Why has the armour of the SWA been reinforced with the green and yellow please?

What's the copper c.s.a. equivalent of the armour? and how does it compare with PME bonding requirements? (presuming there may be extraneous-conductive-parts in the main building.) (JP did do a nice table once, but I can't seem to lay my hands on it now...)

   - Andy.

Why has the armour of the SWA been reinforced with the green and yellow please?

What's the copper c.s.a. equivalent of the armour? and how does it compare with PME bonding requirements? (presuming there may be extraneous-conductive-parts in the main building.) (JP did do a nice table once, but I can't seem to lay my hands on it now...)

   - Andy.

Sorry Andy, I can't answer that one as I've only been on site for about an hour, my last involvement being around 4 years ago when  I flagged out the supply voltage low limit being breach. I'm planning another visit once they get responses from the DNO and meter. owner. 

My recollection is that standard SWA is fine up to a good bit over 25 mm¹ conductors. OK, the armour is steel, but when you add it up, it is quite a high CSA.

Manufacturers' web sites should give the details.

I can understand adding G/Y in conduit, where it is as safe and secure as the live conductors, but laying some G/Y in a trench seems less than ideal. Both may be unnecessary in the strict sense.

After the fire, the DNO contractor joined in a short section replacement running up to the customer intake cabinet, apparently smoke heat/damage precaution. The G/Y goes back to where they added the 3 phase upgrade joint, and earth rod.

 I meant to add a photo earlier of the post fire replacement cabinet, but had finger trouble uploading, but got there in the end. The new inner box with the door interlocked isolator on also contains the post fire 63 amp BS88-3 fuses added prior to the feed to the distribution board some 10 metres away.

Thank you.

There are a few points.

It looks a bit cramped in there. The tails into the "isolator" seem to be bent a little too sharply. And why, oh, why has the green and yellow from the DNO's earth rod not been put directly into the "MET", which could have been supplied with more terminals. Best to avoid unnecessary junctions!

The service head has a sticker, which declares the system to be TN-S. That can only be the case if the G/Y from the earth rod is also connected at the origin of the service cable. And then, I suppose, the DNO is promising that there are no N-PE joints anywhere back to the transformer.

Yes, I agree about the tight bends, and also know that the other customer, about 1010 metres before them, had Ze low enough to "call it" TNC-S, and DNO provided their N-PE connection, and may well have added an earth rod there too.

After my report to the meter owner via the customer, emailed to them yesterday, this was their reply to the customer received today: 

"Thank you for your response. I want to assure you that the issue with the original meter burning was an isolated incident, and we have taken all necessary steps to ensure that it will not happen again. Your current meter is safe, and we are confident that you will not experience this problem in the future.

If there is anything else we can do to address your concerns or if you would like us to take any further actions, please let us know. Your peace of mind is very important to us.

I hope that the above has resolved the complaint to your satisfaction. Please contact me within 3 days to confirm that you are happy to close your complaint.

If we don't have a response from you in 3 days, we will follow up to confirm your complaint is closed.

Alternatively, if you are an existing customer and have online access, you can close your complaint by logging into your online account and accessing the complaint tracker at ScottishPower - Track My Complaint.

If, however, you have any further concerns that have not been addressed, please let me know and I will be happy to review these for you."

I read it as acceptance that their meter (or their connection to/from it) was at fault, with the 3 days being a joke, but I've suggested a reply asking them if they are now prepared to consider the customers costs to replace the damaged kit and get up and running again, so we'll see how we go before considering legal advice.

So some great replies from everyone thank you all, it's also helped my "OldBoy's" brain better understand what is likely to have happened.

OldBoy said:

DNO provided their N-PE connection

So everybody has TN-C-S from that transformer!

There is a N-PE bond under my lawn. The DNO knows it, because they made it. I know it because I saw them make it.

A few yards along, there is a TN-C-S supply. The DNO knows it, because they made it. I know it because I saw them make it.

So my neighbourhood is TN-C-S. Full stop!

but I've suggested a reply asking them if they are now prepared to consider the customers costs to replace the damaged kit and get up and running again, so we'll see how we go before considering legal advice.

It may be better in the form of a "letter before action" i,e a warning alerting them that the customer expects those consequential damages (costs) to be met by the liable party (SSE or whoever), and if no satisfactory response to that effect is received within 14 days, then the process will be started to recover this through the small claims courts.

If there are worries about this approach there are a  great many solicitors who give the 1st half hour of advice free, who could  advise on the wisdom / chances of success of such an approach.

If there is no question they are responsible, then reasonable compensation is due.

M.