Earthing Arrangement

[PaulUK1990]

Hello,

Currently still studying at college. I seen this yesterday on a site. I asked the question but didn’t really get a good answer.

I think this is tns. I see 2 10 mm on the left going to water and gas, 1 10mm going to the board. But where is the cpc coming from to connect back, I don’t see any connection near the cut out.

Thank you

Curious Student

 

[Grezza]

Tn c s I’d say.

That is a 4 way Henly block with earthing conductor inside joined into the service head.

 

[PaulUK1990]

Thank you.

I should clarify the earth to the right is not going into the side of the cutout but into the ply board behind the meter.

Thanks

 

[westward10]

Tn c s I’d say.

That is a 4 way Henly block with earthing conductor inside joined into the service head.

That is a service terminal block, I know it has Henley on it but it is like calling a consumer unit a Wylex

 

[Baker1988]

I would not say it is tn-c-s as the henley block is in the wrong side of the service head the earth block in the head is on the other side. its probily a tn-s or tt but could do with a better pic really.

 

[PaulUK1990]

This is a close up of the right hand side.

Help much appreciated. Thanks guys.

 

[westward10]

On the basis of what you have and the definitions for earthing systems it is either TN-S or TT.

 

[Baker1988]

View attachment 43816

This is a close up of the right hand side.

Help much appreciated. Thanks guys.

its own the right side of the picture but the head its self the henley block is on the left hand side of it so it so I would say either tn-s or tt get a Ze and we will know haha

 

[PaulUK1990]

I’m sure the Ze was 0.58. So would that make it a tns.

 

[Baker1988]

I would say yeah more than likely a tn-s

 

[PaulUK1990]

I would say yeah more than likely a tn-s

Thanks Baker1988. The company I work for has too much work in and just don’t have the time or patience to explain.

Thanks again.

Paul

 

[Baker1988]

no worries pal basically a tn-c-s has the earth and neutral connected in the device head

a tn-s usually connects the earth to the in coming cable armouring to supply the earth and a tt you basically supply your own earth by putting in a rod and connecting your path to that.
check this page on here it will give you a better understanding of earthing systems and has pictures Domestic - Earthing Arrangements Explained + Photo's - https://www.electriciansforums.co.uk/threads/earthing-arrangements-explained-photos.59354/

 

[Toneyz]

Thanks Baker1988. The company I work for has too much work in and just don’t have the time or patience to explain.

Thanks again.

Paul

This is the problem these days.

 

[Toneyz]

If you say there are two 10mm earths going to the water and gas and one to the consumer unit you should have another going to the cutout. Have you got a wider photo?

 

[Grezza]

If you have taken a ze then you must know where the end of the earthing conductors is? Or was this tested with the bonding connected? Might be a tt and the bonding is giving you the low readings.

 

[Risteard]

That is a service terminal block, I know it has Henley on it but it is like calling a consumer unit a Wylex

Indeed. Here they call them ISCOs rather than Henley but I agree that a service connector is a more accurate name for them.

 

[davesparks]

With only that one picture to go on I’d say it’s not possible to confirm anything. My guess would be that the service is TNCS but the earthing conductor has not been installed and the installation is relying on the bonding for an earth connection.

Hopefully a wider view of the setup would reveal an earthing conductor which we can’t see from the picture.

 

[davesparks]

Indeed. Here they call them ISCOs rather than Henley but I agree that a service connector is a more accurate name for them.

Technically calling them ISCO is the same as calling them Henley, ISCO was W.T. Henley’s range of ironclad service cutouts etc for use with PILC cables.

 

[Risteard]

That is a service terminal block, I know it has Henley on it but it is like calling a consumer unit a Wylex

Indeed. Here they call them ISCOs rather than Henley but I agree that a service connector is a more accurate name for them.

Technically calling them ISCO is the same as calling them Henley, ISCO was W.T. Henley’s range of ironclad service cutouts etc for use with PILC cables.

I agree it's no different. Just pointing out that Henley block is not used universally.