On Aug 22, 2:17*pm, Stephen wrote:
On Fri, 21 Aug 2009 13:42:40 -0700 (PDT), NT
wrote:

What makes you think their immersion heater cable may be dangerous?

Sorry, I thought you said in your earlier answer that even a 90 degree
rated PVC cable might overheat when connected to an immersion heater,
implying that PVC should not be used for this purpose?

If youre saying they're selling pvc flex as good for immersion heaters
it would be interesting to see.


What happens to butyl and PVC cables when they overheat?

Short term pvc goes very soft, conductors migrate through it, and
fires tend to happen. Long term is hardens and falls apart
Rubber suffers no ill effect short term, long term it hardens and
breaks.

So rubber has benefits in the short term but long term prospects are
bad with either?

Of course overloaded or overheated cable has poor prospects, thats
what overheated and overloaded mean.


BTW, how accurate are the thermostats? If set to 60C will I get 60C,
or 55-65C, or 50-70C, etc?

Last time I looked at specs for one it had huge hysteresis.


NT