derated cables

[beaver74]

HI all
been to a property to day that has had the loft fully insulated 150 mm deep on top of the existing insulation.question is what code to give it

1 imidiate danger
2 needs improvement as it poses no emidiate danger

I would go for 2
any remarks

 

[Dunc]

What size is the cable? If 1.5mm it may be okay, you need to check the de rating factor. It used to be 50% for cables fully enclosed in insulation with runs greater then 500mm but not sure without checking the BRB.

 

[truckster]

Lighting cables will probably be ok, table4D5 method 101 gives 10.5A for 1.00mm. Shower cables would be more problematic

 

[telectrix]

i'd either calculate the load and whether the cable ( derated) is overloaded or not. if not-- no code. or, give it a code 3 as requiring further investigation.

 

[Guest123]

Or you could do what I would say quite a lot of guys do and put "attic space not inspected":drunk:


On a more serious note, do the sums calculate the applicable factor and see where you are then.

 

[beaver74]

soory yes it is a kitchen ring whch has 2 x 2.5mm spured

I have sugested droping the circuit to a 20A and raising the spured cable above insulation as the cable as installed >100mm of insulation is 17A which leaves the cable still unprotected by the 20A ocp
all heavy loads a seperatly supplied