Insulation and wires

[burntwire]

Hi all,

I went to a job the other day and the customer showed me a PIR from another company. They had failed the lighting circuit due to it being 1.0mm and not 1.5mm running in the loft space with insulation on top.

Has any one else ever put insulation issues on a PIR ?

TIA

 

[EFLImpudence]

They had failed the lighting circuit due to it being 1.0mm and not 1.5mm running in the loft space with insulation on top.

If, as is usual, the circuit is protected by a 5A/6A CPD then the report is just wrong.

 

[PrenticeBoyofDerry]

As stated above the report is wrong if the circuit is protect by 5A fuse or 6A MCB/RCBO.
The maximum de-rating through insulation would be 50%, 1.00mm T&E can carry a maximum current of 16A. So providing there are no other factors to add? even half that capacity is above the protective device rating.
If the circuit was a higher load circuit and protected by a 10A device then there would be cause for concern.

 

[EFLImpudence]

1.00mm T&E can carry a maximum current of 13A.

Actually 16A clipped.

 

[PrenticeBoyofDerry]

I have numb fingers today, edited accordingly.