“never plug extension cords into extension cords” is probably the most common piece of electrical related advice I’ve ever heard. But if you have, say, 2 x 2m long extension cords, and you plug one into the other, why is that considered a lot more unsafe than just using a single 4 or 5 meter cord?
Does it just boil down to that extra connection creating another opportunity for the prongs to slip out and cause a spark or short circuit? Or is there something else happening there?
For that matter - why aren’t super long extension cords (50 or more meters) considered unsafe? Does that also just come down to a matter of only having 2 connections versus 4 or more on a daisy chained cord?
Followup stupid question: is whatever causes piggybacked extension cords to be considered unsafe actually that dangerous, or is it the sort of thing that gets parroted around and misconstrued/blown out of proportion? On a scale from “smoking 20 packs of cigarettes a day” to “stubbing your toe on a really heavy piece of furniture”, how dangerous would you subjectively rate daisy chaining extension cords, assuming it was only 1 hop (2 extension cords, no more), and was kept under 5 or 10 metres?
I’m sure there’s probably somebody bashing their head against a wall at these questions, but I’m not trying to be ignorant, I’m just curious. Thank you for tolerating my stupid questions
“never plug extension cords into extension cords” is probably the most common piece of electrical related advice I’ve ever heard.
Same reason power cables outside are fucking huge and the cord to your TV is tiny.
Electrical loss generates heat, so the longer the cable, the thicker it needs to be before that heat is too much.
Don’t forget a filament in an old school light bulb is just really thin wite. The thinner it is the less energy required to make it glow, which is why there’s like a 200 year old light bulb still going, it’s just a thick filament and very inefficient
So I’d never plug two of those rinky dink indoor extension cords together, it doesn’t take much length before it starts “glowing” like a light bulb filament, which happens at the plug and can burn a house down.
But…
Growing up doing rural construction with heavy gauge extension cords we never thought twice about hooking multiples up as long as it was just something quick for a few minutes at a time. Then never left it plugged into the source when not in use. You’d never do it for like a radio even because eventually it’s gonna heat up back at the aource.
Someone else already mentioned not pulling it right, we’d “doughnut” the connection so that if it did get yanked accidentally it wouldn’t unplug, but obviously it can’t be under constant stress even like that.
So many people here talk about the thickness needed of else it heats up. That is simply wrong. The heat is the same per length and is dissipated the same way with twice the length aka the temperature is the same*. The issue is that the short circuit current could drop below the value needed to actually pop the breaker, allowing for a ton of heat to be generated where it shouldn’t be. The same way a light bulb glows bright hot but does not trip the breaker etc., now just imagine the cable to be the glowing part.
*There is another issue if you do not lay them out, that the heat has nowhere to go. Causing coiled wires to have a far lower rating compared to when they are fully extended.
It increases the risk of electrical overload and overheating as it adds more resistance to the circuit.
Thanks for the response! Would you mind going a bit more in depth about that please? I could understand increasing the risk of overload if you were to daisychain power boards, as they add more power points to the circuit than it was designed for. But extension cords (at least in my experience) only have 2 ends - one with a single plug receptacle, and the other that plugs into a power point
Is it the actual connection between the two that adds more resistance to it? If it were the wiring, then wouldn’t that also pose a problem for longer extension cords?
In either case, what sort of resistance add are we talking about (feel free to pick random lengths of examples make it easier to explain)?
The longer the cable, the thicker (heavier gauge) it needs to be to carry the same current without burning up. One extension cord is rated to carry the current it alone is able to carry. Put two of those in series, and both of them together are able to carry less current than either one by itself. This is how fires start.
