T&E and C/H Pipes

[doit]

Hi

I need to run a lenth of 1.5mm T&E for a fan, however the only route I have means the cable runs alongside a central heating pipe for approx 3ft. Would this be a problem, If yes, is there an alternative cable I can use.

Thanks.

 

[mapj1]

Slip a length of styrofoam pipe insulation over the CH pipe, or tie the cable to one side out of the way. If possible below is best, heat rising and all that. If this makes no sense come back.

 

[plugwash]

carefull what kind of insulation you use some plastics polystyrine attacks pvc cables.

 

[doit]

Sorry, should have said that the pipe and cable would be enclosed in boxing. The enclosed area would only be 2" X 7" and totally enclosed, even with insulation on the pipework it will still get quite hot in there.

Would T&E be OK in this enviroment or should I use a different type of cable/flex.

Thanks.

 

[mapj1]

The 1.5mm cable will be massively under run, so we can neglect self heating, and the PVC cable can go up to 70 degrees without damage (as a reference, about 50 deg is where most people say something rude and let go) If the pipe is lagged, and the cable is to one side of the boxing that is exposed to air on the other side, (and not insulated) I would be most surprised if you had problems.
If you are woried about the pipe insulation not being compatible with the cable, (styrenes can casue problems) fit oval conduit, or trunking to protect the cable.
If your heating is a normal boiler feeding rads, the water temp will be <70 deg to start with, and if the insulation on the pipe has a higher thermal resistance than the boxing in, the cable should be much cooler than the pipe itself.
Otherwise you are looking at pyro wire, which is really hard to use (mineral insulated copper clad) or high temperature PVC. Both are expensive and awkward.