Hi all,

I have course to run around 20meters of 6mm SWA to an outbuilding for power,
and want to run CAT5 into it too. I'll probably use 2 pairs of this for
telephone, and 2 pairs for computer.

Am I likely to get mains hum / interferance from the SWA?

Am intending to use 2inch plastic ducting.

Tim..

On Sun, 3 Oct 2004 10:01:38 +0000 (UTC), " Tim \(Remove NOSPAM."
wrote:

Hi all,

I have course to run around 20meters of 6mm SWA to an outbuilding for power,
and want to run CAT5 into it too. I'll probably use 2 pairs of this for
telephone, and 2 pairs for computer.

Am I likely to get mains hum / interferance from the SWA?

Am intending to use 2inch plastic ducting.

Tim..




They shouldn't be run in the same duct.

Whenever I've done this I bury the SWA in a trench with sand around
it, then electricity warning tape above that.

I run in a duct of 50mm plastic waste pipe for data and phone cables.
The simple solution to cable pulling with this is to tie a small piece
of rag to a bit of string and then use a vacuum cleaner to pull it
through the pipe. I attach a double length of polypropylene cord to
the string, allowing me to pull cables through. One length of cord
remains in the pipe.


..andy

To email, substitute .nospam with .gl

" Tim (Remove NOSPAM." wrote in message
...
Hi all,

I have course to run around 20meters of 6mm SWA to an outbuilding for
power,
and want to run CAT5 into it too. I'll probably use 2 pairs of this for
telephone, and 2 pairs for computer.

Am I likely to get mains hum / interferance from the SWA?

Am intending to use 2inch plastic ducting.

Tim..




It would be less likely with screened CAT5 ..... I take it you know that it
is not allowed to run data comms & power in same conduit or trunking -
unless physically separated?

Rick

Rick Hughes wrote:

It would be less likely with screened CAT5 ..... I take it you know that it
is not allowed to run data comms & power in same conduit or trunking -
unless physically separated?

With a slightly different application in mind I was wondering if the
armour of SWA would count as 'physical separation'? In my case it's
not for being in the same couduit it because I might want a separation
of less than 50mm between the SWA and some non-power cables.

--
Chris Green

On 4 Oct 2004 12:07:10 GMT, wrote:

Rick Hughes wrote:

It would be less likely with screened CAT5 ..... I take it you know that it
is not allowed to run data comms & power in same conduit or trunking -
unless physically separated?

With a slightly different application in mind I was wondering if the
armour of SWA would count as 'physical separation'? In my case it's
not for being in the same couduit it because I might want a separation
of less than 50mm between the SWA and some non-power cables.


No evidence to suggest that it is, Chris

http://www.tlc-direct.co.uk/Book/6.6.1.htm

I agree that one would have to try pretty hard to breach tghe armour
and insulation, but it does say that all cables have to be insulated
to the standard for the highest voltage


..andy

To email, substitute .nospam with .gl

Andy Hall wrote:
On 4 Oct 2004 12:07:10 GMT, wrote:

Rick Hughes wrote:

It would be less likely with screened CAT5 ..... I take it you know that it
is not allowed to run data comms & power in same conduit or trunking -
unless physically separated?

With a slightly different application in mind I was wondering if the
armour of SWA would count as 'physical separation'? In my case it's
not for being in the same couduit it because I might want a separation
of less than 50mm between the SWA and some non-power cables.


No evidence to suggest that it is, Chris

http://www.tlc-direct.co.uk/Book/6.6.1.htm

I agree that one would have to try pretty hard to breach tghe armour
and insulation, but it does say that all cables have to be insulated
to the standard for the highest voltage

Well in this case they would be as the 'other' cable is an electric
fence wire, much more than mains insulation on that. However I still
think the regulations require either mechanical separation or 50mm
between it and any mains wiring. It would be just as dangerous (if
not more so) to have a mains to electric fence fault as a mains to
CAT5 fault.

However personally I would feel quite happy running my electric fence
wire along close to the SWA, I was just wondering what the regulations
said about such a thing.

--
Chris Green

Andy Hall wrote:

I agree that one would have to try pretty hard to breach tghe armour
and insulation, but it does say that all cables have to be insulated
to the standard for the highest voltage

There's more to it than that. BS 7671 Reg. 528-01-02 allows six ways in
which Band I and Band II circuits can be mixed in the same wiring
system. To précis, very briefly, these a

(i) all cables insulated for the highest voltage present;

(ii) cores of multicore Band I voltage cable insulated separately or
_ collectively for the highest voltage present;

(iii) cores of Band I circuit separated from cores of Band II circuit by
* an earthed metal screen with current carrying capacity equal to
* that of the largest Band II core;

(iv) compartmented trunking system;

(v) physical separation barrier when cables are on cable tray or
* ladder;

(vi) separate conduit, trunking or duct.


