn-on, $30, issue solved.
I's kinda weird for me to be hearing all that fuss about input overvoltage problems when cheap and reliable devices like these exist. Is there anything special on certain markets about them that makes them unavailable / not possible to use?The reason is that in countries with well-developed, reliable electrical grids, overvoltage is so rare that it isn’t something that anyone worries about. You only see voltage relays widely used in places with unreliable power.
The reason is that in countries with well-developed, reliable electrical grids, overvoltage is so rare that it isn’t something that anyone worries about. You only see voltage relays widely used in places with unreliable power.
What an ignorant thing to say. The fact that it took you until 1994 to be smart about it isn’t something to be proud of.I should have written “…until further efforts actually cost more lives.” But what I mean is “add safety until doing so makes outcomes worse”, which your example would be an example of. You’re certainly right that people tend to look only at the small picture.When it comes to human life, there is an argument to be made that all effort is justified, up to the point where further efforts actually make safety worse.
No. Unfortunately it does not work that way. Each lobby group has their own eye blinders on. For example, the people who are lobbying for more traffic safety, are vehemently striving for 0 traffic deaths, even if that means nailing all front doors of houses shut. If people then start dying of fat couch potato disease, it's not their problem. They have reached their goal of zero traffic accidents.
However, in terms of safety from preventable hazards like electric shock… I think the thresholds are somewhat different. Nobody is calling for banning electricity. But safety standards on it absolutely make sense, and I don’t see anything in this domain right now that goes so far as to be counterproductive. On the contrary, a lot of shit is still allowed that shouldn’t be, in particular with regards to old installations, where all sorts of shady stuff is tolerated by being grandfathered in. (For example, in USA old installations without grounds are allowed, and you can still buy ungrounded outlets to repair them with. IMHO, it’s long overdue to say “nope, only grounded installations allowed now” (and requiring inspection to ensure it has been done properly, no fake grounds like people like to do).
why is people so hyped up on earth? here earth in sockets didn't become mandatory until 1994 and only in new installations, so most sockets do not have earth and the number of electrocution is still ~0 a year and when it happens pretty much always an electrician
What an ignorant thing to say. The fact that it took you until 1994 to be smart about it isn’t something to be proud of.I should have written “…until further efforts actually cost more lives.” But what I mean is “add safety until doing so makes outcomes worse”, which your example would be an example of. You’re certainly right that people tend to look only at the small picture.When it comes to human life, there is an argument to be made that all effort is justified, up to the point where further efforts actually make safety worse.
No. Unfortunately it does not work that way. Each lobby group has their own eye blinders on. For example, the people who are lobbying for more traffic safety, are vehemently striving for 0 traffic deaths, even if that means nailing all front doors of houses shut. If people then start dying of fat couch potato disease, it's not their problem. They have reached their goal of zero traffic accidents.
However, in terms of safety from preventable hazards like electric shock… I think the thresholds are somewhat different. Nobody is calling for banning electricity. But safety standards on it absolutely make sense, and I don’t see anything in this domain right now that goes so far as to be counterproductive. On the contrary, a lot of shit is still allowed that shouldn’t be, in particular with regards to old installations, where all sorts of shady stuff is tolerated by being grandfathered in. (For example, in USA old installations without grounds are allowed, and you can still buy ungrounded outlets to repair them with. IMHO, it’s long overdue to say “nope, only grounded installations allowed now” (and requiring inspection to ensure it has been done properly, no fake grounds like people like to do).
why is people so hyped up on earth? here earth in sockets didn't become mandatory until 1994 and only in new installations, so most sockets do not have earth and the number of electrocution is still ~0 a year and when it happens pretty much always an electrician
The CDC in USA says that 60% of electrocution deaths involve household appliances. That suggests the majority aren’t electricians. Not all of those will be due to equipment failures, of course. But there’s little doubt that grounding improves the safety situation, including in cases where the user is at fault.
Source: https://worldmetrics.org/electrocution-statistics/
so the US must have a problem with sketchy electrics, when a country with twice the voltage and rarely an earth can have ~0 electrocutionsLike any serious topic, it can’t be summed up to a simpleton sound bite like you’d like it to be.
Let me just stop you right there: Yes, yes it is. Look up how earthing systems work - TT, TN. Only in IT do you not necessarily have a bond, what differs is the location. IT is.. unusual.I'm not familiar with those terms. In my day the company gave you 2 wires coming from the pole (or underground) . you hammered an earth pin in the ground and wired that to the earth pins on all devices. There was no wired connection on premises between that ground pin and either of the two wires. It may have been bonded somewhere, but not in the fuse box. Both wires are "hot". Connecting to earth would create a massive short circuit.
