Mains Spur

All advice from electricians welcome.

As Adam says, advice is welcome from electricians. Fitting or altering mains now has to be passed under stringent guidelines, but provided one meets the req then there are several options available. If i may be so bold as to suggest you do a search over on pink fish, as the conversation here could get modded for a couple of reasons.

regards

andy c!

quote:

seperate consumer unit are there any that i should use in particular

Memera AD4 or AD6 depending on how many spurs you need

quote:

What cable should be used

Min 6mm - but 10mm if you can handle it (difficult to work with but will allow 50 or 63Amp MBC's in the CU - your electrician will know which)

quote:

if i should replace it for a particular socket

Crabtree or MK unswitched sockets

quote:

Is the mains cable directional?

Some say it is - but which way? in any event when installed you are hardly likely to reverse it to compare differences!!!

You might also consider mulitple spurs (one for each powered electronics component) - given the marginal incremental additional cost of installation, the sonic difference of multiple spurs is significant over a single spur IMHO - in any event, you then have the choice.

You should also take the CU feed directly off the incoming supply using 25mm2 tails (i.e. before the domestic consumer unit) to obtain the cleanest supply.

Hope this helps.

....Oops hope I have'nt broke any Forum rules

who invented guyforks?

Some bright spark...

Alan,

My dedicated spurs were installed by a competent electrician, who also tidied up other aspects of my home electrics at the same time. a kind of MOT for my whole electrical system. From a safety point of view i now feel a lot more confident, and shouldnt need to worry for a few more years.

Most of your questions have been answered by ps, who is giving the same advice (and brands) as i was given, when i asked the same question a couple of years ago.

As far as cable directionality goes, i was advised to use doncaster cable (10mm2), and run it with the writing reading away from the cu. I honestly cannot comment as to whether this makes any difference, as i never tried it the other way. Commonsense tells me that it cant make a difference, but i decided to follow the advice i was given anyhow.

After speaking to my sparky and consulting the regs, we decided to terminate the 2 spurs into 2 hydras, rather than unswitched sockets. This has the result of losing two potentially sound damaging connections, and gives as straight a run from cu to boxes, as is possible.Also once again no compromise on safety issues here.


Hope this helps and doesnt break any rules.

Mike.

Having had this done in 2 houses, I would advocate having a seperate ring-main(s) installed, rather than a spur. It requires twice the cable but the impedance of the supply is much lower; power amps in particular can draw current more easily. My electrician did it with 60 amp cable but it was a pig to work with.

Wow.

I thought this thread may get pulled!

I did all the cable runs myself, but the installation of the consumer unit was done by a sparky, as was the termnation of the receiving end which is unswitched double Mk sockets. As said above if you have the space you can run multiple spurs, of which I ran 4. Nothing I installed contravened any regs.

I did the comparisons of: ring main into hydra, one spur into hydra, and then multiple spurs into the equipment as normal. The multiple spurs have stayed plugged in.

I would seriously class this as the biggest differance v cost upgrade I have done. It increased everything, bass, clarity, soundstage etc.

There are those that perfer a single spur as opposed to multiple, but the common thread here is tha they are using at least one seperate spur.

Finally, thanks Adam, for sensible moderating IMV on this thread.

regards,

andy c!

If you do install multiple spurs it is worth making the effort to have each cable run the same length and running with the markings in the same direction just in case the cable is a bit "directional".

The other comment I have is that I found everything on one spur subjectively timed better and the earthing was that bit more direct since only one connection.

regards
Geoff

quote:

Originally posted by Geoff P:


The other comment I have is that I found everything on one spur subjectively timed better and the earthing was that bit more direct since only one connection.

Yes i agree geoff,

I went from multi-spur to hydra recently even on a ring main, and have to say i am enjoying the music more than ever!

regards

Hi Alan,

I would direct you also to the info in the first few pages of the Naim product manuals - there is a paragraph that suggests you may wish to use a dedicated spur to the hi-fi, and that such a spur should be rated at 30amps or preferably 45. This is all the information you should need to give to an electrician, who should be able to complete the work for you from there.

On another note, I take it from your lack of email response and revelation that you have bought a NAP150 that you didn't want to buy my old amplifier, then!!

Best regards,

Richard.

quote:

Originally posted by NaimThatTune:

Hi Alan,

I would direct you also to the info in the first few pages of the Naim product manuals - there is a paragraph that suggests you may wish to use a dedicated spur to the hi-fi, and that such a spur should be rated at 30amps or preferably 45. This is all the information you should need to give to an electrician, who should be able to complete the work for you from there.

