Main Bonding Conductor and other stuff

[madregulator]

I'm following, to do some maintenance at a works, where acontact electrician who is completing the re-wiring of the office area.
The following came to my attention and wonder if the regs change so fast that Icannot remember which was the latest edition or amendment or whether everyelectrician is trying to confuse the rest! If I don’t know something I say so.I would appreciate any comments on -
1. Main bonding of services include central heating. Therefore this may be thecentral hearing pipe at the heating boiler. And to make sure all pipes areconnected some cross bonding of all the pipes to the pipe where the mainbonding conductor was connected.
2. Metal plaster depth back boxes should have an earth fly lead to the circuit protectionconductor e.g. on 13 Amp socket.
3. Grommet should be installed in metal plaster depth boxes even if the sheathof a twin and earth is passing through.
The electrician told me none of the obove is any longer required, that was the old regs.

If all comments come back negative I will give up. How can some things berequired in one issue of BS7671 and then not in another! I can only assume theexperts are not experts!

 

[Tim]

I dont know the answer but i was told the same thing about earthing back boxes and no longer using gromets last week. Regs or not, its still good practice to do so.

 

[Deleted member 26818]

Which edition was it that required all that?

 

[Guest55]

How can some things berequired in one issue of BS7671 and then not in another!

because each edition changes , stuff gets left out or added.

 

[Deleted member 9648]

I'm following, to do some maintenance at a works, where acontact electrician who is completing the re-wiring of the office area.
The following came to my attention and wonder if the regs change so fast that Icannot remember which was the latest edition or amendment or whether everyelectrician is trying to confuse the rest! If I don’t know something I say so.I would appreciate any comments on -
1. Main bonding of services include central heating. Therefore this may be thecentral hearing pipe at the heating boiler. And to make sure all pipes areconnected some cross bonding of all the pipes to the pipe where the mainbonding conductor was connected.Main bonding to INCOMING metallic services which are extraneous conductive parts.It's unlikely that central heating pipes will be incoming or extraneous unless the boiler is external. There is no such thing as 'cross bonding' ,supplementary bonding is only required in special locations as defined in section 7. These requirements have not changed in many years....it's just that vast numbers of electricians dont understand bonding and mythology prevails.
2. Metal plaster depth back boxes should have an earth fly lead to the circuit protectionconductor e.g. on 13 Amp socket. As long as the box has at least one fixed lug and the socket screw holes are connected to the socket earth terminal no flylead is required.
3. Grommet should be installed in metal plaster depth boxes even if the sheathof a twin and earth is passing through.Good practice only...never been a requirement specifically. It is a requirement though to prevent mechanical damage to a cable entering an enclosure...a grommet is one way of achieving that.
The electrician told me none of the obove is any longer required, that was the old regs.

If all comments come back negative I will give up. How can some things berequired in one issue of BS7671 and then not in another! I can only assume theexperts are not experts!.......Never required......like I said,mythology perpetrated by those who will tell you "it's in the regs,innit?"....but can never tell you which reg they are referring to.

...................................

 

[jumpin jax]

Also if the cable is plastered in right up to the box you do not require a grommet as it cannot move

 

[Tim]

Which edition was it that required all that?

Ive always been taught earthback boxes and use gromits since being an apprentice, i just assumed it was in the regs, i guess you learn something new every day

 

[Farmelectrics]

I'll be honest I earth back boxes and use grommets I think it's good practise dosnt take long to do

 

[lauriehurman]

Question 1
try 544.2.5
Question 3
522.8.11