You are egregiously out of date on both the technology and the standards.apparently so.. i'm not familiar with those combo devices. Never even seen those.
Let me just stop you right there: Yes, yes it is. Look up how earthing systems work - TT, TN. Only in IT do you not necessarily have a bond, what differs is the location. IT is.. unusual.I'm not familiar with those terms. In my day the company gave you 2 wires coming from the pole (or underground) . you hammered an earth pin in the ground and wired that to the earth pins on all devices. There was no wired connection on premises between that ground pin and either of the two wires. It may have been bonded somewhere, but not in the fuse box. Both wires are "hot". Connecting to earth would create a massive short circuit.
In my day a ground fault ("aardlekschakelaar") was a separate device. two wires go in , two wires go out. the outgoing goes to the thermal-magnetic fuses that feed the circuits. BOTH wires are interrupted in such a fuse. there were 30mA and 300mA gfci.
Almost everywhere uses 3-phase 4-wire wye, with 230V phase to phase and 400V phase to neutral.
Great write up @Monkeh
When you saidAlmost everywhere uses 3-phase 4-wire wye, with 230V phase to phase and 400V phase to neutral.
I think you mean 230V phase to neutral and 400V phase to phase
as of 2026 the US added a new standard voltage that is a 416/240 60 hz system for use anywhere that needs 240V line - neutral other than residences.
Accidents with more than one victim could be lightning strikes? Or live cables falling down into water during a storm?Neither.
One of the single-victim, non-suicides is a damned Darwin Award contestant, though: the power switch button on an angle grinder broke off, so they jammed a big screw into the hole…
If both wires are 'hot' you have no neutral at all. Belgium does appear to still have a substantial amount of these 3-phase delta systems (of which you got two phases) in service.Correct. Incoming is often 3 phase in delta. no neutral (no star point since it is delta). The main transformer feeding a development is 3 phase. One home sits on l1-l2, the next on l2-3 the next on l3-1 and so on.
If both wires are 'hot' you have no neutral at all. Belgium does appear to still have a substantial amount of these 3-phase delta systems (of which you got two phases) in service.Correct. Incoming is often 3 phase in delta. no neutral (no star point since it is delta). The main transformer feeding a development is 3 phase. One home sits on l1-l2, the next on l2-3 the next on l3-1 and so on.
My mom's house built in 1969 has 3 phase coming in for the cooktop/oven. the other loads are balanced between phases pairs. There is no neutral. Earth is a pin in the ground not connected to anything, except the earthing pin on the power outlets.
i don't know if they still do it that way but it was very common. When the home developments were built you could request to have all three phases.(you needed to pay extra since the underground feeder cable has an extra wire) but most people wanted it for the electric range/oven combo. There is typically a transformer cabin feeding a whole development. i remember having 10kv or 12kv coming in and 3 phase going out to the development.
Maybe it's because she lives in a rather rural area with lots of farms and other power hungry agricultural things that all want 3 phase, so it is readily available.
While the stab connections do fail, I think the real answer is more complex. My casual observation watching news reports is that a very significant source of electrical fires in the US is overloaded extension cords.
That's got to be way out of spec. In the US the National Electrical Code (NEC) recommends 5 ohms or less, but up to 25 ohms meets regs.
Also alot more people DIY electrical work in the US. The US has less strict inspection and maintinence rules than EuropeThat was in the past.
As long as you don't go between actives you're fine.What worries me is 1-phase SMPS possible catastrophic failure when different low voltage equipment units are powered from different phases and wired together via some communication interfaces.
How can that happen? The maximum phase to earth voltage is still the same as single phase.As long as you don't go between actives you're fine.What worries me is 1-phase SMPS possible catastrophic failure when different low voltage equipment units are powered from different phases and wired together via some communication interfaces.
Also alot more people DIY electrical work in the US. The US has less strict inspection and maintinence rules than EuropeThat was in the past.
Nowadays in our country the electrical supply company is only responsible for the installation to the house, the main fuses and meter.
After the meter it is the owners responsibility to obey the rules that are written in expensive NEN specifications, written in almost legal language that normal folks don't understand and electronic engineers or electricians sometimes have to study for or read it four times to follow.
