Extra flexible main lead

Alex Coleman wrote in news:Xns97BA3E7A2DD1F71F3M4@127.0.0.1:

Silicone rubber covering is MUCH more flexible, and stands higher temperatures, but is more expensive and much less resistant to abrasion, cutting and especially crushing. While it's rubbery, it crumbles like a weak crystal under moderate pressure, wheras PVC would be more ductile even at higher pressures. Both give off harmful gasses if you heat them enough to burn. I think silicone rubber might have a higher dielectric strength than similar thickness on PVC, but I'm not sure.

Reply to
Lostgallifreyan
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Reply to
Grunff

Grunff wrote in news:9hcri3- snipped-for-privacy@mercury.tcm.vispa.net.uk:

Can't help wondering how they specify 1.5 mm2 at 16 amps and 2.5 mm2 at 15 amps. :)

Stuff is cheap though, very.

Reply to
Lostgallifreyan

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Reply to
Dave Plowman (News)

I wouldn't think so; silicon isn't very flexible. That's why thermal stress tends to cause power transistors' silicon dies to fail.

Tim (yes, I have to :-p)

Reply to
Tim Williams

Quite right. Silicone flex isn't bad, though. Have some on the small soldering iron.

Reply to
Bob Eager

Ah, silicone not silicon!

And is it a form of rubber or is it just called "silicone rubber" because it is silicone made to behave like rubber?

Interesting about how it crumbles.

Reply to
Alex Coleman

AFAIK, it's always rubbery. I would think heavily crosslinked silicones could have pretty solid structure, but I've never heard of a hard or brittle silicone product so I guess not.

Tim

Reply to
Tim Williams

Alex Coleman wrote in news:Xns97BAECBEA67AF71F3M4@127.0.0.1:

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'm really beginning to like that Wiki)

I didn't know they could be hard plastics too.. They mention silly putty, which is a silicone, and an extreme example of what I was getting at. I think many silicones have an abrupt change of properties under impact either at speed or pressure. Cable covering has a weak pressure resistance, silly putty has a poor speed resistance, and either way what happens is they cease to move as a fluid elastic, and will fracture like glass or crystal.

Reply to
Lostgallifreyan

Yes - my oldest soldering iron with silicone lead which came with a Maplin kit solder station must be well over 10 years old and the lead is still fine despite mucho flexing over the years.

Reply to
Dave Plowman (News)

Nice wiki entry but it doesn't answer if silicone is mixed with rubber (latex) to make what is called "silicone rubber".

But I did find the answer here:

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No latex. Only a similarity with rubber: Organic rubber - carbon linkages, silicone rubber - silicone oxygen linkages

Nice, that wiki thing!.

Reply to
Alex Coleman

I've seem mains cable (240VAC over here) that's super flexible. The examples I've seen use silicone rubber sheathing (which is also exceptionally heatproof, BTW) with cores made from many more & finer strands than usual. Looking at the RS electronics website, (which requires a login, so I can't quote a URL), Beldon's CYSC03.00100 is probably the style of cable you're looking for:

---------- A continental style flexible power control cable, commonly known as ?CY? type. The fine stranding of the cores combined with the tinned copper braid produces a cable with characteristics of a flexible mains cable with the screening properties of a signal cable. This makes the cable ideal for uses such as automated and robotic equipment where screening is required and the equipment may be subjected to vibration or movement. technical specification Conductors Annealed copper Sheath PVC Braid Tinned annealed copper Outer sheath Grey PVC Core colours 3 core Blue, Brown, Green/Yellow 4 core Blue, Brown, Black, Green/Yellow 5 core Blue, Brown, Black, Black, Green/Yellow 7 core Green/Yellow + 6 numbered

key characteristics csa 0·75mm2 1mm2 1·5mm2 2·5mm2 Conductor size 24/0·2 32/0·2 30/0·25 50/0·25 Current rating (A) 6 10 16 20 Overall dia. (max.) 3-core 7·2 7·6 8·2 10·1 4-core - 8·2 9·5 - 5-core - - 10·3 12?·4 7-core - - 11·1 -

Voltage ratings : between conductor and earth 300V between conductors 500V Current ratings: For further details consult IEE Regulations 16th Edition table 4H3 Temperature ratings: Flexing -5°C to +70°C0. Stable -20°C to +70°C

----------

You'd most likely want the 1.5mm^2 (30 strands, 16A) or 2.5mm^ (50 strands, 20A) types.

Reply to
Lionel

I Cables made in the far east are less flexible at normal UK ambient temperatures, they are fine on hot days though. Rubber cable is available but a lot more expensive than PVC. Companies that install cold rooms use rubber because PVC is difficult to handle at low temperatures. Arctic grade PVC is a good compromise but is usually blue or yellow. Silicon rubber cable is available in 0.5mm 3-core, it is usually used for soldering irons and is very flexible. What application did you have in mind?

Reply to
Neil J. Harris

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