I'd rather have and not need, than need and not have... Besides, the way I see it is if I'm running 1, I might as well run 4 🤣

Definitely run 4. My single for the TV now has 4 + 5port switch

Have always run pairs, got a box of cat 5 why not, always found it saves the ball ache. If dual is requested run a 3rd. Better too much than to little

Cat 7 dual is the only cables I got with me. Sometimes they want a telephone outlet later or just a second outlet for a printer or NAS or so without using a switch

They ask for one you run 2 they want 3, they ask for 2 you run 4 they want 10.

Yep. We fitted 10 (5 x 2) of them in our home office. Also lots of power sockets, including 3 doubles fed from the UPS for the computer system.

This is spot on, and the datacentre earthing is in BS EN 50310 if I remember right.

But we would instinctively earth metal back boxes. Please point out where in BS 7671 is says not to bother earthing certain types of exposed conductive parts that could become live under fault conditions, please? Looking forward to your reply!

@@socialscene6361 yes but a metal back box houses single insulated cables so it doesn’t apply in that case. It doesn’t specifically say “don’t earth” them, but regulation 412.2 gives you the requirements for basic protection, then 412.2.4.1 tells you wiring systems such as this one, meet reg 412.2

@@socialscene6361 sorry that’s actually in the now, 3 day old blue book, so numbers may have changed now

@@socialscene6361 back boxes have single insulated wires

@@Rick-bb8xc Although, technically if it's a recessed back box then it's not *exposed*... That said GN8 has a note to say “treat them as if they are exposed conductive parts, but a fixed screw lug is sufficient” (paraphrasing)

That would prevent you running power in there, as the power and data cables need to be separated by 50mm to meet BS6701 safety requirements(maybe more for BS EN 50173/4, but that’s signal quality, not safety). That’s why dado trunking has two cable paths.

@@lkchild Use the middle compartment for the 220v cabling and the outer compartments for the low voltage

淘寶

With double insulated cables it requires two faults (both layers of insulation to fail and then make contact with the tray), the argument is that is extremely unlikely...

@@alexacb63 It is unlikely. But if it did happen, that tray would be at live 230 V potential and unknown (no RCD such as distribution circuit) until someone simultaneously touches that and another metalic part at Earth potential - resulting electric shock! Where in BS 7671 does it say not to bother earthing certain types of exposed conductive parts?

@@socialscene6361 I'd recommend watching the eFixx video I posted in another comment. It does come down to whether you consider it likely to become live, if you don't it's not an exposed conductive part. As another example, would you consider a metal cable clip an exposed conductive part, as if it pushed too hard in to the cable and pierced the insulation for example, it could be live, but we never consider earthing those...

@@alexacb63 I see your point. However, in the past I often used to crawl and climb around metal cable tray and metal pipes and extraneous metal parts all simultaneously accessible, whilst working on Hotel refurbs in roof voids etc. I got some comfort from the knowledge that hopefully it'd all be bonded together before grabbing something. I'm not suggesting anybody will be climbing around in Bundy's client's garage, however, that tray is in very close proximity to metal garage doors and such like. I couldn't walk away from that - I'd earth that tray all day long!

@@socialscene6361 that metal garage door likely _isn't_ an extraneous conductive part (although can't say for certain without testing). An extraneous conductive part is something that is liable to introduce a voltage from _outside_ the installation. I would argue the tray is not an exposed conductive part. It's not like it's a metal enclosure containing single-insulated cables or whatever. Id argue that if you're worried about a fault developing during installation then you're probably not testing your installation adequately. If you're worried about a fault developing afterwards during normal use then you've probably selected the wrong installation method for the scenario. So the only argument I can see for bonding a metal tray supporting double insulated cables is to protect against bad design, bad installation and bad testing. Incidentally, metal cable clips are an interesting example when it comes to exposed conductive parts. The regs actually says small objects that can't be easily gripped don't need to be earthed. IIRC it gives faceplate screws as an example. Edit: 410.3.9 “The provision for fault protection may be omitted for the following equipment: iii) exposed-conductive-parts which, owing to their reduced dimensions (approximate maximum of 50 mm x 50 mm) or their disposition cannot be gripped or come into significant contact with a part of the human body and provided that connection with a protective conductor could only be made with difficulty or would be unreliable NOTE: This exemption applies, for example, to bolts, rivets, nameplates, cable clips, screws and other fixings.”

its great because its quick and cheap to add sockets etc , and it doesn't upset the trouble with the decorating being "ruined "

How do you know? Resilient earthing is needed for high protective conductor current devices, which a lot of modern IT equipment is.