Then they change it every four years , making it even harder to keep track of.
When there is an incident, the insurance company is investigating if they can blame the owner so they don't have to pay ;)
How can that happen? The maximum phase to earth voltage is still the same as single phase.For stationary units it is possible to ensure up to human error that Lx,N aren't swapped, for all other units it depends on the socket layout and wiring.
a Y-cap between the primary and the secondary side that is designed to fail short.
SMPS has a Y-cap between the primary and the secondary side that is designed to fail short.Only if it's RIFA brand, and an old one at that.
So not a catastrophic failure, as you said previously.How can that happen? The maximum phase to earth voltage is still the same as single phase.For stationary units it is possible to ensure up to human error that Lx,N aren't swapped, for all other units it depends on the socket layout and wiring.
I imagine a case when Lx is against Ly instead of N and vice versa. SMPS has a Y-cap between the primary and the secondary side that is designed to fail short. When this Y-cap is against another phase instead of the neutral (and that alone can accelerate its failure) and this may provide Lx and Ly/Lz to secondary GNDs low voltage DC units are referenced to. So if I'm not mistaken this could lead to a short between phases on a secondary side between low voltage equipment units via common GND bus (is any pair of units is not isolated). I know X/Y caps are typically about 2kV standoff voltage, but... it's not a component to which I would trust an important piece of infrastructure.
See e.g. https://blog.knowlescapacitors.com/blog/safety-capacitor-classesHow can that happen? The maximum phase to earth voltage is still the same as single phase.For stationary units it is possible to ensure up to human error that Lx,N aren't swapped, for all other units it depends on the socket layout and wiring.
I imagine a case when Lx is against Ly instead of N and vice versa. SMPS has a Y-cap between the primary and the secondary side that is designed to fail short. When this Y-cap is against another phase instead of the neutral (and that alone can accelerate its failure) and this may provide Lx and Ly/Lz to secondary GNDs low voltage DC units are referenced to. So if I'm not mistaken this could lead to a short between phases on a secondary side between low voltage equipment units via common GND bus (is any pair of units is not isolated). I know X/Y caps are typically about 2kV standoff voltage, but... it's not a component to which I would trust an important piece of infrastructure.
You now appear to be giving an emotive opinion rather than one based on rationality.I think I do indeed. I'm trying to think through a potential failure scenario. Like, I know all HV ceramic caps used in those roles are really high on isolation voltage specs, but I'm trying to think about what would be a backup solution if primary to secondary isolation fails (basically there's only three parts in an SMPS - a transformer, which is usually ends up with its primary shorted, an optocoupler which always fails open, and a denoising capacitor between the primary and secondary sides that I was thinking of initially).
I'm sure he knows that. It's obviously a typing error. Brain being faster than the fingers. Everyone who knows about Y-capacitors, is aware of the fact they're desinged not to fail short circuit.Yeah, that was a brain fart, somehow I totally swapped X/Y in my memory.
Above i mentioned a plan to get 230 V in our 120 V - 0 - 120 V biphase installation. As the street transformer is close to our house, we actually get 245 V most of the time.
I bought a 120 V to 12 V - 0 - 12 V toroid and modified it to output 12 V up to 100 A as an autotransformer, reducing voltage of one phase from 122 to 110 V. The yellow wires with Wago terminals are an unused 8 V helper winding.
It sits near our street entry post, below the counter box. That box has the main 63 A fuse and two overvoltage protection devices. The counter is in a closed section above and visible from the other side.
We have been using the modified setup for a week now and the transformer stays cold. Still want to make or buy a cabinet for weather protection.
I'm showing this as an example of 120 V => 120 V biphase => 230 V migration.
Regards, Dieter
In the UK, correct me if I am wrong. The situations where electrocution from 240V is a real risk, they actually use 110V transformers.
Construction sites for example. Cables get broken, frayed or have metal tools put through them all the time. The 240V out of the wall or generator kills too many people in these accidents, so a lot of "serious" professional contructrion use 110V and transformers if the source is 240V.
Honestly I'm not sure how prevalent the use of 110V on construction sites is these days. Most normal contractors working on my house have used 240V tools... or battery tools for most things.
General electrical safety standards have risen dramatically in the last few decades with things like GFCI/RCD and other safety trips.
In the UK, correct me if I am wrong. The situations where electrocution from 240V is a real risk, they actually use 110V transformers.
