SY cable to replace MICC

[vxwestie]

Bit of advice required guys.
i have to do some refurb work on a listed building where previous works have been required to be in MICC
this works will require a completion cert when finished.

However, recently an approved contractor has carried out work on part of the installation where a fault has occurred on a section of lighting MICC. The sparks has isolation a section of the supply currently in 1.5mm MICC and taken another supply from a light in 1mm 3 core SY flex, in all about a 30ft length, clipped to the stones wall with micc cleats and terminated into the light fittings.
Would you allow this to remain in an installation you sign off?
The fact that fire proof pyro has been replaced with PVC flex is bad enough, but SY has half the current carrying capacity and twice the voltdrop of the pyro. Although still within peramiters acceptable, surely altering the current spec of the circuit is unsatisfactory.

The regs say flexible cable has to be fit for purpose when used for fixed wiring, but I cannot see how replacing MICC for PVC can be fit?
Cable manufacturers state that SY cable is for industrial and motor use. ECA guidance is that "extreme caution should be given to the use of SY to ensure its suitable for use as fixed wiring"
your views please gentlemen ....

(All the muppet had to do was check the gland, which is where I'm confident the fault it...)

 

[cobrauk]

If it is the pot that need fixing then you might be unlucky as once damp has set into the mi its a a goner m8

If the Micc cant be fixed then replace it, Sorted

 

[Engineer54]

If it is the pot that need fixing then you might be unlucky as once damp has set into the mi its a a goner m8

If the Micc cant be fixed then replace it, Sorted

You clearly know little to nothing about MICC cable or how to dispel damp from the cable!!
MICC cable is NOT a gonna by any stretch of the imagination, if in the unlikely event damp manages to get past the potted ends. In the event it does, ....it CAN be fixed!!

 

[Engineer54]

Bit of advice required guys.
i have to do some refurb work on a listed building where previous works have been required to be in MICC
this works will require a completion cert when finished.

However, recently an approved contractor has carried out work on part of the installation where a fault has occurred on a section of lighting MICC. The sparks has isolation a section of the supply currently in 1.5mm MICC and taken another supply from a light in 1mm 3 core SY flex, in all about a 30ft length, clipped to the stones wall with micc cleats and terminated into the light fittings.
Would you allow this to remain in an installation you sign off?
The fact that fire proof pyro has been replaced with PVC flex is bad enough, but SY has half the current carrying capacity and twice the voltdrop of the pyro. Although still within peramiters acceptable, surely altering the current spec of the circuit is unsatisfactory.

The regs say flexible cable has to be fit for purpose when used for fixed wiring, but I cannot see how replacing MICC for PVC can be fit?
Cable manufacturers state that SY cable is for industrial and motor use. ECA guidance is that "extreme caution should be given to the use of SY to ensure its suitable for use as fixed wiring"
your views please gentlemen ....

(All the muppet had to do was check the gland, which is where I'm confident the fault it...)

What's this have to do with Auto electrics then??

It's basically a machine or control wiring cable, certainly not under any circumstances a MICC cable replacement!! Pretty sure the insurance company would have something to say about the use of SY cable replacing MICC cable on a listed building!! lol!!

 

[vxwestie]

Ah, bugger. Put it in the wrong section, can I move it or do I delete it? Sorry

 

[vxwestie]

Ha, found how to move it lol

 

[vxwestie]

All that had to be done was check the pot, cut it back and rejoin if necessary, but the other sparks has put in a new supply from another light fitting, BUT using SY flex. My query is what do I do, knowing that I have to do other works on the installation and certificate it. I cannot see how I permit unsuitable cable to remain a part of the installation. But Im trying to find evidence to my claim..

 

[Engineer54]

Ask the client if they knew about this uncertified replacement cable/flex?? If they did, ask them what their insurance policy states as far as listed building electrical installations safety requirements??

Can't get any better evidence to support your position than being backed up by the insurance company covering the building!! lol!!

 

[Guest55]

what difference does it make what cable another contractor used ?
even if hes used speaker cable then thats his look out isnt it ?
why does that affect your work or the certs you issue ?
and what are you claiming for anyway ?
sounds like youre just stirring up grief tbh.

 

[ian.settle1]

You clearly know little to nothing about MICC cable or how to dispel damp from the cable!!
MICC cable is NOT a gonna by any stretch of the imagination, if in the unlikely event damp manages to get past the potted ends. In the event it does, ....it CAN be fixed!!

With a little help from Mr Blowlamp an't it 54

 

[itselectric]

With a little help from Mr Blowlamp an't it 54

That's not always the case, If the dampness has been there a while the copper sheath swells and you can't get the pot on.

 

[vxwestie]

When I say 'claim' I'm referring to my claim (to the client) that the cable isn't fit for use where it has been used as a replacement for micc
im certainly not stiring anything up, but if I am being employed to refurbish the installation, bring it up to bs7671 and sign the completion certificate. Thus taking responsibility for the safety of the installation.
Using cable not suitable for use is surely unacceptable and me turning a blind eye to it or not reporting it makes me as bad as the bodger who installed it..

