Dedicated mains: separate thread for Blackadder!

[TheFlash]

In thread on linear PSU for NAS, mains noise is discussed and I mentioned my dedicated mains radial. Blackadder asked for info on the project.
I don't particularly want to get into a debate about the merits of doing this at all - it's my money and it's done and there are other threads you can read if you think it's all foolery! - but wanted to share the info to save others time investigating cable specs, cable trunking, consumer boards etc.

Please excuse refs to two other forums, save me much typing. And apologies for any weird fonts as I've cut and pasted to collate this on my phone as my chauffeur/wife negotiates the traffic jams en route to Kendal.

Extract from an initial post I made on AVForums:
It seems there are 3 basic ways of improving the source of whatever system one may have. There are nuances to each of these I'm sure but this is a complex enough topic so bear with me if I simplify. In ascending order of impact:
1) Replace standard switched sockets with hospital or industrial grade unswitched ones, eliminating an unnecessary link in the chain (the switch) and getting a tighter grip by the socket on the plug. (A sub-option here is to to runs spur off an existing socket to give you 4 or 6 such higher grade ones but the electricity is still shared with the rest of your house in the same way).
2) Run a Dedicated Radial Circuit from existing Consumer Unit (typically the thing with fuses in it which comes just after the meter) using similar high quality unswitched sockets. This moves any "contamination" from other domestic apparatus as far away from your hi-fi as possible and thereby minimises the impact at the business end.
3) Install a dedicated Hi-Fi Ring Main which starts with a dedicated Hi-Fi Consumer Unit wired after the meter (of course!) and in parallel with domestic Consumer Unit. This is described and drawn on the following page from Russ Andrews: Fitting a Hi-Fi ring main. In theory this completely isolates your system from any mains-transferred noise, leaving any contamination to come more locally through poor location of cables, inappropriate shielding or whatever.
Does this basically make sense as a ranking?
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And later post same thread:
An update. My dedicated mains was installed last week: Schneider consumer board/components, 4mm cable throughout, routed externally in galvanised shielding into two radial (one for AV, one for HiFi) unswitched silver plated double sockets.
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See also post #50 in this thread on HiFiWigwam which even includes extract from the invoice for the bits...

http://hifiwigwam.com/forum/index.ph...F&share_type=t

Nigel

[The Black Adder]

Many thanks, Nigel.

I'll have a look in to it. I'm just interested in knowing which way is best for bang for pound really. I've wanted to get it done for years and Marco also has some ideas to which should be interesting.

I'll get some details on what I'd need in my case later. I've been quoted for some work by my local electrician but what you have put it looks a bit more indepth than what I've been quoted for.

Any more ideas would be smashing.

[danilo]

Years ago.. when my house was being constructed. I had dedicated wirings with their own direct feeds/breakers fitted to my intended listening room.
Seemed as sensible and no plausible reason beyond cost, not to.
Years later, I experimentally powered my system from an extension cord from another room. Just to test the theory.
Absolutely NO audible differences apparent. Bit crestfallen by that.
So much for theories.
That said; Electricity in my part of the world is notably clean /consistent.
Tread lightly.

[The Black Adder]

Thanks, Danilo.

Does anyone have a diagram or something to what I would need to do ideally?

I just need to know whats involved?

What I have is a Wirelex consumer board and although it's quite old it's quite expensive to replace. Not only that but the house could (ideally) need a re-wire but let's not go in to that.

I've had a technician/sparky round and he said that because there is a spare (RCD) blank on the main board I could use that for the hifi. But from what I've seen is that others doing this have a separate consumer unit running from the meter?

Using the existing board would use the house earth and no separate earthing rod. He said that would be VERY expensive.

Also, because this would be a radial circuit can I use 15Amp round pin plug socket on the hifi end? I've heard this is okay?

Thanks
Jo

[Pharos]

B A, the use of 15A plugs is good, but beware the safety implications.

I use 5A ones after the wall outlet, on my distribution boards, because their connections are much better than square pin 13A ones.

It is hard to accept that special mains routes minimising source impedance can be of a real benefit because most equipment has a power supply containing storage caps which will provide the energy on peaks of drive/demand.

The best analogue I can think of is the mains trickle being like a slowly pouring pipe-flow of water into a reservoir barrel, and the equipment's demands being like us sporadically turning on and off the tap on the barrel.

