I think the time has finally come when I may get to convert the "storage
room" at the end of the garage into a "workshop" as was intended when
the building was erected about 10 years ago. With that in mind I need to
wire up the electrics (there's already a CU there, currently supplying
lighting and a single socket for the garage).

Given the 'workshop' element, I want to fit one ring of surface-mounted
metal-clad sockets (probably these: http://preview.tinyurl.com/2vda3wg)
and was going to use surface-mounted PVC conduit (it's a
single-thickness block-building). Thing is, although I've done plenty of
wiring before I've never used conduit and am not entirely sure how to go
about it: I could really use an on-line how-to-do-it guide but can't
find one - is there such a resource around?

To be honest I have no intention of taking this to Building Control but
still want the work to be up to standard. Is PVC conduit considered
acceptable in this sort of environment? (We're talking a very low-key,
domestic, end-of-garage-type workshop, not one with lots of massive
machine tools etc).

Do you have to use single-core wires; ie, will two 2.5mm2 T&E cables not
fit down a standard 20mm PVC conduit? And/or does that present potential
overheating problems? I'd rather not have to use single-core stuff if I
can help it, as I've got plenty of T&E, and you can only buy the singles
in 100m lengths AFAICS.

How do the couplers, male and female adaptors etc work in connecting up
conduit boxes and socket boxes etc? Probably be obvious when I've got
them in my hands, but I'm putting together an on-line shopping list...

As I say - a simple Noddy guide is probably what I need!

Thanks
David

On 07/12/2010 23:56, Lobster wrote:
I think the time has finally come when I may get to convert the "storage
room" at the end of the garage into a "workshop" as was intended when
the building was erected about 10 years ago. With that in mind I need to
wire up the electrics (there's already a CU there, currently supplying
lighting and a single socket for the garage).

Given the 'workshop' element, I want to fit one ring of surface-mounted
metal-clad sockets (probably these: http://preview.tinyurl.com/2vda3wg)
and was going to use surface-mounted PVC conduit (it's a
single-thickness block-building). Thing is, although I've done plenty of
wiring before I've never used conduit and am not entirely sure how to go
about it: I could really use an on-line how-to-do-it guide but can't
find one - is there such a resource around?

To be honest I have no intention of taking this to Building Control but
still want the work to be up to standard. Is PVC conduit considered
acceptable in this sort of environment?

I've used it for three phase in a factory environment, although I always
bought heavy grade, rather than standard, conduit.

(We're talking a very low-key,
domestic, end-of-garage-type workshop, not one with lots of massive
machine tools etc).

Do you have to use single-core wires; ie, will two 2.5mm2 T&E cables not
fit down a standard 20mm PVC conduit?

It will be a struggle, particularly if you use elbows. I would use 25mm
conduit if I had to run T&E. If you decide to use single core wire, try
to get a trade discount from your local electrical wholesaler - I always
got 65% off list on wire and cable.

....
How do the couplers, male and female adaptors etc work in connecting up
conduit boxes and socket boxes etc?...

Male couplers - push thread into hole in box from outside and do up nut.
Female couplers - put male threaded part through hole from inside and
screw into female part on end of conduit.

Colin Bignell

?
"Lobster" wrote in message
...
I think the time has finally come when I may get to convert the "storage
room" at the end of the garage into a "workshop" as was intended when the
building was erected about 10 years ago. With that in mind I need to wire
up the electrics (there's already a CU there, currently supplying lighting
and a single socket for the garage).

Given the 'workshop' element, I want to fit one ring of surface-mounted
metal-clad sockets (probably these: http://preview.tinyurl.com/2vda3wg)
and was going to use surface-mounted PVC conduit (it's a single-thickness
block-building). Thing is, although I've done plenty of wiring before I've
never used conduit and am not entirely sure how to go about it: I could
really use an on-line how-to-do-it guide but can't find one - is there
such a resource around?

To be honest I have no intention of taking this to Building Control but
still want the work to be up to standard. Is PVC conduit considered
acceptable in this sort of environment? (We're talking a very low-key,
domestic, end-of-garage-type workshop, not one with lots of massive
machine tools etc).

Do you have to use single-core wires; ie, will two 2.5mm2 T&E cables not
fit down a standard 20mm PVC conduit? And/or does that present potential
overheating problems? I'd rather not have to use single-core stuff if I
can help it, as I've got plenty of T&E, and you can only buy the singles
in 100m lengths AFAICS.

How do the couplers, male and female adaptors etc work in connecting up
conduit boxes and socket boxes etc? Probably be obvious when I've got
them in my hands, but I'm putting together an on-line shopping list...

As I say - a simple Noddy guide is probably what I need!