On another note, I take it from your lack of email response and revelation that you have bought a NAP150 that you didn't want to buy my old amplifier, then!!

Best regards,

Richard.

Richard,

The funny thing is that if you show this to an electrician in Europe they look at you as though you are nuts and can't believe that is written down. In fact it has been taken out of the German section of the user manual (the later one) but still exists in the earlier one. I even asked my dealer to ask the Naim distributor in Germany (Musicline) and they came back with a statement that this was illegal and the first time they have heard about it.

It would be nice to see if Naim could make the text a little more specific in the sense are we talking about using high rated cable and/or 30/45 Amp fuses in the consumer unit for this spur, separate consumer units. As it stands the standard Naim mains leads are rated at 16A in Germany and 13A in the UK, which clearly prohibits such high rated fuses in the consumer unit.

All in all, you can do the minimum and install a separate spur 10mm cable with a 16A fuse in the domestic consumer unit and stop getting too obsessed with power for the HiFi. It does make one hell of a difference though.

Regards
Mark

Hi Richard, yes i did get a nap 150 and a nac 112.

I agree with the comment above re. the manaul's vaugness with respect to mains spurs. I also was a little irritated as a North American consumer (Canada) that there was not a discusttion of breaker amp ratings for 120v mains, or how to check that the polarity from your plugs is oriented correctly on a 2 wire system like we have here....

CPG

Hi Folks, Mark, Alan, CPG,

Hmmm, seems to be a problem for some but I mentioned this to an electrician I had around my house and he didn't bat an eyelid.

I am wary of treading into an area where I must be careful in this thread, but if the mains lead is protected by an appropriate device, does it matter what is upstream of it? That's a genuine question rather than a snotty remark (perhaps a smiley is appropriate?).

My understanding was that as long as the cable used for the spur that the consumer unit supplies is rated highly enough for the device in the consumer unit, all is well. So 45amp device in CU is fine as long as the cable is rated at 45amp or above. I agree Naim's advice could be more complete, but I really wouldn't expect it to give an electrician a problem, and neither is it wrong or illegal.

I don't understand why you say that a 16 or 13amp cable 'clearly prohibits such a high rated fuse in the domestic consumer unit'. If said cable is protected by a 16 or 13amp fuse in its plug, surely any fuse upstream of that is completely irrelevant?

My incoming house fuse is 60amp, my ring main fuse is about 45amp and my mains plugs have 13amp fuses in - I see nothing wrong with that and neither does my electrician.

I hope this doesn't warrant this thread getting moderated - after all we're debating what the correct fusing should be rather than proposing unsafe/illegal courses of action.

Best regards,

Rich.

Alan,

Congrats on your new kit - I must admit the 112/150 combo is better than my old stuff, so hopefully you'll get more satisfaction out of it, for longer, before the upgrade bug starts to bite (not that we'd ever suggest making upgrades on this forum, oh no, sir, never, not us!)

Cheers!

R.

Rich

I think the UK plugs and the 'device' fitted may hold the key as to why you are able to have high rated fuses in the consumer unit. Clearly the cable for the spur must be rated accordingly. I'm sure what you have is perfectly sound.

I think this is the main reason why the text still remains in the UK Naim manuals but not in the German section of the Naim manual?

In Europe we don't have these devices in the plugs. The cables supplied with the kit in Europe are rated at 16A. The ones in UK like that supplied with the Grahams hydra are rated at 13A. Maybe to have a mains solution close to yours, I would need to use a UK plug for my Hydra (which it came with) and a wall socket. I think I'll stay with what I've got for the time being, i.e. fat cables and a 16A fuse in the consumer unit.

Regards
Mark

Hi Mark,

I'm with you now - thanks for elaborating. I was unaware that plugs in Germany didn't have fuses such as we do over here. Given that explanation, your previous comment now makes perfect sense, we are in agreement, with no flame-wars and the thread hasn't been pulled (yet?)
Hurrah!!

Cheers!

Rich.

I think its commendable that Naim are allowing this topic to be mentioned. I fully accept that legal req's need to be borne in mind, but nontheless the optimising of the power supply, if done correctly, will reap 'no brainer' benefits to your rig.

Don't wish to be pedantic but the 'spurs' referred to here are actually radials. A spur is an extension to an existing ring (or exsiting radial for that matter). A new connection to the CU that terminates at the last socket (or appliance) and does not return to the CU is a radial.

Anal rant over, I've just had 2 10mm2 radials installed but have yet to set up the system as I've just moved house and the system's still tucked away in the white & blue boxes. I may have to force myself to power the system from the pre-existing ring for a few weeks before switching to the new circuits just so I get to hear the difference!