Author Topic: 4 out of 5 vendors are scamming people with wrong crosssection of cables  (Read 5157 times)

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Offline thm_w

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We had a similar discussion here: https://www.eevblog.com/forum/dodgy-technology/is-the-market-flooded-with-fake-dangerous-solar-cable/
You seem to also be buying from random ebay sellers, who are likely just drop-shippers or importers.

If you provide the requested very relevant information up front instead of holding back, its going to make it easier for others to help out:
- Links to the items you purchased
- Advertised diameter and measured diameter
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Offline eTobeyTopic starter

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We had a similar discussion here: https://www.eevblog.com/forum/dodgy-technology/is-the-market-flooded-with-fake-dangerous-solar-cable/
You seem to also be buying from random ebay sellers, who are likely just drop-shippers or importers.

If you provide the requested very relevant information up front instead of holding back, its going to make it easier for others to help out:
- Links to the items you purchased
- Advertised diameter and measured diameter

I have to repeat myself...

It was never my intention to prove anything. I was trying to get the extend of this fraud from other countrys/people too. As your link prooves, its not just something i came across.

Its a really dissapaointing, that most people cant answer a simple question (see original post), and are instead still questioning the findings of others, that are likely not a case of a simple calculation error, as i tried to make clear.
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Online shapirus

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So I bought a few meters of single-strand cable advertised as 0.75 sq.mm.
Actual measured diameter was between 0.97 mm and 0.98 mm which means 0.739..0.754 sq.mm.

Hope this helps!
 

Offline eTobeyTopic starter

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So I bought a few meters of single-strand cable advertised as 0.75 sq.mm.
Actual measured diameter was between 0.97 mm and 0.98 mm which means 0.739..0.754 sq.mm.

Hope this helps!

I could imagine, that they wont try scamming people on this kind of wire, since it is easy to find out if its scam or not.
"Sometimes, after talking with a person, you want to pet a dog, wave at a monkey, and take off your hat to an elephant." (Maxim Gorki)
 

Offline thm_w

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I have to repeat myself...

It was never my intention to prove anything. I was trying to get the extend of this fraud from other countrys/people too. As your link prooves, its not just something i came across.

Its a really dissapaointing, that most people cant answer a simple question (see original post), and are instead still questioning the findings of others, that are likely not a case of a simple calculation error, as i tried to make clear.

What value is it to just post "Yes I was defrauded by cable thickness" without going into any details? Its meaningless data.
Ten people might have bought 1m from one single ebay seller, or one person might have bought 1,000m from hundreds of authorized distributors. The context matters.

Posting the store you purchased from is a normal thing. The fact that you are so secretive with your data and suppliers makes everyone rightfully suspicious.
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Offline eTobeyTopic starter

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Ten people might have bought 1m from one single ebay seller, or one person might have bought 1,000m from hundreds of authorized distributors. The context matters.

Posting the store you purchased from is a normal thing. The fact that you are so secretive with your data and suppliers makes everyone rightfully suspicious.
People can write where they got the cable from. I can not now, as i have not documented my findings. I could get me in trouble. But i might do this on one occasion if i have the mood for it.

This thread is also intented, to raise awareness about this fraud. This can even get dangerous, if cables are not crimped right, because of wrong crosssections.
"Sometimes, after talking with a person, you want to pet a dog, wave at a monkey, and take off your hat to an elephant." (Maxim Gorki)
 

Offline 5U4GB

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    Where were the cables made?   Undersizing of wire and cables made in China has been widely reported on this and other sites.   A lot of the wire is also reported to be made some kind of junk alloy that isn't solderable.  I've learned to not trust the ratings of anything made in China.

Specifically, the most common one you'll encounter is CCA, copper-covered aluminium.  Less common is CCS, copper-covered steel.  Another variant is CCC, copper-covered-copper, where they coat a thin veneer of copper over a garbage alloy of recovered scrap that may contain copper.  They'll look like they're the right size but won't have anywhere near the current-carrying capacity, as well as breaking if you bend them too much when installing them.

Neighbour of mine was happy about the bargain he got on some cabling, until I pointed out what it was that he'd just finished installing...
 

Offline thm_w

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People can write where they got the cable from. I can not now, as i have not documented my findings. I could get me in trouble. But i might do this on one occasion if i have the mood for it.

This thread is also intented, to raise awareness about this fraud. This can even get dangerous, if cables are not crimped right, because of wrong crosssections.

Get in trouble from who and how?
Go grab the cable, measure OD and wire ID and write the info and seller details here, should take 5 minutes.
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Offline f4eru

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and are instead still questioning the findings of others
We always question the findings, whether ours or from others.
Healthy thing to do, especially when the data provided is incomplete.

likely not a case of a simple calculation error, as i tried to make clear.
Nope. You did not make that clear. If you want to make that clear, please provide a simple measurement report/data everybody can check...

No doubt many chinese wires are out of spec.
No doubt also you made some inacuracies in your measurements.
« Last Edit: May 05, 2024, 01:01:07 pm by f4eru »
 

Offline eTobeyTopic starter

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We always question the findings, whether ours or from others.
Healthy thing to do, especially when the data provided is incomplete.

