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chloebear

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30ish year old T/earth cable - 2.5 with 1mm cpc????? not come accros this one before - was thois a standard back in the dark old days. Also when it starts dripping the good old green gooo, what would you say would be the expected life of the insulation on this type of cable - thinking of singning this one off with a 5 year ticket????
 
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T

thewisdomgeeza

  • Thread Starter Thread Starter
  • #2
I wouldn't. Past experience with using older style cable have ended in a small fire in the circuit!
 
Is this an EICR? Is there any sign of the goo? Are the IR readings good?
 

Top Cat

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Arms
30ish year old T/earth cable - 2.5 with 1mm cpc????? not come accros this one before - was thois a standard back in the dark old days. Also when it starts dripping the good old green gooo, what would you say would be the expected life of the insulation on this type of cable - thinking of singning this one off with a 5 year ticket????
So if you have 1.5mm E/wire that makes all the difference to insulation properties? If next year the earth wire is upgraded to 2.5mm will you condemn what you have put in this year?
 

spark 68

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Arms
Esteemed
I have had this twice lately, but on mine the r1+r2 and/or R1 to R2 ratio was more like 2:1.

It is nearer 2mm and 1mm and it will be old imperial sizes, as I see this as it complied at the time so no code provided the OCPD is sized correctly.
 
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C

chloebear

  • Thread Starter Thread Starter
  • #6
Is this an EICR? Is there any sign of the goo? Are the IR readings good?
IR readings are fine, there would seem to be no problem with the integrity of the insulation at the moment.
 
C

chloebear

  • Thread Starter Thread Starter
  • #7
So if you have 1.5mm E/wire that makes all the difference to insulation properties? If next year the earth wire is upgraded to 2.5mm will you condemn what you have put in this year?
thanks for the comment - seems you may have missed the point though. Just asking for info on the older cable sizing etc, not saying it's incorrect or obsolite - just wanted to know. Cheers.
 

Top Cat

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Arms
thanks for the comment - seems you may have missed the point though. Just asking for info on the older cable sizing etc, not saying it's incorrect or obsolite - just wanted to know. Cheers.
Sorry about the earth wire size, misunderstood that bit. But your comment seemed to imply that a 30 year old cable would start to give off green goo. I have only seen 2 cases of this happening and both times it was a lost neutral so the return was going down the earth wire causing the cable to get hot.
 

kingeri

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Arms
2.5mm with 1mm CPC was available quite briefly I believe, not sure exactly when cos it was before my time! Not a problem really in itself, as long as zs and disconnection times are ok. I have seen a case where the two legs of a RFC were in this, but the middle part was in 2.5+1.5. Wasn't an overly long circuit, and passed all the usual tests, so no code!
 
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steveberry11

  • Thread Starter Thread Starter
  • #10
For some years, 2.5mm2 twin-and-earth PVC/PVCcables to BS 6004 were manufactured with acircuit protective conductor (cpc) of only 1mm2,rather than 1.5mm2 as is incorporated today.
The size of the cpc was increased to 1.5mm2 inBS 6004 because in certain circumstances the1mm2 cpc may not always be properly protectedagainst thermal effects in the event of an earthfault. This is where the cable is used in a ringfinal circuit protected by a 30A semi-enclosed(rewirable) fuse. If this is the case, a competentelectrician should be consulted about upgradingthe cables and/or the consumer unit.
 

HandySparks

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Mentor
Arms
Esteemed
30ish year old T/earth cable - 2.5 with 1mm cpc????? not come accros this one before - was thois a standard back in the dark old days. Also when it starts dripping the good old green gooo, what would you say would be the expected life of the insulation on this type of cable - thinking of singning this one off with a 5 year ticket????
My house was built in about 1975 and has both of the issues here.
There are signs of green goo at a couple of accessories, but I'm not about to rip it all out. Your suggestion of a 5 year re-test date seems a good one.
There have been previous threads on the green goo here. The consensus appears to be that the electrical properties are unaffected and that it doesn't significantly reduce the life of the cable. But wash your hands after touching it.
 
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