 

[vxwestie]

What cable another contractor uses is he look out, but as in taking responsibility for the installation I have to be confident in its safety. Are you telling be you'd be happy signing the completion certificate, saying the installation conforms with regs when this was left in circuit?

 

[Engineer54]

That's not always the case, If the dampness has been there a while the copper sheath swells and you can't get the pot on.

Never had, or seen that situation with MICC cable, never known the affected length of the cable to be over a couple of foot or more either. And yes, you can drive out any moisture present with a heat gun or blow torch (blowtorch not recommended with PVC covered MICC)....

 

[itselectric]

ENG 54. I've definitely had it happen with the pyro. swelling and proved it by using a micrometer,
When at college they took us to the pyro factory local to us and one of the things they told us there was the dampness never travels down the cable any more than about 6in. No matter how long it was exposed to damp, so we were always told to size the about a foot in. (if size was unknown). This was the old imperial micc. I do believe they actually treated the manganese in later cable to stop dampness travelling.

The point I was trying to make was if damp had gotten into the cable then the end may have needed to be stripped back a bit more, thus making the cable a bit short.

 

[Engineer54]

ENG 54. I've definitely had it happen with the pyro. swelling and proved it by using a micrometer,
When at college they took us to the pyro factory local to us and one of the things they told us there was the dampness never travels down the cable any more than about 6in. No matter how long it was exposed to damp, so we were always told to size the about a foot in. (if size was unknown). This was the old imperial micc. I do believe they actually treated the manganese in later cable to stop dampness travelling.

The point I was trying to make was if damp had gotten into the cable then the end may have needed to be stripped back a bit more, thus making the cable a bit short.

As i say, i've never come across this. maybe you're right if we're talking about the light duty stuff, but to be honest, i can't ever remembering using it. I can't really see the thicker walled MICC cable sheaths being expanded by damp in the magnesium, copper may be soft but not that soft. Come across plenty of pot's that have been slightly undersized and been a real bugger to get threaded on to cable though!! lol!!

Always used to chop the first foot or so off a new coil before use, whether it had been sealed or not, ...just became a habit!! lol!!

 

[Guest55]

What cable another contractor uses is he look out, but as in taking responsibility for the installation I have to be confident in its safety. Are you telling be you'd be happy signing the completion certificate, saying the installation conforms with regs when this was left in circuit?

why do you need to complete a certificate that covers another contractors work ?

 

[UNG]

ENG 54. I've definitely had it happen with the pyro. swelling and proved it by using a micrometer,
When at college they took us to the pyro factory local to us and one of the things they told us there was the dampness never travels down the cable any more than about 6in. No matter how long it was exposed to damp, so we were always told to size the about a foot in. (if size was unknown). This was the old imperial micc. I do believe they actually treated the manganese in later cable to stop dampness travelling.

The point I was trying to make was if damp had gotten into the cable then the end may have needed to be stripped back a bit more, thus making the cable a bit short.

You must be the only one that has seen Pyro swell with damp this is a new one on me not seen any slight hint of this in the 30+ years I've been installing Pyro and repairing Pyro faults

The method by which Pyro is made would account for the slight variations in sheath diameter and the accepted manufacturing tolerances probably account for this with other companies using different manufacturing methods including seam welding the sheath this could also affect sheath diameter depending on which axis of the sheath the measurement was taken, the fact that to measure this swell needed a micrometer makes me think this is a case of mountains and molehills as the increase in diameter was marginal and of no consequence

Some people are to quick to jump to conclusions with Pyro through a lack of understanding and knowledge of how to work it

 

[itselectric]

You must be the only one that has seen Pyro swell with damp this is a new one on me not seen any slight hint of this in the 30+ years I've been installing Pyro and repairing Pyro faults

The method by which Pyro is made would account for the slight variations in sheath diameter and the accepted manufacturing tolerances probably account for this with other companies using different manufacturing methods including seam welding the sheath this could also affect sheath diameter depending on which axis of the sheath the measurement was taken, the fact that to measure this swell needed a micrometer makes me think this is a case of mountains and molehills as the increase in diameter was marginal and of no consequence

Some people are to quick to jump to conclusions with Pyro through a lack of understanding and knowledge of how to work it

I can go back to mid 60's and I can assure you it has happened to me and others at the time.
As I said in my previous post I think the manganese was treated to stop dampness migrating as far
And as eng 54 said it was on the smaller cables.

 

[Dcf]

maybe a bit of fp would have been a better choice of cable...or dare i say it a bit of micc!
on another thread i bemoaned the use of yy in shopfit situations. sy without the braid
as i stated these are control cables for use in automation etc not fixed wiring cables in my book
i bet you the sy braid wasnt even earthed