Main Bonding question?

[chrisgc]

Just a question on main bonding to the main incoming gas pipe.

Where the location of the gas pipe is to be laid and where it is in relation to the MET in the CU, I was wondering if it is allowed to bond (with 10mm earth) the main gas pipe directly to the earth rod? (TT system).

I am guessing not but am simply asking just due to the access for running the earth cable to the CU.

Chris

 

[telectrix]

but the main earthing conductor goes from the rod to the CU, you could break that and fit a MET in a convenient place to bond you gas to. then you've got a readily accessible MET.

 

[chrisgc]

What then happens to all the other earth cables which are currently connected to the met in the exusting cu?

 

[Richard Burns]

The MET would now be the one by the gas pipe and this would be connected to the earth bar in the CU (now no longer MET) by the main earthing conductor. This is just having an MET outside the CU. You have probably seen supplies set up with an earth block mounted on the back board connected to the incoming earth and the main earth conductor going into the CU, where all the CPCs are connected. This is the same but a longer distance away.

 

[chrisgc]

Update......
just updating in that the main incoming gas pipe is going in a service channel (filled in and then expensive floor tiles will be put on top for finish.
i know your meant to main bond within 600mm etc so where would I main bond gas pipe if its not visible?

 

[Engineer54]

The MET would now be the one by the gas pipe and this would be connected to the earth bar in the CU (now no longer MET) by the main earthing conductor. This is just having an MET outside the CU. You have probably seen supplies set up with an earth block mounted on the back board connected to the incoming earth and the main earth conductor going into the CU, where all the CPCs are connected. This is the same but a longer distance away.

And that is exactly where it should be, in the same local location as the cut-out and CU, ''Not'' in some remote corner of the house!!

 

[Richard Burns]

As near to the point of entry to the building as possible (presumably here, where it exits the service channel) and before any branch, so long as it is accessible.
What do you mean by the service channel being filled in?

 

[Engineer54]

Update......
just updating in that the main incoming gas pipe is going in a service channel (filled in and then expensive floor tiles will be put on top for finish.
i know your meant to main bond within 600mm etc so where would I main bond gas pipe if its not visible?

That is not then a service channel if it's going to be filled in, it's just a chase!!

You would bond the gas pipe at the nearest accessible location, hopefully before any splitting of the gas main, as in the same way you would for a water main... Where is the gas meter located then??

 

[spark 68]

The Bonding should also be done on the consumer side of the meter (within 600mm) before any branch work, and not on or before any flexi pipes, not on the supply side

 

[chrisgc]

Bear with me on this then.

Main gas pipe enters house underneath front door. Into ex service channel (but this is being back filled).
immediately to left of front door understairs cupboard is cu.
the main gas will then head off and go upstairs to where boiler location is going to be.
location of boiler is maximum of 15 metres away from met of existing cu.

 

[spark 68]

Where is the gas meter ?, and stop tap for the gas ?

 

[telectrix]

so where's the bloody gas meter then? outside the house, under the floor, below the CU?

 

[Deleted member 26818]

Your point of bonding should be where the pipe becomes an extraneous-conductive-part.
In otherwords, where it can be touched.
The connection should also be accessible for inspection and maintenance.

 

[Octopus]

Within 600mm is a recommendation, you can be outside this dimension if it makes the point more logical/accessible etc.

 

[spark 68]

Within 600mm is a recommendation

Yeah Murdoch, I should have said or as near as practicable