The demand we place is 'insulated' from the source pipe, because extreme demands from our tap turning are easily fed by the reservoir in the bucket, changing little its provision ability.

[alphaGT]

Having a separate breaker box from the house, parallel to the breaker box for the house, does give it equal distribution of power. But doesn't completely isolate it from electrical disturbances in the parallel box. I have heard of filtered panel boxes, in fact at a company I worked for they had a large metal box on the floor about a meter long and 20cm tall, a giant transformer with coils and caps the size of coffee cans inside. It was between the main supply and the special computer room panel box. This prevented any electrical irregularities in the building from affecting anything in the computer room, and visa verse. To make it worth all the extra expense of routing all this extra wire, panels and breakers, top quality outlets, etc. one may as well pop the extra for such a filter from the onset, and get the most from such a project. True isolation. I've read about an Audiophile who built a shed outside that had a bank of batteries that could power his system for probably days, it had a huge inverter that could supply ten times the demand of his system, so he charged the batteries all the time, and when he listened he would disconnect them from the power, and play his system with new power inverted from his bank of lead acid batteries. I imagine a smaller system could have worked just as well.


Sent from my iPad using Tapatalk

[The Black Adder]

Thanks guys.... all very informative, and all very much appreciated.

To be honest I just need to know what to say to a sparky, not decided upon one yet so I need to make whoever it is understand whats needed...

[TheFlash]

Thanks, Danilo.

Does anyone have a diagram or something to what I would need to do ideally?

I just need to know whats involved?

What I have is a Wirelex consumer board and although it's quite old it's quite expensive to replace. Not only that but the house could (ideally) need a re-wire but let's not go in to that.

I've had a technician/sparky round and he said that because there is a spare (RCD) blank on the main board I could use that for the hifi. But from what I've seen is that others doing this have a separate consumer unit running from the meter?

Using the existing board would use the house earth and no separate earthing rod. He said that would be VERY expensive.

Also, because this would be a radial circuit can I use 15Amp round pin plug socket on the hifi end? I've heard this is okay?

Thanks
Jo

No, spare RCD won't do it. Separate consumer unit IN ADDITION TO main house one. Either junction box taking feed off mains before it hits consumer unit i.e. basically splitting the feed visibly. Or my sparky took a feed off the input wire inside existing consumer unit but before it hit any of the RCDs. Look at my parts list and I think you'll see it includes 2 separate RCBOs which are RCD+breaker combined. These go in the hifi consumer unit. I'm not a sparky...

[Barry]

Running a dedicated ring from a new 30A RCB fitted into the spare way of your Wylex consumer unit will be perfectly acceptable. If you use a completely separate consumer unit for your dedicated ring; joining it to the meter tails via a Henley block, all you are doing is replacing the RCB of your 'house' consumer unit with that of the new unit of your dedicated ring.

Whilst redecorating my living/listening room and replacing the carpet, I took the opportunity to have a dedicated ring of 12 double sockets fitted for my audio system. The existing consumer unit was fully utilised, so a separate unit was fitted for the new ring. I can't say the new ring has made any difference, but since extra sockets were desperately needed, having a separate ring (rather than enlarging the existing ring) seemed a good idea for little extra outlay.
I haven't measured the source impedance of the dedicated ring, but measurement at a wall socket of the existing main gave a figure of 0.2Ohm, which is a good result. It may explain why fortunately I'm not troubled by mains quality issues.

[TheFlash]

Running a dedicated ring from a new 30A RCB fitted into the spare way of your Wylex consumer unit will be perfectly acceptable. If you use a completely separate consumer unit for your dedicated ring; joining it to the meter tails via a Henley block, all you are doing is replacing the RCB of your 'house' consumer unit with that of the new unit of your dedicated ring.

Whilst redecorating my living/listening room and replacing the carpet, I took the opportunity to have a dedicated ring of 12 double sockets fitted for my audio system. The existing consumer unit was fully utilised, so a separate unit was fitted for the new ring. I can't say the new ring has made any difference, but since extra sockets were desperately needed, having a separate ring (rather than enlarging the existing ring) seemed a good idea for little extra outlay.
I haven't measured the source impedance of the dedicated ring, but measurement at a wall socket of the existing main gave a figure of 0.2Ohm, which is a good result. It may explain why fortunately I'm not troubled by mains quality issues.

Yes, RCB not RCD.