Is the market flooded with fake dangerous solar cable

[robint]

I have taken delivery of samples of TUV solar cables 6mm2 from EB. I was curious to know if these conformed to the specs. Correct me if I am wrong but we should have tinned Cu annealed wire 0.3mm dia x 84 strands. This gives 5.94mm2 thats ok for 70A. according to TUV specs

 The samples I got
a) looked genuine printed on the outside "6 sqmm DUCAB C BICC PV cable 1.5kV but it had 84 x 0.25 dia core = 4.124mm2
b) unmarked plain black pvc with inner white sheath 84 x 0.22mm dia strands = 3.193mm2

Both seemed to have stiff strands (IMHO not annealed (springy) hence potentially fragile especially round crimp connections - soldered? flapping in the wind when not fully secured)

Clearly a very important discrepancy

Before I go Nuclear with the suppliers, has anyone else noticed this issue as I took one look at the cable construction and immediately thought that its an obvious area for cheating.

I think you will agree that a 40 -50% undersized cable is a cause for concern

[coppercone2]

well if they change the diameter of the inner strand without increasing the strand count its clear fraud. You could increase strand count to get a different more flexible cable, with slightly lower ampacity, and slightly different crimping parameters.

A single strand has the highest ampacity for strait DC, for AC strands might actually help a tiny bit (we are talking HF) based on stuff that user 't3slaco1l' discovered about stranded wires, but this is true for only something like a induction coil running in the ultrasonic + frequency. I believe changing the strand size might have a <5% effect.


But given that we are not getting solar power from a relativistic speed binary system of a star and a black hole and its steady sunlight, you would ideally want a single strand.


The rule is for everything conventional: if it weighs less in comparison without the insulation its simple fraud. you are getting skimmed on a commodity metal :'(


I recommend stripping insulation from some 2 meter segments, coiling them up, and weighing them, to see how much copper got skimmed.


Now there is also the question of the insulation. That is harder to test. But if they skimming copper wanna bet its something lower quality? Common test might be to burn it in a kiln at some temperature that leaves inorganic materials to measure percent of inorganic additive i.e. barium sulfate or sand that is pure filler. Common in plastics but its a  very specific proportion that you need. You can mess with the ratios to reduce cost and make it weaker etc.

[SeanB]

Simplest test for the plastic is to take a 10cm strip of it, remove the copper, and use a lighter to try to ignite it. If it goes out within 30 seconds of removing the flame, or does not burn, unless you keep the flame on, it is the correct insulation with flame retardant, but if it carries on burning then cheap non flame retardant plastic was used.

[Ian.M]

Stiff strands are suspicious from a conductor composition viewpoint.  See https://www.fscables.com/other/blog/CCA-CCS-CCC-vs-pure-copper-know-the-difference.html

• CCS is easy to spot - a magnet sticks to the core.
• CCA is a bit harder but the flame test easily detects it.
• CCC can only be detected by resistance and lack of ductility.

[coppercone2]

oh yeah I forgot about CCC wire. better get your mohm meter

[Ian.M]

Its not too difficult if you extract a single strand.  1m of 0.22mm dia copper wire should have a resistance of about 0.45 ohms.  Any low ohm meter, even an analog capacitor ESR meter should be able to tell you whether or not the resistance is under 0.5 ohms per meter given a one meter sample.  If you don't have a low ohm meter, a four wire resistance test using a 100 mA current source + a battery powered x10 OPAMP amplifier will give you direct readout 1V/ohm, easily readable on a handheld DMM's mV range. 

N.B. Reverse the 'force' connection from the current source and average the absolute value of the two readings to cancel thermal EMFs. 

The current source  can be as simple as a well heatsinked LM317 with a 1.5 ohm 1W sense resistor between OUT and ADJ (current output from ADJ) and a 47 ohm trimmer in series with a 56 ohm resistor across the sense resistor so you can trim to 100mA.

Some  sample 1% or better low ohm resistors would be useful to check accuracy.

[Spar59]

Unfortunately the market is flooded with fake/dangerous everything, be wary when buying from Ebay/Ali and even Amazon.

Now I am not saying all the stuff they sell is junk, some is genuine, some is decent but just not from a top brand manufacturer, but if it seems too good a price to be true then you need to ask yourself why.

Now if the price is just a little cheaper than you expect, you have an issue - it may be genuine, or it may still be fake but with a better profit margin for the scammers.

My own stance is to always inspect stuff before use:

Are the cables really solid copper or copper coated aluminium, or even worse from a conductivity point, copper coated steel - easy to tell based on flexibility, colour and weight before you go all the way to checking their resistance.

