17th edition bonding regs

Supplementary Bonding Supplementary Bonding is the use of a slighter thinner 4mm green and yellow copper cable to connect together all metal pipes and possible circuits in a particular area. This area is typically the bathroom, or any other room containing a bath or shower.

There may be cases when no supplementary bonding is required in the bathroom, i. Electrical Safety Services. Under the 17th Edition Wiring regulations BS supplementary earth bonding to the hot and cold pipework and the steel sinks is no longer required. This regulation dates from the 15th edition wiring regulations. The mains water pipework and mains gas pipework must be earth bonded and ideally the installation RCD protected. Emelec Electrical Services.

No requirement for supplementary earthing within kitchen area but you should have an earth to your water stop tap and gas meter. CliveDiy , 31 Jan Metallic central heating pipes need included in the supplementary bonding for a bathroom if you have not met all the criteria for the ommision of supplementary bonding in section of the IEE regs.

If your heating is done in placcy pipes then no need to bond the radiator at all. Spark , 31 Jan Hi One way to tell if something is extraneous is to conduct a measurement between the said item and the MET. You seem to know your stuff, so if it's ok I'd like to ask you something about down lighting and also wiring for an oven.

The oven first. It's maximum wattage is w, the cable run is only 9 metres, I've run the cable in 6mm and was going to put it on a 32 amp RCBO, do you think this will be ok? The downlights, I'm installing some in a kitchen and others in a bathroom. They are all mains voltage, the ones in the bathroom I thought of using IP65 rating because some are over the bath and there is one in the shower cubicle. The ones in the kitchen will be just the run of the mill downlights.

Question: Do they all need to be firecheck, with regs stating I could be helping the spread of fire by cutting holes through the plasterboard ceilings? Instead the 16mm incoming earth goes straight onto the earth connecting strip within the consumer unit, the 10mm earths are then run from the consumer unit to the various services.

I take it that the above method of connection is also ok? If it is when you talk of testing resistance of extraneous parts back to the MET, am I right in assuming this would be back to suppliers earth and not the earth connecting strip within the consumer unit?

The ground floor and upstairs lights will be on two separate RCDs, with the bathroom lights being on their own RCBO, so three lighting circuits in effect. Yes I have notified the LABC and had the first fix checked, may I add not by them, I had to find a registered company myself and pay them to check it.

I note your comment about the down lights going into a fire barrier, I live in a detached house, but when I saw something about fire barriers and down lights, I wondered if it also meant such things as kitchen ceilings with perhaps a bedroom or bathroom above but in a single dwelling not flats.

Connection of a lightning protection system to the protective equipotential bonding shall be made in accordance with BS EN and best determined by a lightning protection system designer. It is important to remember that the above items are only examples of items which may require protective equipotential bonding and it must be verified if these parts actually meet the definition of an extraneous-conductive-part before deciding to connect to the main earthing terminal MET. Protective equipotential bonding is different from supplementary bonding.

Supplementary bonding is the practice of connecting two conductive simultaneously accessible parts together to reduce the potential difference between the parts. It should be noted that the term extraneous-conductive-part is hyphenated, which means it is a single term which has a specific meaning.

It can sometimes be difficult to determine if a part meets this requirement, therefore it is sometimes easier to break the definition down into three separate parts. Earth potential is generally assumed to be 0 volts introduced by the general mass of Earth more commonly known as the planet we stand on.

With a couple of minor changes in terms of wording there is bound to be some confusion, but what exactly has changed since the previous edition? Table Practically speaking, nothing has changed regarding this Regulation except for the addition of the above statement, but it will undoubtedly make people question whether protective bonding is required at all.

So, the part has to be conductive, for example a metallic water pipe, and not part of the electrical installation and essentially able to introduce Earth potential. This would usually mean a conductive part going outside the building and touching the ground or going to another building.

If this can be verified by visual inspection, the part does need main protective bonding. If an installation pipe is constructed from a plastic type material such as medium density polyethene MDPE which is most commonly installed, it is unlikely to be considered an extraneous-conductive-part, but this must be verified.