If you areny going to be pulling huge amounts of current why not use
suitable armoured cable and surface mount it using the proper clips ?
Might look a little less pretty, but the end result will be the same if you
aren't taking it that far.
Otherwise pop into a local "shed" and have a play with the conduit and
connectors, all will be revealed once you get to handling it.
T & E through conduit is a bit overkill on the mechanical protection front
and can be quite challenging at corners/bends when pushing it through, but
for shortish runs (Say under 3m to a join) then I have done it with some
success using a squirt of silicon spray (NOT WD40!) to help it through.
Boxes and CUs willl need to have the corect size holes in preferably with
push out blanks ot alternatively the relevant size hole saw to make the
apertures.

Lobster wrote:
I think the time has finally come when I may get to convert the
"storage room" at the end of the garage into a "workshop" as was
intended when the building was erected about 10 years ago. With that
in mind I need to wire up the electrics (there's already a CU there,
currently supplying lighting and a single socket for the garage).

Given the 'workshop' element, I want to fit one ring of
surface-mounted metal-clad sockets (probably these:
http://preview.tinyurl.com/2vda3wg) and was going to use
surface-mounted PVC conduit (it's a single-thickness block-building).
Thing is, although I've done plenty of wiring before I've never used
conduit and am not entirely sure how to go about it: I could really
use an on-line how-to-do-it guide but can't find one - is there such
a resource around?
To be honest I have no intention of taking this to Building Control
but still want the work to be up to standard. Is PVC conduit
considered acceptable in this sort of environment? (We're talking a
very low-key, domestic, end-of-garage-type workshop, not one with
lots of massive machine tools etc).

Do you have to use single-core wires; ie, will two 2.5mm2 T&E cables
not fit down a standard 20mm PVC conduit? And/or does that present
potential overheating problems? I'd rather not have to use
single-core stuff if I can help it, as I've got plenty of T&E, and
you can only buy the singles in 100m lengths AFAICS.

How do the couplers, male and female adaptors etc work in connecting
up conduit boxes and socket boxes etc? Probably be obvious when I've
got them in my hands, but I'm putting together an on-line shopping
list...
As I say - a simple Noddy guide is probably what I need!

Thanks
David

Are you wanting the cable in conduit in all the workshop or just for the
drops down to switches and sockets? If it is all conduit then you need to
use single cables not T&E.
I would not attempt to pull T&E down anything other than straight runs.

The adaptors eg http://www.tlc-direct.co.uk/Products/MT20FMAB.html are used
for connecting up to socket backboxes etc. Undo the nut on the adaptor, fit
into the hole and screw the nut back on. The conduit then just pushes into
the adaptor. You do not use these adaptors for connecting the conduit to
conduit boxes and bends, the conduit just shoves into those without the need
for adaptors.

I often just run a big piece of trunking around the garage between the
ceiling and wall and just use conduit for the drops (a 20mm hole cutter is
needed). That way I can use T&E and any additions later are easy. It is a
damn site easier and faster than using conduit all over the place.

--

Cheers

Adam

On Dec 8, 8:45*am, "ARWadsworth"
wrote:
Lobster wrote:
I think the time has finally come when I may get to convert the
"storage room" at the end of the garage into a "workshop" as was
intended when the building was erected about 10 years ago. With that
in mind I need to wire up the electrics (there's already a CU there,
currently supplying lighting and a single socket for the garage).

Given the 'workshop' element, I want to fit one ring of
surface-mounted metal-clad sockets (probably these:
http://preview.tinyurl.com/2vda3wg) and was going to use
surface-mounted PVC conduit (it's a single-thickness block-building).
Thing is, although I've done plenty of wiring before I've never used
conduit and am not entirely sure how to go about it: I could really
use an on-line how-to-do-it guide but can't find one - is there such
a resource around?
To be honest I have no intention of taking this to Building Control
but still want the work to be up to standard. *Is PVC conduit
considered acceptable in this sort of environment? *(We're talking a
very low-key, domestic, end-of-garage-type workshop, not one with
lots of massive machine tools etc).

Do you have to use single-core wires; ie, will two 2.5mm2 T&E cables
not fit down a standard 20mm PVC conduit? And/or does that present
potential overheating problems? I'd rather not have to use
single-core stuff if I can help it, as I've got plenty of T&E, and
you can only buy the singles in 100m lengths AFAICS.

How do the couplers, male and female adaptors etc work in connecting
up conduit boxes and socket boxes etc? *Probably be obvious when I've
got them in my hands, but I'm putting together an on-line shopping
list...
As I say - a simple Noddy guide is probably what I need!

Thanks
David

Are you wanting the cable in conduit in all the workshop or just for the
drops down to switches and sockets? If it is all conduit then you need to
use single cables not T&E.
I would not attempt to pull T&E down anything other than straight runs.

The adaptors eghttp://www.tlc-direct.co.uk/Products/MT20FMAB.htmlare used
for connecting up to socket backboxes etc. Undo the nut on the adaptor, fit
into the hole and screw the nut back on. The conduit then just pushes into
the adaptor. You do not use these adaptors for connecting the conduit to
conduit boxes and bends, the conduit just shoves into those without the need
for adaptors.