This is incorrect. I need to increase gauge for voltage drop. Overloading the cable via length can only happen if I have a motor or other magnetic load at the end. A motor will try to draw it’s designed wattage regardless of voltage. A wire of a given ampacity will handle that many amps regardless of the length of the conductor. The relationship is power = voltage x current and voltage = current x resistance for single phase. The fire concern on extension cords tied together indoors is you have 100% strung that shit through a doorway or window, which is a code violation. You are going to pinch it and burn your shit down. all outdoor plugs are gfci these days and on site i can have 4 or 5 extension cords tied together. i only get 109 volts at the end but a heater is a resistive load. Doesnt matter for that application.
It’s obvious you know more or less all there is to know about this topic. So much so that I suspect you have trouble explaining it to laypersons like me because it’s difficult for you to determine which parts of your knowledge are obvious common knowledge and which parts are specialist knowledge.
This is junior highschool level stuff. Not a vector or phasor in sight.
Your school taught anything at all about electricity? Mine sure didn’t.
My high school had a lot of vocational courses. I took auto shop, construction, welding, and small engine mechanics. Several of those covered electricity.
The super simple explanation is that the wires are too small. The water hose analogy breaks down fairly quickly, but I’ll try using it. Imagine a garden hose, with a regular nozzle on the end. But it’s not a perfect world, and our hose doesn’t transfer all the water that goes into it. Think of this as ten pinprick holes along every meter of hose. If we have ten meters of hose, that’s fine, we only need to turn on the tap a little bit to get a decent spray out of the nozzle, and a little bit will dribble out these holes. Now let’s join another hose on. We lose more water to leakage, so to get the same amount of water out of our nozzle, we have to turn on the tap more, giving it a bit more water flow. Now, our pinprick holes are not just dribbling, they’re flowing freely. Now let’s take it to the extreme- we join a thousand garden hoses together, all leaking a little bit. We have to turn the tap on A Lot More, and suddenly our pinpricks are spraying a serious amount of water everywhere. Now imagine we use a bigger hose. Let’s take it to the extreme again and say it’s a big stormwater pipe. But the key part here is that it has the same amount of holes, ten pinpricks per meter. This way, we can get heaps more water down that pipe, more than enough to give that water nozzle everything it wants. Also, because our pressure can remain low, those pinpricks are only leaking a little bit, not spraying everywhere. This is getting pretty wordy and unwieldy to type out on my phone, so I’ll try and bring it into the real world a bit more. An electrical load, like a motor (say a compressor in a fridge, a circular saw, etc) is like to our nozzle. It will pull more current (amps, or water flow) to maintain the same amount of power output (water coming out of the nozzle). As we get a longer conductor, the voltage drop (pressure reduction due to water lost to the pinpricks) gets larger, and our voltage at the end of a conductor gets lower. Power = voltage * current, so if that voltage is lower, to get the same power we need more current. More current means more heating. More heat in a small cable means melting. Physics has a way out for us, thankfully! The thicker a cable is, the less voltage drop it has, kind of like our stormwater pipe. So the voltage remains at a normal level at the motor, and consequently the motor draws a normal amount of current. This is why longer extensions are generally a lot thicker than shorter ones. If you’re interested in the math, let me know, it’s actually pretty fascinating, and ties into why long distance power lines are all super high voltage, among many other things. The basic equations are also not too hard to work with.
Do you mean inductive load rather than magnetic load? Or are all inductive loads attributed to electromagnets?
Edit: also, don’t like… a lot of appliances create inductive loads?
Most inductive loads are motors. I used the term magnetic rather than inductive in the Hope of making my response less jargon filled and more intelligible. Very generally speaking inductance is the magnetic portion of the circuit or more technically it would the contribution to the circuit that causes the wave form to lag. That is specific to an AC circuit.
I wonder what kind of safety margin is calculated into these…
Admittedly I’ve seen some wildly different shielding or thickness in my time
For extension cords? Pretty much nothing. They can be dangerous all by themselves. You have an outlet on a 15A circuit. You can plug all sorts of things into that outlet all at the same time, especially if you’re daisy chaining cords and adapters. The sum total of current from all those things can be less than 15A, so the circuit breaker never trips, but more than what your mess of extension cords can handle. Even worse, if it’s just a little more than the extension cords can handle, you might not notice right away, and then you’ll come home later to a pile of smoldering ash.
