Can you join Main Protective bonding conductor

[Michaelwgroves]

I have a 6mm main protective bonding conductor from a 1981 install; adiabatic equation says this is sufficient and no signs of thermal damage. (Discussed in separate thread).

Gas was not bonded, it's a big job to run new cable so I've used redundant water bonding as now all plastic to bond gas but need to join as too short. Is this allowed?

It's a TN-C-S

 

[Octopus]

There is NOTHING in the regs that says bonding cables HAVE TO BE CONTINUOUS.

 

[Dave OCD]

Michael I think as far as main bonding goes now 10mm is the minimum with TNCS especially with new work. But if the underground gas service to the property is actually plastic the internal pipework may not be extraneous and require bonding.

 

[Pete999]

I have a 6mm main protective bonding conductor from a 1981 install; adiabatic equation says this is sufficient and no signs of thermal damage. (Discussed in separate thread).

Gas was not bonded, it's a big job to run new cable so I've used redundant water bonding as now all plastic to bond gas but need to join as too short. Is this allowed?

It's a TN-C-S

How are you intending to make the joint?

 

[Michaelwgroves]

How are you intending to make the joint?

Joint will be accessible so could screw, but probably crimp?

 

[Michaelwgroves]

Michael I think as far as main bonding goes now 10mm is the minimum with TNCS especially with new work. But if the underground gas service to the property is actually plastic the internal pipework may not be extraneous and require bonding.

I need to check underground pipe, school boy error!

Does extending a cable to correct location count as new, or is this existing?
I know TN-C-S is treated different..............

 

[westward10]

There is a question, I would argue that the "new" bond to the gas should comply to current standards that being a minimum of 10.0

 

[Michaelwgroves]

There is NOTHING in the regs that says bonding cables HAVE TO BE CONTINUOUS.

That'll be why having spent last hour trolling through OSG, Regs & Guidance Note 8 I found nothing.

Thanks,

 

[Dave OCD]

I need to check underground pipe, school boy error!

Does extending a cable to correct location count as new, or is this existing?
I know TN-C-S is treated different..............

I'd say new work and if bonding is necessary it needs to be 10mm.

 

[westward10]

I don't see how you can justify utilizing the redundant 6.0 for a new bond.

 

[Michaelwgroves]

Bit more info on current install to help ascertain if should be treated as new or existing.
Current install bonded water, but was disconnected sometime ago when plumbing was upgraded to plastic. Previously as this pipe was also connected to boiler you could argue boiler was bonded (Sort of). Then all pipes looped at boiler. I'm putting join on water bonding here and extending to meter box.

 

[Pete999]

Bit more info on current install to help ascertain if should be treated as new or existing.
Current install bonded water, but was disconnected sometime ago when plumbing was upgraded to plastic. Previously as this pipe was also connected to boiler you could argue boiler was bonded (Sort of). Then all pipes looped at boiler. I'm putting join on water bonding here and extending to meter box.

Is the water pipe capable of introducing a voltage into the house? if it is then bond it. If it doesn't then test any copper pipework to see if is extraneous.

 

[Michaelwgroves]

Is the water pipe capable of introducing a voltage into the house? if it is then bond it. If it doesn't then test any copper pipework to see if is extraneous.

Only copper pipe is within 1M of boiler, rest plastic. Water main feed is plastic.

 

[Michaelwgroves]

Off topic, previous EICR done after plumbing upgrade noted 10mm bonding and 16mm earth. He also ticked checked continuity of both. Beyond belief..........

 

[westward10]

If the gas has never been bonded and you are now going to put one in place it must comply with current standards, 6.0 does not satisfy this requirement.

 

[bigspark17]

Why are you extending to meter box? Perfectly fine to bond at 1st accessible point into building. If your extending that then you are altering it therefore needs to be 10mm all the way to the MET imo.
I chuckled at your comment "pipework was UPGRADED to plastic" not sure plastic can be considered an upgrade rather than good old solid copper.

 

[Michaelwgroves]

The devil is in the detail, so if you extend an existing bonding cable that becomes new?
Looks like a fine line, I could go either way.

 

[Risteard]

I have a 6mm main protective bonding conductor from a 1981 install; adiabatic equation says this is sufficient and no signs of thermal damage. (Discussed in separate thread).

How have you performed an adiabatic calculation on a cable which isn't there to disconnect any protective device? Main protective bonding is not sized based on adiabatic calculations.

 

[gazdkw82]

So why is it taught in colleges/courses that binding must be 1 continuous length? We covered this again only last week.

 

[Dave OCD]

I think that's the case, it's a bit like if you ran a spur from an older RFC, you wouldn't use 2.5 with the old 1mm CPC, generally any new work which includes alterations or additions must comply with current standards.