For method (iii) the condition is met by the armour of 2-core SWA cables
(to BS 5467) up to an including 10 mm^2. Since the OP mentioned 6 mm^2
SWA the arrangement originally proposed complies with BS 7671.

But I agree that direct burial of the SWA is preferable. It increases
the current rating too.

--
Andy

On Mon, 04 Oct 2004 14:57:04 +0100, Andy Wade
wrote:

Andy Hall wrote:

I agree that one would have to try pretty hard to breach tghe armour
and insulation, but it does say that all cables have to be insulated
to the standard for the highest voltage

There's more to it than that. BS 7671 Reg. 528-01-02 allows six ways in
which Band I and Band II circuits can be mixed in the same wiring
system. To précis, very briefly, these a

(i) all cables insulated for the highest voltage present;

(ii) cores of multicore Band I voltage cable insulated separately or
_ collectively for the highest voltage present;

(iii) cores of Band I circuit separated from cores of Band II circuit by
* an earthed metal screen with current carrying capacity equal to
* that of the largest Band II core;

(iv) compartmented trunking system;

(v) physical separation barrier when cables are on cable tray or
* ladder;

(vi) separate conduit, trunking or duct.


For method (iii) the condition is met by the armour of 2-core SWA cables
(to BS 5467) up to an including 10 mm^2. Since the OP mentioned 6 mm^2
SWA the arrangement originally proposed complies with BS 7671.

OK. I took (iii) as being applicable to metal trunking with a divider
- but I see your point.



But I agree that direct burial of the SWA is preferable. It increases
the current rating too.

Do you happen to have a table reference for SWA current carrying
capacities for buried, ducted and clipped to a wall, Andy?


..andy

To email, substitute .nospam with .gl

On Mon, 04 Oct 2004 13:13:28 +0100, Andy Hall wrote:

On 4 Oct 2004 12:07:10 GMT, wrote:

Rick Hughes wrote:

It would be less likely with screened CAT5 ..... I take it you know that it
is not allowed to run data comms & power in same conduit or trunking -
unless physically separated?

With a slightly different application in mind I was wondering if the
armour of SWA would count as 'physical separation'? In my case it's
not for being in the same couduit it because I might want a separation
of less than 50mm between the SWA and some non-power cables.


No evidence to suggest that it is, Chris

http://www.tlc-direct.co.uk/Book/6.6.1.htm

I agree that one would have to try pretty hard to breach tghe armour
and insulation, but it does say that all cables have to be insulated
to the standard for the highest voltage.

I'm sure that I've seen CAT5 cable rated to 250V. Still not the best
solution though.

Steve W

In article , Tim (Remove NOSPAM.
writes
Hi all,

I have course to run around 20meters of 6mm SWA to an outbuilding for power,
and want to run CAT5 into it too. I'll probably use 2 pairs of this for
telephone, and 2 pairs for computer.

Am I likely to get mains hum / interferance from the SWA?

Am intending to use 2inch plastic ducting.

Tim..




Shouldn't worry about it at all, we've done this and have had no
problems at all. CAT 5 is an inherently balanced system like balanced
audio where you can run circuits around willy nilly without problems.

Anyway the SWA cable does much to contain the mains "field" within.

So No, don't worry.....
--
Tony Sayer

"tony sayer" wrote in message
...
In article , Tim (Remove NOSPAM.
writes
Hi all,

I have course to run around 20meters of 6mm SWA to an outbuilding for
power,
and want to run CAT5 into it too. I'll probably use 2 pairs of this for
telephone, and 2 pairs for computer.

Am I likely to get mains hum / interferance from the SWA?

Am intending to use 2inch plastic ducting.


Shouldn't worry about it at all, we've done this and have had no
problems at all. CAT 5 is an inherently balanced system like balanced
audio where you can run circuits around willy nilly without problems.

Anyway the SWA cable does much to contain the mains "field" within.

So No, don't worry.....


Except that you're not keeping medium voltage separate from low voltage...

