Insulation of old reel of enamelled copper wire? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: January 24, 2024, 06:35:53 pm
content: Hi,Our customer has found an old reel of enamelled copper wire marked.."Rowan cable Products LtdPART 1230978 0.4MMWIRE COPPER ENAMELLED”Rowan cable Products Ltd exists no more, neither the given part number.Is there any chance that the wire's insulation is any lower than those in the below from elektrisola ?That would be 2300V for 0.4mm Grade 1 enamelled copper wire.https://www.elektrisola.com/en/Products/Enamelled-Wire/Technical-Data

author: Gyro
author_rank: Super Contributor
timestamp: January 24, 2024, 07:04:14 pm
content: Impossible to answer of course! Use known current production products, not old unknown reels from who knows where!

author: Stray Electron
author_rank: Super Contributor
timestamp: January 24, 2024, 07:22:39 pm
content: I've never worked with that brand cable so I can't really answer your question directly but I worked with enamelled wire a very long time ago and I don't think that the insulation was rated at anywhere near 2300 volts! Most electrical in the US today is only rated at 600 Volt insulation and it uses a much thinker insulation than the enamelled covered wire.My advice is that if you really want to attempt to use that cable then make a test stand with a variable AC output and test some samples and see what voltage the insulation fails at. OTOH if you're building a commercial product andliabilityis a concern then you should forget that stuff and go buy wire with insulation that IS rated for the necessary voltage.

author: audiotubes
author_rank: Regular Contributor
timestamp: January 24, 2024, 07:39:22 pm
content: Quote from: Faringdon on January 24, 2024, 06:35:53 pmNot an answer to your question, but amateur radio operators and shortwave radio listeners would definitely be interested in enameled copper wire in good condition.Some mumble-grumble number or years ago I made a 40M dipole out of enameled wire and it worked a hoot.Worst case, I'm sure they can find a buyer on the 'bay.

author: tggzzz
author_rank: Super Contributor
timestamp: January 24, 2024, 09:10:02 pm
content: Quote from: Faringdon on January 24, 2024, 06:35:53 pmYes, there is.You areYour customer is an idiot for asking such a question.In other words, a typical faringdon/treez/ocset question/troll.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: January 24, 2024, 10:15:57 pm
content: Quote from: tggzzz on January 24, 2024, 09:10:02 pmThat's what I was thinking too.The stuff is probably good enough for DIY applications, but for anything industrial or even commercial, labor costs are likely much more then a roll of copper, and recycling it makes more sense.

author: jc101
author_rank: Frequent Contributor
timestamp: January 24, 2024, 10:45:37 pm
content: Rowan Cable Products Ltd is still a company, albeit a dormant one. According to Company's House, it seems to have spent much of its time dormant.Dispose of it as a totally unknown thing, more so if it going anywhere near to mains power.

author: langwadt
author_rank: Super Contributor
timestamp: January 24, 2024, 10:53:26 pm
content: Quote from: tggzzz on January 24, 2024, 09:10:02 pmand undoubtedly made up, for just that reason

author: jonpaul
author_rank: Super Contributor
timestamp: January 26, 2024, 01:27:43 pm
content: Old stock magnet wire will be susceptible to cracks in the insulation.Just recycle and buy new wirej

author: Faringdon
author_rank: Super Contributor
timestamp: January 26, 2024, 07:05:42 pm
content: Thanks,Today i got an empty old solder spool....i then tightly wound a 4cm layer of the enamelled copper wire on the spool.I then tightly wound another layer on top of it.I then connected one coil to mains line, and the other to mains neutral(240vac). Also added a 500mA fuse.When i switched the mains on.....there was no flashover...nothing happened. I then added a 10k resistor in the neutral line and probed it and confirmed that there was no leakage current flowing through it.The end pieces of the wires got pretty badly kinked, and were against each other where they had been stressed and kinked..but no problem.I did this with the 0.4mm and the 0.224mm enamelled copper wirefrom Rowan Cable.This shows IMHO that this kind of wire is ok for rough prototyping of SMPStransformers for offline SMPS.I confess that eg flyback peak drain voltages will be more voltage stress...but ive done it before and had no problem.I think i need to repeat this with a mains doubler voltage rectifier, to get a nice 680V DC between the coils.

author: langwadt
author_rank: Super Contributor
timestamp: January 27, 2024, 12:38:42 am
content: just keeps on getting more and more silly, undoubtedly on purpose ...

author: Gyro
author_rank: Super Contributor
timestamp: January 27, 2024, 11:09:10 am
content: Quote from: Faringdon on January 26, 2024, 07:05:42 pmIsn't it 'your customer' who has found this reel of old wire? It sounds like "rough prototyping" = production to me.Of course 'the customer' is probably another of your flights of fantasy.