[OT] What are the characteristics of 13 amp mains flex?

I am in the UK and have an old portable electric heater.

The mains flex to the heater is like that to a domestic iron: woven fabric outer overlaying a rubber (?) outer sheath. With each of the three leads covered in rubber insulation and three cords running alongside the three leads.

(1) Is the fabric outer to make the flex resistent to KINKING? Or is it there for HEAT PROTECTION?

(2) Is the RUBBER used in this sort of flex especially resistent to TEMPERATURE?

(3) Are the alternative materials (such as silicone rubber) used in modern equivalents to this type of lead SUPERIOR IN ALL RESPECTS to the sort of flex I have described?

Reply to
Urman
Loading thread data ...

I have found that the silicone rubber modern ones tend to split rather easily if frequently flexed. Examples : a/ Weller bench mounted soldering iron - lasts about a year before cable needing replacing. b/ My dentists magic camera that he pokes in my mouth - silicone rubber sheath cable split within 6 months

AWEM

Reply to
Andrew Mawson

The answers to these questions have completely changed over time. Back when your heater was bought, the cotten cover improved the heat resistance of the cord against coming in contact with hot surfaces. Nowadays, various types of man-made rubber can survive higher temperatures than cotten so it's no longer used for this purpose.

However, you'll still find cotten covering on iron cords. The reason for this is that rubber cords catch on the fabric you are trying to iron and move it on the ironing board, whereas the cotten covering helps reduce the effect as it slides easier against fabrics.

Reply to
Andrew Gabriel

So donate it to a museum or scrap yard.

| The mains flex to the heater is like that to a domestic iron: woven | fabric outer overlaying a rubber (?) outer sheath.

Yes, it is vulcanized latex, better known as "rubber".

| With each of the | three leads covered in rubber insulation and three cords running | alongside the three leads.

The string is to prevent stretching.

| (1) Is the fabric outer to make the flex resistent to KINKING?

Yes. But it frays with excessive twisting/bending, usually where it enters the appliance. No need to shout.

| Or is | it there for HEAT PROTECTION?

No. Cotton is flammable.

| (2) Is the RUBBER used in this sort of flex especially resistent to | TEMPERATURE?

No. The cord or flex should be kept away from direct heat. After entering the appliance (iron, toaster, heater) the rubber sheath and fabric is stripped away and the conductors sheathed in a heat resistant material that also insulates, such as fibreglass.

| (3) Are the alternative materials (such as silicone rubber) used in | modern equivalents to this type of lead SUPERIOR IN ALL RESPECTS to the | sort of flex I have described?

In general, yes, material science has made improvements over older technology, although the techniques of insulation have changed little.

A neighbour of mine recently asked me if I knew of anyone interested in a Betamax VCR. I told him he had to be joking and found one on e-bay to show him, £0.99. If you want to use old technology, go the whole hog and light a coal fire, clean out the ashes each day and hire a chimney sweep on a regular basis - if you can find one - see Mary Poppins. Get a wooden clothes horse and dry your knickers in front of the fire. Otherwise find an empty space in a bin or scrap yard before you incinerate yourself and your family accidentally.

Androcles

(Note to Dork Van de merde: it's ok for *you* to use old appliances.)

Reply to
Androcles

Hmm. My oldest Antex must be something like 15 years old. I do have several and swop them to the PS rather than change bits, but of course one gets the most use and I've not had any problems. Is your Weller in heavy use?

Reply to
Dave Plowman (News)

My Antex must be over 20 years old and still on its first flex, been used for everything from soldering to pyrography to, erm, well quite a lot of things.

IIRC the stand had to get glued back together where it got dropped and the coily wire would no longer stay in.

Owain

Reply to
Owain

Dave Plowman (News) wrote

My Wellers are much older than that and havent split.

Reply to
Rod Speed

Urman wrote

Nope, its just there to keep the 3 inner wires together.

Its a bit more flexible than the more common plastic or rubber outer.

NOpe.

Nope, its what was used before plastic was cheaper.

Not really, its just cheaper now than rubber.

Reply to
Rod Speed

Never really saw that with all the production Wellers we had in the factory, must have had 20-30 going 8 hours a day, 5 days a week.

Dave

Reply to
gort

no, they probably kink more than any other type of flex

sort of, it offers some protection but not a lot. Modern pvc flexes are nowhere near as heat tolerant as cotton/rubber.

relative to pvc, yes. Relative to any other rubber, no

butyl rubber

NT

Reply to
meow2222

By "cord" here, I mean the whole cable, and not the three pieces of string (which are just fillers to keep the outer shape circular, which helps avoid kinking).

Reply to
Andrew Gabriel

Indeed - but of course not all Antex irons use silicone flex.

Mine is screwed to the bench. ;-)

Reply to
Dave Plowman (News)

I wasn't carrying a bench down six flights of stairs and halfway across campus every time something fell apart in the student radio station.

Anyway, anything screwed down would probably have got nicked. I hardwired everything in without fuses so if someone tried to walk off with owt they'd have got some sparks for their trouble.

Owain

Reply to
Owain

they dont do that anymore

Reply to
Squibbly

Is there somewhere on the net where I can see the British Standard for main cables for free? The sites I try seem to charge for it.

Based on this search

formatting link
I think the standard is BS6500 (1990).

Reply to
Urman

Is Butyl Rubber better than silicone rubber for heat resistance?

Reply to
Alex Coleman

That's because British Standards charge for all their standards. When the standard is a joint one with some other body (as in the case of the Wiring Regs), it is usually cheaper from the other body.

"Electric cables. Flexible cords rated at 300/500V, for use with appliances and equipment intended for domestic, office and similar environments."

A 1990 version would be out of date (I see a reference to a

2000 version, but I don't know if that's the latest).
Reply to
Andrew Gabriel

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.