No Main Earth Connection

[JohnD]

I've certainly seen wooden power poles with a copper strap running down the side and going into the ground, in this semi-rural area.

To me, it would make sense that they were the "M" in PME

 

[JohnW2]

I've certainly seen wooden power poles with a copper strap running down the side and going into the ground, in this semi-rural area. To me, it would make sense that they were the "M" in PME

Seemingly quite possible.

As I've said, "PME" is a characteristic of the local LV distribution network, not of how consumers (or their electricians) chose to earth their installations. I think it's probably terminologically correct to say that I have a 'PME supply' but a TT installation.

Kind Regards, John

 

[firapara]

OP

Have you managed to get a gander inside another flat in the block?

Not yet, hopefully on Friday, when back home

 

[aptsys]

Seemingly quite possible.

As I've said, "PME" is a characteristic of the local LV distribution network, not of how consumers (or their electricians) chose to earth their installations. I think it's probably terminologically correct to say that I have a 'PME supply' but a TT installation.

Kind Regards, John

Correct, it is. PME is not synonymous with TN-C-S, TN-S, TT or any other arrangement.

 

[securespark]

Not yet, hopefully on Friday, when back home

 

[SUNRAY]

when I had a house with a 1920's supply cable in outer London, looking like the OP's, there was a wound-on steel "bandage" armour (which went rusty in the ground, might originally have had bituminous paint), and a bituminous cloth bandage, inside which was a lead sheath with two conductors (I have an idea they might have been wax-paper insulated).

An electrician had previously incorrectly put a pipe clamp on the armour, but when a new meter was fitted, the iron service-head was replaced with modern grey plastic, the fitter stripped back the armour and put an earth clip on the lead sheath. I had an idea they would change it to PME, but I don't think they did. I wrote and asked if they would, and they said yes, but only if I had an EICR done first.

I think the iron head originally provided some kind of earth as it must have clamped the steel armour and the lead sheath.

This stuff?

Cotton & rubber red and black, waxy paper, lead, pitch, spiral steel, hessian/pitch

 

[firapara]

Had a visit from a UK Power Networks engineer today, he checked the earth in the flat downstairs and found a fault in the cable there. He fixed it and my flat is all good now.

But when he was bonding my earth I asked him what type of earth it was, TN or TN-S or TN-C-S or something else, he replied "it is a standard straight earth"...

a) He is a not a trained Electrical Engineer

b) He was too tired to answer my question

 

[JohnD]

he was bonding my earth

what did he do?

got a pic?

 

[JohnW2]

Had a visit from a UK Power Networks engineer today .... But when he was bonding my earth I asked him what type of earth it was, TN or TN-S or TN-C-S or something else, he replied "it is a standard straight earth"...

Oh dear

What do you mean when you say that he was "bonding your earth"?

Kind Regards, John

 

[securespark]

The definition he was using may not be what we as sparks understand it.

Bonding could be the general definition:

2.
the action of joining things securely by means of adhesive, heat, or pressure or by chemical bonds.

We know from the picture of the cutout that the earth connection to the DNO cable sheath was pants, so he would have had to "bond" (the above definition) the earthing conductor to the cable sheath.

His reply "straight" could refer to the cable type, but for the fact that the supply cable feeding your flat isn't straight concentric cable.

I'm not sure what he means.

Did he tell you the Ze?

Sometimes it is written on the board near the cutout.

Edited for clarity.

.

 

[JohnW2]

The definition he was using may not be what we as sparks understand it. Bonding could be the general definition: ....

Indeed so - which is why I asked the OP what he was describing by 'bonding'. As you imply, it probably was not 'bonding' in the electrician's sense.

His reply "straight" could refer to the cable type, but for the fact that the supply cable feeding your flat isn't straight concentric cable. I'm not sure what he means.

Quite so - I think we're all in that position.

I suspect that the guy either "didn't have a clue" or else that he is a poor communicator!

Kind Regards, John

 

[securespark]

It would be very interesting to know the Ze.

 

[JohnW2]

It would be very interesting to know the Ze.

It would - but I'm certainly not holding my breath

Kind Regards, John

 

[firapara]

This is what was meant by bonding:

 

[JohnD]

it looks like he's dribbled some solder on. Is that copper foil? or yellow/brown paper?