reference methods

[cagedanimal2010]

hi guys,
whats the reference method, of t&e clipped direct to wooden joists above ceiling with insulation??
cheers guys!!

 

[dichroic]

Is the cable totally surrounded by thermal insulation ?

Regards

Dichroic

 

[dichroic]

For a cable likely to be totally surrounded by thermal insulation over a length of more than 0.5 m, the current-carrying capacity is to be taken as the current-carrying capacity for that cable clipped direct to a surface and open (Reference Method C) multiplied by a derating factor (

) for thermal insulation. In the absence of more precise information,

is to be given a value of 0.5.

Tabulated current-carrying capacities for various types of cable installed in a thermally insulating wall or above a thermally insulating ceiling - the cable being in contact with a thermally conductive surface on one side are given in Appendix 4 of BS 7671.

Regards

Dichroic

 

[Guest123]

It'll either be method 100 or 101 depending on the thickness of the insulation, i.e less than 100mm = method 100, more than 100mm thick = 101.

 

[cagedanimal2010]

thats what i thought lenny, but keep getting told i'm wrong its "C" .
cheers buddy

 

[JUD]

thats what i thought lenny, but keep getting told i'm wrong its "C" .
cheers buddy

Whoever it is telling you it's wrong, direct their attention to page 265 (Table 4A2) of BS 7671.

Ref. Methods 100 - 103 are specifically for T&E cables in insulation.

 

[cagedanimal2010]

cheers again guys!!! will take great pleasure in gloating tomorrow!!! :-D