Surface mounted cabling, regs please

[leezer3]

OK, so small regulations question please gents. Getting a slightly conflicting answer to this from a search- I want to install another socket in my lounge.

The wiring in this house is typical 70s, and the two other sockets in the room are on opposite walls, but I have a socket on the same wall plane in the next room. I would like to do this:
*2.5mm T+E in surface mounted mini trunking from the existing socket, in an approx 1m run along the wall. (This trunking is already in place carrying network cables, I believe if I add a divider I am OK. Could alternatively add a second piece of trunking)
* Drill a hole through the wall and into the cupboard under the stairs. Pass the cable through this hole, and clip direct to the top of the cupboard.
* Drill through the second wall of the cupboard and into the rear of the new surface mounted backbox.

The downstairs sockets are on a 16a radial, consisting of one branch of two, and two singles.
RCD protection is present.

Am I doing anything to contravene any regs please?
Not clear either on whether I can legally do this due to Part P. It's not a special location or anything, but I am planning to go between rooms.
I also can't find any regs on the size of hole I should be using. 2.5mm T+E fits through a 10mm masonry bit hole, but do I need to go bigger?

Doing this most other ways would involve messy removal of floorboards. (These were screwed and nailed down by a previous owner before varnishing. I've had one up in the past, and they're a pig to remove))

 

[ericmark]

I am aware of nothing to stop you doing this work.

I have just don't something similar for a friend. That reminds me must issue him the minor works certificate.

Clearly you must test as I did. Earth loop impedance and RCD trip times do need entering on the minor works certificate but nothing to stop you doing the work.

 

[securespark]

The wiring in this house is typical 70s,

What, wearing flares and whistling "Go Your Own Way"?

16A radial is an odd choice for sockets. How many are there on the run? And what floor area do they cover?

 

[leezer3]

The wiring in this house is typical 70s,

What, wearing flares and whistling "Go Your Own Way"?

16A radial is an odd choice for sockets. How many are there on the run? And what floor area do they cover?

Lol, yeah
4 double sockets on this circut, covering 32m² total.
Covers the front and back downstairs rooms of a standard Victorian terraced house.

Shoddy MSPaint diagram of the circuit in question, if you assume the dashed line is the stairs:

Complete list of the circuits for what it's worth:
32a- Cooker & cooker socket.
32a- Shower.
16a radial- Upstairs plugs & loft.
16a radial- Downstairs plugs.
16a radial- Kitchen plugs & boiler FCU.
16a- Labelled as spare. Left off, doesn't appear to be connected to anything & I'm not taking the front off the CU to find out.
10a- Lighting radial for whole house.

All Volex MCBs (Board is labelled Volex Protector, can't see an exact model) running off a single 30ma RCD, so not absolutely idea, but works perfectly, just not enough sockets!

 

[plugwash]

I don't think dividers exist for mini trunking, so you will probablly have to use a seperate run of trunking from your mains cables from the existing peice for data cables.

 

[leezer3]

I don't think dividers exist for mini trunking, so you will probablly have to use a seperate run of trunking from your mains cables from the existing peice for data cables.

Quite possibly true
The trunking is a reasonable size, I'd have to look into the options there TBQH.
From what I can find, the separation requirement comes from EN 50174-1, and interestingly enough, I found this little titbidt:

The original draft proposed:-

No separation between horizontal data and power required if the parallel run is less than 35 m.

For runs longer than 35 m, separation distances shall apply except for the final 15 m to the outlet.

( http://home2.btconnect.com/KnowHow-Networks/spec_50174.htm )

The data cables are a mix of Cat6 and Cat5e on a gigabit network, and I'm almost tempted to test transfer speeds with them in the same trunking.
This guidance seems to have been written with industrial setups in mind, as if you look later on, it mentions 10 cables being the maximum allowed with these distances

 

[PrenticeBoyofDerry]

I would be tempted to upgrade to 20A on the radial, depending on what it is going to power that is.
The hole size should allow the cable to pass through without causing damage or stress to the cable, it can always be filled in afterwards.

