Supplier earth terminal on intake

SJD · May 7, 2021

The attached photo shows the suppliers head that includes an earth terminal.
The incoming supply cable is a single phase plastic sheathed cable containing L & N.
The earth terminal is not actually connected to anything (not internally linked).
The DNO is SSE.

A previous contractor was under the impression this was the suppliers earth and used it for earthing.
However, they did leave a comment that the earth impedance was "a little high"!

Historically the property was TT, but there is no longer any sign of an earth rod etc.
This is a fairly old property, now with a number of somewhat less-old properties nearby.
Likely the original supply was overhead, before the area got developed a few decades ago.

Question:
With this head fitted, with an accessible earth terminal, would it be correct to say the DNO has supplied an earth?
And in which case they should maintain it?
Or are there circumstances when this head would fitted but with the earth terminal not connected?

Ideally one would simply ask SSE what type of supply is available, but this seems to be proving difficult.
If it is reasonable to say this should be a supplier's earth, I'm tempted to log a call to say the earth appears to have failed.

Samhhh · May 9, 2021

SJD said:
Thanks for all the replies.

Opinion seems to vary, and I'm veering towards the customer just asking for the earth to be checked, perhaps giving enough reason to get this done urgently (rather than in 6 weeks), and see if it can just be internally linked there and then (I suspect it can).

If SSE won't provide the earth, then I'm going to have to fit an earth rod, and the front outside (everywhere near the intake) is all block paving, so rather hoping I don't have to!

If the customer rings SSE and tells them a electrician has reported there is no earth coming into the property they will attend ASAP usually within and hour or two

Vortigern · May 9, 2021

Regulation 24 (1) ESQCR requires the DNO to maintain their earth, they have no choice in the matter. Having said that I have found that the DNO for my area always respond promptly on these matters so no real need to go in with the big guns. Clearly no earth or a high resistance earth is a danger sufficient to phone the DNO on the spot and get them to sort out the earth. It looks like it is a simple matter to rectify so no need for hesitation on the matter.

UNG · May 9, 2021

The supplier / DNO earth appears to becoming a big issue in recent times, from my experience of contacting my local DNO's over the last 5- 10 years a lot problem seems to be down to the DNO guy who attends site, earthing problems I have found mostly seem to be where metal service heads have been replaced with plastic and no earth lead has been connected to the PILC sheath, had one and the DNO guy was adamant it was a TT supply as they "all were TT supplies in the area" I pointed out to him that unlike some of the properties in the area this property had never had a mural supply and when the metal service head was replaced the earth from the incoming cable sheath was lost and the PILC sheath clearly had a TNS earth available as the ELI test confirmed this he still wouldn't have it and left telling me to put a rod in so I rang the DNO again and raised a complaint this was followed by a call from an engineer in Glasgow who agreed with me that they needed to fix the earth

So I'm beginning to wonder given the changes to training in recent years are the DNO's praying on the lack of knowledge and experience of some of the electricians out there who don't know how to argue the case although an incoming PVC cable makes it harder to identify what earthing type should be available I usually find a quick knock on a few doors next to a property can also glean some information to press the case

Samhhh · May 9, 2021

UNG said:
The supplier / DNO earth appears to becoming a big issue in recent times, from my experience of contacting my local DNO's over the last 5- 10 years a lot problem seems to be down to the DNO guy who attends site, earthing problems I have found mostly seem to be where metal service heads have been replaced with plastic and no earth lead has been connected to the PILC sheath, had one and the DNO guy was adamant it was a TT supply as they "all were TT supplies in the area" I pointed out to him that unlike some of the properties in the area this property had never had a mural supply and when the metal service head was replaced the earth from the incoming cable sheath was lost and the PILC sheath clearly had a TNS earth available as the ELI test confirmed this he still wouldn't have it and left telling me to put a rod in so I rang the DNO again and raised a complaint this was followed by a call from an engineer in Glasgow who agreed with me that they needed to fix the earth