In article , :::Jerry::::
writes

"tony sayer" wrote in message
...
In article , Tim (Remove NOSPAM.
writes
Hi all,

I have course to run around 20meters of 6mm SWA to an outbuilding for
power,
and want to run CAT5 into it too. I'll probably use 2 pairs of this for
telephone, and 2 pairs for computer.

Am I likely to get mains hum / interferance from the SWA?

Am intending to use 2inch plastic ducting.


Shouldn't worry about it at all, we've done this and have had no
problems at all. CAT 5 is an inherently balanced system like balanced
audio where you can run circuits around willy nilly without problems.

Anyway the SWA cable does much to contain the mains "field" within.

So No, don't worry.....


Except that you're not keeping medium voltage separate from low voltage...



Yes maybe, but does that *really matter* in this instance?.

Consider the number of places where CAT5, phone, and power leads are in
very close proximity to each other?, like behind most every PC
workstation or home PC, and I've never heard of a problem as yet.

Andy wossisnames Idea of burying the SWA cable separately is quite a
good one though, after all you've paid for something that you can direct
bury, so I suppose you might as well make use of it unless you really
want to be able to pull it up occasionally.....
--
Tony Sayer

On Sun, 3 Oct 2004 12:03:55 UTC, tony sayer wrote:

Except that you're not keeping medium voltage separate from low voltage...

Yes maybe, but does that *really matter* in this instance?.

The regs?

--
Bob Eager
begin a new life...dump Windows!

In article , Bob Eager
writes
On Sun, 3 Oct 2004 12:03:55 UTC, tony sayer wrote:

Except that you're not keeping medium voltage separate from low voltage...

Yes maybe, but does that *really matter* in this instance?.

The regs?


Yes the regulations etc state that...but its not a problem otherwise,
and if any one cops the strop about that here if we decide to sell then
I'll just cut the data cable and that will be that.

If there was a political party promoting its self on de-regulation than
they'd get my vote anyday)
--
Tony Sayer

On Sun, 3 Oct 2004 13:03:55 +0100, tony sayer
wrote:


Yes maybe, but does that *really matter* in this instance?.

If you want to stick to the wiring regulations you aren't supposed to
put mains (LV) cables and signal cables in the same duct.

If it becomes subject to inspection at some point in the future (e.g.
on sale) this might be detected and flagged.



Consider the number of places where CAT5, phone, and power leads are in
very close proximity to each other?, like behind most every PC
workstation or home PC, and I've never heard of a problem as yet.

From the EMC perspective, probably not a problem, I agree.



Andy wossisnames Idea of burying the SWA cable separately is quite a
good one though, after all you've paid for something that you can direct
bury, so I suppose you might as well make use of it unless you really
want to be able to pull it up occasionally.....

The other factor in this is if duct like 50mm waste pipe with bends is
used, it may be hard to get SWA to go through it.
Flexible cables will of course.



..andy

To email, substitute .nospam with .gl

On Sun, 03 Oct 2004 13:51:32 +0100, Andy Hall wrote:

The other factor in this is if duct like 50mm waste pipe with bends
is used, it may be hard to get SWA to go through it. Flexible cables
will of course.

SWA may as well be buried direct. As for pulling cables through a duct
they might come round a swept 90 bend when the duct is empty but once
you get a few cables in there it'll start to get tight and two 90
bends I'd say is really asking for them not to pull at all. Plan to
have access points at changes of direction, makes life so much easyier
in the long run, straight pulls are *much* easier.

--
Cheers
Dave. pam is missing e-mail

On Sun, 3 Oct 2004 10:01:38 +0000 (UTC), " Tim \(Remove NOSPAM."
wrote:

Hi all,

I have course to run around 20meters of 6mm SWA to an outbuilding for power,
and want to run CAT5 into it too. I'll probably use 2 pairs of this for
telephone, and 2 pairs for computer.

Am I likely to get mains hum / interferance from the SWA?

Am intending to use 2inch plastic ducting.

Tim..




Sir

Its unlikley to interfer with each other. Its only when you run the
CAT 5 past MRI machies, and the like you have to start worring.

Its normal to run the CAT 5 and the 240v in two seperate trunkings, so
your sparkies don't screw the computer data comms, and the data comms
guys don't kill themselves with 240v. This is because the two are
different skill sets, and two different sets of people.

In my house I run them both together.

I would run a 110mm pipe, and have gentle bends. Its just easier when
you want to push something else through later.