No doubt also you made some inacuracies in your measurements.
There were some inaccuracys, but i questioned and answered my findings until they proved to be right...

You also did not answer my original question...
"Sometimes, after talking with a person, you want to pet a dog, wave at a monkey, and take off your hat to an elephant." (Maxim Gorki)
 

Offline eTobeyTopic starter

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New cable order:
From the vendor i had previously bought good cables:
- Measured length. -> 10m
- Has "LEONI P" written on it every 13 cm.
- At 4A and a bit of wiggle, the lowest value of Voltage drop i could achieve was 300mV.
- With my caliber, i measured 0.22mm to 0.23mm (on the most inner side) and up to 0.24mm , when pulling it out.
- After the voltage drop did not speak for a 2.5mm2 cable, i went to the microscope (see picture)
- I counted (2 times) 50 strands. And then again i did that again, and made damn sure, i did not cut/lose any strands.
- Using this https://www.redcrab-software.com/de/Rechner/Elektro/Spannungsverlust it didnt add up.
- The specs on the site of the vendor says: "Leiteraufbau gemäß ISO 6722 (50 x 0,0531mm²)" (Which is 50x0.26mm)

2.5mm2 would be 50 x 0.252mm.
« Last Edit: May 18, 2024, 09:52:57 am by eTobey »
"Sometimes, after talking with a person, you want to pet a dog, wave at a monkey, and take off your hat to an elephant." (Maxim Gorki)
 
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Offline f4eru

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Now, the correct question is : what does this ISO6722 specify as a minimum tolerance for resistance, and/or section...

Quote
- At 4A and a bit of wiggle, the lowest value of Voltage drop i could achieve was 300mV.
That is a sign that your measurement setup was not good.
Did you solder together all the strands at the entry and exit points?
Did you measure with a good 4-wire setup ?

Offline eTobeyTopic starter

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Now, the correct question is : what does this ISO6722 specify as a minimum tolerance for resistance, and/or section...

Quote
- At 4A and a bit of wiggle, the lowest value of Voltage drop i could achieve was 300mV.
That is a sign that your measurement setup was not good.
Did you solder together all the strands at the entry and exit points?
Did you measure with a good 4-wire setup ?

Of course, it can be done better here, but i do not care in this case, as the other measurement confirmes the data. Not exactly, but id say close enough.

I even went to the effort, to measure a strand visually and turning it 90° to make sure it wouldnt be a eliptic shape. I also looked at more strands, but they are all the same diameter.
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Online Zero999

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... I ask because measuring cross section of a multi-stranded wire is not trivial at all. Which is also why, to answer your question: I have never checked. I think the risk of me measuring incorrectly would be larger than the manufacturer lying.

Current, voltage drop and ust a few calculations, and then you have the cross section. Nowadays with internet i would call this trivial.

I could not find the very same measurments, but i can give you an example, that is as good. (Scamed by the PCB manufacturer, as he did not mention a tolerance of 20%. Seems to be a chinese thing, yes).
What does that have to do with cables? You also haven't provided any units or how thick the traces are supposed to be.

People can write where they got the cable from. I can not now, as i have not documented my findings. I could get me in trouble. But i might do this on one occasion if i have the mood for it.

This thread is also intented, to raise awareness about this fraud. This can even get dangerous, if cables are not crimped right, because of wrong crosssections.

Get in trouble from who and how?
Go grab the cable, measure OD and wire ID and write the info and seller details here, should take 5 minutes.
Stranded wire is a little more difficult.

You'll need to measure the diameter of each strand, which would require a micrometer, or at least decent calipers, then count the number of strands and perform the calculations to work out the crossectional area or wire gauge.
 

Offline eTobeyTopic starter

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Stranded wire is a little more difficult.

You'll need to measure the diameter of each strand, which would require a micrometer, or at least decent calipers, then count the number of strands and perform the calculations to work out the crossectional area or wire gauge.


Guess what i did....  :palm: :palm: :palm:
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Offline mzzj

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New cable order:
From the vendor i had previously bought good cables:
- Measured length. -> 10m
- Has "LEONI P" written on it every 13 cm.
- At 4A and a bit of wiggle, the lowest value of Voltage drop i could achieve was 300mV.
- With my caliber, i measured 0.22mm to 0.23mm (on the most inner side) and up to 0.24mm , when pulling it out.
- After the voltage drop did not speak for a 2.5mm2 cable, i went to the microscope (see picture)
- I counted (2 times) 50 strands. And then again i did that again, and made damn sure, i did not cut/lose any strands.
- Using this https://www.redcrab-software.com/de/Rechner/Elektro/Spannungsverlust it didnt add up.
- The specs on the site of the vendor says: "Leiteraufbau gemäß ISO 6722 (50 x 0,0531mm²)" (Which is 50x0.26mm)

2.5mm2 would be 50 x 0.252mm.

