Electrical Bonding

[Iggle Piggle]

At work the pipes under a sink have been electrically bonded together but no connection has been made to electrical earth. I'm rusty with my knowledge but I thought that bonded pipes should be connected to electrical earth too.
Anyone know for sure?
I can't find my 17th edition regs. book :-(

[PeelerPal]

All you need is an earth bond from the outside to the cold feed (6mm) taps do not need to be cross bonded any more although some sparx still do it just for good measure

[Zacs-Master]

http://www.diydoctor.org.uk/projects/bondingbathroom.htm

[The Builder]

This is often referred to, wrongly, as "earth bonding". There's actually no such thing. It's either earthing, OR bonding.

Earthing is largely for any metalwork, including gas/oil/water/armoured cables, that must be connected to earth in case they become "live" as the result of a fault.

Bonding is a now redundant procedure that connects copper tube, sinks etc together to ensure that they are all of the same potential (voltage). It's called "equipotential bonding" or "supplementary bonding". The idea was to create a "Faraday Cage" where no shock results from touching two parts simultaneously.

In older systems where there is no RCD (earth trip) provided, bonding is still necessary. With RCDs, it's not required. In short, leave it as it is. It shouldn't be earthed.

[BRIGHT SPARK]

The 17th edition amendment 3 says that supplementary equipotential bonding as installed in bathrooms kitchens etc is no longer required if all circuits passing through the area or feeding outlets within the area are protected with a working 30mA RCD and all main bonding to gas, water, oil services etc is confirmed continuous and sized according to the incoming service cable.That said the regs are a minimum requirement and so its still installed by some contractors.