Flexishield cable

[atm84]

Does anyone know if the aluminium sheath is earthed. The way the manufacturers talk it negates the need to protect circuits by RCD but as the sheath is not earthed and can be penetrated by a nail or screw, i can't really see the benefit of the stuff other than for interference.

I guess its quite expensive too.

 

[Pete999]

Does anyone know if the aluminium sheath is earthed. The way the manufacturers talk it negates the need to protect circuits by RCD but as the sheath is not earthed and can be penetrated by a nail or screw, i can't really see the benefit of the stuff other than for interference.

I guess its quite expensive too.

What are you using it for, is it T and E or the circular crud

 

[Leesparkykent]

http://www.napitonline.com/downloads/CP 3 08 P 11-12 BS 8436 Cables.pdf

Have a read through that link. There is certain criteria that has to be met like has to be on a B type and only up to 2.5mm for the omission of RCD protection if buried in a wall at a depth of less than 50mm.

 

[atm84]

Cheers, can't understand how RCD can be omitted though as in my opinion it could quite easily be penetrated by a nail or screw.

 

[Leesparkykent]

Cheers, can't understand how RCD can be omitted though as in my opinion it could quite easily be penetrated by a nail or screw.

Here you go.

http://www.aeicables.co.uk/literature/NailPenetrationTest.pdf

 

[Darkwood]

Cheers, can't understand how RCD can be omitted though as in my opinion it could quite easily be penetrated by a nail or screw.

Because the path of the fault will not go throught he unsuspecting DIYer and instead users the 360 degrees sheath to ensure any nail etc passing through the cable is grounded at point of entry... what my concern is is that your looking for a way to dodge the use of an rcd so would like more info as to why removing personal protection from a circuit is what you intend to do.

 

[atm84]

Because the path of the fault will not go throught he unsuspecting DIYer and instead users the 360 degrees sheath to ensure any nail etc passing through the cable is grounded at point of entry... what my concern is is that your looking for a way to dodge the use of an rcd so would like more info as to why removing personal protection from a circuit is what you intend to do.

I'm not looking at dodging anything. I'm sceptical about the claims that the manufactuers are making. If it is true however, then there could be potential to use it for lighting circuits or similar.

 

[123]

Cheers, can't understand how RCD can be omitted though as in my opinion it could quite easily be penetrated by a nail or screw.

So can SWA

 

[Leesparkykent]

There was a thread on here recently where the OP had to install a pump for a fire sprinkler system and the manufactures instructions stated that the pump should not be on an RCD for obvious reasons. The customer also didn't want the new circuit surface and wanted it chased so one of the options was to use cable complying to bs8436.

 

[atm84]

There was a thread on here recently where the OP had to install a pump for a fire sprinkler system and the manufactures instructions stated that the pump should not be on a RCD for obvious reasons. The customer also didn't want the new circuit surface and wanted it chased so one of the options was to use cable complying to bs8436.

Ok, maybe I am being too scepticle. I'm quite suprised that the circuit to serve a pump for a fire sprinkler system would be rated at less than 32 amps and can be installed in 2.5mm cable though but thats another story.

 

[atm84]

So can SWA

ummm 'roll head'. Need to think about that one more. It certainly can but a much greater force would be required in my opinion.

 

[Darkwood]

This cable was introduced when rcd boards were first appearing and the 16th brought in reg's about 50mm deep etc to allow you to wire to the old method and negate the need for rcd, but regs and times have changed and it really limits the use of this cable to special circumstances like mentioned above for it to be cost effective and practical ...

 

[Darkwood]

ummm 'roll head'. Need to think about that one more. It certainly can but a much greater force would be required in my opinion.

Already explained this... its about any conductive penetrating object been grounded at point of entry thus the fault current does not travel through the person on the end of the drill or nail, its not about been able to stop a nail or drill.

 

[atm84]

Already explained this... its about any conductive penetrating object been grounded at point of entry thus the fault current does not travel through the person on the end of the drill or nail, its not about been able to stop a nail or drill.

Excuse me, my response was in regards to whether SWA could be penetrated by a nail or not.

 

[atm84]

This cable was introduced when rcd boards were first appearing and the 16th brought in reg's about 50mm deep etc to allow you to wire to the old method and negate the need for rcd, but regs and times have changed and it really limits the use of this cable to special circumstances like mentioned above for it to be cost effective and practical ...

It was the 17th that brought the requirement of cables 50mm deep

 

[Daveash123]

On my current project in central London, 275 very expensive apartments are being cabled in fp200. I assume the designer has a reason for this. Note that my company are not installing this, we are purely data and AV on this project.
I will check out a CU for RCD protection when I get a chance

 

[Darkwood]

It was the 17th that brought the requirement of cables 50mm deep

My bad too many ammendments and regs since my days ...its all just a blur ..

 

[123]

Excuse me, my response was in regards to whether SWA could be penetrated by a nail or not.

Its surprisingly easy to put a screw through SWA. The screw will just slip through the steel strands.