This Power Cord Is Dangerous

In this video, I tested a generic IEC power cord. It is rated for 10A, but is it safe to use? Let's find out.

[@stevensexton5801]

Wow, I need to check my power cords.

[@pault6533]

Not a bad idea, even if you checked them before. Cords and terminals go bad over time because of mechanical, thermal, or electrical cycling.

[@Janktzoni]

I like your testing method. Straightforward and easily replicated. If it was real copper then 0.75m² should have been fine for 10A of current.

[@vincei4252]

I have 4/0 copper conductors that go from my home solar inverter to a large battery bank. That routinely carries 120 amps at 48+ volts for charging and slightly less at discharge. I buy my cabling and electrical components from reputable sources like McMasterCarr / Grainger etc because buying from anywhere else like Amazon or eBay is gambling with someone who really doesn't care if they burn your house down and probably have burned several peoples houses down. It never occurred to me to test the cables that have come with test gear that I've bought over the years.

[@pault6533]

Even if there is no fire, an inefficient cable wastes your photovoltaic energy. You can test the conductivity of the wire against published resistance values per length of wire for each AWG.

[@tedmoss]

Check everything from China twice.

[@Dennis-uc2gm]

This is where cheap ends and disaster begins.

[@jp040759]

YIKES. I will be testing cords like this from now on. THANX. I never considered this to be an issue.

[@fiddlerJohn]

Great info. Thanks

[@bertoid]

Another way these cables can be dodgy is having the live and neutral reversed. I had one with an AU/NZ plug like that, and got a boot from it. (another fault had caused some exposed metal to contact the neutral - I was saved by an RCD)

[@txd]

0.75mm is actually rated for 10 amps when not inside a wall. However steel cores are a huge concern.

[@andymouse]

Fascinating! gonna grab a magnet and check some stuff.....cheers !!

[@LarryKapp1]

Try soldering on them - I bet the solder won't stick . I have come across wire that no solder would stick to but I never tried a magnet on them - will do that in the future now !

[@unknownhours]

The wire looks to be at least copper plated, so I would expect the solder to stick.

[@fayyazbahrami296]

iron is solder-able better than copper , aluminum needs copper coating to solder

[@tedmoss]

@@fayyazbahrami296 Iron is most definitely harder to solder than copper, have you ever tried it? We use acid flux to solder iron and that will ruin electric circuits Rosin flux is used on copper but will not work well with iron (actually its steel in this case).

[@cambridgemart2075]

@@tedmoss Many component leads used to be iron or steel with a tin / lead coating.

[@roflchopter11]

​@@cambridgemart2075 Yes, and that coating was necessary for the beast easily solderable.

[@calvinbrowne2126]

Neat video, thanks!

Never thought I would see a power cord like this. I would not be able to distinguish the wire without the magnet so I would assume they are copper.

[@TYGAMatt]

I think magnet sales are going to go up now lol!

[@barrybogart5436]

Fascinating and scary. But not surprising. You should track down the source.

[@pault6533]

The scrap industry calls this "fools copper" because it is copper-plated or copper-clad steel. Scrappers carry magnets to check everything that looks like pure copper to make sure it really is. There are places for such metal constructions because if it's strength, but certainly not for it's conductivity. Definitely a cost-reduction move on the cord you tested. I check all wire, fuses, and connectors coming out of retail and online sources for 4-wire resistance, and sometimes magnetism to determine if the wire is undersized or not a good alloy. If it's not what I expected I return the item.

[@Pillowcase]

It's indeed very scary that something that is marked and dressed up as a legitimate device ends up being so underperforming.

[@longjohn526]

This is why a legit UL rating in the US is important .... No way would copper plated steel wire pass UL standards which frankly aren't all that high to begin with

[@JouMxyzptlk]

Wow, nice little detail to check the cable print. I never thought of that. But my 0.75mm² cables are all copper, just checked. On the other hand: I would not dare to send 2000 watts (aka up to 8.5 amps in Germany) continuous over such a plug. But what happens at 5 amps? I suspect it would still heat up way to much.

[@cybermaus]

Huh. Copper clad iron. Not even aluminium. I knew about those ridiculously thin wires on some of the cheap stuff, but I never thought they would be iron.