So you get 7,50 mOhm/meter resistance per your measurement, your online calculator gives theoretical value of 6,9mOhm/m but the actual  IEC 60228 standard for fine-stranded wire is maximum 7,98 mOhm/meter.
I don't see huge issue here as your cable passes the IEC 60228 easily. 
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Offline mzzj

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IEC 60228:
 

Offline eTobeyTopic starter

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I don't see huge issue here as your cable passes the IEC 60228 easily. 

Why should i care about the IEC 60228 standard ?
"Sometimes, after talking with a person, you want to pet a dog, wave at a monkey, and take off your hat to an elephant." (Maxim Gorki)
 

Offline thm_w

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ISO6722 https://cdn.standards.iteh.ai/samples/50022/025962355eb24d95b13c98566c51f17e/ISO-6722-1-2011.pdf

2.5mm2
plain copper = 7.6mOhm/m max
tin plated = 7.8mOhm/m max

So it falls within the max no?
Diameter might be off but there are thin and thick versions you'd have to figure out which one it is.
« Last Edit: May 21, 2024, 09:12:39 pm by thm_w »
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Online Zero999

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I don't see huge issue here as your cable passes the IEC 60228 easily. 

Why should i care about the IEC 60228 standard ?
Why do you care about the thickness, if the resistance is within the limit permitted by the relevant standard?
 

Offline thm_w

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Why do you care about the thickness, if the resistance is within the limit permitted by the relevant standard?

It was sold as ISO6722 so should pass that. It seems to be slightly different from the IEC one.
Anyway, thickness, if you really were using this cable industrially you might care what the insulation thickness was. In this case there are some variations of ISO6722, one of them is ultra thin which allows down to 2.4mm. No idea which one OP bought.

Maybe this is the company? https://www.leoni.com/about-us/quality
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Offline eTobeyTopic starter

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I don't see huge issue here as your cable passes the IEC 60228 easily. 

Why should i care about the IEC 60228 standard ?
Why do you care about the thickness, if the resistance is within the limit permitted by the relevant standard?

I dont care about the thickness, i care about the cross section. It was specified on the product page.

Why are there no dimensions in the standart? As per product details it said its dimensions is from that standard. To me its still a scam, because it says 2.5mm2 everywhere, and not directly that there is a standard for this 2.5mm2 (it should have a '*' and a mention somehwere!
« Last Edit: May 22, 2024, 05:06:32 am by eTobey »
"Sometimes, after talking with a person, you want to pet a dog, wave at a monkey, and take off your hat to an elephant." (Maxim Gorki)
 

Online Zero999

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I don't see huge issue here as your cable passes the IEC 60228 easily. 

Why should i care about the IEC 60228 standard ?
Why do you care about the thickness, if the resistance is within the limit permitted by the relevant standard?

I dont care about the thickness, i care about the cross section. It was specified on the product page.

Why are there no dimensions in the standart? As per product details it said its dimensions is from that standard. To me its still a scam, because it says 2.5mm2 everywhere, and not directly that there is a standard for this 2.5mm2 (it should have a '*' and a mention somehwere!
1) The cross section is determined by the conductor thickness.  :palm:

2) Who cares about the dimensions, so long as it isn't too thick i.e. it fits in the terminals and meets the minimum resistance specification?

3) Would you rather have thicker cables, with the same resistance?

There are different grades of copper. If the manufacturer can use less of a higher grade material, then they can make their cables thinner, whist achieving the same resistance.
 
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Offline eTobeyTopic starter

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1) The cross section is determined by the conductor thickness.  :palm:

2) Who cares about the dimensions, so long as it isn't too thick i.e. it fits in the terminals and meets the minimum resistance specification?

3) Would you rather have thicker cables, with the same resistance?

There are different grades of copper. If the manufacturer can use less of a higher grade material, then they can make their cables thinner, whist achieving the same resistance.

1. Please define "thickness".

2. I do care. Because i dont really care about some standards that tell me "this resistance is good enough for you".

3. Yes, i could live with 2,7mm2 cross section, that has the same restance as a 2.5mm2 (perfect copper) one. Unless it would not be briddle!
"Sometimes, after talking with a person, you want to pet a dog, wave at a monkey, and take off your hat to an elephant." (Maxim Gorki)
 

Offline krish2487

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Then I would suggest for your sanity, and more importantly our sanity - get in touch with a cable manufacturer and get the damn thing manufactured to your preferred specifications.
Since you dont care about standards, and most of these run of the mill commercially available stuff is made to some sort of standard ( loose or otherwise )

1) The cross section is determined by the conductor thickness.  :palm:

2) Who cares about the dimensions, so long as it isn't too thick i.e. it fits in the terminals and meets the minimum resistance specification?

3) Would you rather have thicker cables, with the same resistance?

There are different grades of copper. If the manufacturer can use less of a higher grade material, then they can make their cables thinner, whist achieving the same resistance.

1. Please define "thickness".

2. I do care. Because i dont really care about some standards that tell me "this resistance is good enough for you".

3. Yes, i could live with 2,7mm2 cross section, that has the same restance as a 2.5mm2 (perfect copper) one. Unless it would not be briddle!
If god made us in his image,
and we are this stupid
then....
 


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