On 21/11/2017 13:35, Dave Plowman (News) wrote:
In article ,
GB wrote:
On 21/11/2017 09:29, Bob Minchin wrote:
GB wrote:
Wiring immersion heater - how important is it to use special heat
resistant flex?

Also, will 1.5mm2 do for a length of just over 1m in open air, or is
2.5mm2 required?
Vital! The terminals on the element run hot by conduction and ordinary
PVC goes very limp and insulation could easily be displaced.
1.5mm should be adequate for the current but not sure what the regs
might have to say.

Thanks. How do I determine whether the existing flex is heat resistant?

There are two common types. Butyl which has a cream sleeve and much softer
to the touch than PVC. There is also a heat resistant version of something
like PVC which is usually engraved as heat resistant. That is much less
flexible than butyl.


The butyl is suitable for use in contact with grease and oil and so
often seen used on cooking appliances.

It also, as you said is more flexible than the standard heat resistant
stuff.

--
Adam