So I'm beginning to wonder given the changes to training in recent years are the DNO's praying on the lack of knowledge and experience of some of the electricians out there who don't know how to argue the case although an incoming PVC cable makes it harder to identify what earthing type should be available I usually find a quick knock on a few doors next to a property can also glean some information to press the case

If the cable is pilc the earth will always be the lead 100% of the time, all new pilc terminations should have a shrink kit applied and an earth braid fitted into the inside of the cut out meaning the top terminal is earthed, however depending on the set up that is already installed depends on what earth is left. If its a pilc supply and the current earth is an electricians clamp directly to the lead this should be removed as it can put stress on the lead and cause corrosion, in this case a shrink kit will be applied and a new earth braid as I said above. However if the earth that is applied to the lead is a plumbed earth it is the norm to leave this in place as it is the best connection type. In this scenario the plumbed earth would generally be ran to an external block at the side of the cut out making the top earth block redundant. Like you say the difficulty lies in proving it on a pvc service as the connection is internal which only the DNO has access to. But in the case of pvc the upper earth terminal should always be earthed via the internal PME link or via the actual earth's from a split service

UNG · May 9, 2021

Samhhh said:
If the cable is pilc the earth will always be the lead 100% of the time, all new pilc terminations should have a shrink kit applied and an earth braid fitted into the inside of the cut out meaning the top terminal is earthed, however depending on the set up that is already installed depends on what earth is left. If its a pilc supply and the current earth is an electricians clamp directly to the lead this should be removed as it can put stress on the lead and cause corrosion, in this case a shrink kit will be applied and a new earth braid as I said above. However if the earth that is applied to the lead is a plumbed earth it is the norm to leave this in place as it is the best connection type. In this scenario the plumbed earth would generally be ran to an external block at the side of the cut out making the top earth block redundant. Like you say the difficulty lies in proving it on a pvc service as the connection is internal which only the DNO has access to. But in the case of pvc the upper earth terminal should always be earthed via the internal PME link or via the actual earth's from a split service

From the two DNO's in the areas I work the shrink kit and braid earth is ENWL's solution which is quite neat and tidy while SP Energy Networks use something similar to a "jubilee" clamp around the PILC for the earth with a 6491x 16mm earth cable connected to it and a sheet rubber self adhesive wrap around it which looks quite bulky and a bit rough

Samhhh · May 9, 2021

UNG said:
From the two DNO's in the areas I work the shrink kit and braid earth is ENWL's solution which is quite neat and tidy while SP Energy Networks use something similar to a "jubilee" clamp around the PILC for the earth with a 6491x 16mm earth cable connected to it and a sheet rubber self adhesive wrap around it which looks quite bulky and a bit rough

I've never been a fan of jubilees on lead, always makes me nervous. The good thing about enwl kit Is that it's not tight pressure to the lead but it's more than enough to create a good and secure bond, especially with the mesh around the lead and the braid tied into it before the roll springs are applied. I've worked across multiple dnos over the years and find enw to have the best jointing techniques and terminations compared to other DNO's

SJD · May 12, 2021

Update to original post.

SSE attended earlier this week. I wasn't there and initially they said the connection was fine, it was a PME supply. The customer had to insist it wasn't, so they opened it up, muttered something about the earth being in the wrong terminal, and reconnected it per the updated photo.

Ze now measured 0.23 Ohm.
Perhaps needs a warning label that the "earth" terminal is not actually earthed?

Strima · May 12, 2021

SJD said:
Perhaps needs a warning label that the "earth" terminal is not actually earthed?

But that makes sense and would cost a couple of pence, not going to happen.

UNG · May 12, 2021

SJD said:
Perhaps needs a warning label that the "earth" terminal is not actually earthed?

How about a label to indicate it is now a PME supply
Does the earth cable connect to a separate earth block now

SJD · May 12, 2021

UNG said:
How about a label to indicate it is now a PME supply
Does the earth cable connect to a separate earth block now

Yes, a PME label would also be helpful.
The earth cable connects to an earth block nearby, with gas & water bonding & earthing for the consumer unit.

Supplier earth terminal on intake

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