I often just run a big piece of trunking around the garage between the
ceiling and wall and just use conduit for the drops (a 20mm hole cutter is
needed). That way I can use T&E and any additions later are easy. It is a
damn site easier and faster than using conduit all over the place.

--

Cheers

Adam

I've wired two workshops using the self adhesive trunking from
Screwfix

http://www.screwfix.com/prods/19624/...king-25-x-16mm

Perfectly satisfactory and will take several T & E cables. Best if
you use a staple gun to assist the adhesive.

Rob

On 07/12/10 23:56, Lobster wrote:
I think the time has finally come when I may get to convert the "storage
room" at the end of the garage into a "workshop" as was intended when
the building was erected about 10 years ago. With that in mind I need to
wire up the electrics (there's already a CU there, currently supplying
lighting and a single socket for the garage).

Given the 'workshop' element, I want to fit one ring of surface-mounted
metal-clad sockets (probably these: http://preview.tinyurl.com/2vda3wg)
and was going to use surface-mounted PVC conduit (it's a
single-thickness block-building). Thing is, although I've done plenty of
wiring before I've never used conduit and am not entirely sure how to go
about it: I could really use an on-line how-to-do-it guide but can't
find one - is there such a resource around?

To be honest I have no intention of taking this to Building Control but
still want the work to be up to standard. Is PVC conduit considered
acceptable in this sort of environment? (We're talking a very low-key,
domestic, end-of-garage-type workshop, not one with lots of massive
machine tools etc).

PVC is perfectly acceptible.

You now have the choice of pulling T+E *or* singles through it - but for
the record 2.5mm2 T+E will pull round 2 90 deg hand-bent sections over a
5m length with fishwire - I know because I've tried.


Do you have to use single-core wires; ie, will two 2.5mm2 T&E cables not
fit down a standard 20mm PVC conduit? And/or does that present potential
overheating problems? I'd rather not have to use single-core stuff if I
can help it, as I've got plenty of T&E, and you can only buy the singles
in 100m lengths AFAICS.

How do the couplers, male and female adaptors etc work in connecting up
conduit boxes and socket boxes etc? Probably be obvious when I've got
them in my hands, but I'm putting together an on-line shopping list...

I prefer female couplers - just because they leave a smooth bore in the
socket box but you can use male too.

In either case, knock out the knockout, insert adaptor, apply male or
female nut from inside - done. PVC conduit cuts very nicely with a pair
of JG Speedfit type hand shears - quicker than a hacksaw, square cut no
burr. There are these too:

http://www.tlc-direct.co.uk/Products/MTCUT20.html

Glue the tube to the adaptors with solvent weld a la waste pipe.

If you can a low section hanging of conduit it is worth drilling a 1mm
hole in the bottom at the lowest point (before cabling!) to act a a
drain hole for condensate.

Bends - for one or two in a section, hand bend with a pipe spring over
knee or use a pre formed solvent bend with or without inspection cover.
Or use a round box. Good idea to make sur eyou get the gastkets -
sometimes sold sepeartely.

MK tube is better than some no name stuff - I have noticed that one
no-name is no smooth and dirties quickly - still works but will look
grubby and won't wipe clean. MK is polished. Black looks very smart too.

Clips - two types - saddle or these:

http://www.tlc-direct.co.uk/Products/MTMEC2B.html which I rather like
for one screw and neatness.

Have a browse here - pretty much everything you need:

http://www.tlc-direct.co.uk/Main_Ind...ack/index.html


As I say - a simple Noddy guide is probably what I need!

Go into B&Q and have a feel so to speak - it will become clearer then.
Then make a list and go to the wholesalers with a printout of the TLC
page to avoid rapage from either establishment!

Thanks
David


--
Tim Watts

On 08/12/10 08:45, ARWadsworth wrote:
wrote:
I think the time has finally come when I may get to convert the
"storage room" at the end of the garage into a "workshop" as was
intended when the building was erected about 10 years ago. With that
in mind I need to wire up the electrics (there's already a CU there,
currently supplying lighting and a single socket for the garage).

Given the 'workshop' element, I want to fit one ring of
surface-mounted metal-clad sockets (probably these:
http://preview.tinyurl.com/2vda3wg) and was going to use
surface-mounted PVC conduit (it's a single-thickness block-building).
Thing is, although I've done plenty of wiring before I've never used
conduit and am not entirely sure how to go about it: I could really
use an on-line how-to-do-it guide but can't find one - is there such
a resource around?
To be honest I have no intention of taking this to Building Control
but still want the work to be up to standard. Is PVC conduit
considered acceptable in this sort of environment? (We're talking a
very low-key, domestic, end-of-garage-type workshop, not one with
lots of massive machine tools etc).

Do you have to use single-core wires; ie, will two 2.5mm2 T&E cables
not fit down a standard 20mm PVC conduit? And/or does that present
potential overheating problems? I'd rather not have to use
single-core stuff if I can help it, as I've got plenty of T&E, and
you can only buy the singles in 100m lengths AFAICS.