Construction sites for example. Cables get broken, frayed or have metal tools put through them all the time. The 240V out of the wall or generator kills too many people in these accidents, so a lot of "serious" professional contructrion use 110V and transformers if the source is 240V.
As it used to be a 120 V system here in São Paulo, installation is a bit stronger and we have pretty small losses.Thats fascinating, so you had a real issue a quick search shows Brazil's national standards are is either '220' or '127' or a 220/127 based system.
The high current wiring is 16 mm² with 20 mm² (10 times 2 mm²) inside the toroid. I used solder connections to prepare the toroid and screw connectors inside the wall box, working with mains disconnected. The spare green wire can serve as PE connection for a metal cabinet.
My idea is that our 230 V equipment should last better: Hair dryer, toaster, microwave oven, air conditioners. At 245 V our 230 V microwave oven made a horrible noise. That improved to the usual transformer hum. Of course it needs a little longer now, maybe 2:20 instead of 2 minutes. My wife is satisfied that the hairdryer no longer gets as hot. Once a hairdryer melted. I also brought some lab equipment from Germany that will be near impossible to replace here in São Paulo.
Regards, Dieter
The strong trend to cordless power tools is good for construction safety.
I hate the blasted things. I believe they date from a time before RCDs, certainly before they were rugged enough to be thrown around a building site. I bet they cause more injuries due to poor manual handling than they save in electrocutions.In the UK, correct me if I am wrong. The situations where electrocution from 240V is a real risk, they actually use 110V transformers.
Construction sites for example. Cables get broken, frayed or have metal tools put through them all the time. The 240V out of the wall or generator kills too many people in these accidents, so a lot of "serious" professional contructrion use 110V and transformers if the source is 240V.
Honestly I'm not sure how prevalent the use of 110V on construction sites is these days. Most normal contractors working on my house have used 240V tools... or battery tools for most things.
General electrical safety standards have risen dramatically in the last few decades with things like GFCI/RCD and other safety trips.
Its also worth noting that the 110V site transformers are center tap grounded by design so in the event of a fault the operator can only see 55V to ground in a ground fault.
They are quite common here far as I'm aware, You'd find them more on large sites overseen by a company or such instead of more general work at a domestic house.
Sizes from 1kVA up to 10kVA are common and you will find a lot of lighting equipment and large tools run off this on large construction sites, You do find them other places here where there is a higher risk of damage to a cable/portable equipment but that can fall down to how the company want to implement it, There may be regulations on this too.
Things like cherry pickers and scissor lifts here normally have a feed for 110V tools and also charge from 110V for battery operated units.
The strong trend to cordless power tools is good for construction safety.
Yep, in most cases you just do not need mains power, brushless cordless have just as much power, sometimes more.
Wow thats very curious and quite relevant, do you know if the UK regulations really changed? Do they no longer require the 55/110V 50Hz split-phase system ? If the basis for lifting the regulation was a RCD is equivalent that would be interesting to see. An RCD still exposes the worker to almost to the full fault current until it trips, and its trip time is amazingly fast something like 300ms, much faster than US GFCI's, but it will not protect a worker from a hi resistance ground fault between 5mA and 30mA such as may be found with a compromised ground wire in a portable cord.
I believe they date from a time before RCDs, certainly before ../..
Where I work, there's even a part of the site with no 230V power, just 110VAC,
Wow thats very curious and quite relevant, do you know if the UK regulations really changed? Do they no longer require the 55/110V 50Hz split-phase system ? If the basis for lifting the regulation was a RCD is equivalent that would be interesting to see. An RCD still exposes the worker to almost to the full fault current until it trips, and its trip time is amazingly fast something like 300ms, much faster than US GFCI's, but it will not protect a worker from a hi resistance ground fault between 5mA and 30mA such as may be found with a compromised ground wire in a portable cord.
I believe they date from a time before RCDs, certainly before ../..
Where I work, there's even a part of the site with no 230V power, just 110VAC,
But in similarly "bad luck" cases, non-current-limited 55V AC can be deadly too. Very unlikely, but possible.
This presents a challenge, one which commercial buildings had to solve first. SMPSUs leak current to the PE. If you get enough of them, say an office building floor with 200 PCs on it... the RCDs just constantly trip.
One huge RCD is also a bad idea due to the redundancy issue, you don't want everything possible shut down if there is a fault somewhere.
RCDs have moved into the breakers in most consumer units updated in the past 5-10 years.
This presents a challenge, one which commercial buildings had to solve first. SMPSUs leak current to the PE. If you get enough of them, say an office building floor with 200 PCs on it... the RCDs just constantly trip.