[@artursmihelsons415]

Great test video! 👍 Yeah, fake cords are issue. One time I get locally C13/C14 power cord for rack project. I cut it, because I needed only C14 part. Didn't noticed anything strange, because I was using screw terminals. Few years later, for other project, I decided to reuse other half and I needed to solder it.. Only then I noticed strange behavior and decided to check with magnet.. 😂 Sometimes, there is great cables included from China too, but that's rare. My first check is with multimeter - resistance and test for short. Highest, so far, was 4 ohms only one wire. Magnet didn't show anything. I cut it and find out that it was made from aluminum.. 😬

[@foogod4237]

Aluminum is actually a pretty good conductor (not as good as copper, but only about 50% worse, and still 10-50 times better than things like steel), so if you were getting something as high as 4 ohms from any kind of short length, that probably wasn't actually aluminum, either. What gauge/diameter and length was that wire you tested? Note that not all kinds of steel are magnetic, either, so it's possible for a wire to actually be steel but still not react to a magnet, too.

[@tedmoss]

I figured that the wire must be copper coated because the resistance of iron wire should be about 9 times as much as copper, they used wire for a different use entirely that they got at a lower price than copper to make the cord and cheated the buyer in China, it happens all the time. Same with the plastic.

[@TradeWorks_Construction]

Looks like those markings “3CX0.75mm” mean “3-Conductors x 0.75mm” While the H03VV-F is a Euro designation for Light Duty Harmonized PVC 300V max coating (usually rated for 70°C as a general light duty cord and sometimes 80/90°C in specific fixtures as non-moving component) Since i’m mainly accustomed to working North American Split Phase 120/240V systems and residential codes I often need to shift mind sets away from the established safety Amperage Ratings but after seeing those thin ass steel wires with a coating of copper electroplating to fool consumers and initial scrutiny 🤯. It really hits home the importance of doing what you can to leave yourself some head-room for the unexpected. Not so easy to accept when a faceless corporation screws you in the ass because of greed/desperation/lack of effort [Maybe one of their guys read a little on “skin effect” and thought they could get away with copper plating thin stranded steel wires w/o reading more than what a cursory google search generated]

[@elpolaco7654]

This cable is a fake (made of steel) H03VV-F. For real H03VV-F, which is defined in European and IEC standards, the current carrying capacity in air is 6A for 3x0.75mm^2. The sheath should be made of PVC type TM2. 60-70C is still considered a safe value, although this is already the limit. By the way, for a stranded wire, its cross-sectional area (gauge) is not determined directly by measuring the physical size, but by giving the cross-sectional area (gauge) of a corresponding solid wire made of the same material that can carry the same current as the stranded one.

[@amogusenjoyer]

What's the usual usage for this type of cord/wire? Like let's say, actual "legal" usage?

[@elpolaco7654]

@@amogusenjoyer "Cable for powering electrical appliances in homes and offices. Small mechanical loads for the H03VV-F cable, such as radios, table lamps, hanging lamps, and offce equipment. Medium mechanical loads for the H05VV-F cable, such as washing machines and refrigerators."

[@foogod4237]

A typical rule of thumb is that stranded wire needs to have about 15% larger diameter to have the same cross-sectional area as equivalent solid wire, so you can usually get reasonably close by just "derating" your measurement by 15% if it's stranded. Of course, measuring the diameter of (small gauge) stranded wire using calipers is almost always going to give you a very inaccurate result anyway. It's much better to use a gauge that employs round holes or some such instead.

[@elpolaco7654]

@@foogod4237 Of course, this is true, after all, the idea is that the actual sum of all the cross sections of the individual wires used in the cable should be as stated in the specs, because this determines the conductivity/resistivity of the cable. I noticed another inaccuracy in this video. E.g. also in the description under the video there is a statement that the cable is rated for 10 A, but this is not true, because this information is on the "plug" and applies to the theoretical capabilities of the C13/14 connector/inlet pair. Even on good quality cables from well-known companies there is information about 10 A on the connector, which does not mean that the cable is designed for 10 A, because as I already wrote in this thread for cable H03VV-F 3G0.75mm² the maximum allowable current according to the standard is 6 A.

[@foogod4237]

For measuring stranded wire size, I usually just use a wire-stripper (the kind with multiple notches for different wire size), and just find which position fits the wire conductors best (with the tool fully closed). It's more reliable than trying to use something like calipers.

