Gas meter - earthing / new smart meter

missile

bris wrote: »

Ideally it should be bonded with 10mm earth wire back to the consumer unit.


Are you sure the water pipes are all bonded in one continuous loop, no breaks, no plastic pipe anywhere It would be difficult to tell unless you did the original work.


It's a mistake to just bond it to a water pipe and hope for the best.

Might not be what it says in BS7671:2018 Requirements for Electrical Installations, but I feel confident that a metal water pipe filled with water going to ground will provide satisfactory earth bonding. Just as good if not better than the old spike in the ground?

I would argue that even if there was a length of plastic in the system. The water inside is an excellent conductor for electricity.

neilmcl

Gloomendoom wrote: »

I had a new gas meter fitted fairly recently. Earth bonding isn't present and it wasn't mentioned by the fitter.

However, the meter is outside on the other side of the drive. Would it need bonding? The pipe from the meter is bonded with 10mm earth cable back to the consumer unit from where it enters the house.

That's fine, it needs to be bonded within 600mm (where practicable) of where it enters the property.

badmemory

Once you accept that all the boiler fitting/meter fitting cowboys are just that (cowboys/scam merchants) then it becomes much easier to accept that they are going to find as many ways as possible to rip you off for another few hundred. Just don't expect them to tell you the truth about anything until THEY have to sign on the dotted line.

Tom99

Just out of interest, since many gas and water pipes are plastic where they enter the property, is this need to 'bond' close to the point of entry as important as it once was?
If a gas pipe was next to the consumer unit in say the kitchen, why is a bond to that gas pipe not good enough and an earth wire has to be run say 20/30m to the gas meter wherever that is?

Homersimpson

Interestingly the new 18th edition of BS7671 recognises the issue of non-metallic incoming pipes which no longer need to be bonded.

The reason for bonding them originally was that a metallic pipe entering the building could be at a different electrical potential to the electrical earth in the building, this could mean a voltage existed between say the water tap in the bathroom and the radiator.

If this were significant it could be dangerous to human life and therefore by bonding everything together we removed the risk (i.e. everything rises and falls at the same potential).

Homersimpson

Tom99 wrote: »

Just out of interest, since many gas and water pipes are plastic where they enter the property, is this need to 'bond' close to the point of entry as important as it once was?
If a gas pipe was next to the consumer unit in say the kitchen, why is a bond to that gas pipe not good enough and an earth wire has to be run say 20/30m to the gas meter wherever that is?

Regarding the bonding position, if you bond in a remote position two things may be an issue:

The service you are bonding to is not inherently intended to be electrically continuous and therefore the joints might introduce resistance and/or may not be able to carry any current that might flow, also (in the case of water pipes) someone could now put an insulated fitting into the system (for example a pushfit connector) and the bonding is lost, by connecting at source you ensure that any imported voltage on the incoming service is tied to earth.

By connecting at the remote end you may find that the voltage along the service is not all at the same potential, i.e. the voltage between the incoming pipe position and the bond 30 meters away might be different. This shouldn't be a problem as we are trying to limit this to 50V in a normal domestic/commercial/industrial installations which is fairly easy but does this does need to be considered.

malky39

As mentioned Bonding is the responsibility of the home owner. When you new meters are fitted you should be advised that the Gas pipe is not adequately bonded and receive a card which show where and why it should have it. This may not have been mentioned when your boiler gets its annual check as if it is a standard efficiency boiler there is no need for the engineer to go to the gas meter therefore they will probably not advise on it, even though as you say the boiler and meter are both in the garage

baldelectrician

missile wrote: »

Might not be what it says in BS7671:2018 Requirements for Electrical Installations, but I feel confident that a metal water pipe filled with water going to ground will provide satisfactory earth bonding. Just as good if not better than the old spike in the ground?

I would argue that even if there was a length of plastic in the system. The water inside is an excellent conductor for electricity.

I assume you tested this 'bond' with a long lead continuity tester, bond cables are required to be continuous with no breaks

It may look bonded but it may not be so- I tested a new build dwelling in Dalmellington (old electrician ran away) and there was a gas bond clamp and cable at the meter which disappeared inside the wall outside but it went nowhere.
There was no cable at the consumer unit or the main earth terminal and therefore no actual bond

Ectophile

missile wrote: »

I would argue that even if there was a length of plastic in the system. The water inside is an excellent conductor for electricity.

Clean water is a very poor conductor of electricity.


https://www.thoughtco.com/table-of-electrical-resistivity-conductivity-608499


Copper is approximately one billion times better as a conductor than drinking water.