 

[ban-all-sheds]

Not clear either on whether I can legally do this due to Part P.

As long as you comply with Part P it will be legal.

 

[ban-all-sheds]

From what I can find, the separation requirement comes from EN 50174-1, and interestingly enough, I found this little titbidt:

The original draft proposed:-

No separation between horizontal data and power required if the parallel run is less than 35 m.

For runs longer than 35 m, separation distances shall apply except for the final 15 m to the outlet.

( http://home2.btconnect.com/KnowHow-Networks/spec_50174.htm )

The data cables are a mix of Cat6 and Cat5e on a gigabit network, and I'm almost tempted to test transfer speeds with them in the same trunking.

IHNI why whoever wrote that b******s thought they could pretend that the Wiring Regulations do not exist.

Because that's where the separation requirement comes from, and it has absolutely nothing to do with interference, and absolutely everything to do with the fact that network cables, phone cables, etc, do not have insulation rated at 230V and it is therefore unsafe to have them in the same enclosure as cables carrying 230V.

 

[stillp]

From what I can find, the separation requirement comes from EN 50174-1, and interestingly enough, I found this little titbidt:

The original draft proposed:-

No separation between horizontal data and power required if the parallel run is less than 35 m.

For runs longer than 35 m, separation distances shall apply except for the final 15 m to the outlet.

( http://home2.btconnect.com/KnowHow-Networks/spec_50174.htm )

The data cables are a mix of Cat6 and Cat5e on a gigabit network, and I'm almost tempted to test transfer speeds with them in the same trunking.

IHNI why whoever wrote that b******s thought they could pretend that the Wiring Regulations do not exist.

Because that's where the separation requirement comes from, and it has absolutely nothing to do with interference, and absolutely everything to do with the fact that network cables, phone cables, etc, do not have insulation rated at 230V and it is therefore unsafe to have them in the same enclosure as cables carrying 230V.

That's fairly typical of IT standards. However in this case the standard does state "local regulations, including safety, that are more stringent than the requirements listed in a) to e) shall be met."
OOI, and to save me looking it up, what is the rated insulation voltage of Cat 5 and 6?

 

[ban-all-sheds]

Pretty sure it's 125V.

Looking at a Cat5e patch cable here, and it doesn't say on the sheath, but it's certainly no more substantial than a USB cable (one of the thick ones which is about the same size as UTP) I can see which says 150V.

 

[stillp]

Hmm, interesting...
Draka don't quote an insulation voltage. The maximum operating voltage for Cat 5E is 125 V, but that really relates to the insulation between cores, rather than the insulation of the sheath.
I checked the ANSI TIA standard that defines these cables, and there's no mention of insulation voltage at all, although the insulation thickness is defined, so I suspect it depends on the individual manufacturer.

 

[ban-all-sheds]

Well - IMO rated at 125V, or not rated at all, gets you to the same answer to "can I mix it with 230V cables?"

 

[stillp]

BAS, the maximum operating voltage isn't relevant to the question. A rating is simply a value assigned by a manufacturer, and it seems the manufacturers don't assign a rated insulation voltage.
I suppose you mean that there's no reason to assume it will be safe to mix it with 230V cables? If so that's true, but my "gut feeling" is that it'll be OK.

Yes, I know "gut feeling" isn't a recognised test method for electrical safety!

 

[ban-all-sheds]

BAS, the maximum operating voltage isn't relevant to the question.

No - but "125V" was a figure I thought I remembered - didn't know why. Clearly now we know it's because I was remembering the operating voltage rather than anything else.

A rating is simply a value assigned by a manufacturer,

Indeed, but hopefully they do more than simply assign it

and it seems the manufacturers don't assign a rated insulation voltage.

No.

A bit odd, because at least one has on a USB cable I have. At least I assume that's what it is - I don't think that 150V is anywhere near what you might operate a USB cable at, is it?

I suppose you mean that there's no reason to assume it will be safe to mix it with 230V cables?

I do.

If so that's true, but my "gut feeling" is that it'll be OK.

Mine isn't.