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S

spikey

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hi all,about to do a re-wire tns supply.the earthing isn't brazed onto the supply cable but connected with a earth clamp.have asked a sparky more experiance than me and he says no problem,but does'nt seem right to me.could you knowledable chaps throw some light on this.cheers:confused:
 
B

bahco

  • Thread Starter Thread Starter
  • #2
ive seen this done a few times before, if i where you before you do the rewire take a quick test on the ze see if it comes in under, if its high reading give the dno a ring and let them sort it.
 
S

spikey

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  • #3
thanks for that,just couldn't find any thing in regs to say it was wrong
 
B

bahco

  • Thread Starter Thread Starter
  • #4
im not sure if its right or wrong tbh mate, ive heard bad things about it like if you tighten the clamp up to much it breakes inside the cable.

i surpose as long as your readings are good you should be ok, i think i would ring the dno just to double check
 
D

DanBrown

  • Thread Starter Thread Starter
  • #6
According to the ''NICEIC Snags and Solutions'' book on earthing and bonding, its says that this is unacceptable, due to the electrolytic effect etc..

Fully quoted from SNAG 8 of the book.

Earthing clamps not to be used on cables. SNAG 8
Under no circumstances should an earthing clamp (complying with BS 951 or an other type) be attached to the lead sheath of any cable. In the case of a supply cable this practice is wrong for two reasons;
1.. the supply cable is th property of the electricity distributor and
2.. the securing of the clamp to any lead sheath is likely to damage the conductor insulation of the supply and, with the cold flow of the lead, the connection is liable to loosen over time. BS 951:1999 states in Note 3 (second sentance) to its scope that such clamps are not intended for connection to the armouring or sheath of a cable.

In worst cases, this practice may lead to increased risks from the hazards of fire or electric shock...


HOPE THIS HELPS..:)
 
G

Guest123

  • Thread Starter Thread Starter
  • #7
Hey.

Earth clamps on lead sheathed cables are a big no no.

I quote "under no circumstances should an earthing clamp to BS 951 be attached to the lead sheath of any cable" for the following 2 reasons -

1. The supply cable is the property of the distributor
2. The securing of the clamp to the lead sheath is likely to damage the conductor insulation.

Source for the above - NICEIC Snags ans Solutions book.

The only thing to do is as has already been said contact the DNO.

Hope this helps.


Dan beat me to it.:p
 
Last edited by a moderator:
D

DanBrown

  • Thread Starter Thread Starter
  • #8
Yeah sorry Lenny.
At least we've confirmed it :D..
 
S

spikey

  • Thread Starter Thread Starter
  • #9
cheers all,to phone the dno i go
 
J

jellen

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  • #10
or you could put an earth braid on and a self tightening spring clamp
 
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