How do the couplers, male and female adaptors etc work in connecting
up conduit boxes and socket boxes etc? Probably be obvious when I've
got them in my hands, but I'm putting together an on-line shopping
list...
As I say - a simple Noddy guide is probably what I need!

Thanks
David

Are you wanting the cable in conduit in all the workshop or just for the
drops down to switches and sockets? If it is all conduit then you need to
use single cables not T&E.
I would not attempt to pull T&E down anything other than straight runs.

Can be done if the bends are very gentle IME - but the bugger are any
joins with straight couplers - there is always a lip the cable end snags
on - can take some fiddling with pulling on a tape at one end and
pushing the cable gently at the other.

The adaptors eg http://www.tlc-direct.co.uk/Products/MT20FMAB.html are used
for connecting up to socket backboxes etc. Undo the nut on the adaptor, fit
into the hole and screw the nut back on. The conduit then just pushes into
the adaptor. You do not use these adaptors for connecting the conduit to
conduit boxes and bends, the conduit just shoves into those without the need
for adaptors.

I often just run a big piece of trunking around the garage between the
ceiling and wall and just use conduit for the drops (a 20mm hole cutter is
needed). That way I can use T&E and any additions later are easy. It is a
damn site easier and faster than using conduit all over the place.


I like that approach - it is what they seem to do here (Imperial
College) a lot - sometimes using all plastic, sometimes galvanised
trunking and steel conduit (depending on the environment) - but always
that sort of layout. I would add that is for final drops - all the
feeders from 32A upwards tend to be SWA.

Still some MICC around but I don't see anyone installing it new anymore.

--
Tim Watts

On 08/12/10 09:27, robgraham wrote:
On Dec 8, 8:45 am,
wrote:
wrote:
I think the time has finally come when I may get to convert the
"storage room" at the end of the garage into a "workshop" as was
intended when the building was erected about 10 years ago. With that
in mind I need to wire up the electrics (there's already a CU there,
currently supplying lighting and a single socket for the garage).

Given the 'workshop' element, I want to fit one ring of
surface-mounted metal-clad sockets (probably these:
http://preview.tinyurl.com/2vda3wg) and was going to use
surface-mounted PVC conduit (it's a single-thickness block-building).
Thing is, although I've done plenty of wiring before I've never used
conduit and am not entirely sure how to go about it: I could really
use an on-line how-to-do-it guide but can't find one - is there such
a resource around?
To be honest I have no intention of taking this to Building Control
but still want the work to be up to standard. Is PVC conduit
considered acceptable in this sort of environment? (We're talking a
very low-key, domestic, end-of-garage-type workshop, not one with
lots of massive machine tools etc).

Do you have to use single-core wires; ie, will two 2.5mm2 T&E cables
not fit down a standard 20mm PVC conduit? And/or does that present
potential overheating problems? I'd rather not have to use
single-core stuff if I can help it, as I've got plenty of T&E, and
you can only buy the singles in 100m lengths AFAICS.

How do the couplers, male and female adaptors etc work in connecting
up conduit boxes and socket boxes etc? Probably be obvious when I've
got them in my hands, but I'm putting together an on-line shopping
list...
As I say - a simple Noddy guide is probably what I need!

Thanks
David

Are you wanting the cable in conduit in all the workshop or just for the
drops down to switches and sockets? If it is all conduit then you need to
use single cables not T&E.
I would not attempt to pull T&E down anything other than straight runs.

The adaptors eghttp://www.tlc-direct.co.uk/Products/MT20FMAB.htmlare used
for connecting up to socket backboxes etc. Undo the nut on the adaptor, fit
into the hole and screw the nut back on. The conduit then just pushes into
the adaptor. You do not use these adaptors for connecting the conduit to
conduit boxes and bends, the conduit just shoves into those without the need
for adaptors.

I often just run a big piece of trunking around the garage between the
ceiling and wall and just use conduit for the drops (a 20mm hole cutter is
needed). That way I can use T&E and any additions later are easy. It is a
damn site easier and faster than using conduit all over the place.

--

Cheers

Adam

I've wired two workshops using the self adhesive trunking from
Screwfix

http://www.screwfix.com/prods/19624/...king-25-x-16mm

Perfectly satisfactory and will take several T& E cables. Best if
you use a staple gun to assist the adhesive.

Rob

I would add I had to pull some ancient self adhesive trunking off a lab
wall at work prior to painting the other day. Needed a jemmy from the
workshop the stuff was so strongly attached! Onto a painted surface it
is as strong as the paint!

--
Tim Watts

On Wed, 08 Dec 2010 10:22:23 +0000, Tim Watts wrote:

Can be done if the bends are very gentle IME - but the bugger are any
joins with straight couplers - there is always a lip the cable end snags
on - can take some fiddling with pulling on a tape at one end and
pushing the cable gently at the other.