Is a mains power supply safely contructed? - visual inspection is worthwhile if you know what you are looking for.

Are those 1% tolerance resistors really 1% or better? - maybe not but if they are say 2% and cheap is it really an issue - I don't tend to stock 5%, 2% & 1%, just 1%, if the value is critical I measure the actual resistor before sticking it in the circuit.

But is that transistor or integrated circuit genuine? - now it gets really complicated and only time (or poor/unreliable performance) may tell.

[robint]

Well it hasnt got any better.  I now have 4 samples of potentially fraudulent cable - Listed or labeled as 6mm2 but measures as 4mm2.  That a BIG difference in Solar terms 70A to 50A  and btw this assumes xlpe covering to operate up to 90C vs PVC to 60C (which would become brittle with ordinary domestic twin and earth stuff.

The latest sample has a major US cable makers name on the jacket.  I am sending a sample to confirm it is fake

Really I am having trouble getting a wholesaler to cooperate by sending me a short 1m sample, surprisingly coy so far?? .  But this is UK and our gov wasted billions on a similar scam involving PPE masks (fake markings)

[BrokenYugo]

My rule of thumb is if it could realistically burn the house down (mains powered unsupervised, large lithium batteries, building wiring, etc.), buy from trusted suppliers you can easily drag into court over it, gambling with Chinesium is for fun only.

With real actual copper wire/cable I think the bulk of the price is the copper cost if you aren't in some high margin hardware store. There really are no deals beyond whichever trusted local supplier has the thinnest margin.

[themadhippy]

Really I am having trouble getting a wholesaler to cooperate by sending me a short 1m sample, surprisingly coy so far?

wholesalers will SELL you a meter of cable,but depending on type expect a cutting charge as they'll be left with the rest of the drum to try and get rid of,and1 meter aint really a sample .If your dealing with a well known wholesaler(city electrical/rexel/denmens//edmsons/tlc for example) youll pay more than ebay,but are fairly certain you'll get what you paid for,most of them will even give you a choice of manufacter.

[AVGresponding]

Really I am having trouble getting a wholesaler to cooperate by sending me a short 1m sample, surprisingly coy so far?

wholesalers will SELL you a meter of cable,but depending on type expect a cutting charge as they'll be left with the rest of the drum to try and get rid of,and1 meter aint really a sample .If your dealing with a well known wholesaler(city electrical/rexel/denmens//edmsons/tlc for example) youll pay more than ebay,but are fairly certain you'll get what you paid for,most of them will even give you a choice of manufacter.

If you go to the trade counter, you can have a look at the cable before you buy.

[thm_w]

I have taken delivery of samples of TUV solar cables 6mm2 from EB.

What the hell is "EB"?
Can you say where these samples are coming from?

As mentioned above, if its ebay or amazon, you are completely wasting your time.

[Haenk]

I'd certainly not exclude ebay and Amazon, at least not in Germany (and probably some other parts of Europe).
As soon as it is a "branded part" for a regulated area of craftsmanship, local dealers will only sell at full list price, which is often way beyond reasonable pricing.
However these dealers don't have a problem with selling these parts on ebay or Amazon (or from their own online store), in this case they don't hurt anyones' business within their own regulated area.
So for your stuff you want to install on your own, shopping online is the way to go, and fake products are very uncommon, at least, if buying from an obviously established german company. Of course, don't buy from dodgy chinese companies (which sometimes do have a registered company in Germany, but still dodgy products).

Just two examples: I bought my premade solar cables on Amazon, from a large local company, which did venture into solar business, but quit solar again, and sold their solar inventory pretty cheap (I think it was like 15 EUR including shipping for a 5m mains cable with plugs plus 5x 1m panel cables with plugs. Obviously good quality.) Annoyingly, it was cheaper for my 4 solar panels to be shipped across the country than buying them locally, by like 30%.

[robint]

Well guys I think the takeaway here is that , if you are going to invest in solar cable, dont believe what you are shown. IMHO snip a bit off say 100mm and strips it, count the strands and measure the strand thickness.  Look carefully at the jacket printing, take photo if possible (difficult if black embossed into the jacket) otherwise write the whole text down accurately then go away and study your results.  There should be a manufacturer so you can check with his catalog, or call them up.

You might save yourself some downstream trouble and expense.

So far I am deeply suspicious, I have 4 fake samples to date and have more samples on the way.  I wouldnt want to push 70A thru 4mm2 core on a sunny day with ambient over 30C. That cable will be way to hot to touch

I would like to do some load current tests but I have to set up a 100A rig and an oven - it takes time and I have many other Lifpo an SiB cells tests on the go.  It will have to wait till Spring

[themadhippy]

Well guys I think the takeaway here is that , if you are going to invest in solar cable

Buy it from a reputable dealer.

