who's right

[leep82]

ok so today i went to a job with a colleague where he has already been and made a start. Its a full rewire for a builder who we do a bit of work for. The house is completely empty and is getting completely gutted from top to bottom.

As mentioned my colleague has already been to the house, to isolate all of the existing circuits and to install a temp supply for power tools, battery chargers etc.

The exisitng board, which will obviously be getting upgraded, has rewireable fuses and there is no RCD protection. The main earth is by means of the incoming water and there is no bonding to the gas or the water. The temporary supplys that have been installed are RCD socket outlets.

Although only a temporary job i suggested that both main bonding to gas and water should be installed and if no PME connection was available, an earth rod installed. Even if this was only a temporary measure. He thinks i am going over the top and that once the property is finished everything will be up to current standard.

So thoughts please, am i being OTT or is in fact my colleague being a little carefree?

 

[Risteard]

You are correct. Even temporary installations must comply with BS7671.

 

[Octopus]

Sounds like another cost cutting exercise and/or the regs not being clear enough!

 

[Leesparkykent]

Sounds like another cost cutting exercise and/or the regs not being clear enough!

What do you mean by the regs not being clear enough....what part?

 

[cliffed]

This is quite the norm on temp electrics for building sites,seen it everywhere,& when you say this is wrong then you just get shot at.
Always for me tt system with rcbo's protection on circuits,this way you are then covered on extraneous conductive parts not earthed ie: scaffold poles etc etc.

 

[Octopus]

What do you mean by the regs not being clear enough....what part?

Err ....... Most of it!

 

[Midwest]

ok so today i went to a job with a colleague where he has already been and made a start. Its a full rewire for a builder who we do a bit of work for. The house is completely empty and is getting completely gutted from top to bottom.

As mentioned my colleague has already been to the house, to isolate all of the existing circuits and to install a temp supply for power tools, battery chargers etc.

The exisitng board, which will obviously be getting upgraded, has rewireable fuses and there is no RCD protection. The main earth is by means of the incoming water and there is no bonding to the gas or the water. The temporary supplys that have been installed are RCD socket outlets.

Although only a temporary job i suggested that both main bonding to gas and water should be installed and if no PME connection was available, an earth rod installed. Even if this was only a temporary measure. He thinks i am going over the top and that once the property is finished everything will be up to current standard.

So thoughts please, am i being OTT or is in fact my colleague being a little carefree?

These things tend to go on without notice, until something goes wrong and H&S will be pouring all over it. CDM 2015 require H&S assessments etc, even in small domestic works with responsibilities for certain individuals. As someone has mentioned, it sometimes is not possible to cover every aspect, as required by the regs.

Are the gas & water services metal?

Are you saying the property does not have a functional earth? That seems a bit risky to say the least.

 

[7029 dave]

These things tend to go on without notice, until something goes wrong and H&S will be pouring all over it. CDM 2015 require H&S assessments etc, even in small domestic works with responsibilities for certain individuals. As someone has mentioned, it sometimes is not possible to cover every aspect, as required by the regs.

Are the gas & water services metal?

Are you saying the property does not have a functional earth? That seems a bit risky to say the least.

I think that is exactly what he is saying.

 

[Richard Burns]

I would agree that the situation would not be in accordance with the wiring regulations.
It could definitely present a shock risk to someone working there. The sort of fault that occurs is rare but in a building site is just the place for such a fault to occur.
From what you say there is earthing but via a water service which is no longer permitted, however you do not mention if this is a good earth, if it were a good earth then there would be no need to bond the water as it is already at the MET potential, however in building work it is quite possible that the metal water service may be replaced and therefore remove the earth functionality.

As also said it happens a lot, but it is the temporary arrangements that tend to be the most dangerous.

 

[leep82]

Hi all thanks for the replys, yes there is an earth albeit via the main water feed. My colleague says he took a Ze at the board and got around 5ohms. There is no plan to change the incoming services ( gas or water ). Just seems a bit of a cost cutting excuse as for not providing RCD protection to the cables supplying the temps. His argument that the cable is clipped direct and is literally a metre from the board, and not likely to get damaged We could quite easily throw a bond in to the gas and water and tidy them up at a later date.

 

[Midwest]

Hi all thanks for the replys, yes there is an earth albeit via the main water feed. My colleague says he took a Ze at the board and got around 5ohms. There is no plan to change the incoming services ( gas or water ). Just seems a bit of a cost cutting excuse as for not providing RCD protection to the cables supplying the temps. His argument that the cable is clipped direct and is literally a metre from the board, and not likely to get damaged We could quite easily throw a bond in to the gas and water and tidy them up at a later date.

I wouldn't be overly concerned with the gas and water, as the plumber would probably cost you a fortune in clamps, by the time they've finished mucking around with them.

What I wouldn't be doing is relying on the water as an earth because of what I've said above. Surely the incoming electrical supply has an earth or not? If not, you'll need to rod it?

Your temporary supply for power tools etc, should be RCD protected or 110v.

 

[Deleted member 9648]

This is quite the norm on temp electrics for building sites,seen it everywhere,& when you say this is wrong then you just get shot at.
Always for me tt system with rcbo's protection on circuits,this way you are then covered on extraneous conductive parts not earthed ie: scaffold poles etc etc.

......Eh?

 

[Adam W]

If you've got a Ze of 5Ω I don't see the problem with continuing to use the water main as an earthing system, although best to change it as part of the rewire in case the water board come along and change it for a plastic pipe.

The temporary supply needs RCD protection though - the idea of someone going through the cables supplying the sockets is only a small consideration, you need to allow for non electrically skilled people using power tools in what is basically outdoors. The intention might be to use the sockets just for battery chargers, but you can't guarantee nobody is going to come in and run an extension lead across the site.

On one site I worked on one of the labourers used to use the battery charging sockets to power his hair straighteners; personally I wouldn't have foreseen that when installing the sockets.

 

[davesparks]

If the water main is providing a good earth, and as long as you keep a look out for the water board suddenly changing it for plastic then in practical terms it will do the job.


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[andyb]

Putting in some sockets as a temporary supply for the builders will need an EIC. Everything will follow from there.
Type of supply, earthing arrangement, method of protection etc etc. It should be no different than if you were putting some sockets in someone's house. So of course you will need a main earth (not the water pipe) you will need bonding to gas and water and whatever else your installation method demands and rcd protection for sockets.
Or was no certificate issued?