When attaching the fish tape to the cable wrap a bit of tape around
the square cable end and fish tape to make a rough cone. Reduces such
snagging a great deal.

--
Cheers
Dave.

On Dec 7, 11:56*pm, Lobster wrote:
To be honest I have no intention of taking this to Building Control but
still want the work to be up to standard.

Extending circuits in a garage or shed or porch is non-notifiable
works.

Search online for 6491X (singles) in cut lengths.
www.tradingdepot.co.uk do 1.5mm & 2.5mm 6491X at 16p & 22p per metre.
I think there is another supplier out there, perhaps another on Ebay.
Perhaps the sheds do a 50m reel (which would be a good length).

On 08/12/10 11:34, js.b1 wrote:
On Dec 7, 11:56 pm, wrote:
To be honest I have no intention of taking this to Building Control but
still want the work to be up to standard.

Extending circuits in a garage or shed or porch is non-notifiable
works.

Search online for 6491X (singles) in cut lengths.
www.tradingdepot.co.uk do 1.5mm& 2.5mm 6491X at 16p& 22p per metre.
I think there is another supplier out there, perhaps another on Ebay.
Perhaps the sheds do a 50m reel (which would be a good length).

Woohoo - thanks for that - had been wondering how to get a few in short
length.

--
Tim Watts

In message , Tim Watts
writes
On 08/12/10 08:45, ARWadsworth wrote:
wrote:
I think the time has finally come when I may get to convert the
"storage room" at the end of the garage into a "workshop" as was
intended when the building was erected about 10 years ago. With that
in mind I need to wire up the electrics (there's already a CU there,
currently supplying lighting and a single socket for the garage).

Given the 'workshop' element, I want to fit one ring of
surface-mounted metal-clad sockets (probably these:
http://preview.tinyurl.com/2vda3wg) and was going to use
surface-mounted PVC conduit (it's a single-thickness block-building).
Thing is, although I've done plenty of wiring before I've never used
conduit and am not entirely sure how to go about it: I could really
use an on-line how-to-do-it guide but can't find one - is there such
a resource around?
To be honest I have no intention of taking this to Building Control
but still want the work to be up to standard. Is PVC conduit
considered acceptable in this sort of environment? (We're talking a
very low-key, domestic, end-of-garage-type workshop, not one with
lots of massive machine tools etc).

Do you have to use single-core wires; ie, will two 2.5mm2 T&E cables
not fit down a standard 20mm PVC conduit? And/or does that present
potential overheating problems? I'd rather not have to use
single-core stuff if I can help it, as I've got plenty of T&E, and
you can only buy the singles in 100m lengths AFAICS.

How do the couplers, male and female adaptors etc work in connecting
up conduit boxes and socket boxes etc? Probably be obvious when I've
got them in my hands, but I'm putting together an on-line shopping
list...
As I say - a simple Noddy guide is probably what I need!

Thanks
David

Are you wanting the cable in conduit in all the workshop or just for the
drops down to switches and sockets? If it is all conduit then you need to
use single cables not T&E.
I would not attempt to pull T&E down anything other than straight runs.

Can be done if the bends are very gentle IME - but the bugger are any
joins with straight couplers - there is always a lip the cable end
snags on - can take some fiddling with pulling on a tape at one end and
pushing the cable gently at the other.

The adaptors eg http://www.tlc-direct.co.uk/Products/MT20FMAB.html are used
for connecting up to socket backboxes etc. Undo the nut on the adaptor, fit
into the hole and screw the nut back on. The conduit then just pushes into
the adaptor. You do not use these adaptors for connecting the conduit to
conduit boxes and bends, the conduit just shoves into those without the need
for adaptors.

I often just run a big piece of trunking around the garage between the
ceiling and wall and just use conduit for the drops (a 20mm hole cutter is
needed). That way I can use T&E and any additions later are easy. It is a
damn site easier and faster than using conduit all over the place.


I like that approach - it is what they seem to do here (Imperial
College) a lot - sometimes using all plastic, sometimes galvanised
trunking and steel conduit (depending on the environment) - but always
that sort of layout. I would add that is for final drops - all the
feeders from 32A upwards tend to be SWA.

AOL

Galvanised steel 2" trunk. Use stranded singles. Trap clear of lid with
strips of polystyrene etc. foam.

You can purchase corners but I usually *angle grind* out the sides and
fold to 90deg.

Twin metal clad socket boxes stood off on two straight conduit couplers
secured with two brass bushes.

Run a separate earth wire.

Future proof:-)


Still some MICC around but I don't see anyone installing it new anymore.

Not surprising!

regards


--
Tim Lamb

On 07/12/2010 23:56, Lobster wrote:
I think the time has finally come when I may get to convert the "storage
room" at the end of the garage into a "workshop" as was intended when
the building was erected about 10 years ago. With that in mind I need to
wire up the electrics (there's already a CU there, currently supplying
lighting and a single socket for the garage).