Don’t chain extension cords.
Nailed it in far fewer words than me.
Another bit of explanation I just thought of –
Think of an incandescent light bulb. It has a filament. You run electricity through the filament and it heats up enough to glow, producing light to see by. It does that because the thin filament has high resistance; it resists allowing current to flow through it.
Any piece of conductive material will do the same thing if you put enough current through it. Even an extension cord. It will heat up enough to glow. Being an extension cord, it will then melt the insulation and dramatically increase the likelihood of setting something on fire.
This is primarily a concern because extension cords aren’t fused, and there’s no control over how they are routed.
Most wiring in your walls come after a circuit breaker and are designed to allow for a certain amount of heating. The electrician follows a code that guarantees that the circuit breaker will trip before there’s any possibility of too much heat. This table indicates a higher ampacity rating for higher temperature ratings.
Now most extension cords are made cheaper by using lower gauge than the wiring in your walls. The general assumption is that they’re spread out, so the heat has no way to build up, and you won’t be plugging them permanently into something drawing the peak 15A allowed by the circuit breaker.
If you were to pile up a 100 foot extension cable and plug in a hairdryer, you’d probably start a fire. If it was all spread out, likely your hair dryer would just receive less than the 120V it’s expecting, and it wouldn’t get very hot.
Ironically, dinky christmas lights make very safe extension cords because they’re fused inside the plug.
And because the wire gauge is less than the wiring in the wall the breaker won’t trip before it reaches the point where it’s overloaded either.
I don’t think what they said is actually a problem, it’s just a back-justification for the original trope. Daisy chaining them and strictly sticking to only the few appliances that would fit in one extension strip is fine. But that’s complicated to explain, it’s better to just tell people not to do it rather than expect them to understand what’s going on
A couple things that can happen…
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plugging in too many appliances over several daisy chained power strips trips the circuit breaker because too much current is being drawn
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if the country you live in has lax electrical safety standards then, yes, perhaps you can overload the daisy chain without tripping the main circuit which would lead to overheating
When the breaker trips then the fundamental issue is unlikely to be present. But to be able to push enough current to cause it to break the connection needs to have a sufficiently low resistance. If that gets too high it will never break, even if you short the cables. And that will result in a fire, because the protection does not work anymore. That is the dangerous part.
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Isn’t the added cable resistance small enough to not cause issues so soon? In case you just chain a few ( < 10 ) together.
It’s not just the cable resistance, but the added resistance at each connection point. Since the plugs aren’t the same piece of metal, just touching.
I have an RV with 2x 10 gauge, 50’ extensions running power to it. I have a built-to-purpose coverat the connection point. Its fine and safe enough. Just keep slack at the connection. It cant be under pull stress.
Check the neutral pin at the pedestal and the connection. After a few months running an AC unit, it’ll be char broiled somewhere along the way.
On a scale from “smoking 20 packs of cigarettes a day” to “stubbing your toe on a really heavy piece of furniture”, how dangerous would you subjectively rate daisy chaining extension cords
As dangerous as one extension cord of their combined length. Don’t forget to verify that every cord rating is above load rating. I recommend to use at least same rating as circuit breaker or get extension cord with circuit breaker built in and never decrease rating down the line without circuit breaker before it, so even if you somehow overload it, there will be protection from it.
AND NEVER COIL OR THERMALY INSULATE! Cords rely on convection for heat dissipation, and spooling and insulating reduces it, thus increasing insulation temperature until it melts and spontaneously combusts. This applies to extension cords in general.
Because this is the Internet, I’ll be pedantic and say the interface where each cord plugs into the next probably adds some resistance as well.
