bonding of pipework with flexible connectors

[maffa ent]

afternoon all!

doing a pir / ecr, whatever you wanna call it now, bonding readings ok on pipework coming from under floor, but not on sinktop or taps, only slightly higher but high enough to be above satisfactory.

what would you do, or recommend, or note?

thanks

 

[maffa ent]

forgot to mention, the difference is caused by flexible pipe connectors, you know the braided ones

 

[Deleted member 26818]

The earth safety connection should be connected to the solid part of the pipework.
If flexible pipes are introducing a difference in potential, then you should really bridge across to either side of the flexible pipe.
Two earth safety connections one either side of the flexible pipe linked by a conductor.

 

[HandySparks]

If this is in a kitchen, I don't think that there's any requirement.

On Site Guide, Amd 1, section 4.7:
If the installation meets the requirements of BS 7671:2008(2011) for earthing and bonding, there is no specific requirement for supplementary equipotential bonding of:
- kitchen pipes, sinks or draining boards
- etc, etc

 

[maffa ent]

thanks for the replies.

ok, so if i remember rightly, the requirements for no supp bonding required are:

1 - all rcd protected

2 - main bonding in place

3 - all disconnection times met

all of the above are present, it's just these slightly higher readings from the last, accessible, bits of pipework above the flexi connectors.

the readings are fractionally too high to comply - am i being picky?

don't really want to fit clamps either side of the flexi's, but..................

 

[HandySparks]

maffa, I think that you're thinking of locations containing a bath or shower. A kitchen isn't a special location, so no special measures needed.

 

[Deleted member 9648]

thanks for the replies.

ok, so if i remember rightly, the requirements for no supp bonding required are:

1 - all rcd protected

2 - main bonding in place

3 - all disconnection times met

all of the above are present, it's just these slightly higher readings from the last, accessible, bits of pipework above the flexi connectors.

the readings are fractionally too high to comply - am i being picky?

don't really want to fit clamps either side of the flexi's, but..................

1. There is no requirement for supplementary bonding in a kitchen.
2. Pipes which are deemed to be extraneous conductive parts in a special location only need to be supplementary bonded at the point of entry to the special location....continuity beyond that point is irrelevant.
3. TBH if you are carrying out PIR's/ECR's you should understand the requirements for supplementary bonding.

 

[maffa ent]

me and my lack of info!

2 instances on this job - kitchen and bathroom.

ok, i understand all that's been said - except for the bit about supp. bonding at entry to the room - haven't heard that before. any reference to where that comes from please?

the requirement for main bonding being in place, in order to be able to omit supp. bonding - i thought all continuity readings had to be less than 0.05 ohms, rather than just saying "main bonding's there, forget supplementary".

with this job, the readings on these small sections of extraneous metal are 0.1 -0.2 ohms (as mentioned the rise is definitely across the braided connectors).

should i bother?

 

[SPARTYKUS]

Surely it depends what edition the kitchen was installed to?

As in not the 17th?

I know thats the ONE now before someone jumps on me but supp bonding might definately be required in its current state. Don't know can't see it/wander lead isnt long enough :yawn:

 

[maffa ent]

17th db, upgraded by kitchen sparky, not us!

 

[Deleted member 9648]

Surely it depends what edition the kitchen was installed to?

As in not the 17th?

I know thats the ONE now before someone jumps on me but supp bonding might definately be required in its current state. Don't know can't see it/wander lead isnt long enough :yawn:

It's never been required in kitchens....It's always been a myth which I believe came about following an illustration in a guide to the wiring regulations,which showed for reasons unknown bonding between a sink and a socket.

 

[Deleted member 9648]

me and my lack of info!

2 instances on this job - kitchen and bathroom.

ok, i understand all that's been said - except for the bit about supp. bonding at entry to the room - haven't heard that before. any reference to where that comes from please?

the requirement for main bonding being in place, in order to be able to omit supp. bonding - i thought all continuity readings had to be less than 0.05 ohms, rather than just saying "main bonding's there, forget supplementary".

with this job, the readings on these small sections of extraneous metal are 0.1 -0.2 ohms (as mentioned the rise is definitely across the braided connectors).

should i bother?

The purpose of supplementary bonding in special locations is to prevent a PD between extraneous conductive parts and conductive parts within the location under fault conditions until the protective device clears the fault.
As an extraneous conductive part,by definition, is introducing an earth potential from outside the location,it follows then that by bonding at the point of entry to the location the hazard has been dealt with. It is also permitted to use an electrically continuous ECP as a supp bonding conductor,which is why it is often possible to supp bond outside the location in a more convenient place such as an airing cupboard....but once again,what happens to the pipework within the location is irrelevant,it is no longer extraneous.

 

[SPARTYKUS]

It's never been required in kitchens....It's always been a myth which I believe came about following an illustration in a guide to the wiring regulations,which showed for reasons unknown bonding between a sink and a socket.

....
Hello WP, yeah I know... I won't go on about it I just meant that irrespective of where it is or was 'required' the general rule still applies be it a study/lounge /kitchen/bedroom.

B
ut yes I know the kitchen is not a special locn

 

[cook1e]

why are you doing a pir on the installation ? ie what is the purpose, and is the electrical installation paperwork available from when the db was upgraded ?

If the installation has been brought to 17th standards then surely there is no requirement for supp. bonding anyway

 

[maffa ent]

pir is simply to assess safety for the homeowner. no certs issued when unit fitted, but we're used to that now eh!

my only concern is regarding continuity to these section s of pipework above the connectors. readings apparently, so my sparky tells me, were 6ohms on the pipework in places. would it just cover all eventualities to bond across the connectors?

 

[SPARTYKUS]

17th ed does not preclude supplementary bonding cookie... Don't get caught out on that one!