On Feb 4, 10:42*pm, Part timer wrote:
Does anyone here have experience of self-regulating trace heating
cable within domestic settings? Keen to prevent future 'occurrences'
if December's conditions are repeated, I've been looking at my options
to protect a mixture of 15 and 22mm copper in our eaves.
I have found the following 10W/m cable:http://www.qvsdirect.com/Trace-J-Sel...g-Cable-pr-166...
What does “Maximum exposure temperatu 85°C - intermittent, 65°C
continuous” actually mean? I'm thinking along the lines of don't power
it up in free air unattached to a pipe. Am I correct?
I notice that the same company sells a connection and end seal kit:http://www.qvsdirect.com/Frostop-Con...-pr-16689.html
Is this expensive for what it is if I was to install several separate
cable runs? Could I just purchase heatshrink etc of appropriate
diameters instead.
I have read of the need for C type MCBs due to inrush currents,
thermostats, etc.

Would anyone care to do a wiki page along the lines of the one on SWA:http://wiki.diyfaq.org.uk/index.php?...erminating_SWA

Thank you very much.

In days of yore trace heating was exclusively done with steam. Later,
non regulating electric tapes came i that were wound round pipework
and left permanently on. They were just a bit of nichrome wire
insulated with butyl rubber, the same stuff as was used in underfloor
heating. They were fixed wattage and fixed length, single wire.
The stuff you refer to came in about twenty years ago and has two
parallel conductors and the higher resistance stuff between them that
heats up. They are rated in X wats per meter run (Variable ratings
available). This means you can just cut a bit off, attach the leads to
one end and a "blanking cap" to the other end, usually crimped on.
The wattage per meter you select depends on the insulation of the pipe
& temperature (ambient and pipe). Some are self regulating to a
degree in that as they get hotter the resistance of the tricky bit
betweem the conductors increases.

Back then when I had anything to do with them they were quite
unreliable, maybe the technology has been sorted out by now.