Do you have your system on its own dedicated ring on the house electrical supply?

Any comments on having a separate spur for each Naim box compared to having just one Spur that is used for all Naim boxes?

Richard

S3 posted:

I am looking into this and have my electrician coming round this week to discuss. 

His initial view is that, using 10mm squared cable from a separate consumer unit with 50amp breakers, he’d only be able to have one twin socket on the end and not two.

He could wire 2 x4mm as a ring and have a two dedicated sockets. He said that this would be the equivalent of an 8mm direct supply.

Today I power my 272 via XPSDR and my 250DR from a twin socket using Powerlines. 

I also use a Powerline lite to a wireworld matrix 2 block from which I connect my Rega Aria, Rega TTPS, my Cisco 2960 switch and my UnitiServe.

Question - should I go for the single dedicated double socket on a 10mm direct supply and have the 250 and XPS as the only components benefitting from it with the other components essentially on the main mains circuit as they are today or have two double sockets but with a 8mm dedicated supply with everything on that same supply?

many thanks

David

David - I don't follow this, as you can (obviously) have several circuits wired from the CU (as you do for the house) i.e. whether these be rings or radials (former means 2 cables instead of one in the CU's breakers so as to complete the wiring 'loop').

10mm cabling (electric cooker cable by another parlance) is very challenging to bend and make in to a ring circuit as the terminals in the sockets and at the CU(?) aren't big enough to accept 2 x 10mm cables  - i.e. you should be able to have several 10mm radial sockets from the same CU. 

Richard's question is topical for me (& you?) as I have a 6 circuit 'h-fi' CU (I think sparks call them gangs - spelling?), with 6 x 10mm radials - with dedicated earthing (all done by a sparks). A dealer suggested I might be better off using 1 for my Naim kit with a star-earthed distribution block - within which I assume the feeds would be tapped off a single point in the block, so no bit of kit would have 'priority', as is currently the case with the bus bar in the CU.

FangfossFlyer posted:

Any comments on having a separate spur for each Naim box compared to having just one Spur that is used for all Naim boxes?

Richard

I had three 10mm spurs put in - one for the power amp, one for the pre, one for my main source (was CD555, now Dave). Some folks have a separate Consumer Unit for their spurs, but as I’d inherited separate CUs for the kitchen and the rest of the house I thought I’d pushed my domestic luck as far as it would go...

I did once try fitting two 10mm cables into the same connection on an MK socket, and it was a challenge, but it can be done. Discussing this with my electrician, he suggested splitting the cable with a Henley block under the floorboards, and running the feeds to the two double sockets from there. The Henley block is designed to take 10mm cable, and it was easier to make nice tight connections  with it.

Most small consumer units used for this purpose have more than one way available, so if you can run two cables from there, maybe that would be better. I have two 10mm radials from mine, but they supply two different rooms. 

Has anyone used something called SY cable for this? My electrician said it would be perfect for the job; screened and fine stranded with a 10mm earth cable inside it.

S3 posted:

Has anyone used something called SY cable for this? My electrician said it would be perfect for the job; screened and fine stranded with a 10mm earth cable inside it.

I’ve seen SY cable rebranded as an ‘audiophile’ mains cable at a vastly increased price in the past, so somebody must think it’s worth trying. 

My electrician just popped round to take a look. We discussed options and he will quote for a new MK consumer unit with a 10mm feed up the outside side wall of the house to the loft where my listening room is. From there he’ll connect the cable up to a Henly block from where he can run two further 10mm cables to two unswitched MK double sockets. I’ll get a quote for the standard 10mm cable and for the SY cable too.

FangfossFlyer posted:

Any comments on having a separate spur for each Naim box compared to having just one Spur that is used for all Naim boxes?

Richard

I recall that a local hi-fi dealer tried using NAPS1s on separate spurs and it wasn't a success, but then my memory is less reliable than a very leaky watering can.

Quote received. It’s £50 more to have this done with “SY cable” verses the “standard” 10mm cable.

Should I opt for this SY cable or stick with the standard? 

I guess it can’t do any harm going with the SY but I’m also conscious that no one here (that I’m aware of) has used it so may be safer to stick with the standard.

Regards

David

S3 posted:

Quote received. It’s £50 more to have this done with “SY cable” verses the “standard” 10mm cable.

Should I opt for this SY cable or stick with the standard? 

I guess it can’t do any harm going with the SY but I’m also conscious that no one here (that I’m aware of) has used it so may be safer to stick with the standard.

Regards

David

I assume the SY cable is two core plus earth, but what size is it?

Just thinking aloud; but if it's 6mm² it will have the advantage of daisy chaining an additional unswitched double socket or two, and also the screening which in theory could trump ordinary 10mm². 

