In message ,
"David Pearson" wrote:

Hi everyone.

Putting cable in contact with expanded polystyrene is a bad idea,
because it causes the PVC insulation on the cable to become
brittle.

Can this, or any other problem, occur when running cable
next to other thermal insulants?


Polystyrene (not just the expanded variety) somehow causes the
plasticiser to leach out of PVC (turning it into uPVC?). This is what
causes it to go brittle. It's a chemical thing and I'm no chemist.

There are other issues to worry about when running cable next to or in
thermal insulation, the most obvious being the thermal capacity and
hence current-carrying capacity of the cable. There are regulations and
guidelines about this, but to get a sensible answer you're going to need
to provide us with a few more details of your problem. For example, what
size cable on which circuit for how long over/under/in/through what kind
of insulation in what kind of installation.

Hwyl!

M.


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Martin Angove: http://www.tridwr.demon.co.uk/
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