Just wanted to check that I was reading the OSG correctly!

If I use Reference method A (i.e. enclosed in conduit in insulated wall)
then 2.5mm flat T+E cable will be sufficient for a ring circuit.

Presumably I cannot put 2 cables in the conduit (i.e. to and from the
socket) as this will derate the circuit under 20A and I would need to
increase the size of the cable.

The alternative is to ensure that the cable is touching the inner
surface of the plasterboard and that the two cables do not run in close
proximity to each other.

Cheers

Martin
--
Martin Carroll

"Martin Carroll" wrote in message
...
Just wanted to check that I was reading the OSG correctly!

If I use Reference method A (i.e. enclosed in conduit in insulated wall)
then 2.5mm flat T+E cable will be sufficient for a ring circuit.

Presumably I cannot put 2 cables in the conduit (i.e. to and from the
socket) as this will derate the circuit under 20A and I would need to
increase the size of the cable.

The alternative is to ensure that the cable is touching the inner
surface of the plasterboard and that the two cables do not run in close
proximity to each other.

You can't do that unless the cable is protected or you have 2" plasterboard.

In article , dennis@home
writes


"Martin Carroll" wrote in message
...
Just wanted to check that I was reading the OSG correctly!

If I use Reference method A (i.e. enclosed in conduit in insulated wall)
then 2.5mm flat T+E cable will be sufficient for a ring circuit.

Presumably I cannot put 2 cables in the conduit (i.e. to and from the
socket) as this will derate the circuit under 20A and I would need to
increase the size of the cable.

The alternative is to ensure that the cable is touching the inner
surface of the plasterboard and that the two cables do not run in close
proximity to each other.

You can't do that unless the cable is protected or you have 2" plasterboard.

Or the cable run is in the zone horizontally/vertically to the socket.
--
Martin Carroll

"Martin Carroll" wrote in message
...
In article , dennis@home
writes


"Martin Carroll" wrote in message
...
Just wanted to check that I was reading the OSG correctly!

If I use Reference method A (i.e. enclosed in conduit in insulated wall)
then 2.5mm flat T+E cable will be sufficient for a ring circuit.

Presumably I cannot put 2 cables in the conduit (i.e. to and from the
socket) as this will derate the circuit under 20A and I would need to
increase the size of the cable.

The alternative is to ensure that the cable is touching the inner
surface of the plasterboard and that the two cables do not run in close
proximity to each other.

You can't do that unless the cable is protected or you have 2"
plasterboard.

Or the cable run is in the zone horizontally/vertically to the socket.

That doesn't satisfy the new regs AFAIK

In article , dennis@home
writes


"Martin Carroll" wrote in message
...
In article , dennis@home
writes


"Martin Carroll" wrote in message
...
Just wanted to check that I was reading the OSG correctly!

If I use Reference method A (i.e. enclosed in conduit in insulated wall)
then 2.5mm flat T+E cable will be sufficient for a ring circuit.

Presumably I cannot put 2 cables in the conduit (i.e. to and from the
socket) as this will derate the circuit under 20A and I would need to
increase the size of the cable.

The alternative is to ensure that the cable is touching the inner
surface of the plasterboard and that the two cables do not run in close
proximity to each other.

You can't do that unless the cable is protected or you have 2"
plasterboard.

Or the cable run is in the zone horizontally/vertically to the socket.

That doesn't satisfy the new regs AFAIK

Why not? AIUI as long as a cable runs in a line horizontally or
vertically to an accessory or within 150mm of top of wall or angle
formed by two walls.

Martin
--
Martin Carroll

Martin Carroll wrote:

Why not? AIUI as long as a cable runs in a line horizontally or
vertically to an accessory or within 150mm of top of wall or angle
formed by two walls.

Used to be, now 17th edition requires either

cable is buried more than 50mm

or

cable is not buried at all

or

conductors are fully enclosed by an earth (e.g. T&E within earthed metal
capping, or a cable such as SWA, or BS8436 cable with foil screen, or
pyro etc)

or

protected by 30mA RCD or RCBO

or

something else I missed?