TN-S Code Two??

[gap30]

Was talking to a friend earlier about the number of installs i have been to recently with no main earth, he told me that the NICEIC are now saying any TN-S with no soldered connection (earth clamp on metal sheath etc) should be made into a TT and Code 2 it, bear in mind this is for a large social housing company. I recently discussed this myself on my 12 month NICEIC renewal and was told roughly the same thing. Anyway i have reported this several times to Scottish Power on some consumer unit upgrades, when i have spoken to guys from Scottish Power about this they are happy with an earth clamp in most cases.

My friend reckons the NICEIC are soon going to insist on this.

I always thought another way around this was to use a Hepworth clamp (have never done so myself tbh)

Thoughts anyone?

 

[imago]

the NIC are NOT giving advice on DNO matters.....

No they are dictating what must be done, as well as stating what is unacceptable without viewing the job in question.

Fortunately they are not in charge of anything, nor setting the regulations. So they can huff and puff all they like.

 

[Engineer54]

My point all along has been the NIC are NOT giving advice on DNO matters.....despite E54's comments I dont believe the vast majority of 951 clamps were fitted by the DNO,but by electricians without the DNO's consent. It is therefore perfectly reasonable to take the view that such a clamp is not fit for the purpose and should be coded.
Out of interest how many electricians on this forum would apply a 951 clamp to an SWA sheath to earth it?....not many I'll wager.....whats the difference?

FFS!!.....do you really think the DNO would fit a 951 clamp???.....it would have been fitted by a sparks and not the DNO.​

​

Now that's a bit of a come down from your previous statement!! lol!! At least you accept now, that DNO's have in the past and even now have used 951 clamps on service head cables!! I didn't say anything about others applying these clamps to service cables and your probably right, that most have been fitted unofficially!!


As for applying a 951 clamp to a SWA cable, it depends what the situation is, where the clamp is to be fitted. I can think of at least two situations off the top of my head, where a gland isn't an option, and where you would need to use a 951 type clamp or similar...

 

[Deleted member 9648]

Now that's a bit of a come down from your previous statement!! lol!! At least you accept now, that DNO's have in the past and even now have used 951 clamps on service head cables!! I didn't say anything about others applying these clamps to service cables and your probably right, that most have been fitted unofficially!!


As for applying a 951 clamp to a SWA cable, it depends what the situation is, where the clamp is to be fitted. I can think of at least two situations off the top of my head, where a gland isn't an option, and where you would need to use a 951 type clamp or similar...

It'd be wrong for me to ignore your statement that you have witnessed the DNO fitting a clamp,I've no reason to doubt your integrity. But I can say I have never seen it personally,and dont expect to!

 

[TAZ]

I would be interested to know how the means of earthing would have been provided in the first place. If there has never been any evidence of a plumbed earth & no evidence of an Elcb or RCD/ TT system surely the electricity supply company must have put the clamp on as there would be no other way of providing an earth connection on there cable. I agree the bs 951 clamp is not ideal & where possible i do try to get that issue addressed (but as you all know they do not make this straight forward) I think possibly one other issue is whether or not under fault conditions the lead sheath itself may not be of suffcient csa to handle the fault current There are literaly millions of these clamps in operation still & i would like to know how many of these have actually caused a PILS cable to go up like a roman candle ( Anyone know of any)

 

[JD6400]

I have mentioned this several times before but around 10 - 12 years ago while working for one of the firm's that looked after the council housing stock around Aylesbury in Bucks , they used a separate nic registered firm to test all the work and they always flagged non sweated joints up as needing replacing with a stake .

 

[Knobhead]

Can I ask a simple question. How many of you have worked with PILC cable?

So much pontificating about a subject most know nothing about.

 

[gap30]

Hi all so back to the original post, i have contacted Scottish Power SEVERAL times regarding this and they never batted an eyelid, i have fitted 951 clamps many times but I am now starting to doubt this method.

I just know what reaction i am going to get when i suggest earth rods to customers which is going to add an extra £150 to the job (inspection pit, rod, lifting the flags etc).

Work is already tight as it is without stuff like this, another problem now.

 

[imago]

Can I ask a simple question. How many of you have worked with PILC cable?

Not ever. I have watched others work with it out of interest, but never been hands on.

I have also seen a builder grab one with the head attached and start to drag it back on itself (even though I'd told him it was a bad idea) to change the position of the head. I emphasise "start" because as soon as he grabbed it I was off. Nothing happened fortunately, but I wasn't hanging around to watch.

 

[JD6400]

Can I ask a simple question. How many of you have worked with PILC cable?

So much pontificating about a subject most know nothing about.

Not me !

 

[Guest55]

Can I ask a simple question. How many of you have worked with PILC cable?

So much pontificating about a subject most know nothing about.

occasionally , usually on the underground jointing scene rather than building wiring.

 

[Deleted member 9648]

Can I ask a simple question. How many of you have worked with PILC cable?

So much pontificating about a subject most know nothing about.

Never worked on one and never seen or heard of one going up while a clamp was being tightened....but.....knowing how the cable is constructed I would liken it to inflating a balloon...it would always be in your mind that it could go pop at any moment.
One thing I can say hand on heart,I've found many loose 951 clamps on lead.IMO the clamps exert uneven pressure and distort the lead over time,causing it to work loose.

 

[Nivag316]

As with most things DNO does what they want.

 

[GLENNSPARK]

Was talking to a friend earlier about the number of installs i have been to recently with no main earth, he told me that the NICEIC are now saying any TN-S with no soldered connection (earth clamp on metal sheath etc) should be made into a TT and Code 2 it, bear in mind this is for a large social housing company. I recently discussed this myself on my 12 month NICEIC renewal and was told roughly the same thing. Anyway i have reported this several times to Scottish Power on some consumer unit upgrades, when i have spoken to guys from Scottish Power about this they are happy with an earth clamp in most cases.

My friend reckons the NICEIC are soon going to insist on this.

I always thought another way around this was to use a Hepworth clamp (have never done so myself tbh)

Thoughts anyone?

and how much backsheesh have the NIC taken for that little beaut?...

 

[Engineer54]

I think possibly one other issue is whether or not under fault conditions the lead sheath itself may not be of suffcient csa to handle the fault current

So you are definitly one who has never worked on PILC cable, otherwise you wouldn't come out with a daft statement like that cracker!!​

 

[GLENNSPARK]

So you are definitly one who has never worked on PILC cable, otherwise you wouldn't come out with a daft statement like that cracker!!​

thing is eng...i havn`t worked on paper leads myself....but the sheath has been used for years as a fault path....
christ, even i knew that...lol...