OK firstly my apologies for raising this old chestnut again, and for not searching previous threads to find if this has been answered before.
I have gathered from prior discussions on the topic that the recommended configuration is to have a separate Consumer Unit and 10mm2 cable to unswitched sockets, a recommendation I am minded to bite the bullet on and get done.
Perhaps like others on here, this doesn’t make a lot of ‘sense’ to the electrician I have been speaking to, though he has assured me he will do whatever I want. He has two main questions which I couldn’t answer :-
He says that 10mm2 is enough for 60 amps of current (or at least 30). So he doesn’t understand why I need that if I will have a 13 amp fuse in the plug. I could only tell him that ‘it is all about configuring the power supply for the best music reproduction from premium hi-fi equipment’ and that this is what ‘those with expert knowledge recommend’. But can anyone answer his doubt in a better way ?
He also suggested having at least an isolation switch to turn the power off, rather than having unswitched sockets by themselves with no way to turn the power off. Again I just suggested it was to make the supply an unfettered as possible by switches and other components not necessarily required.
Any suggestions / views I can go back to him with ?
He will of course just do what I want him to do, but thought to ask you knowledgable folk on here …
What you said in para 1 sounds perfectly adequate to me. Two pieces of advice: have an uninterrupted run of cable from the dedicated consumer unit to the unswitched socket, definitely no isolation switch; get the earth from the dedicated CU run back to the meter, do not piggy back off the house unit. I have a 50amp type C breaker in my CU.
1- the purpose is to provide the cleanest and most enabling (for want of a word) supply, which will serve the ‘moment in time’ needs of the kit. The 13 amp fuse isn’t the issue here. You’re trying to avoid/minimise any bottlenecking via multiple connections, fuses et al.
2- The kit has on/off switches (and internal fusing) so, arguably, an on/off switch on the socket is superfluous and, per (1), just creates another ‘contact’ in the line of supply.
If it’s any help, I said to the electrician that it was the manufacturer’s recommendation for best performance. I had spent a lot of money on the equipment and wanted to get the best out of it, and I as I only had one opportunity to get it done I wanted to know I had done it fully according to their recommendations.
I tried not to get into discussion about why this would make a difference, but there’s no way around it, it’s an unusual request. I tried to show a bit of humour about it even though I found the whole thing a bit embarrassing.
The sparky ended up running solid core 10mm2 cable around the outside of the house, which was so stiff it kept pushing the back box out of the wall. There was some swearing, but it’s all done and signed off now and sounds good. Didn’t help with transformer hum though.
the electrician is at my house now installing the new Consumer Unit. I see HH says he’s got a 50 amp breaker in his dedicated CU and I asked the electrician about this. He’s got a CU with a 16 amp breaker but says if I want he can swap it for a 50 amp one (next week).
Does a 50 amp breaker make any difference from a 16 amp breaker, given that if more than 13 amps runs through the cable the fuses in the plugs will blow?
The breaker should be selected to suit the size and length of cable and the system. For me, Naim recommended 32 Amp when I was using NDX/282/200. If your electrician is happy to install and certify a larger breaker, go for it.
Also ask him to install a type C breaker rather than type B to prevent it from tripping when switched on (except for New Classic systems which shouldn’t have this problem.)
It’s not a comparison I’ve ever tried I’m afraid. My logic was that if I’ve gone to the trouble of having a big fat 10mm2 cable installed, it makes sense to have the highest rated breaker possible, to limit the passage of current as little as possible. My mains was installed many years ago now, by an electrician who was used to installing dedicated mains for hifi, and it was probably them that suggested 50amps.
Don’t forget to ensure the new earth is taken right back to the meter.
There’s more to it than that Will. Lowering the impedance on the AC has proven positive effects on our hifi systems. Bigger gauge cables provide that. If you only need one double wall socket then a 6mm run of cable from a 32amp RCB in the form of a radial is great. Because I prefer my power amps into their own wall sockets I use a dedicated ring to two double wall sockets fed by 4mm cable which impedance wise is equivalent to a hypothetical 8mm radial. Switch less sockets are better and as HL points out are logically safe. Also HH refers to attention to earthing. I feel that this is as important from a hifi perspective as the AC itself. Enjoy!
Yeah so I’ve got 2 runs of 10mm2, each to a double unswitched socket. Dedicated consumer unit with earth wired back to the meter. The CU currently has 16 amp breakers in but the electrician said he’d swap them for 50 amp if I want.
So consensus seems to be do that ?
It did with mine although from memory I uprated once the circuit had bedded in (if that made a difference) many years since I installed mine using Roy Riches template.
I’ve just moved in to a new build and getting floors laid and electrical work done, including the mains feed, so I’ve not put it to the test yet.
Plus I’m going to be upgrading to the 200 or 300 NC series so the mains feed was to get the best out of that yet to bought gear.