So, 50 cords 1 ft each plugged into each other would have a higher resistance than the same wire at a single 50ft length.
I doubt it really matters in the practical terms of your answer and the question being asked though.
*insert technically correct*
Meanwhile landlords: "one 50 year old outlet should be enough for two bedrooms right?*
50 years old? Most of the landlords I’ve dealt with in my life consider 100 year old outlets to be perfectly sufficient, along with their carrying capacity and number in each room.
“ it was enough to power a lightbulb in 1925, so it should be perfectly sufficient for your needs with all of your TVs and computers and such.”
With one landlord, I actually had to call the city inspector into the building in order to verify that the power supply for each apartment fell beneath city requirements (it’s more complicated than this, but this is a simple explanation for casual readers). He spent the next three years doing everything in his power to get me out.
But the building got rewired pretty quickly after my report to the city. I even got compensation to stay in the hotel for a couple of days while they worked on my apartment.
This, along with hotels that hide their only PowerPoint behind the bed but have 50 bloody phone jacks, are my pet peeves. But it kinda makes sense when you consider they were mostly built before the days of having a ton of devices in the bedroom. A lamp and alarm clock, maybe a TV if you’re well off, would’ve been perfectly fine for a lot of people
The absolute worst is when the Word Documents are stashed away in some random drawer. Or when you find an Excel spreadsheet under the mattress!
Not so awful, but it’s disappointing when you open the drawer expecting a Bible, but there’s only OneNote there.
I really wish my autocorrect would stop doing that. I can count on one hand the amount of times I’ve actually wanted to write “PowerPoint”. I couldn’t even count on 10 hands the amount of times it’s assumed I’m some kind of idiot that doesn’t know “PowerPoint” is a single word when I type “power point”
I like when it only autocorrects the second word. “I’m going to home Depot”
I once read a theory on an electricians forum about how the USA electrical code’s mandated maximum distance between adjacent outlets on a wall, coupled with the typical bedroom layout, as well as home builders trying to be as cheap as possible, led to only a single outlet being placed directly in the middle of the longest wall. This is also the most logical position for a bed, so the theory is that the bed pressing against the outlet over time was a contributing factor to electrical-related house fires.
I cannot find where I read that originally, and certainly the granularity of nationally-reported fire data is not sufficient to prove that theory. And while the electrical code’s distance requirements haven’t changed, more homes will now put enough outlets so the only one isn’t behind the bed.
Years ago, I used to play live music. We played in a lot of shitty dive bars. Thinking back on all the ancient decrepit plugs we used to power our instruments, amplifiers, and stage lights with…it’s a miracle we never started a fire. Nightmare fuel now that I’m older and a little bit wiser.
I always thought it was to stop people from plugging too many appliances into all the outlets.
I think that would be more relevant to power boards than extension cords. Unless nomenclature is different elsewhere, extension cords here generally only have a single plug. Although there are usually warnings to not run things like clothes dryers or portable stovetops through an extension cord because it can apparently melt the cable. Truthfully, I don’t entirely get that either, as I would’ve assumed they’d be built to the same standard as internal wiring
Oh sorry I didn’t know the distinction, am not a native English speaker
Ah, no worries! I’m not sure if it’s even universally agreed upon across native English speakers. Where I’m from though, a powerboard (or power strip in other parts of the world) has one plug that then leads on to usually 4 or more additional power points/sockets. An extension cord on the other hand usually only allows a single device be connected to it (whether that’s another extension cord or something else)
This is the correct answer.
First, I’m not an electrician, or anything even vaguely approaching one.
I’ve never heard that advice with extension cords, only power strips.
You could theoretically link enough extension cords together to cause problems, but it would need to be some extremely shit extension cords or a LOT of them. Resistance increases over distance, which in power cables manifests as them getting hotter. That isn’t a problem until all the sudden it is a problem.