Given the 'workshop' element, I want to fit one ring of surface-mounted
metal-clad sockets (probably these: http://preview.tinyurl.com/2vda3wg)
and was going to use surface-mounted PVC conduit (it's a
single-thickness block-building). Thing is, although I've done plenty of
wiring before I've never used conduit and am not entirely sure how to go
about it: I could really use an on-line how-to-do-it guide but can't
find one - is there such a resource around?

To be honest I have no intention of taking this to Building Control but
still want the work to be up to standard. Is PVC conduit considered
acceptable in this sort of environment? (We're talking a very low-key,
domestic, end-of-garage-type workshop, not one with lots of massive
machine tools etc).

Do you have to use single-core wires; ie, will two 2.5mm2 T&E cables not
fit down a standard 20mm PVC conduit? And/or does that present potential
overheating problems? I'd rather not have to use single-core stuff if I
can help it, as I've got plenty of T&E, and you can only buy the singles
in 100m lengths AFAICS.

How do the couplers, male and female adaptors etc work in connecting up
conduit boxes and socket boxes etc? Probably be obvious when I've got
them in my hands, but I'm putting together an on-line shopping list...

As I say - a simple Noddy guide is probably what I need!

Thanks
David

Is conduit required by the regs? I can't see how a plastic conduit is
going to offer much protection to an already visible cable.

On 08/12/10 12:07, nicknoxx wrote:

Is conduit required by the regs? I can't see how a plastic conduit is
going to offer much protection to an already visible cable.

Plastic - no explicitly, though it could be argued as providing
protection suitable for the environment.

Don't underestimate it - it's pretty tough. I'd rather a mis-aimed
chisel or knife or lump of wood struck tube than T+E cable. The former
might sustain some damage but you'd have to belt it pretty hard to
damage what's inside.

--
Tim Watts

On Dec 7, 11:56*pm, Lobster wrote:
I think the time has finally come when I may get to convert the "storage
room" at the end of the garage into a "workshop" as was intended when
the building was erected about 10 years ago.

I've got a garage as a "storage room" (for cars) on the end of my
workshop. Just cabled some of it in the same way you describe, T&E in
20mm (and some 25mm), but I'll probably do the rest in singles in
20mm. I can easily use 100m reels, but for a small job I'd struggle
with the T&E.

I would really have benefitted from a "Guide to goood workmanship in
PVC conduit" It's not all obvious from the first, particularly in
terms of which type of bend to use. One for the DIY wiki?

Do you have to use single-core wires; ie, will two 2.5mm2 T&E cables not
fit down a standard 20mm PVC conduit?

You can get two 2.5mm^2 T&E _and_ a 1mm^2 down there, but that's just
about the limit.

In practical terms you can get two 2.5s down there "easily" so long as
you do the following:

* The cables are straight and unkinked. You need a reel stand.
* You push (or pull) both from the same end
* You're only pulling through straight conduit, i.e each length is a
separate pull and you cable as you install the conduit.
* If it won't push, try pulling it.
* You never want to replace cables!

So you can see that it's workable for a small one-off, but if you're
in someone like Adam's position and time is money, then it's a crazy
way to do it. Singles are certainly easier.

And/or does that present potential
overheating problems?

The numbers change (in your OSG), but it's no big deal. Bundled cables
are bundled cables, and there's less de-rating due to heat from
surface conduit than under loft insulation.

How do the couplers, male and female adaptors etc work in connecting up
conduit boxes and socket boxes etc? *

I bought a sackful of round conduit boxes, then hardly used them. You
need lots of bends, a few tees, very few round boxes. You need more
female & male adaptors than you expect. Female adaptors _should_ allow
you to slip lengths of conduit in between boxes, then insert the
screwed bush from inside the box. In practice they don't, because
you've got the other end in a moulded socket and it's not that bendy.
I mostly used males, as I find them easier to tighten inside the box.

Bends come in many shapes and about three different radii. The CED
ones (from TLC?) with a screwed lid are a bit ugly, but their two
radii are neat for multiple fan outs from a CU. I preferred the clip
lid sort from discount-electrical, which have a fixed base and the
whole lid and sides clips off. Easy access when open and they look
cleaner installed too. You can pull cable through a nice bend or
elbow, but not through a round box (take the lid off and treat as two
pulls).

You need a bending spring (and a hot air gun), because many odd
corners in an existing old building just aren't straight or square.
It's also handy for dog-legging over other conduits or services.

Conduit clips vary. Two-piece saddle clips screw beneath the conduit,
so need to be installed early. I like the single-sided P clips from
discount-electrical from horizontal runs in the roofspace, two screw
saddles where there's a mechanical risk, and two-piece near the ends
where I might want to dismantle it again.

Rolson's conduit cutter is crap. Cuts well enough, but really slow and
clumsy to use. Again, it'll do for a garage but you wouldn't put up
with it commercially.

