bonding

[soulman]

hi Can someone please explain what the difference is between supplementry bonding and cross bonding and an example of when you would use one over the other

cheers

 

[Adam W]

Supplimentary bonding connects directly to the electrical system, eg a 6mm cable running directly from an electric shower back to the MET.
Cross bonding keeps everything at the same potential, eg connecting a stainless steel worktop in a kitchen to a metal water pipe, or bonding between 2 parallel water pipes.

 

[Deleted member 9648]

Supplementary bonding is in addition to main bonding and may be required in special locations as defined in Bs 7671.
Supplementary bonding links conductive parts in the special location with extraneous conductive parts.This is because of the increased shock risk in special locations.
"Cross bonding" is a mythical practice which is still unessesarily carried out at boilers and kitchen sinks etc......Main bonding and supplementary bonding are the only requirements in the BRB.
I'm afraid NovusSparkus's description of supplementary bonding is not correct......in the case of a shower the supplementary bonding would link the earth terminal of the shower...(a conductive part).and any other conductive parts such as a luminaire..to extraneous conductive parts entering the shower room,(metallic services,such as copper pipes).

 

[Sparky Ninja]

The practice of running the bonding back to the MET was called cage bonding.

 

[SirKit Breaker]

The practice of running the bonding back to the MET was called cage bonding.

Crikey, i am getting old, not heard that term for many years

 

[GrannySmiff]

[quote ]Supplimentary bonding connects directly to the electrical system, eg a 6mm cable running directly from an electric shower back to the MET.
[/quote]

Supplementary bonding doesn't go back to the MET, it would go from the bonded source back to a part of the installation and connect with the cpc. I believe.

 

[Adam W]

Well i wasn't too sure about that but my point was supplimentary bonding connects directly to the installation, whereas cross bonding connects between extraneous conductive parts.

 

[GrannySmiff]

I like bonding I do