For power strips, the main danger is that you’re potentially introducing more outlets than any of them are rated for. If you’re just using 2 3ft power bars to functionally make a 6ft cable that you’re only plugging a single thing into… you’re fine. Or at least I was, idk I did it for like a whole year. If you’re plugging 16 things into a single wall outlet via power strips you can trip the circuit breaker, or potentially much worse stuff can happen like things getting melty and starting a fire.
If you know enough of what you’re doing to math out the power draw+what your outlet/power strips are rated for you can pretty (afaik) safely daisy chain them if you wanna.
Yeah, there are two components here
- Adding extra length.
- Adding more outlets.
2 is the main problem, but you need a little of 1 to have it fail in an unsafe way (ie. not just tripping the circuit breaker).
If you just add a lot of extra outlets and plug lots of stuff in then you will simply trip the circuit breaker. (Assuming that everything is properly set up according to code.) In order to create a problem you need some extra wiring that is rated for less load than the wall wiring. (Now in practice every splitter has some amount of wiring, so these can be the same device, but most power bars are rated to be “fully used” or have a fuse internally). So the problem looks something like this:
- Have a 20A wall circuit.
- Plug a 10A extension cord into it.
- Plug a power bar or other splitter into the extension cord.
- Put enough devices into the splitter to generate 15A of current.
Now you are overloading the extension cord and risking fire.
The longer the distance, the larger the diameter of the wire you need, due to resistance/heat.
Typically, extension cords are going to be manufactured with the thinnest wire they can get away with based on the safety requirements, in order to save on materials cost.
So plugging 2 short cords together might cover the same distance as 1 longer cord, but the longer cord will use thicker wire to maintain the proper margin of safety.
But unless coiled up on the ground the longer cable also has more area to dissipate heat, so the longer cable doesn’t change anything here. The heat output will be consistent for any section of the cable no matter how much more cable there is on easier side of it.
The only think that the different resistance would affect is the voltage drop to the end device. But voltage drop varies wildly so you are unlikely to have a meaningful difference caused by a few extension cords (unless maybe you are already a bad case like an apartment building to start).
The longer wire (being also thicker) has less resistance and is therefore wasting less power as heat, that’s where the Voltage drop is going.
Sure, most of the time it’s fine if you know what you’re doing, but that’s why it’s general wisdom and not a hard rule, like “don’t put metal in the microwave”, it’s said to protect those that have no idea what they’re doing/why the saying exists
Resistance of a cable is (resistivity x Length)/(πr^2) so the residence increases with length, which is why longer extension cords are designed thicker to reduce resistance. Power grids are voltage stabilized so the voltage drop will be negligible but it will take more power to get down the daisy chain, producing more heat.
And temperature difference to ambient temperature is
thermal resistivity * dissipated power / (2\*π\*radius\*length). If you will plugdissipated power = resistance * current^2and resistance into it, you will see, that temperature difference is invariant of length.
I have no idea whether this really is the answer but it seems like the most plausible answer.
Said another way: Each cable is given the minimum copper and shielding that cable needs for the length it is made.
As soon as you plug two together, you’re operating at greater resistance than either one was made for, and relying on the margin of error.
I’ve run a full DJ setup with speakers, a mixer, soundboard, laptop, etc. off a single line of 6-8 daisy-chained extension cords more times than I can count.
…uh…how have I never learned of this.
DJ’s really will find any excuse to tell you they’re a DJ
Honestly that’s probably not a huge electrical load.
Because you ain’t loud enough lol
The longer the wire, the more heat it can dissipate, so no, you don’t need wire to be thicker.
Not sure if you’ve ever used fuse wire before. It’s what was used before capsule fuses and breakers. Essentially, if too much current goes through it, it will melt, breaking the circuit as protection. The thicker the fuse wire, the more current it can pass through without melting. The length of the wire doesn’t come into it. 1cm of 10 amp fuse wire will melt at the same current as 1 meter of 10 amp fuse wire.
