Grouping factors

[DuncanS]

Hello Sparks, I'm quite new to all of this having quite recently gotten my certificates in the post. Today I started down the road of having my NAPIT inspection and I've come up with a concern whilst designing the circuits for installation... I'm installing a 10.2kw oven and a 9.5kw shower... After accounting for diversity on the oven I have settled on 6mm T&E 27 meters with a 32a breaker and 10mm T&E for the the shower with a 45a breaker for 15meters... Both clipped direct to wooden joists and plasterboard. I have accounted for an ambient temperature of 50*c as both circuits will be in the loft for a decent portion of the cable run... All checks out fine in terms of volt drop... My two questions are 1) how far apart do I need to clip the cables from each other in order to avoid any derating factor? 2) neither cable runs along side any other cables but I have no choice but to cross other circuits on three occasions, they will cross the path of a ring final circuit twice and a lighting circuit once, do I need to account for this in my calculations?
Thanks in advance to anyone who can help

 

[Richard Burns]

Grouping factors need not apply if the cables are spaced greater than twice the cable diameter apart, if cables cross each other at 90º then there should be no problem with this.

 

[telectrix]

what he said ^^^^^.

 

[DuncanS]

Thanks guys, that's what I thought, just couldn't find the exact words in my osg, and the 17th edition has been giving my funny looks from on the shelf, so I daren't open it!