[@tiagoferreira086]

Unfortunately I've came across this situation several times before, it's always stuff from china in the form of power cord extensions, power cord plugs like that you show, and equipment built-in power cords. The most recent ones were one of those small no control just on/off hot air gun, and in a desoldering/sucker tool. 🤬😠

[@jimwolsiffer4397]

Copper clad steel wire, cheap for sure. Did you measure the resistance, would be a good reference to the quality version resistance and an easy way to identify the cheapo types but of course heating it up can be fun to... Thanks for taking the time to make this known!

[@amogusenjoyer]

I can't even think about a use case where steel wire could be valid for electrical current. Is it just made to be put in fake stuff or is it legitimately used in actual electrical systems ?

[@rocketman221projects]

@@amogusenjoyer It's often used in coax and antenna wire. Copper clad steel is much stronger than copper, so it works great for wire antennas. Because of the skin depth the current will only flow through the copper plating. At 1.8MHz, the copper only needs to be 50 microns thick to carry all of the current. It gets thinner as the frequency goes up.

[@KerryWongBlog]

Given the voltage drop at 10A is around 5V and since the way I was measuring effectively double the wire length, the 3 foot wire has a resistance of roughly 0.25 Ohm (5/10/2).

[@anullhandle]

​@@amogusenjoyerit is used in high tension lines for its tensile strength. The have to consider tower installation cost span requirements sag from temp changes etc. Copper clad aluminum is used for non mil std coax and low reliability network cable. As copper prices get more ridiculous alternative materials show up in more and more inappropriate places.

[@longjohn526]

@@rocketman221projects A lot of antenna wire is copper coated steel but it's not to be used for power just for antennas

[@tanithrosenbaum]

It's a combined Type E and Type F plug (aka CEE 7/7), so it might be from France or Germany where these two systems originate from, or any of the countries that use one of the two systems, which is the majority of countries in the EU and neighboring countries.

[@elpolaco7654]

I can assure you that this cable was not manufactured in any European country, although it is mainly intended for this market. It is interesting to note that the type E plug rather originates from Belgium.

[@tanithrosenbaum]

@@elpolaco7654 Oh yes, that definitely wasn't manufactured in the EU, because if it was and anything went wrong with that cable (as it inevitably will sooner or later), EU authorities would make very sure that company has just dug its own financial grave, whereas a company in a non-EU-country like, say, china (to name a random non-EU-country ;) ) might just keep going on their merry ways, business-wise.

[@anullhandle]

Power cords, usb, ethernet, coax the list goes on. We're not staffed to impound and destroy enough shipping containers to make a dent. Customs will sometimes open and destroy every carton in a container shoe horn it all back in floor loaded and let the importer deal with the scrap cost when he opens the container.

[@foogod4237]

There isn't necessarily anything wrong with the use of copper-coated conductors in Ethernet, or coax, or even sometimes USB, depending on how it's used. For data transmission, the frequencies involved are often high enough that only the outer layer of the conductor is actually used (due to skin effect), so it doesn't really matter what the core is made of, so CCA or CCS actually work just as well, and using copper for the whole thing would actually just be a waste of both money and materials. However, with power cables like this, the AC frequency is low enough that the skin effect is negligible, and they are often used to carry enough current that heat generation can be a problem, so it really does matter.

[@elpolaco7654]

@@foogod4237In addition to thermal effects, there is also a voltage drop. In fact, I saw a case here where someone asked me to check why his mains-powered garden appliance was not working on a new extension cord he bought at the flea market. After investigating, it turned out that the single-phase induction motor in the device couldn't start because the voltage drop over the 15 meter (50 ft.) length was too great. Of course, it turned out that the wires were made of steel and looked similar to those in the video.

[@davidv1289]

In addition to checking for copper clad steel wire and under-sized wire you also need to check for improperly wired cables. I came across one in my shop that had the line and neutral swapped - this is a cable with molded connectors. I checked all my cables and found two more with swapped line and neutral! Buyer beware I guess. Thank you for the video. Regards, David

[@elpolaco7654]

In Europe it doesn't matter, because we don't have a standard here that defines "polarity." Well-designed devices should work well and be safe when swapping the line and neutral wires.

