Insulation etc

[revolt3k]

What cables you guys using when running in stood wall's, and ceiling's that will be insulated.(mainly new builds) Allot of other sparks dont do cable calcs for factors such as insulation and are just running 2.5 for sockets and 1mm for lights even tho they will be totally surrounded by insulation.

Never been to a house yet that has 4mm for sockets and 1.5+ for all lights?

 

[Spudnik]

I am very slowly edging towards the 4mm radial.

Much easier testing too.

 

[revolt3k]

I am very slowly edging towards the 4mm radial.

Much easier testing too.

How are you finding getting 2 or 3 4mm cables into sockets? Some of the brush stell click i used only just allowed 2x 2.5mm in would'nt like to think what getting 3 or 2 of the 4mm in.

You using 1.5 fot litghts mate?

 

[revolt3k]

Not much response to this one. Any other people willing to say what they are doing?

 

[Guest123]

Hey.

Myself I always use 1.5mm for lighting, and only ever the 35mm metal backboxes as is with todays trend the flatplate accessories make it almost impssible to use 25mm ones, particularly for ring circuits.

Nearly always 2.5mm for rings with no more than 8 twin sockets to a ring, less if a kitchen ring. With regard to radials, if it's a simple dedicated circuit to one piece of equipment then take loading and factors into account. If a multiple socket outlet radial i.e garage then 4mm, but would again tend to install a ring.

Cheers

 

[flukey]

Hey.

Nearly always 2.5mm for rings with no more than 8 twin sockets to a ring, less if a kitchen ring.

whats the thinking behind this lenny, max 8 twin sockets for a 2.5 ring

 

[spark1]

2.5 T&E can be o.k. in an insulated stud wall providing the cable is in contact with at least one internal surface ..[ 21A. ]

..it will not be o.k. if not in contact with aninternal surface...[ 13.5 A ]


2.5 T&E can be o.k in a ceiling with up to 100mm of installed insulation..[ 21A ]

..it will not be ok. if insulation thickness exeeds 100mm.[ 17 a. ]

* The above is based on a 32 A ring final circuit



1.0mm T&E can be o.k.in all of the above installed methods provided the protective device is no larger than 6 A.


Note the word CAN is used ,as this advice is based on the thermal restraint requirements as the o.p.
enquired...............Other circuit considerations may be applicable..



Regards...........spark1

 

[Guest123]

2.5 T&E can be o.k. in an insulated stud wall providing the cable is in contact with at least one internal surface ..[ 21A. ]

..it will not be o.k. if not in contact with aninternal surface...[ 13.5 A ]


2.5 T&E can be o.k in a ceiling with up to 100mm of installed insulation..[ 21A ]

..it will not be ok. if insulation thickness exeeds 100mm.[ 17 a. ]

* The above is based on a 32 A ring final circuit



1.0mm T&E can be o.k.in all of the above installed methods provided the protective device is no larger than 6 A.


Note the word CAN is used ,as this advice is based on the thermal restraint requirements as the o.p.
enquired...............Other circuit considerations may be applicable..



Regards...........spark1

So what would YOU use then??

whats the thinking behind this lenny, max 8 twin sockets for a 2.5 ring

Just always been my way really. Used to be 10 but with all these new appliances and overkill on derating factors from masses of insulation I dropped it to 8.

IMHO 100mSq for a ring circuit is rediculous but I dont make the rules.

 

[flukey]

So what would YOU use then??



Just always been my way really. Used to be 10 but with all these new appliances and overkill on derating factors from masses of insulation I dropped it to 8.

IMHO 100mSq for a ring circuit is rediculous but I dont make the rules.

i like to keep the kitchen separate but would always use the regs and cable calcs to design ring for rest of house and have never had as little as 8 twins on my circuit

 

[spark1]

Lenny.

I would use 2.5 T&e for Sockets provided clipped to studwork and not buried in more than 100mm insulation in the ceiling...if the above cant be adhered to then 4.0 T&E would have to be used ...but
good luck at connections to accessories

..and as I said 1.0 T&E is usually o.k for all cases of installation.




.....just my thoughts..others may have others.


.I Have no restrictions on the number of outlets...and a serperate circuit is usually the norm for a Kitchen where most heavy loaded equipment is installed....I would also install dedicated circuit for built in oven if no cooker circuit being installed.




Regards.........................spark1

 

[Guest123]

Why this then?? why is it so wrong??

 

[flukey]

Why this then?? why is it so wrong??

sorry lenny should have been a wink

 

[Scott F]

Hey.

Myself I always use 1.5mm for lighting, and only ever the 35mm metal backboxes as is with todays trend the flatplate accessories make it almost impssible to use 25mm ones, particularly for ring circuits.

Nearly always 2.5mm for rings with no more than 8 twin sockets to a ring, less if a kitchen ring. With regard to radials, if it's a simple dedicated circuit to one piece of equipment then take loading and factors into account. If a multiple socket outlet radial i.e garage then 4mm, but would again tend to install a ring.

Cheers

Lenny just out of intrest If its a upstairs ring 4 bed house and each room has 4 twin sockets in would you really wire 2 rings.?

 

[Guest123]

Cool.

Think about it though, to comply with the current regs circuits should be divided so as to cause minimum disruption in the event of fault. So what do we do - split the sockets into upstairs and downstairs circuits and kitchen.

In a normal 3 bed, you would rarely have more than 8-10 sockets upstairs or downstairs anyway so I've always just stuck with that.

Not right or wrong just my way.

 

[Scott F]

I know what your saying Len .but in the situation where its a 4 bed house ,4 sockets in each room would you wire 2 rings bearing in mind that upstairs is unlikley to be drawing much current