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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[sparksburnout]

Absolutely, and I won't do it again. My point is that I understood what I was doing was dangerous - potentially fatal if done incorrectly. I wanted to visually check which earthing arrangement it was before carrying out a test and I was a bit hasty in dismantling the head whereas I should've done the tests. Lesson Learnt.

Look, give WPD (I assume) a ring. They will most likely give you the phone number of the local team. Tell them you need a PME check done and meet them there. The ones round here are really nice blokes and very helpful/friendly, it's a good idea to get them onside. Once you know them you may be able to call them directly, they are just ordinary guys. They have come and pulled cut-outs for me without going through all the front office malarky. If you are going to continue working on domestic, they are a very useful resource.

 

[Pete999]

I expect you joined the thread late Pete,I refer you to the post I made previously

quote
That 10mm or 16mm green /yellow is probably your earthing conductor from the cut out to your consumer unit
You can verify with a continuity test
At the consumer unit you may then find some bonding cables for services

Sorry Des, yes you are correct

 

[Pete999]

Don't think that's the gas bond Westy thats the main earth to the CU and OP for info that cable is a concentric cable

Sorry to anyone who has said the same before, I joined in late

 

[HandySparks]

Absolutely, and I won't do it again. My point is that I understood what I was doing was dangerous - potentially fatal if done incorrectly. I wanted to visually check which earthing arrangement it was before carrying out a test and I was a bit hasty in dismantling the head whereas I should've done the tests. Lesson Learnt.

Don't take it too hard. I've tightened the odd supplier's head terminal screw where the tails were on the point of falling out. Just take things slowly and think twice before you do anything. Obviously, if anything's in poor condition, leave well alone.

 

[Gazthesparky]

Had a quick scan of the whole thread and cannot understand what the hell is going on here ??? The service head is a TNCS system with a concentric cable which has a LIVE red conductor and a unsheathed armouring which is a combined neutral/earth. You shouldn't be dismantling the cutout to look at connections. With 600a plus fuses protecting the cut out it is dangerous to mess or tamper with it. It looks like you have removed the bottom cable cover which exposes the cable armouring.

you can measure the loop impedance and can determine what earthing type you have from that. If the earth cable terminates in the side of the cut out the majority of the time it is PME (there are some cases that there is a link that has been removed inside the cutout but most of the time you can see the Earth connection of a TNS system sweated to the outside of the cable head.

or am I missing something.......

 

[7029 dave]

WHAT THE HELL ARE YOU DOING!.? Report that ASAP, That is all I am going to say.

 

[sparksburnout]

WHAT THE HELL ARE YOU DOING!.? Report that ASAP, That is all I am going to say.

I was hoping Dave didn't notice.......

 

[Wilko]

Sharp intake of breath I suspect ...

 

[Lorzor]

Had a quick scan of the whole thread and cannot understand what the hell is going on here ??? The service head is a TNCS system with a concentric cable which has a LIVE red conductor and a unsheathed armouring which is a combined neutral/earth. You shouldn't be dismantling the cutout to look at connections. With 600a plus fuses protecting the cut out it is dangerous to mess or tamper with it. It looks like you have removed the bottom cable cover which exposes the cable armouring.

you can measure the loop impedance and can determine what earthing type you have from that. If the earth cable terminates in the side of the cut out the majority of the time it is PME (there are some cases that there is a link that has been removed inside the cutout but most of the time you can see the Earth connection of a TNS system sweated to the outside of the cable head.

or am I missing something.......

Before I removed the covers, you couldn't see ANY of that. It was just a bunch of black boxes. I couldn't see the cable armouring(which isn't armour, its copper), I couldn't see the MET, I couldn't see the main earth. The one in the picture is the gas bond.

Because I couldn't see the MET or any earth cabling - I didn't know if it was TNCS or TNS for sure. Infact, at one point, due to the nature of the equipment it was suggested it may actually be TT but it isn't as the Ze is only 0.11 ohms.

So this is a TNCS system with an MET that can only be viewed or accessed by removing the main fuse. I have since learnt that I shouldn't have removed the covers and I'm getting it sorted with the suppliers. Lesson Learnt.

 

[sparksburnout]

Sharp intake of breath I suspect ...

Maybe he could put some seals in the post..

 

[Pete999]

Maybe he could put some seals in the post..

I still got my SWEB sealing kit

 

[Sparkie30]

Hi dude,the world won't end,and we have all done madder things...just don't talk about it,and provide pictures.
The original information you seek,may have been found with a phone call.

What type of property is it?

Do some deleting,have a think,and come back to us.

@ best reply to your issue pal.

Also ignore some of the replies because im they are perfect and have been been perfect since day 1.

Good luck

 

[Wilko]

So this is a TNCS system with an MET that can only be viewed or accessed by removing the main fuse. I have since learnt that I shouldn't have removed the covers.

Hi - I think this is not the MET. It is DNO infra, which is why it was inaccessible to you. The site might not be wired correctly and may not have a MET (if so you should create one).

 

[westward10]

Aside from the fact you deconstructed the head if that is definitely the gas bond it begs the question what is providing the earth. The MET can be in your dist board by the way.

 

[hightower]

Can you share a photo of the inside of the board?