New CU, Bonding & Earthing conductor.

[Steve Brown]

Hi.

I fit kitchens again now(fit Solar for a while inbetween), so most of my work is and has been done in kitchens. I have changed quite a few consumer units in the past - but never where it's a TT system.

A customer I'm fitting a kitchen for this week asked me to change her consumer unit, but I declined as it's TT with a 6mm Main Earthing Conductor - and there's no bonding at all to either incoming Gas or Water. As the CU is in one corner of house, incoming water in another, and gas in yet another - it wasn't something I fancied tackling and declined.

She's had another electrician go and do it. He's left the 6mm Main Earthing Conductor, and not bonded either gas or water.

Is there any way he can fit a new CU and justify not doing bonding? Also, is it likely that 6mm MEC is adequate? I believe the tails are 25mm if that helps.

I've got stuff to alter in the kitchen, but feel reluctant in it's present condition as I may be responsible.

Cheers, Steve

 

[Steve Brown]

OK, so I've looked in on site guide, and 6mm Main Earthing Conducter is probably fine. I can see no circumstance where where bonding to gas and water would be exempt though.

 

[drew35]

You've kind of shot yourself in the foot, you've lost out on the additional work of the consumer unit, and now someone has half done it, and without certification I bet, and left you with a few problems.

If you're carrying out work you need to bring the bonding up to standard, and then issue a certificate. Except any certificate you give now would have to state the lack of bonding, which means you can't give one.

Basically he's F'd you in the A!!! Its now down to you to sort the bonding somehow after a conversation with the customer.

 

[Steve Brown]

Cheers.

He only did it last week. I'm not sure if she's paid him yet, but he was organised by builder who's still there. I text her a while ago to ask the builder or electrician if it's been done (I know it's not, cos it's a big job and she says he's not been back). I've got to do alterations to kitchen electrics, and I'm just not going to untill it's done.

 

[Octopus]

Did the electrician give the customer a certificate? If so what does it show about bonding?

Changing a CU and not doing the bonding is a big no, no, IMHO.

Makes you wonder if the person is registered.

 

[Steve Brown]

Cheers for replies guys. Earlier the customer told me the Electrician was finished. Now I've asked her to confirm bonding has been done with either him or builder, apparantly he's coming back this week to do it.

 

[rich.250]

You never know, I might not need it.......
>23k ohms?!?!

 

[SPARTYKUS]

As Murdoch says it's a big NO NO in my book too.

I seem to remember being batted around the head about the bonding bit being paramount and statutory not just regulatory. So he's probably theoretically broken the law.

And again if not notified

 

[Steve Brown]

OK, so if the resistance of part is >23k ohm to MET, then it's not an extraneous conductive part? Has anyone tested and found gas and water above that before, and what affects it - type of ground/distance to earth rod?

Can't find this in onsite guide, and not been through regs book. I did contact NIC Technical and asked if there were circumstances where bonding not required, and they gave none.

The guy has bonded boiler in garage - where gas supply is. If he'd not cut cable, he could have taken round to gas.

Thanks for further replies.

 

[Octopus]

OK, so if the resistance of part is >23k ohm to MET, then it's not an extraneous conductive part? Has anyone tested and found gas and water above that before, and what affects it - type of ground/distance to earth rod?

Can't find this in onsite guide, and not been through regs book. I did contact NIC Technical and asked if there were circumstances where bonding not required, and they gave none.

The guy has bonded boiler in garage - where gas supply is. If he'd not cut cable, he could have taken round to gas.

Thanks for further replies.

How about where the incoming water is using a plastic pipe?

 

[Paul.M]

Best practice guide 6. Section 6.2 explains a lot. Google it and print it off for your customer.

 

[SPARTYKUS]

How about where the incoming water is using a plastic pipe?

Slightly suprising that the NIC technical couldn't come up with that !

 

[Steve Brown]

I agree. This came up on my first NIC assessment, and he wanted to see there was an earth bond in place(which there was) even though it was to plastic. I mentioned the plastic pipe, and he still said he needed to see it. Obviously in a test, this will >23k. It's not relevant in this case though.

I still cross bond under sinks if the hot and cold run to sink has been in plastic, (I have as little as possible pipework in cupboard, and only metal on show), cos I know someones going to look for it and create if not there, so easier to just do it.

 

[dagrat]

The requirement to bond water and gas now applies to the "installation" and not "services" as previously. in my opinion this is to ensure that copper installation pipes are bonded in the case of plastic services

 

[dagrat]

The bs 7671 requirement to bond water and gas now applies to the "installation" and not "services" as previously. in my opinion this is to ensure that copper installation pipes are bonded in the case of plastic services