25mm conduit is only useful for lighting where you have junctions in
multiple conduit boxes and a lot of separate circuits, with lots of
wires between. Otherwise you find that its adaptors into the boxes at
the ends are just the same size as 20mm, so you can't pull any more
cable than you could with 20mm conduit.

If you have racks of adjacent metalclad sockets, you need metal
conduit nipples and spare lockrings to bolt them together. There used
to be a brass thing for doing this in one piece, but no-one seems to
stock them? Remember to crop the faceplate screws to clear these, or
you'll break the screw lugs out of the back boxes. Remember to tell
your teenage assistant this, or at least "Don't force it if it won't
go, stop and ask". It's a right pain to be "finished", then find that
half your backboxes are now broken and you have to strip the whole lot
out! Don't use teenagers as labourers if they're likely to take the
"sweep it under the carpet" approach to problems, especially not if
they then repeat it on a whole row before you find out.

On Dec 8, 12:07*pm, nicknoxx
wrote:

Is conduit required by the regs? I can't see how a plastic conduit is
going to offer much protection to an already visible cable.

Who cares about the paper, this is a practical issue. Plastic conduit
on screwed clips survives common impacts that will pull T&E out of
nailed clips.

Andy Dingley wrote:
On Dec 7, 11:56 pm, Lobster wrote:

And/or does that present potential
overheating problems?

The numbers change (in your OSG), but it's no big deal. Bundled cables
are bundled cables, and there's less de-rating due to heat from
surface conduit than under loft insulation.

Have a look here

http://wiki.diyfaq.org.uk/index.php?...lation_Methods

Although the figures are correct the page is halfway through an update to
fetch it into line with the 17th edition reference methods (I'll see if I
can update it a little more tonight)

A 32A ring and 6A lighting are unlikely to cause problems when used in
conduit together. It may well be possible to ignore the lighting circuit for
grouping factors if it is only at 33% of it's capacity.

Remember to tell
your teenage assistant this, or at least "Don't force it if it won't
go, stop and ask". It's a right pain to be "finished", then find that
half your backboxes are now broken and you have to strip the whole lot
out! Don't use teenagers as labourers if they're likely to take the
"sweep it under the carpet" approach to problems, especially not if
they then repeat it on a whole row before you find out.

Do you speak from experience here? I sense a bit of ill feeling. Do tell us.

--
Adam

In article ,
Tim Watts writes:

Glue the tube to the adaptors with solvent weld a la waste pipe.

PVC has quite a significant coefficient of expansion. If you have
long runs in a dry location with large temperature changes, it's
a good idea not to glue all the ends, but allow some to act as
expansion joins like with guttering.

Also, allow several hours from last solvent weld before drawing in
any of the cable, or you may find residual solvent in the tubing
ends up welding the cable to it. (Regs used to say you must finish
the whole conduit/trunking installation before you start drawing
in any cables.)

If you are forming your own bends, don't use a plumber's bending
spring as they aren't the right size and pipe will crinkle.
You need a conduit bending spring.
However, a plumbers 22mm pipe bender will just about bend 20mm
conduit with just a little flattening, although that may be
enough to stop you using a pair of T&E.
Bends have a slight tendancy to try to undo themselves, so
position the clips so this can't happen.

If you can a low section hanging of conduit it is worth drilling a 1mm
hole in the bottom at the lowest point (before cabling!) to act a a
drain hole for condensate.

When I cable up, I always assume the odd drip will run out of
any vertical runs. Form the wires into a drip loop inside the
accessory box, so this drips off rather than being directed
into the back of the wiring accessory, and also drill a drain
hole in the bottom of the back box (I usually go for 3-5mm).
If the conduit runs through a wall to a different temperature,
then condensation formation can be a very significant issue,
but even temperature changes in the one location will generate
some.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On Dec 8, 1:23*pm, "ARWadsworth"
wrote:

Do you speak from experience here? I sense a bit of ill feeling. Do tell us.

Some days I feel like Jim Henson - I have sired a Muppet.

On 08/12/2010 08:45, ARWadsworth wrote:
wrote:
I think the time has finally come when I may get to convert the
"storage room" at the end of the garage into a "workshop" as was
intended when the building was erected about 10 years ago. With that
in mind I need to wire up the electrics (there's already a CU there,
currently supplying lighting and a single socket for the garage).

Thanks to all for lots of really useful advice - I feel much more
confident about this now.

Are you wanting the cable in conduit in all the workshop or just for the
drops down to switches and sockets? If it is all conduit then you need to
use single cables not T&E.

[...]

I often just run a big piece of trunking around the garage between the
ceiling and wall and just use conduit for the drops (a 20mm hole cutter is
needed). That way I can use T&E and any additions later are easy. It is a
damn site easier and faster than using conduit all over the place.

Well in fact, thinking about it, that will suit my purposes really well.
I was indeed intending just to install drops to sockets and switches;
the workshop has a plasterboarded ceiling and there's a semi-permanent
floor above sitting on the ceiling joists, so I see no reason why I
can't just run 'horizontal' runs of T&E above the ceiling unprotected
(ie as I would in the house) and then have 2xT&E drops down to all the
accessories, within 1-metre-ish straight lengths of 20mm trunking, which
pokes through the ceiling. All very much easier than I'd envisaged!