@@lkchild My generalisation in practical terms: it's required at the point that 19 inch rack cabinets become involved. Freestanding equipment that's plugged into normal socket outlets, in a domestic situation, non issue. An office with many computers and associated ITE, again may be a non issue, the division of circuits would also consider the protective conductor current as well as the loading. And of course, if the mfr's instructions say it needs it, you provide it.

Let's see if I've got this right... "clean earth" is what the Americans call "isolated ground". You carry 2 CPCs through the installation. One is connected as CPC for the installation itself and would as normal loop between parts, this is just as normal. The other is attached *only* to the "equipment ground", or CPC for the earth pin of the socket, therefore also the plug and equipment attached to it. That "clean earth" is carried back directly to your main earthing point (which may or may not be the consumer unit) without being broken or connected to anything else. The "clean" part is that it is supposed to stop any extraneous current that might appear on the CPC reaching and potentially damaging your expensive computer equipment or life saving medial equipment. Actually if it's connected to the main earthing block with everything else then should there be a fault that energises the CPC the so called clean earth is potentially compromised as well. To really work as advertised it needs an entirely separate grounding arrangement and that's a whole other can of worms. I've only ever heard it being discussed in the context of big data centres where we kept the power for computers separate from power for everything else right back to the DNO supply. For domestic? or even small office? Who has time for this s… er… stuff? And right. If that's not what's being talked about I also have no idea why you would connect a CPC to a socket in the way that was being described. It seems to serve no purpose at all and possibly make the CPC connections more fragile than they need to be. Here's Dustin Seltzer explaining isolate ground for Yanks. ukposts.info/have/v-deo/o3alqmtwqqOnkZc.html

@@calmeilles correct. Commonly used in IT and also sound systems circuits to reduce the “noise”

I think he was referred to high integrity earthing. 453.7 says any circuit where the designer suspects >10mA leakage current should be designed with high integrity earthing. It lists a few ways of doing that; make the CPC a 10mm, run a 4mm CPC in flexi-con, or supply two CPC cables. 543.7.1.204 then says that if you use the third option (two CPC cables) they should each have their own separate terminals at the socket/dist board/etc. 543.7.2 gives a few options specific to socket circuits; the easiest one is just use a ring circuit, but avoid adding spurs...

I have been involved with several projects involving large quantities of IT equipment (100s computers) and usually requested high integrity earthing (the subcontractors usually used MK) as described above and also due to earth leakage of IT equipment, especially in large quantities.

Bend radius is generally 4 time OD of the cable so for Cat 6 / 6a around 4 x 7mm = 28mm, bend Radii, so diameter of loop should be 56mm, Nick's looked tighter than that. That been said unless it was a Certified install its unlikely, in a domestic environment it would matter too much. I doubt it was even a Qualified install, most likely just verified (wire-mapped).

lol

在香港都是，因是電流保護方法

@@o0li553 - I appreciate the help but I have no what you’ve just wrote. 😩

​@@joeypriestman6783 he said in "In Hong Kong, because it is a current protection method" At least according to google translate anyway

There is no risk of cross interference from mains to network, cables the reason for separation is induced voltage in the network cable. Mains cabling 50Hz - Cat 6 upto 500Mhz. Shielded is only needed where there is very noisy RF environments.

Sure the cable consists of basic insulation and an outer sheath (or jacket). But that outer sheath _is_ rated as a 300/500v insulator. If it wasn't double insulated, then you wouldn't be allowed to install it outside of containment/enclosures.

finally

He did only have 1 Mic on

​@@AndyK.1​But the one Mic was come out of both speaker channels!

@@NBundyElectrical Definitely worth using the little wind muffs. They really help cut out the wind noise if you are outside. If you have always got them on then you never forget.

Answered in video

good and bad days still mate

@@NBundyElectrical keep going at it mate👍🏽 day by day For me it helps to sleep only on back