Bonding gas/water yellow and blue

[Houndogg10]

Hi I am recently qualified and still have a lot of learning/reading to do but Blue plastic waterpipe incoming, seems to always be a grey area with electricians I work with, me personally wouldn’t bond it..... Although we have to prove that in the plumbers install their is no copper going to earth?? Can someone enlighten me on this please

Many thanks..... and go easy on me lol

 

[Midwest]

It is up to the designer to decide what level of safety is required for the installation and so then specify the required level of resistance that is acceptable to determine the identification of extraneous conductive parts.
Generally 10mA is used because it is a catch all situation, not too bad not perfect.
If you have lots of large animals then less than 2mA may be the best approach, if there is minimal chance of any accidental contact and everyone in the area is adult then 30mA may be suitable.

I was thinking that might be in an industrial or commercial setting, but then the chance of accidental contact would probably be greater.

 

[Deleted member 26818]

Page 48. Quite a good piece, forgot I had it (and read it!), till this thread started.
Connections Magazine Autumn 2014 - https://issuu.com/redactive/docs/con_aut14

That’s the same article as I have posted:A guide to the determination of extraneous-conductive-parts - https://www.voltimum.co.uk/articles/guide-determination-extraneous
Makes no mention of RCDs.

 

[Midwest]

That’s the same article as I have posted:A guide to the determination of extraneous-conductive-parts - https://www.voltimum.co.uk/articles/guide-determination-extraneous
Makes no mention of RCDs.

Yes it is, I forgotten you'd posted that. The two articles appear to be by the same author.

However, the one I posted has one difference, the example.

It suggests 'Based on the risk presented by the particular installation conditions, the relevant values for IB & ZTL, should be chosen from DD IEC/TS 60479-1', which as I haven't a copy, I guess are the figures given in GN8 6.1?

It then go's on to calculate RCP 'based on the 30mA (RCD)' for IB.

If you have a read, and see what you think.

 

[Deleted member 26818]

As I read it, it’s not stating that a 30mA RCD has to be present, just that they are using the value of 30mA.
Here’s a graph based on the info from DD IEC/TS 60479-1:

AC-1: imperceptible
AC-2: perceptible but no muscle reaction
AC-3: muscle contraction with reversible effects
AC-4: possible irreversible effects
AC-4.1: up to 5% probability of heart fibrillation
AC-4.2: 5-50% probability of fibrillation
AC-4.3: over 50% probability of fibrillation

 

[Midwest]

I did see that web page when I googled it this morning, but thanks for taking the time to post it.

Think I'll stick with the value given in GN8 6.1, got it in black & white (and I'm not paying $310 for DD IEC/TS 60479-1 either!).

Think GN8 is erring on the side of caution, but if I am subjected to litigation, I got a simple book I can produce in Court

 

[Deleted member 26818]

Biggest problem I have with the 30mA value, is that it is the value for healthy adults.

 

[Midwest]

What about the large ones on all fours

 

[DPG]

What about the large ones on all fours

Reminds me of last Friday night.

 

[Deleted member 26818]

re spinlondon's post:

The other problem is that the minimum CSA for an Earth conductor buried in the ground and not protected against corrosion by a sheath is 25mm2, 16mm2 if protected.

sureley that's for an earthing conductor, as in connected to a rod., not for a bonding conductor?

Where a protective conductor is buried in the ground, the Regulation for buried earthing conductors also applies.