If you take a look under the floor in the data center of most large
companies, you will find miles of all types of cables just chucked
under there, no trunking, no labels, no neetness. When you stop using
a cable, you just cut the ends off and leave it down there. Now some
new places do it all neet, but I have never seen one stay that way for
long.

Rick

Rick Dipper wrote:

If you take a look under the floor in the data center of most large
companies, you will find miles of all types of cables just chucked
under there, no trunking, no labels, no neetness. When you stop using
a cable, you just cut the ends off and leave it down there. Now some
new places do it all neet, but I have never seen one stay that way for
long.

I'm sure some places do get that way; whether it's "most" is not
something I have enough data on. I know that *our* computer room
and office underfloors do keep the Cat5 runs quite neat and separated
from the 240VAC - the Cat5 (of which there really is rather a lot:
80-100 cubicle-placement-opportunities per floor, floodwired with 8+
Cat5 ports each, and more for the machine rooms in the central area
of each floor!) runs on chromed-wire cable trays, loosely cable-tied
in place. The 240VAC feeds run lower, with singles running in closed
galvanised trunking, feeding floorports either directly or through
Klik-style sockets. There's vertical separation between 'em (the
mains trunking sits on the underfloor, the Cat5 trays are on stands,
so that the two can cross without needing to change levels), there
aren't many places where the two run parallel for long; and the lighting
runs (oddly enough) in the suspended ceiling rather'n down below. It's
a bit more of a mess up there, though the clear intention is that the
lighting wiring runs on cable tray - but there's door-security cabling,
some CCTV, and other stuff which various contractors have added with
not as much neatness as the building services people would like ;-)

Stefek

"Stefek Zaba" wrote in message
...
snip
aren't many places where the two run parallel for long; and the lighting
runs (oddly enough) in the suspended ceiling rather'n down below.

I assume you were trying to be ironic there, had to read it twice though !..
:~)

Snipped a tad.....
as much neatness as the building services people would like ;-)

Stefek

I reckon thats why we have insulation
--
Tony Sayer

"Rick Dipper" wrote in message
...
On Sun, 3 Oct 2004 10:01:38 +0000 (UTC), " Tim \(Remove NOSPAM."
wrote:

Hi all,

I have course to run around 20meters of 6mm SWA to an outbuilding for
power,
and want to run CAT5 into it too. I'll probably use 2 pairs of this for
telephone, and 2 pairs for computer.

Am I likely to get mains hum / interferance from the SWA?

Am intending to use 2inch plastic ducting.

Tim..




Sir

Its unlikley to interfer with each other. Its only when you run the
CAT 5 past MRI machies, and the like you have to start worring.

Its normal to run the CAT 5 and the 240v in two seperate trunkings, so
your sparkies don't screw the computer data comms, and the data comms
guys don't kill themselves with 240v. This is because the two are
different skill sets, and two different sets of people.

In my house I run them both together.

I would run a 110mm pipe, and have gentle bends. Its just easier when
you want to push something else through later.


Many thanks to all contributors!

Tim..

I would run a 110mm pipe, and have gentle bends. Its just easier when
you want to push something else through later.



FWIW I used 4 inch soil pipe round our gaff for that very reason. The
only place I've used 50 mm is for the ducts that come in from the two
sat dishes hidden out in our garden, where there are only two cables
involved......
--
Tony Sayer

I would have thought the seperation provided by the outer insulation and the
armouring would satisfy the regs.

"tony sayer" wrote in message
...
I would run a 110mm pipe, and have gentle bends. Its just easier when
you want to push something else through later.



FWIW I used 4 inch soil pipe round our gaff for that very reason. The
only place I've used 50 mm is for the ducts that come in from the two
sat dishes hidden out in our garden, where there are only two cables
involved......
--
Tony Sayer

On Mon, 04 Oct 2004 10:44:22 GMT, "martin.shaw11"
wrote:

I would have thought the seperation provided by the outer insulation and the
armouring would satisfy the regs.


Not really

*Every* cable in the duct would have to be insulated to the standard
required of the highest voltage.

http://www.tlc-direct.co.uk/Book/6.6.1.htm

CAT5 and phone cable does not meet those requirements.



"tony sayer" wrote in message
...
I would run a 110mm pipe, and have gentle bends. Its just easier when
you want to push something else through later.



FWIW I used 4 inch soil pipe round our gaff for that very reason. The
only place I've used 50 mm is for the ducts that come in from the two
sat dishes hidden out in our garden, where there are only two cables
involved......
--
Tony Sayer




..andy

To email, substitute .nospam with .gl