Heat Resistant Cable - Cable Touching Pipework is This ok? Ask questions and find answers to many subjects relating to electrics and electrical work

[terry38102]

i just wandered i had new boiler installed about 6 months ago the pipes were boxed in and it had been wired with fire proof cable going through the box.(prysman fp200 gold stamped on the side) i know you cant use normal twin and earth next to pipes so i just wandered if this is ok? the wires are touching the pipes at some points i just to ask if this was ok before i call the company who put it in and end up looking a total idiot.

[DIYorNot]

FP200 Gold can withstand high temperatures but is usually used for fire detectors and emergency lighting cabling in commercial installations.

The cable should really be secured and avoid touching central heating pipes where possible. If it touches in a few places, that shouldn't be a problem.

To confirm, why don't you contact FP Cables?

[terry38102]

there is part of it in trunking about 1 meter long where it was run along side a pipe. there was a electrician working on my neighbours house today i asked him if could have a quick look at it and he said its not how he would have done it but it should be ok. like you say i will speak to the manufacturer and check with them. cheers

[ericmark]

Most Ali-tube cable is rated at 90 degs C however FP200 says:-
5. What is the maximum operating temperature of FP200 Gold®?

Minimum operating temperature is – 20°C and the maximum is + 70ºC as laid down in the cable construction standard BS 7629 as required by BS 5839 and BS 5266.

6. Can FP200 Gold® be used at higher temperatures? e.g. 180 - 250ºC.

No, fire resistant cables are tested with a 950ºC flame for a defined period and are unsuitable for re-use after that. Special high temperature cables should be used for applications requiring 200ºC or similar continuous operating conditions.

So reading the specifications Guardian Ali-Tube/LSZH Cable BS8436 is in fact rated higher than FP200 that says:-
Operating temperature: Maximum 90°C, minimum bending -10°C

Since parts of the central heating water goes through metal radiators that you can touch regulation 423.1 table 42.1 gives 80°C as a max so only mineral insulated bare with a temperature rating of 105°C is sure to comply.

I can't see the current rating of FP200 it is not really designed to carry current other than fire alarm one would use other Ali-tube cables.

In real terms any ali-tube cable will transmit heat away from the conductors better than a 624B Twin & Earth LSZH Cable 300/500V BS7211 cable but rating remains the same. With 624Y Twin & Earth PVC Cable BS6004 A05VVH4-U you are limited to conductor temperature of 70°C but with LSZH Cable this rises to 90°C but that is conductor not outside and the conductor will be hotter than the outside.

Again in real terms likely nothing will go wrong, but it does not comply so get him back to change it. Info on cable is here http://cse-distributors.co.uk/cable/fp200.htm

[proptech]

I suspect the installer has used this cable in good faith, thinking it to be heat resistant. In fact as has already been said it is meant for fir alarm systems, and is only rated at 70 degrees.
For central heating system use, including the connection of pumps, it would be normal to use PVC heat resistant flex sold for the purpose rated at 90 degrees. Available in 3,4,5,and 6 core. Take a look at TLC's web site. If this is used and only touching a hot pipe here and there, it will be fine.

[terry38102]

i have tried to contact the company who put the boiler in phones all dead went round to there office and company gone bust(great) anyway i cant afford to get someone else in just now but from what everyone is saying if it will be ok i will get it fixed next year. the only reason i found out about it is because i was taking stuff in the door and hit the box with the pipes with a step ladder and burst a hole in it so i took it off the check the pipes for damage and thats when i noticed the cable. anyway cheers for the help.

[ericmark]

In real terms unlikely to be a problem.