So can you run standard T&E cable in plastic trunking?
It doesn’t have to be an outdoor or steel wire armoured cable if it’s in trunking?
Also, do you know of any good ways to mount some kind of cabinet on the outside wall to house a dedicated CU so that water in big storms will not penetrate into the cabinet?
Or is that a lost cause?
Hi Jim - you can get suitable IP rated outdoor cabinets. Your electrician should be able to advise here of suitability. No problem with running the T&E in conduit externally. No conduit would mean a run of SWA cable.
Be mindful that trying to feed armoured cable through a wall at 90-degrees is very challenging, as it’s obviously thick and tough!
Hasn’t @ChrisSU already guided on this aspect earlier in the thread?
On the latter aspect, have a look at Amazon (purely as a guide) vis searching things like ‘waterproof external electrical cabinet (or box)’. There’s much comment around the externally designated kit that it’s up to the discretion of the sparks fitting it, as to whether it’s acceptable (to them).
See pic below:
Armoured cable is certainly harder to fit, but an electrician should be able to handle it. They may prefer to use regular T&E and put it in trunking on the exterior wall in order to make the interior run easier to instal. Hard to say which option would be best without knowing the location but this is all basic stuff for a competent electrician so I would just let them deal with it.
I just spoke to an NICEIC electrician who has experience of installing audio circuits in homes and in an audio parts supplier’s showroom.
I asked him to install 6 radials to (probably) 5 single and 1 double unswitched sockets in the front right corner of my listening wall.
He unscrewed the faceplate of my house mains ring CU under the stairs, and we saw the two 25mm grey cables that come from the meter.
We did not decide yet whether the sockets will be flush-mounted or surface-mounted - TBC.
I asked him to install one RCBO per radial (instead of RCD and MCB).
He will install a dedicated hifi CU near the existing mains ring CU under the stairs, and send the six cables through that wall directly into the rear right corner of the listening room, and along the right side wall to the sockets in trunking that will sit just above the skirting board.
This gets around problems of running the cables outside or inside along the front wall immediately behind the SL2s.
Would it be normal to run all 6 cables lying on top of one another in, say, 3mm plastic trunking?
Or can he get some trunking that can separate the cables in individual conduits?
I would expect the latter to give better isolation of the radials from one another, which is the main reason for putting each box on a separate radial.
Surely your electrician is the one to answer these questions.
Yes, he will.
I am just wondering what is possible or normal in other people’s experience.
I can’t see any issues with that, however keen to know what size cables he is using, and what size rcbo’s. For HiFi, people go either 6mm or 10mm. If he is doing anything less, then in my opinion I wouldn’t go ahead if you want close to the best.
Was there a reason he wouldn’t go directly from the outside meter? Or was it just convenience.
I asked for 10mm T&E.
(I will probably ask him to get Doncaster Cables T&E, unless anyone else or he tells me some other make of T&E is likely to be better - although I did not discuss this with him on today’s first meeting.)
He did originally say he’d take the meter tails straight through the wall into the front left corner of the listening room and add a CU there, but I mentioned that I have speakers, crossovers and speaker cables that need to be right next to that wall, so we agreed that would not work.
We didn’t discuss the outside route in detail - but the problem with that if I’m having 6 x 10mm SWA cables is that they would have to be routed over the gas meter, which is more cable and would be visible from some angles from the front of the house, which is becoming an eyesore, and then there’s the issue of possible water ingress into the mounting box as the storms slam into the house over the coming decades.
Thus routing it from the house mains ring CU and along the right hand wall into the front right corner seems best.
This that not right where the 25mm cable enters the property - but how much difference will that make?
Also, what route will the earth take back to the meter earth?
Mcru has various cables, sockets etc which might be worth a look before you take the plunge.
So your earth from the New CU will be shared, and possibly taken from the old CU. A possible improvement might be to ensure the earth goes to an earth block, and then you take two feeds off that for each CU. Perhaps he would do that anyway, but worth confirming.
I think it is @ChrisSU amongst others that suggested one 10mm radial is better than multiple runs. No doubt others will disagree. Of course you then need a Mains Block, but that does ensure all the earth wires are exactly the same length - how much that matters, who can accurately say without lots of discussion and heresy.