Not sure were your getting 70A for 6mm from,everywhere im looking is saying 50-55A which is more in line with what id expect, the only 6mm cable id trust  to take 70A is heavy duty micc,and even then its at the limit of its rating and it aint known for its flexibility.

[thm_w]

I'd certainly not exclude ebay and Amazon, at least not in Germany (and probably some other parts of Europe).
As soon as it is a "branded part" for a regulated area of craftsmanship, local dealers will only sell at full list price, which is often way beyond reasonable pricing.
However these dealers don't have a problem with selling these parts on ebay or Amazon (or from their own online store), in this case they don't hurt anyones' business within their own regulated area.

Sure if you find a known good dealer that sells on Amazon or Ebay, then its an option, of course. That is not what the OP has done, they've probably sorted by cheapest and just bought from random china importers.

[Psi]

I need to get some solar cable at some point soon, thanks for the heads up.

[AVGresponding]

I have taken delivery of samples of TUV solar cables 6mm2 from EB.

What the hell is "EB"?
Can you say where these samples are coming from?

As mentioned above, if its ebay or amazon, you are completely wasting your time.

Edwardes Brothers, I guess? Never used them myself.

Well guys I think the takeaway here is that , if you are going to invest in solar cable

Buy it from a reputable dealer.

Not sure were your getting 70A for 6mm from,everywhere im looking is saying 50-55A which is more in line with what id expect, the only 6mm cable id trust  to take 70A is heavy duty micc,and even then its at the limit of its rating and it aint known for its flexibility.

Agreed, I'd want 16mmsq (100A) tri-rated for this, for a bit more safety margin than 10mmsq (75A).

[Berni]

Springy strands are usually a red flag for fake copper plated wires.

The quick check for that is to scrape the wires with a knife. If you can start seeing a silvery shine coming from the wires after scraping then you likely have copper coated aluminium.

Another way to check is resistance. A typical multimeter will have trouble measuring that low. But the easy way is to just take your lab PSU, set it for 1A output and hook it across the wire, then use your multimeter to also measure the voltage drop across the wire, for even 1mV of drop you got 1mOhm of resistance.

The resistance check is the best test for a wire because that directly tells you how hot the wire will get at a certain current. So no matter what the wire is made out of and how thick it is. If the resistance is the same as the desired copper wire in the data tables, then it will be able to carry the current.

If you are buying the cable locally then you don't need to get samples. Just buy it and check. If it is fake cable take it back to them for a refund. If they refuse to give you a refund report them to your local consumer protection body for selling fake goods.

[Electronicgeek]

Interesting! Worried about mine so borrowed a calibrated micrometer from work. Came out at 0.301mm diameter counted 84 strands.

[robint]

@madhippy
Q
Not sure were your getting 70A for 6mm from,everywhere im looking is saying 50-55A
UQ
This TUV specs for silicone sheathed solar cable - runs much hotter to 90C  that PVC 60C whici is 50-55C

[robint]

Lucky for you , its the real thing  84 x 0.3mm is 6mm2

[Electronicgeek]

  Got it off eBay as well so not too bad!
The max current rating for 6mm2 solar cable is 70A but this is in free air. Reduced rating as with all electrical cable must be applied is cable clipped to a wall and it would go down to 57A if two cables are ran along side each other.
I have been having a chat with a friend and he said Doncaster Cables do 84 x 0.283mm cable with is advertised as 6mm.

[Electronicgeek]

Just found this on Doncaster Cables website. It says 84 strands at 0.283mm but the next column says 0.3mm!

[robint]

Had to post this - how to disconnect solar panels live on a sunny day  https://www.youtube.com/shorts/hF9gZvCh70g?feature=share

[AVGresponding]

Had to post this - how to disconnect solar panels live on a sunny day  https://www.youtube.com/shorts/hF9gZvCh70g?feature=share

 

I guess tarps/blankets to throw over the panels are a yet-to-be-discovered technology in that part of the world...

[AVGresponding]

Just found this on Doncaster Cables website. It says 84 strands at 0.283mm but the next column says 0.3mm!

No, they list the strand diameter as 0.283mm, and the overall conductor diameter as 3.02mm.

[Electronicgeek]

That is insane!

[robint]

IMHO, the take away here is, if you are going to buy drums of solar cable , make sure you test a sample before parting with your cash, If a decent length is available, say 100m, 500m the a 4 point resistance measurement is what industry does (but you need a quality meter with a precalibration made beforehand)