[@davidv1289]

@@elpolaco7654 Seriously? The brown conductor isn't the "live" conductor and the blue wire isn't a grounded conductor (not "grounding" - yellow with green stripe) and the brown wire isn't connected via the fuse (if installed) so that, if a ground fault occurs and the fuse opens, power is no longer present after the fuse???? Sounds like a Seriously flawed and unsafe system. Regards, David

[@elpolaco7654]

@@davidv1289 Of course, the electrical system in the house is as you wrote: brown live, blue neutral (yellow-green protective earth) and the fuse is on the live wire. In contrast, already in a socket in the wall, there is no guarantee that the live is, for example, always on the left side. Therefore, inside the appliance, you can't be sure which wire is live and which is neutral. As I wrote correctly designed device should always work properly and meet safety requirements regardless of how the input live and neutral wires are connected.

[@davidv1289]

Actually that is incorrect, in Europe as in the US , the electrical outlet is polarized. The neutral (blue) wire should always be connected to the left side and the hot should always be connected to the right side of the CEE 7-3 and CEE 7-5 recepticals (looking at the front of the receptical). While connected devices will perform correctly with either orientation of live and neutral during NORMAL operation the maintenance of correct polarity is essential for abnormal conditions such as ground faults (i.e. a short circuit between the live and chassis). Reversing the live and neutral connections can result in a open fuse in the neutral and a chassis at line potential to earth (i.e. electrocution). Regards, David

[@elpolaco7654]

@@davidv1289 Can you give some reference to the applicable standard or law? The Schuko (type F) most common in Europe is not polarized. You can turn the plug however you want. In the type E used in my country, the plug is polarized, but there is no standard that dictates where the live conductor should go. Besides, double sockets are sold here, where the top socket is symmetrical with respect to the other, i.e. the protective prong of the top and bottom are next to each other. This causes that if you plug into the socket at the bottom you will have the live on the left prong, for example, but if you plug into the top one, due to the fact that you will have to rotate the plug the live will be on the right prong. Besides, of course, the Europlug (2.5 A), which is used almost all over Europe, has no protective earth and you can rotate it as you wish.

[@d00dEEE]

Magnetic copper, that's sort of like transparent aluminum!

[@netroy]

Would this issue be as severe with AC? or would the skin effect ensure that most of the power is transmitted over the copper?

[@KerryWongBlog]

For mains frequency, the skin effects won't be at play here as the skin depth is more than 8mm.

[@robinsattahip2376]

I've encountered the cheap Chinese wire that absolutely will not stick to solder no matte how much flux you use. Is that steel or aluminum?

[@_droid]

Wow, that's a new one. I've honestly never seen such a poor quality cord even on the cheapest bargain garbage. Undersized *and* made with high resistance wire.

[@ElectroAtletico]

....mmmm...time to double check all the stuff I brought back from Europe!!😬

[@JouMxyzptlk]

And quarduple check the stuff from China. Europe is quite picky. Such a thing would lead to a big scandal.

[@foogod4237]

It doesn't really matter where you bought it. There are plenty of cables like this being sold in the US too.

[@vincei4252]

What the hell

[@SeanBZA]

Common enough, and you also get those with only 2 conductors, despite the socket having the ground connector in there, and the plugtop being a grounded one, but the cord is actually only 2 conductors. Possibly steel, or CCA, or the mystery copper with conductivity approximately midway between copper and steel, which is not magnetic, but also not copper either.

[@andymouse]

Aluminium.@@SeanBZA

[@logmeindog]

Chinese garbage never ceases to amaze me. I go through decent lengths to stay away and buy from a reputable country's manufacturers and suppliers.

[@foogod4237]

It's kinda stupid to tar an entire country full of manufacturers using the same brush. Yeah, there's a lot of crap from China, but also some of the best-made products I've ever bought have been from certain Chinese manufacturers (who actually do care about quality), and I've also bought some "made in the US" (and elsewhere) products that were absolute crap, too. It's really more about whether you're using a reputable manufacturer/supplier, not about the country they happen to be from. (More than anything, it usually has to do with whether you're willing to pay a reasonable amount for a decent product, or always just buy the cheapest thing you can find instead.)

[@elpolaco7654]

In addition, this product does not have to come from China at all, but from some other Asian country, where you can also find plenty of counterfeit and low-quality products. Although the probability of Chinese origin is the highest, if only because of the size and industrial potential of the country.