Yes, maximum carried current is indeed invariant of length. I explained math behind it in https://lemm.ee/comment/17115060
We may be discussing slightly different things here, I’m not sure if I follow the application of your math in this context.
My point is that a thinner wire will get much hotter than a thicker wire, given the same amount of current. Is this not the case?
I think a lot of people are mostly on the money here. It’s to do with resistance. Now, I’m not a qualified electrician, but I’m an amateur radio license holder and a lot of what you learn for that is applicable here.
The main problem as many have said is resistance. This comes about from both the length of the conductors but also from every plug/socket connection adds resistance. Also in the case of the non extension socket multipliers, as you add more the weight bearing down would also likely start to make the connections less secure causing more resistance and possibly adding to the problem through arcing.
Now the resistance alone on small loads likely wouldn’t be a huge problem. But if you had a large enough load (specifically at the end of the stacked connectors/extensions), or a fault that caused a larger than expected load the current would cause the resistance to generate heat.
There’s a lot of ifs and maybes involved, but really why do it? There’s really no real world situation to need to have a dangerous amount of extensions like this though.
For larger loads here in the UK there’s some very specific other concerns when dealing with ring mains. But really you’d need to do really weird/unusual things for that to become a problem.
On the contrary, practically every single person in this thread that mentions resistance is talking precisely backwards. Higher resistance will not cause overheating. Except for certain motor loads, it will cause malfunction due to voltage drop. The actual fire hazard is the increased chance of faulty cable, faulty connection, and, inevitably, overloading.
Resistance alone doesn’t cause heat. Drawing current through resistance causes heat at the point (or points) of resistance. Which is why I clarified that it’s not likely so much a problem on small loads.
This is why resisters come in different physical sizes. Because they have differing abilities to dissipate power as heat.
A good example is of dummy loads in radio use. Which needs to dissipate the power output of a radio. That can be anything from milliwatts to a kilowatt. Up to probably 50w they will have a basic heatsink. I’ve seen huge drums filled with oil as 50ohm resisters to handle up to a kilowatt of dissipation.
There are two things going on here.
The first is that yes, more connections causes more opportunities for the plugs to slip. So you can get short circuits or even arcing that can start a fire.
The second is that the wire in the cord has a certain rating on it. Many of those cords do not use 12 (20 amp) or 14 (15 amp) gauge wire; so, they’re not rated for the full capacity of the wire in the wall. The breakers are sized to protect the wires in the wall, they don’t know anything about the things plugged into them. So what can happen is you plug too much into the extension cord (particularly if it’s a power strip) and the load on the extension cord is not enough to trip the breaker (because the walls are fine) but it’s enough to overload the extension cord wire. In other words, the extension cord can start getting so hot it melts and possibly arcs up as the insulation fails.
You can have a fire from overloading a single power strip in just the same way. However, the more you chain together, the more likely you are to overload the power strip.
Ideally, you just think about what you’re doing… But historically the easy answer is just to tell people not to chain things.
In short it’s not about the distance, it’s about the insulation and quality of the wire itself along with the number of connections.
Awesome answer - thank you!!
Although I guess a more general question - why aren’t all power boards and extension cords mandatorily fitted with their own circuit breakers/overload protection circuits? I guess it’s cheaper to just tell people never to daisy chain, but at the same time, when you factor in overall costs incurred by anybody (or insurance companies, etc) from people unintentionally overloading them and causing them to melt and burn down houses, wouldn’t it be in everybody’s best interests to raise the price a few dollars and include a resettable overload protection system?
Technology Connections made a 25 minute video about American extension cords and why they’re dangerous, if you want to watch a long form answer.
Edit: oops, just saw I’m late to the party with this video
Some power systems do actually put a fuse in the extension cord… I think it’s the UK that does this. Basically every power system other than the US uses different (safer) plug designs that solve the arcing problem.
