Earthing inside a submain panel from main swa incomer

[davesparks]

You can quote the relevant sections of such a document, or post an image of the appropriate section. But you can't post big chunks of the book like whole pages

 

[Skimpy Wan]

Okay. I'll pay reference to the page / document when I get a chance over the weekend.

 

[Guest 004]

This still will not answer my OP.
FYI the supply cable is FP600, so please post the relevant docs.

 

[Leesparkykent]

This still will not answer my OP.
FYI the supply cable is FP600, so please post the relevant docs.

Your OP asks if you need to have a fly lead from the banjo to the earth bar.....you have had the answer several times and even been quoted reg numbers.

 

[Darkwood]

Reg 543.2.7...where the protective conductor is formed by metal conduit, trunking or ducting or the metal sheath and/or armour of a cable, the earthing terminal of each accessory shall be connected by a separate protective conductor to an earthing terminal incorporated in the associated box or other enclosure.

Not too sure this reg' actually covers the OP's situation, the main switchgear and or distribution equipment isn't classed as an accessory like equipment tapped of each circuit would be IMHO, I did think of this reg' myself but decided it wasn't for this situe'.

 

[Leesparkykent]

Not too sure this reg' actually covers the OP's situation, the main switchgear and or distribution equipment isn't classed as an accessory like equipment tapped of each circuit would be IMHO, I did think of this reg' myself but decided it wasn't for this situe'.

How come you wouldn't class it as the same situation?

 

[Darkwood]

How come you wouldn't class it as the same situation?

Just checking the definitions in the BYB and it seems they have either revised the wording or I'm mixing my regs up as I don't just sit under the BS7671 in my job, so I'll stand corrected on that point, this regulation is applicable although I would argue the case that if you can effectively show you have taked the steps to ensure good solid contact and your not going through gland plates or screwed panelling and the earthing bolt/bar is fixed and grounded to the enclosure directly then you can argue by construction the gland doesn't require a tail.
I think the regulation is too broad in its application but like I said 'If in doubt, tail it out'

 

[Skimpy Wan]

I was referring to GN8 Appendix B (page 161)

 

[Simlec]

I was referring to GN8 Appendix B (page 161)

Would you not use table B2 on the next page? or are you using equipment rated above 70deg?

 

[davesparks]

This still will not answer my OP.
FYI the supply cable is FP600, so please post the relevant docs.

And you didn't think to mention that it's not standard SWA in the OP?

Either way that makes no difference whatsoever to this question.

 

[davesparks]

I was referring to GN8 Appendix B (page 161)

Which is completely useless with regards the question, that only tells you the CSA of the steel armour and compares it to the requirements of table 54.7
It doesn't tell you hat size the cpc needs to be

 

[Guest 004]

Thanks Dave, you have just made me remember why I have not used this forum for a long time.

 

[i=p/u]

Use a 95mm Earth or scratch paint with 2p/screwdriver an use none

 

[Guest 004]

Thank you i=p/u
As the supply is 150, I will probably use a 70mm, but as previously said the ohmic value between the points is 0.01, which suggests to me no 'tail' required. Then you have regulations to contend with. What I was trying to assertain is whether I could use a 35mm as the ohmic value was so low anyway. End of the day whatever I use to 'comply with regs' will just be a cosmetic price of cable, and just a complete waste of time and materials. That said a tail needs (and will) be installed.

 

[davesparks]

How did you arrive at the value of 70mm

Just because the resistance is 0.01 ohms it does not mean it will handle the fault current safely.
You could measure the resistance of a short piece of 1.0mm T&E and get the same result, but it sure as hell won't cope with the fault current