I just checked ChrisSU’s 8 posts in this thread and he does not say that 1 radial/socket is better than multiple radials/sockets in those posts that I can see.
My decision is whether to go for 6 radials into 6 sockets and then have 6 Powerlines to my 6 IECs, which gives isolation of the lines and is less expensive?
Or 1 radial/socket and then a ‘block and Powerlines’ or a very good Hydra - where I could make the radial from posher materials but the whole thing is even more expensive and there are more junctions and components in the chains and it could get a lot more expensive and the cable dressing might be harder to control?
These 2 topologies are the extremes of ‘less’ vs ‘more’ and there are lots of other variants in between.
You might consider quality vs quantity. 10mm perhaps a good hedge for bog standard cable but I don’t know of any “audiophile” in wall cables that are bigger than 4 or 5mm. Given the deep pockets of “audiophiles”, that’s a surprise unless there really is no benefit vs smaller, higher purity copper and more advanced constructions.
Yes, that’s exactly what I discuss in the above post that I wrote as you wrote your post.
One aspect of this is how much I should spend on the in-wall cable from CU to sockets vs on the final cables from sockets to Naim boxes?
(And how much on the sockets themselves?)
As a general principle I think I should prioritise the final cables from sockets to Naim boxes a lot more than the in-wall cable, which is one step removed.
Getting a good fat copper in-wall cable seems sensible - and going from one Powerline currently (plus a Graham’s Hydra and one other cable) to all Naim Powerlines seems like a sensible way to stick to excellent Naim cables within a reasonable budget.
This prioritises isolation of the radials over the ‘Hydra effect’.
As I cannot actually test these 2 options I’ll never know which would have been best.
But my recent experience with a Powerigel hydra (not made of Powerlines) that didn’t work well in my old system has pushed me away from the hydra option in the end.
Getting multipack radials at least gives you choice at not too great a cost
I didn’t mean single vs multiple runs, I was referring to the size and quality of the cable in the run(s). Regular 10mm T&E vs say 3mm OFC with an audio considered construction. There are lots of in wall cables on the market designed for audio installations, I don’t know of any that are 10mm.
Yes, but in my budget constrained world I can buy 40m metres of 10mm T&E and have 6 radials for a lot less than 6m of much thinner Furutech OFC in-wall cable for 1 radial.
And the Furutech in-wall might not make sense in my system until I have much better IEC leads, etc.
Got you. Was just wondering if you had considered it, clearly you have 
Hi @JimDog – I must have missed something in this continuing project, as I thought the cabling had all been sorted - obviously not (perhaps need to pay closer attention 
). Some thoughts:
1- I’ve been advised that single 10mm radial in to a quality block is better than 6 radials from a dedicated CU – but, TBH, I’ve not been able to do this in my own home (yet!).
2- have you considered the Gigabit breakers, which seem to offer an improvement (if I’ve read other threads correctly?).
3- the thing about the dedicated CU is to:
a- get improved earthing and away from any ‘noise’, ideally dedicated earthing arrangements if these are possible (depends on the house’s wiring set-up).
b- ensure, as best possible, the bus bars in the CU offer the best feeds to the radials, which means (ideally) having 2 bus bars – if you have one, then (AFAIK) the radials will pick up solely ‘in series’, hence why one radial + (star-wired?) block is considered better(?)
Above said, it seems star wiring has been eschewed by the likes of Chord in their latest blocks, which appear to have 2/3 bus bars, one for each cable?
Obviously, if you’ve been diverted per your experience with the Powerigel, then fair enough. Overtly, using the likes of a Chord block is very expensive, especially when one includes the power cable to this (which is non-standard 16A IIRC).
To be honest, I went one direction many years ago and simply now live with it (vis 6 radials), as it’s too messy to muck about with sockets/blocks et al.
Yes, I have considered the Gigabit, Siemens and/or Dopke breakers but that itself is costly before you even start on the rest of the circuits and the IEC leads.
Are your radials 10mm T&E (I forgot) and are you happy with them?
Thanks - that’s a great reminder about the 2 busbars - is that what your CU has?
I have PME earthing system and I discussed improving the earth with the electrician but we did not reach a conclusion as to whether this is do-able in my house.
Do you have Powerlines to the Naim gear?