In practice daisy chaining rarely causes a serious problem and it makes things more expensive so it never really became a thing that was legislated or common within the US. Similar to how the plug designs themselves rarely cause a problem so it hasn’t made sense to actually change them.
iirc British plugs do have a fuse built in to every plug, but they are also the only ones who do that
I’m not an electrician, but I recall that this video explains it pretty well (along with other interesting things): https://www.youtube.com/watch?v=K_q-xnYRugQ
Here’s another good example: https://www.youtube.com/watch?v=4cp28hIMP94
Stacking 283(!) double mains adapters and measuring the voltage drop. Because it’s not just the cable, each plug/socket adds additional resistance.
The longer the cord is the more resistance there is; ie the more electrical load on the circuit. As long as you are pulling less than what the circuit and cord is rated for, there isn’t an issue, you will just be wasting a little extra power from the extra resistance. The plugs themselves can also have a bit of extra resistance.
Two pieces of advice that will make the biggest difference:
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Keep the total length of all extension cables used as short as is reasonable. Don’t use a 20m cable when a 4m cable will do.
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Buy extension cords with higher wire gauges (higher wire thicknesses). A 12 gauge cable (4mm2) will provide notably less resistance than a 14 (2.5mm2) or 16 gauge cable (1.5mm2). The packaging will say what gauge it is. Note, I’m talking about the thickness of the metal itself, not the thickness of the extension cord as a whole. I have seen some very, very thick extension cords with absolute trash wires inside.
The more resistance there is, the less the electrical load is. Maximum electrical load would be a short circuit (near zero resistance, maximum current flow); minimum would be a cord or device with infinite resistance (no current flow).
Considering V=I*R and P=I^2 * R, increasing resistance will decrease current and this will decrease power.
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It’s going to be down to the gauge of the wire and if it’s rated for hard usage. There would be no difference if the 4m cable was the same gauge and insulation type as two 2m cables connected by cord and plug. You couldn’t say how dangerous it is specifically without calculating the load, wire ampacity, ambient temperature, insulation type, distance, and on and on so it’s general advice to prevent fires from overheating wires.
I think it is partly a US specific problem as the quality of the extension cords really suck. Meanwhile in Eurpoe (or at least in Germany) the extension cords actually use the same wire grade as your in wall wires, so there is a basically no difference in using daisy chained extension cords versus different wall outlets (as long as the outlets are in the same curcuit)
Yep, came here to write the same. We have 240V and not 120V like the US. To power the same appliance in the US you have double the Ampere and therefore higher risk of fire (correct me if I’m wrong)
I strongly disagree… We just have higher standards regarding power wires. Since we have more voltage running through the wires we need tougher ones, but that is what regulation is for
So the higher Ampere doesn’t require thicker cables? Genuinely asking. The higher standards and regulations are absolutely part of why you don’t hear this rule here.
Yes, as US uses an voltage of 120 V, the current drawn by a load is approximately double the current drawn by the same load in EU with 230 V. Thus the wires used in Europe only need approximately half the cross section compared to US. However, the insulation of the wires needs to be of higher standard.
Its higher voltage,but yes It does. However the higher standards take care of that, so you don’t have too weak power cables available
The wires in your wall usually have 1.5 mm^2 while the extension cables have 0.75 mm^2 cross section.
I mean it is hard to find out if they are the exact same, since power strips often don’t specify it, but from handling both I’d say they are pretty much the same…
The cable specification is usually written into or molded onto the outer insulation, at least in Europe / EU.
Not necessarily exactly the same wires, but all rated for 16A, so the circuit beaker will trip long before any wire gets a chance to heat up
Extension cords are rated for certain levels of resistive load based on their length. It typically has to do with the gauge of the wire used in the chord itself. Electrical resistance is typically converted into heat energy. If you daisy chain extension cords and have them plugged into appliances, then the resistive load of the chained cords can be higher than the rating of one or more of the extension cords. This can cause fire.
