Polyurethane insulation

[Lilyrose08]

Hi
Needs some advice on running T and E in contact or along side Quinn Therm insulation which is basically the same as celotex I've been told it can melt the insulation of t and e cable when in contact I've got a big job coming up and don't want to risk it so might use fp 200 to be on the safe side if that is alright to use.

Any suggestions pls

 

[Top Cat]

Hi
Needs some advice on running T and E in contact or along side Quinn Therm insulation which is basically the same as celotex I've been told it can melt the insulation of t and e cable when in contact I've got a big job coming up and don't want to risk it so might use fp 200 to be on the safe side if that is alright to use.

Any suggestions pls

Just use LSF twe.

 

[MarkieSparkie]

Most manufacturers of insulation board, including Quinn and Celotex, have switched from Polyurethane to the more stable Polyisocyanurate material. The older Polyurethane board often reacts PVC cable insulation plasticiser causing de-polymerisation of the board, resulting in the melting and fusing together of the cable and board. Polyisocyanurate is far more stable and resistant to de-polymerisation with most current PVC cable insulation formulae.

 

[Midwest]

Hi
Needs some advice on running T and E in contact or along side Quinn Therm insulation which is basically the same as celotex I've been told it can melt the insulation of t and e cable when in contact I've got a big job coming up and don't want to risk it so might use fp 200 to be on the safe side if that is alright to use.

Any suggestions pls

Are we suggesting there can be some sort of chemical reaction between a PVC cable and polyurethane foam insulation, or of the need to derate the cable’s current carrying capacity because of the thermal insulation effect on the cable? Celotex state ' Celotex has no detrimental effect on the cable sheathing'.

Here's a link to their technical support.

Celotex Insulation | Technical

 

[Midwest]

Celotex state that polyisocyanurate foam is more widely used in thermal insulation over polyurethane foam, because it is more difficult to ignite. No mention of polyurethane foam having a chemical reaction with pvc cables. Can you point me to the study on this?

 

[Top Cat]

Found this:-
Q & A of the Day – PVC cable in conduit when passing through polyurethane insulation? - Voltimum UK - Electrical Installation Products and Contracting

Did an Eco house a while back and all walls were Celotex or polystyrene covered concrete blocks. The spec. said to use LSF cable to stop detrimental affect on cables. I also put cables in oval conduit so i didn't have to upgrade size of cables.

LSF twe cables are a bitch to use though!

 

[Lilyrose08]

So what's the answer to this can I use normal PVC t and e cable with Quinn therm polyurathane insulation and just protect it where it passes through the foam part.
Or do I need to use LSF cable instead of PVC and protect it as well.
Any help would be appreciated.