Debs

S3 posted:

Quote received. It’s £50 more to have this done with “SY cable” verses the “standard” 10mm cable.

Should I opt for this SY cable or stick with the standard? 

I guess it can’t do any harm going with the SY but I’m also conscious that no one here (that I’m aware of) has used it so may be safer to stick with the standard.

Regards

David

Out of interest, how much was your quote, David ?

Just had mine done yesterday, 10mm radial on own consumer unit with 32a type C exactly as recommended by Naim. £200 all fitted and certified.

Decorating at the moment so yet to see if I hear a difference. Electrician said my supply was very good and had a fantastic earth reading and had and extremely steady 50htz supply.

Hi Debs - yes it’s a two core plus 10mm earth which I understand is larger than the standard 10mm cable so may have advantages or may not. The cable will go into a Henly block and from there will feed two double sockets. 

Hi James - my quote is more than Popeye’s but it’s a fairly involved job with 14m high ladder work and then running cables under the house to the new consumer unit etc.

Regards

David

Yes my socket is only 3m from the consumer unit and I had left a pull in place to get the cable through very easily.

S3 posted:

Quote received. It’s £50 more to have this done with “SY cable” verses the “standard” 10mm cable.

Should I opt for this SY cable or stick with the standard? 

I guess it can’t do any harm going with the SY but I’m also conscious that no one here (that I’m aware of) has used it so may be safer to stick with the standard.

Regards

David

David,

I have 4mm SY running in conduit round the outside to its entry point behind the right hand of my brawn brain stack. It was put in before I joined the forum on the recommendation of an electrical contractor known to my dealer. I have a block of 5 daisy chained unswitched Crabtree double sockets. No Henley block because the electrician said it would require isolation back at the meter box, and no dedicated CU for that reason. 

No point me dwelling on whether I should have used 10mm etc. The system sounds really good, and I haven’t had the problems another member (Mark?) had with the 10mm. I experimented with the order I plug the boxes in. The Power Supplies are nearest the entry and the sources furthest away. I didn’t like Powerlines, although I have PL Lites on the SuperCap DR and NAPSC.

Like Popeye the electrician said my earth was incredible low impedance.

Phil

Cheers chaps 

Chaps - another quick question. I’ve (finally) got an electrician coming to quote on Friday. I’m going the separate CU, single 10mm radial to a un-switched double socket route - simple enough. For the separate CU, did you have it fitted with just a double pole isolator and MCB (no RCD) and if so, did you have the socket(s) labelled to indicate they were non RCD protected ?

James

james n posted:

Chaps - another quick question. I’ve (finally) got an electrician coming to quote on Friday. I’m going the separate CU, single 10mm radial to a un-switched double socket route - simple enough. For the separate CU, did you have it fitted with just a double pole isolator and MCB (no RCD) and if so, did you have the socket(s) labelled to indicate they were non RCD protected ?

James, I bought a small MK consumer unit. It’s a 4-way, with a DP switch that takes up 2, leaving 2 free ways. I put 2 MCBs in these as I was putting 2 radials in different rooms. Ask him to fit Type C MCBs - he may well say that you should label the sockets to comply with the regs. 

Perfect - Thanks for the info, Chris.

James

Popeye, thank you for starting this thread. My spur was installed about fifteen years ago, with what I’ve always called a ‘50 amp breaker’. With all this talk of type B, type C, RCD and MCB I convinced myself I probably had the wrong thing. I finally plucked up courage to take a look earlier, and what do you know, it’s a type C. Hurrah. In my research I’ve also discovered that they types refer to how easily they blow, and that the mysterious MCB is simply the acronym for miniature circuit breaker. Now I can advise others to use a Type C MCB, rather than just a ‘breaker’. 

When the second consumer unit was installed, its Earth was connected back to the main house consumer unit. When that was replaced a couple of years ago I asked for the earth from the hifi consumer unit to be taken back directly to the meter rather than going via the other consumer unit or the Henley block. It seemed to make the backgrounds a bit blacker and quieter, but I may be deluding myself. Anyway, it’s worth doing, if only for peace of mind. 

Also worth pointing out that you should test these 'breakers' (as HH defines) at least every 12m i.e. press the test button and then reset them - ideally more frequently.

I’ve not done that in all those fifteen years, though I see why it’s a good idea. Presumably one would turn the system off first? 

Nigel - yes. Also noted your comment regarding taking the earth connection back from the new CU to the incoming supply earth connection. Thanks again to all, very useful info. 

James

Hungryhalibut posted:

I’ve not done that in all those fifteen years, though I see why it’s a good idea. Presumably one would turn the system off first? 

Yes, close down in the normal orderly fashion - if the test works as it should the power to the circuit should be cut just like throwing the master switch. And if it doesn’t work it needs replacing!