Difficult Service head

[Lorzor]

Hello all,

I've recently put a new circuit in a house and when filling out my EIC, I needed to access the service head (attached).

I'm relatively new to this and I'm struggling here.

In order to access ANY part of this, you have to pull the main fuse and I had to cut a few metal tallys off. As you can see on the left is where the main fuse sits, to the right there is a cover for the MET and underneath is a cover for the incoming cables. The black box between the meter and thefuse housing is not removable - I can't see where the main earth is. The earth cable you can see is bonding from the gas pipe.

Also, immediately I thought it was a TNS system but it gets quite strange. The what looks like SWA is not SWA, it looks and feels like copper!! IT DEFINITELY isn't steel. Additionally, I can't find a neutral anywhere, I can't see if it is in with the red incoming wire but I'd be pretty surprised if it was.

Could the copper SWA (I know) actually be the PME neutral and we are actually looking at a TNCS system here?

Either way, I have never seen anything like this cable before.

Thanks in advance, I genuinely don't know if I'm just being stupid or inexperienced here but I'm kinda stuck with a way ahead.

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[SparkyChick]

Don't think you should have opened that. But if you do, I would personally turn the isolator off first so there is no load on the service head fuse, less chance of arcing.

<Deleted because I was wrong>

But why did you need to open it exactly?

 

[Taylortwocities]

Ooh err missus. I hope it was the seal fairy and fuse wizard that took that apart. You really should not even be in there, at all.

To absolutely confirm the supply type you need to contact SWEB (good luck). It looks like TNC-S but it could be a DIY effort and the supply type was originally TT.

The outer conductor for that cable (as with split concentric) should be earth - "connected with earth" is the phrase the ESQCR uses - but then (in the UK) the supply N is regarded as being reliably earthed, so I think a concentric N is acceptable to the supply bods, even if it isn't under BS 7671.

 

[hightower]

I'm with Sparky, why did you need to open it? There's an isolator right there.....

 

[Andy78]

I'd call the DNO, tell them you have pulled the service head apart but can't get the info you want. They should be quite forthcoming with advice.

 

[Wilko]

Hi - was that earthing block under a cover with a seal?
If so then it's not the MET and is part of DNO infra, in my view. Although I'm averting my eyes lest I be struck by a bolt of lightning

 

[Lorzor]

I had to remove everything because there was literally no way of telling what type of earthing arrangement this is. I can't see the main earth, I couldn't see the MET.

Due to the design, you have to pull the main fuse in order to get the other pieces off.

The isolator does not help at all.

 

[sparksburnout]

Your a raving lunatic.

 

[David Prosser]

Western Power are pretty good about giving out this information if they have it. From what I can remember back when I lived in Cornwall TT was very common especially around the clay villages. A lot of them where converted to TNCS when they had an upgrade of meters back in the late 90s early 2000. Not sure if they carried on when they switch to WPD as I had moved away by then.

 

[SparkyChick]

Then that isn't the MET, that's part of the suppliers equipment.

The isolator doesn't help in identifying the earthing sure, but without knowing why you pulled the fuse, I think we may have assumed you pulled it to isolate or find out what rating it was or something.

You should never clip the seals on the service head (except maybe in an absolute life/death emergency). If in doubt phone the DNO and make an enquiry. I would have said it's TNCS but as @Taylortwocities pointed out it may not be.

My understanding of the regs is this, if that earthing conductor goes just to the gas, you can't complete an EIC and sign it off because the earthing and bonding does meet the current requirements and therefore your new circuit is unlikely to meet safety requirements. Certainly I would be looking to sort it out before I signed it off.

Any chance of a pic of the inside of the consumer unit and the surrounding area?

And as @Andy78 has suggested a call to the DNO is in order I think to get the info and maybe get them to come and reseal.

 

[Andy78]

Your a raving lunatic.

Just poorly trained I think.

 

[westward10]

Are you sure that is the gas bond, what Ze have you got.

 

[sparksburnout]

Wait till Davesparks sees this, wonder what time he gets home today?

 

[DPG]

Wait till Davesparks sees this, wonder what time he gets home today?

Tea time.

 

[Lorzor]

Just poorly trained I think.

I understand that I may have been hasty to take apart the service head but I have a job to do and I don't want to be wasting time. I'm not going to lose any sleep about cutting some tallies off. I'll phone up the suppliers, If they're going to get upset about it then I'll take it up with them.

Now to sound like a complete -------: while I'm new to the domestic game (and service heads!), I am an electrical engineer trained to degree level through an apprenticeship with 15 years experience in industrial electrics.

Back to the original problem: I've finally found the water bond behind a kitchen panel underneath the sink. I have absolutely no idea where it goes. Every single cable that exits the consumer unit goes up some trunking straight in to the ceiling void. There is no TT spike or cabling anywhere to be found.

 

[sparksburnout]

Well, I'm sure the guy from WPD will be very impressed with those qualifications when he comes to put his service head back together. Let us know what he says?

 

[DPG]

I understand that I may have been hasty to take apart the service head but I have a job to do and I don't want to be wasting time. I'm not going to lose any sleep about cutting some tallies off. I'll phone up the suppliers, If they're going to get upset about it then I'll take it up with them.

Now to sound like a complete -------: while I'm new to the domestic game (and service heads!), I am an electrical engineer trained to degree level through an apprenticeship with 15 years experience in industrial electrics.

Back to the original problem: I've finally found the water bond behind a kitchen panel underneath the sink. I have absolutely no idea where it goes. Every single cable that exits the consumer unit goes up some trunking straight in to the ceiling void. There is no TT spike or cabling anywhere to be found.

What continuity reading do you get between the water bond cable in the kitchen and the consumer unit earth bar?
Daz

 

[Lorzor]

Well, I'm sure the guy from WPD will be very impressed with those qualifications when he comes to put his service head back together. Let us know what he says?

It is back together. It is just missing 2 metal tallies.

If someone is going to call me poorly trained then I think I have a right to reply to that.

 

[SparkyChick]

Back to the original problem: I've finally found the water bond behind a kitchen panel underneath the sink. I have absolutely no idea where it goes. Every single cable that exits the consumer unit goes up some trunking straight in to the ceiling void. There is no TT spike or cabling anywhere to be found.

My advice is Isolate the property, disconnect the bonding conductors from the CU earth bar and use a wander lead to continuity check each conductor in turn to try and identify where they go from the CU. This verification is part of the EIC anyhow so you're not going to lose anything by doing this.

 

[Taylortwocities]

There is no TT spike or cabling anywhere to be found.

That may be because somebody decided to turn the TT into a DIY TNCS.

But as above. It doesn't matter if you have a job to do. Unless you really know what you are doing, (and with respect, you have demonstrated that you don't) what you have done is dangerous. There's nothing between the base of that old, shaky looking service head and the substation, maybe a 600A fuse there. Instant meltdown and ambulance if you get it wrong.