Afternoon all.

I have just done an ECR of a house. The earthing system is TNS but the connection to the cable sheath is made via an earth clamp.

I know this is unacceptable should installation work be carried out but on an ECR how would this be coded? The Zs and Ze readings are ok and the bonding to the services is ok. Code 3?

I'm not sure it's unacceptable - some DNOs used BS 951 clamps on lead cables - such use is outside of the BS, but could be within their own technical specifications. My own TN-S supply has a different type of clamp - not BS 951 but mechanical clamping all the same (and identical to the one in my previous house - so seems likely it was supplier issue).

New EICR checklists not withstanding, it's a DNO matter, not a BS 7671 one - just as long as it's providing an adequate connection.

- Andy.

Thanks for that Andy.

A chap from the local DNO told me that the TNS connection clamp they use is called a Hepworth Joint. No sure what it looks like, I thought a Hepworth connection was one of those spring connectors that you fit a braided csble under, the sort you get with a SWA jointing kit

The problem is that "what they do now" isn't necessarily what they (or their REC/Board predecessors) did in the past. If you go back even further then nothing less than a wiped solder joint would have done! Provided it's supplying the solid earth connection that BS 7671 requires, I'd regard the details as being supplier's problem (or not).
- Andy.

Providing the reading is ok and the clamp is tight on the cable don't worry about it. In fact several years ago I was chatting to a DNO chap and asked if I could scrounge a couple of earth clamps from him, his reply was "just use bs951's, that's what they give us to use"!

Dave.

If you look at the condition report inspection schedule (Page 396) for an EICR, would section 1.0 and 3.0 (1.1 and 3.1) be the place where you record your concerns ?

Subject to an EFLI (Ze) test and a pit of a poke and a prod, then C3 ?

Regards

OMS

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Failure is always an option

--the hepworth clamp for lead sheaths is our latest method
of earth connection on supply cables.
it is a braided strip wrapped around the sheath and then fixed
by a clip similar to the type used to fix rubber hoses on vehicles.
finished off by a rubber sleeve.

PNB? we know what it says in our network design manuals.

Regards.

A Jubilee clip then? massive technology advance there then?

951 clamps were standard issue round here in EDF land, they fitted them everywhere.

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Lack of planning on your part doesn't make it an emergency on mine....

Every man has to know his limitations- Dirty Harry

LoL - there are far more things on heaven and earth that that contained in a DNO design manual for sure -

Hepworth clamps are OK - but still a risk on old PILC cables - better if the DNO used constant pressure springs - at least until they re skill and learn how to solder the connections again.

DNO's and 951 clamps - that really is scraping the barrel of poor engineering

Regards

OMS

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Failure is always an option

We would choose to "wipe" a copper earth cable onto the lead sheath. I believe that we are one of the last DNOs in the British Isles who train our apprentices in soldering of lead.

Regards,

Alan.

Well I guess it takes time and money to do that Alan - can you see UK DNO's spending the time and money to teach "PILC" skills to thier jointers - somehow I can't -

regards

OMS

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Failure is always an option

Oms the EICR box 3.1 was the bit I was concerned about. I thought the same, a Code 3 providing the connection is good and the reading is OK. It has to be some sort of code as you cant really tick the box and say its OK when the incorrect clamp is used

Incidently, I found the Hepworth consumer bond on the site for sicame.
The clamps is not a jubilee clips, its like a buckle clip that it fitted around the cable with a tensioning tool. The copper braid goes under it.

The clamp whatever type it is belongs to the DNO if it should be there. It may not comply with BS7671, but it doesn't have to. I am interested how you are proposing to code a clamping arrangement which may or may not comply with the appropriate DNO's technical manual - a document I suspect you don't have.

Regards,

Alan.

I think to be fair Alan, a 951 on a pilc service cable is always going to fall into the category of "risky" - given the method by which a 951 clamp tightens and the high creep of lead under cold flow pressures, the potential for significant compression of paper insulation has to be high - with attendant results !!

I'd comment on it if I was undertaking a EICR - regardless of what the DNO happend to be using at the time. You and I both know that lead sheaths were never designed for compression clamping except at spreader boxes - it was why we wiped a tail on

Scroll fowqrd a few decades and we have constant pressure clamps and hepworth braid clamps - 951's were never really suppose to be there - were they ?

Regards

OMS

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Failure is always an option

OMS

It is not a case of skills but hot works. I know that EDF and now UKPN do not allow their jointers to do hot works inside premises. They still do some hot works outside.

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John Peckham

http://www.astutetechnicalservices.co.uk/

I'd suggest it's a case of both John - however my point was that BS 951's on a PILC lead sheath is never good practice - use a constant pressure spring or a hepworth tail if you want to avoid hot works - not a 951 clamp.

I've seen the legacy of one or two on private PILC distribution - usually applied by some goon who thought the bit of bare copper wiped on the sheath was inadequate - the resulting flash and bang proved just how adequate it actually was !!

Regards

OMS

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Failure is always an option

There are no arguments from me on this one. We still wipe earths on where we discover the compression clamps. I do know that other DNOs have differing standards due to issues of working with lead / hot works / hot works in customer's premises.

My point is that it cannot really be coded on an EICR, as it is outside the scope of BS7671 and the DNO's LV Technical Guide / LV Earthing Manual would probably not be available to the person undertaking the inspection. I do however agree that it should be commented on.

Regards,

Alan.

Well it may be outside bs7671 but there is a box to fill in on the eicr. Now we can't put a tick, so presumably it must have a code? What else can I put in the box?
A comment can also be made, but what goes in the box?
The condition of the service head it not in bs7671, but again there is a box?

I don't think any code is appropriate for this, as long as the clamp is secure and not damaged (albeit the "wrong" type) just tick the box, same with the service head, as long as it's not smashed/broken causing it to be unsafe just tick as ok.

Dave.

I think there is confusion - on one hand the guidance is clear: we should only be inspecting against BS 7671 alone ... yet they then go on to say we should be checking for plastic water cisterns if the immersion doesn't have a non-resettable cutout and now "inspecting" the DNO's/supplier's equipment and issuing "codes". It doesn't stack up.
- Andy.