Connecting gas bonding cable to old consumer unit (pictured)

[danmanchester]

Good morning all,

My gas pipe isn't bonded to the consumer unit so I've run the cable from the gas pipe upto the consumer unit internally, but I'm just looking for some advice on the final connection.

If I remove the fuses and unscrew the face plate of my consumer unit will I find a nice main earthing terminal or do I need some sort of additional adaptor?

Untitled

• danmanchester
• 27 Feb 2012
• 1

Thanks in advance

 

[plugwash]

there will be an earth bar but it may be difficult to connect modern larger earth cables to it. What size is your new bonding cable?

 

[danmanchester]

there will be an earth bar but it may be difficult to connect modern larger earth cables to it. What size is your new bonding cable?

Morning plugwash,

Thanks for your reply.

New bonding cable is 10mm2 (as per regs I believe)

 

[plugwash]

I think 10mm will fit in the earth bar of an old wylex, pretty sure 16mm won't.

If you do remove the lid from that CU be EXTREMELY careful. That style of CU predates the modern style of termination (deeply burried screws) and while there is SUPPOSED to be a cover on the mains input it may well be missing.

 

[danmanchester]

I think 10mm will fit in the earth bar of an old wylex, pretty sure 16mm won't.

If you do remove the lid from that CU be EXTREMELY careful. That style of CU predates the modern style of termination (deeply burried screws) and while there is SUPPOSED to be a cover on the mains input it may well be missing.

Thanks again Pugwash, yes I've read some horror stories about these CU and hence my nervous approach to taking off the cover. Do you have a picture of what I'll expect to see when I open it? (just so I can perpare myself and don't have to open it twice!).

Oh and perhaps best I have my girlfriend near by to rush me to hospital...

 

[ricicle]

If you are in any doubt about this then please do not open the cover. The terminals are highly exposed and will present an immediate, dangerous hazard. Even with the plastic cover on there is still some exposed terminal.
It is easy for you to forget they are there when you are trying to terminate an awkward cable.

 

[mikhailfaradayski]

Ditto Ricicle,

If in doubt, don't even take the lid off. Many of those old wylexs have an exposed bus bar, even the incoming tails can have exposed parts at the terminals.

Also, i think you might have difficulty getting a 10mm into the earth bar. I don't think the terminal holes are big enough for 10mm.

Where i have added bonding in a situation like yours, I tend to use a earth block and take the earth conductor and the bonding conductors directly to that. Then take the largest size g/y single (probably 6mm) from the earth bar in the board to the new earth block.

Is you water service bonded?

Can't quite tell, but is that a pipe clamp fitted to the incoming service sheath? If so, give your DNO a call. They should come out to modify/improve it.

 

[ban-all-sheds]

I love the way it looks as if Mr Cockburn has been in there and bonded the coat rack...

 

[AndyPRK]

On the plus side, switch off the main switch before removing the cover.

The live bits are above the switch I think.

And the earth terminal on the top left, so you should be working far enough away.

But if it hasn't got the cover on the live terminals, then don't risk it.

I'm amazed your bothered about gas bonding on the instalation. I would have thought there were other things to worry about.

So don't risk your life for the sake of some bonding.

Also make sure you leave plenty of slack on that earth cable, so it can go into a new CU one day.

 

[mfarrow]

I've put 10mm into the line and neutral in those boards before, so I'm sure you'll be OK.

Just turn it off at the main switch and be careful. Treat everything as live.

 

[RF Lighting]

I would never advise a diyer to go opening an old wylex.

Even with the main switch off there is a big live lump of brass 3mm away from a large neutral lump. It is just too easy for things to go very wrong.

Why not turn off the main switch, cut the main earth and terminate both ends into a new earth block along with the new bonding cable.

 

[Sherbertlion]

I would never advise a diyer to go opening an old wylex.

Even with the main switch off there is a big live lump of brass 3mm away from a large neutral lump. It is just too easy for things to go very wrong.

Why not turn off the main switch, cut the main earth and terminate both ends into a new earth block along with the new bonding cable.

Without a doubt, the best suggestion yet.

 

[Sherbertlion]

Can't quite tell, but is that a pipe clamp fitted to the incoming service sheath? If so, give your DNO a call. They should come out to modify/improve it.

Probably at a cost as it's not sweated on.

 

[danmanchester]

On the plus side, switch off the main switch before removing the cover.

The live bits are above the switch I think.

And the earth terminal on the top left, so you should be working far enough away.

But if it hasn't got the cover on the live terminals, then don't risk it.

I'm amazed your bothered about gas bonding on the instalation. I would have thought there were other things to worry about.

So don't risk your life for the sake of some bonding.

Also make sure you leave plenty of slack on that earth cable, so it can go into a new CU one day.

Evening,

I'd agree with not bothering if we didn't need a gas safety inspection as foster carers and it was an advisor last year and therefore a requirement this year!

 

[danmanchester]

I would never advise a diyer to go opening an old wylex.

Even with the main switch off there is a big live lump of brass 3mm away from a large neutral lump. It is just too easy for things to go very wrong.

Why not turn off the main switch, cut the main earth and terminate both ends into a new earth block along with the new bonding cable.

Without a doubt, the best suggestion yet.

Thanks both and I agree, I'll open the cover and assess the situation, any idea how much I should expect to pay if I have to get a sparky in?

Sparks ever want danger money?!?