Appendix 6 OSG Ask questions and find answers to many subjects relating to electrics and electrical work

[kbrownie]

Hi all, I'm sorry if I keep coming up with questions regarding subjects that may be out of the scope of your average DIYer.
Just been doing some cable calcs. Whilst doing these there was a sentence on page 125 in The OSG which reads as follows; For cable installed in thermal insulation as described in Tables 6D1, 6E1 and 6F no correction is required.
Does anyone no the reason for this as these cables are of a typical type and would be expected to be installed in a whole host of places.
Also why is there a correction factor 0f 0.9 for cable buried underground and what is considered to be buried, this is regarding to correction factor Cc.
Any thoughts are welcome.
Kb

[sparx]

Hi. KB (&EricM),
I think this is another example of poor English in both the guide & the regs itself.
Tables in OSG are as you will have seen are just renumbered versions of the regs tables (why do they not keep them the same?)!!!!
ie 6D1 = 4D1A, 6E1 = 4D2A, 6F = 4D5.
I believe the comment only applies to column headed ref method A, and should SAY SO!,
As for buried cables I presume opposite of 'Free Air' ie poor heat loss possible from cable due to being surrounded by 'insulating' soil as opposed to being in a duct,
I await contradictions to above with interest.
BTW there is someone called 'Henry' who 'lifts' posts from this site & reposts them verbatum on the NAPIT members forum in a very derogatory manner....
one day we shall meet!!!
regards SPARX

[kbrownie]

Hi Sparx, Thanks for reply now that makes a little more sense!
It's a shame that they found this not important enough to put in to print!
I agree totally about renumbering of tables it's drives me nuts! What's the reasoning about it!
Cheers again Sparx