Service head

[Atty]

I know we all like pictures here so I have taken one of the service head in my property. There is no earth clamp on the supply cables and there is no earth rod so would this be a TN-C-S supply?

Since there are 2 supply cables would you say this is a looped supply to/from next door?

 

[Doc Hudson]

Thanks for the photo Atty, pictures are always good. I think they help less experienced members get a better idea about what the various bits and stuff actually look like, often hard to describe. Your assumptions sound right to me, but I shall let the others confirm if this is correct.

Doc H.

 

[Brian 157]

Looks like TN-C-S to me, inside the service head the main earth is joined to the neutral (the "C" in TN-C-S). As for the two supply cables I would agree, the supply is probably looped, if you're in a flat it's probably to upstairs or next door.

 

[NozSpark]

Definitely looped, but there is a chance that it's TNS.... those cables could be split con!?!?!?!?

 

[Andy™]

may be TNS. a loop reading L-E & L-N should give you a better answer

and who changed that meter? the neutrals are the wrong way, but it wont effect it

 

[binky]

I would say TN-s, round my way TN-C-S usually have the earth clamp within the housing. Might be worth phoning DNO to check, or test to see.

 

[a1]

[quote name='Andy

 

[ianmacd]

Lets hoe the polarity isn't too. Happends far too often with meter changes. Would have like to not have seen the inner insulation on the tails too.

I would side with the TN-S camp too.

 

[Atty]

Thanks for the replys, this isn't as straight forward as I first thought. I assumed that because I have no earth rod it can't be TT and because I can't see an earth clamp on the cable it's not TN-S. Now I understand it could be TN-S if the clamp is hidden behind the cover below the main fuse.

I was only looking at this out of curiosity when reading my OSG. I may look into this further when I have covered it at college as I have no experience of testing here.

Thanks again

Liam

 

[ianmacd]

Get a Zs done as close to the source as possible. If its low and no substation near then its probably not TN-S.

 

[Voltimax]

I would say it's TN-C-S. Only because we have alot of those cutouts round my way and they're always TN-C-S. Usually though they have a PME warning label fitted somewhere, so it could very well be I'm wrong. As it has been suggested though a measurement of Ze may well give it away.

 

[Andy™]

Now I understand it could be TN-S if the clamp is hidden behind the cover below the main fuse.

if its split con, then its TNS, and there wont be a clamp

 

[Badger]

I know we all like pictures here so I have taken one of the service head in my property. There is no earth clamp on the supply cables and there is no earth rod so would this be a TN-C-S supply?Since there are 2 supply cables would you say this is a looped supply to/from next door?

looks like that fuseboard is a bit outdated, id get in replaced with a nice shiny new one if i was you ] ] ] :coat

 

[Voltimax]

Short on work eh badger?

 

[SLIPSHOD & SLAPDASH]

looks like that fuseboard is a bit outdated, id get in replaced with a nice shiny new one if i was you ] ] ] :coat

Not as outdated as your terminology :good night:

 

[steptoe]

16mm tails? and 10mm earth conductor anyone?

harmonised tails and a 16th edition board..........

seems strange.........

BTW, I would stagger a guess at TNCS, certainly looks like it, but only a test would confirm.

the other thing,

I'll bet top of that CU isnt IP rated where the tails enter.! :|

an there is no test label either, or 230V warning label either,

my oh my,

you could do with having a PIR done, :innocent

 

[Sidewinder]

The presentation to the installation has to be TN-C-S it can't be anything else as there is no earth connection prior to the cut out.

Regardless of test results, thus by law it must be PME, thus the DNO has broken ESQCR by not fitting PME label.

Think about it...

 

[steptoe]

The presentation to the installation has to be TN-C-S it can't be anything else as there is no earth connection prior to the cut out.Regardless of test results, thus by law it must be PME, thus the DNO has broken ESQCR by not fitting PME label.

Think about it...

not until next year.?

I do agree with the presentation thought though,

 

[SLIPSHOD & SLAPDASH]

I only see PME stickers on about 25% of installs. When on site and the jointers are leaving i have asked them to normally get a reply of 'we haven't had any of those for ages, put your own on if your that bothered'.

 

[Sidewinder]

This is the problem though Slips we put up with this it is an apathy throughout the industry that is destroying it to the core.

You really should be taking their names and reporting them for not fitting the stickers, this is the only way we will bring the DNO's to task, they are NOT above the law by a long way!

Trouble is we all feel that we are too busy to do things correctly in all aspects.