Thanks
David

Lobster wrote:
On 08/12/2010 08:45, ARWadsworth wrote:
wrote:
I think the time has finally come when I may get to convert the
"storage room" at the end of the garage into a "workshop" as was
intended when the building was erected about 10 years ago. With that
in mind I need to wire up the electrics (there's already a CU there,
currently supplying lighting and a single socket for the garage).

Thanks to all for lots of really useful advice - I feel much more
confident about this now.

Are you wanting the cable in conduit in all the workshop or just for
the drops down to switches and sockets? If it is all conduit then
you need to use single cables not T&E.

[...]

I often just run a big piece of trunking around the garage between
the ceiling and wall and just use conduit for the drops (a 20mm hole
cutter is needed). That way I can use T&E and any additions later
are easy. It is a damn site easier and faster than using conduit all
over the place.

Well in fact, thinking about it, that will suit my purposes really
well. I was indeed intending just to install drops to sockets and
switches; the workshop has a plasterboarded ceiling and there's a
semi-permanent floor above sitting on the ceiling joists, so I see no
reason why I can't just run 'horizontal' runs of T&E above the
ceiling unprotected (ie as I would in the house) and then have 2xT&E
drops down to all the accessories, within 1-metre-ish straight
lengths of 20mm trunking, which pokes through the ceiling. All very
much easier than I'd envisaged!

There is no reason at all why you cannot do it that way. Just remember to
keep the T&E flat when pulling/pushing it through the conduit.

--
Adam

Andy Dingley wrote:
On Dec 8, 1:23 pm, "ARWadsworth"
wrote:

Do you speak from experience here? I sense a bit of ill feeling. Do
tell us.

Some days I feel like Jim Henson - I have sired a Muppet.

Don't worry. I've employed worse.

--
Adam

Andy Dingley wrote:
On Dec 8, 12:07 pm, nicknoxx
wrote:

Is conduit required by the regs? I can't see how a plastic conduit is
going to offer much protection to an already visible cable.

Who cares about the paper, this is a practical issue. Plastic conduit
on screwed clips survives common impacts that will pull T&E out of
nailed clips.

You also get the benefit of it looking like a nice professional job.

--
Adam

The old method used to be to use conduit round-elbows and rount-T
boxes.
I suspect that is because they allow the use of gaskets & brass M4
screws, so providing better water proofing than the mere "snap
together elbow".

A garage has quite a temperature range, so watch the expansion re
plastic.

Saddle clips require precision location, snap-over single clips have a
slot so tolerant of miss-location.

As mentioned MK Egatube fittings (including bush-female adapter) are
the nicest, keep their finish well and generally fit together. There
are some tubes which are slightly oversize and fit far too tightly (or
not at all) into fittings, avoid.

js.b1 wrote:

Saddle clips require precision location, snap-over single clips have a
slot so tolerant of miss-location.

I have never used the snap-over clips so I cannot comment.

The snap-on clips have no adjustment (similar to pipe clips).

However the saddle bar type clips have a slot on the base for adjustment.


--
Adam

On 08/12/10 19:05, ARWadsworth wrote:
wrote:
On 08/12/2010 08:45, ARWadsworth wrote:
wrote:
I think the time has finally come when I may get to convert the
"storage room" at the end of the garage into a "workshop" as was
intended when the building was erected about 10 years ago. With that
in mind I need to wire up the electrics (there's already a CU there,
currently supplying lighting and a single socket for the garage).

Thanks to all for lots of really useful advice - I feel much more
confident about this now.

Are you wanting the cable in conduit in all the workshop or just for
the drops down to switches and sockets? If it is all conduit then
you need to use single cables not T&E.

[...]

I often just run a big piece of trunking around the garage between
the ceiling and wall and just use conduit for the drops (a 20mm hole
cutter is needed). That way I can use T&E and any additions later
are easy. It is a damn site easier and faster than using conduit all
over the place.

Well in fact, thinking about it, that will suit my purposes really
well. I was indeed intending just to install drops to sockets and
switches; the workshop has a plasterboarded ceiling and there's a
semi-permanent floor above sitting on the ceiling joists, so I see no
reason why I can't just run 'horizontal' runs of T&E above the
ceiling unprotected (ie as I would in the house) and then have 2xT&E
drops down to all the accessories, within 1-metre-ish straight
lengths of 20mm trunking, which pokes through the ceiling. All very
much easier than I'd envisaged!

There is no reason at all why you cannot do it that way. Just remember to
keep the T&E flat when pulling/pushing it through the conduit.

I think you can just clip the T&E to the wall,
no need for conduit.

It will be on an RCD so the most dangerous thing is falling off a ladder
fitting it! (and what you plug into it)

[g]