The solution is to put the 30mA/30mS trips in the plug sockets for each desk. Expensive, but satisfies the need.
My house has a "master RCD" in the 100A isolator. It is 100mA/30mS. Not designed to save humans really, just to detect a leakage event house wide.
It tripped when I cut a disconnected circuits cable in the garage. The breaker was pulled, the wire was tested as "dead". I cut it. Trip popped.
It detected the current flow from Neutral to Earth.
EDIT: Which is 'odd'. The house has N and E bonded at the presentation point. There is a very short 16mm cable to the consumer unit, the bus bars and the cable out to where I cut it. The only current that could cause a E/N potential is in the consumer unit, the cable I cut was dead and no current flowing, so no voltage drop. So how did 100mA of current actually flow between N and E on a dead circuit? Even upstairs with load on, the N-E potential is like 2V.
RCDs have moved into the breakers in most consumer units updated in the past 5-10 years.
This presents a challenge, one which commercial buildings had to solve first. SMPSUs leak current to the PE. If you get enough of them, say an office building floor with 200 PCs on it... the RCDs just constantly trip.
The solution is to put the 30mA/30mS trips in the plug sockets for each desk. Expensive, but satisfies the need.
My house has a "master RCD" in the 100A isolator. It is 100mA/30mS. Not designed to save humans really, just to detect a leakage event house wide.
It tripped when I cut a disconnected circuits cable in the garage. The breaker was pulled, the wire was tested as "dead". I cut it. Trip popped.
It detected the current flow from Neutral to Earth.
EDIT: Which is 'odd'. The house has N and E bonded at the presentation point. There is a very short 16mm cable to the consumer unit, the bus bars and the cable out to where I cut it. The only current that could cause a E/N potential is in the consumer unit, the cable I cut was dead and no current flowing, so no voltage drop. So how did 100mA of current actually flow between N and E on a dead circuit? Even upstairs with load on, the N-E potential is like 2V.
Here is an interesting thought experiment I tried today.
If you were handed a live mains lead, UK 240V, locally bonded N-E (ie, 2 wire mains phase cable) and a gun pointed to your head. You must touch one.
Which one?
Personally I would go with Earth if I had to make a rapid decision, but if I had time to think about it I would check where my feet were before anything else.
Here is an interesting thought experiment I tried today.Well, given the choices presented, I’d touch the gun!
If you were handed a live mains lead, UK 240V, locally bonded N-E (ie, 2 wire mains phase cable) and a gun pointed to your head. You must touch one.
Which one?
With my elbow while grabbing the live conductor!Here is an interesting thought experiment I tried today.Well, given the choices presented, I’d touch the gun!
If you were handed a live mains lead, UK 240V, locally bonded N-E (ie, 2 wire mains phase cable) and a gun pointed to your head. You must touch one.
Which one?
Here is an interesting thought experiment I tried today.
If you were handed a live mains lead, UK 240V, locally bonded N-E (ie, 2 wire mains phase cable) and a gun pointed to your head. You must touch one.
Which one?
Personally I would go with Earth if I had to make a rapid decision, but if I had time to think about it I would check where my feet were before anything else.
2-106 Circuit voltage-to-ground — Dwelling unitsI am not sure if it changed since 2012 so in Canada they apparently also view or viewed the global the standard world voltage (220/230/240V to ground ) as a "undue electrical shock risk" at least in 2012 they did.
Branch circuits in dwelling units shall not have a voltage exceeding 150 volts-to-ground except that, where the
calculated load on the service conductors of an apartment or similar building exceeds 250 kV•A and where
qualified electrical maintenance personnel are available, higher voltages not exceeding the voltage-to-ground of
a nominal system voltage of 347/600Y shall be permitted to be used in the dwelling unit to supply the following
fixed (not portable) equipment:
(a) space heating, provided that wall-mounted thermostats operate at a voltage not exceeding 300 volts-to-
ground;
(b) water heating; and
(c) air conditioning.
Here is an interesting thought experiment I tried today.
If you were handed a live mains lead, UK 240V, locally bonded N-E (ie, 2 wire mains phase cable) and a gun pointed to your head. You must touch one.
Which one?
Personally I would go with Earth if I had to make a rapid decision, but if I had time to think about it I would check where my feet were before anything else.
I'd touch the Neutral
I resisted the temptation to report my most impressive electrocutions.