Important earthing question

Spoke to somebody who states they were a sparky, i suppose many people can call themseleves what they want. We soon moved on to discussing all different things but his earthing theories raised questions with me.

He stated that he wouldn't earth radiators, waterpipes etc in bathrooms as they are earthed at the combination boiler and therefore don't need to be further bonded.

What does need to be earthed in a house? I take it it starts from the consumer unit and goes around the whole house back to the CU in a full ring, which will offer protection.

Are there any maximum lengths of earth wire used in bonding?

Your friend talks rubbish.

Get hold of a copy of earthing & bonding snags and solutions pub by NIC.

Library may have?

andemz said:

Spoke to somebody who states they were a sparky... He stated that he wouldn't earth radiators, waterpipes etc in bathrooms as they are earthed at the combination boiler and therefore don't need to be further bonded.

Click to expand...

You should always supplimentary bond metal pipes and radiators (if fed by metal pipes) in the bathroom. What if the boiler engineer replaces the boiler and removes but doesn't replace the bonding? What if there is a plastic speedfit fitting somewhere between bolier and bathroom? Or some work is done to the property which involves one being inserted later?

What does need to be earthed in a house? I take it it starts from the consumer unit and goes around the whole house back to the CU in a full ring, which will offer protection.

Click to expand...

(reg 413-02-02 paraphrased) main equipotential bonding between the main earthing terminal and
metal water service pipes*
metal gas service pipes*
other metal service pipes (including oil) and ducting"
metal central heating and and air conditioning systems
exposed metallic structural parts of the building
lightning protection systems

*entering and leaving the building.

(regs 471 and 601 paraphrased) supplimentary equipotential bonding is required to be provided connecting together the protective condictors of circuits supplying equipment inside bathroom zones 1,2 or 3 with:
metal service pipes and waste pipes
metal central heating pipes and air conditioning systems
metal baths and shower basins
accessible metal structure of the building
...again in zones 1, 2 or 3

Section 4 of the IEE on-site guide (£15 or borrow from your local library) gives all the details including some nice diagrams. You'll find some of the diagrams in one of the appendices to the "Approved Document P" document which is available on the web.

--
Michael

Thanks for that gang, i will have a good read on the above stated documents. I may buy the book as it sounds pretty good. I like diagrams

If your friend acts like he thinks he's a sparky, and not just talks, then he's dangerous.