Another Armoured Cable Qestion

[Jim2287]

NIC tech manual shows that if you supply out building the earth you provide has to be main bonding conductor and CPC combined

the calc i did above does give the equivalent steel CSA to copper, right ?

a cable manufacturer said that you have to multiply the required csa of copper by 7.5 .... which sounds quite strange to me, surely steel isnt 7 times less conductive ? 10mm copper would mean you need 75mm steel

 

[Spark123]

From what I remember it is the K1/K2 value which you need to multiply to give the required CSA equivalent of the copper conductor i.e. see table 54G. I'll have to have a look at Guidance Notes 5 & 8 and get back to you on sizing.

 

[Spark123]

GN8 "Where a circuit protective conductor also acts as a bonding conductor the requirements for both functions will have to be met. In other words, as well as meeting the requirements of regulation group 543-01 for a CPC, the requirements of regulation 547-02-01 also have to be met."

 

[Jim2287]

ok, thanks everyone for the help