Dedicated Spur advice please

Posted by: Docv on 04 October 2018

I have an friendly electrician lined up to fit a dedicated spur for my hifi. Could someone please send a fact sheet or link with recommendations for the cable gauge and fittings which I can pass to the chap. The consumer unit is already there.

Should I get 2 spurs? Thank you

 

 

 

Posted on: 12 October 2018 by james n
ChrisR_EPL posted:

Had a spark round tonight for an estimate; he tells me that unswitched sockets are no longer allowed as there must be a local means of isolation. Googling around it seems to be a grey area in terms of interpreting the regs and their meaning. Anyone had any issue with this?

My electrician's concern was not the unswitched sockets but that the isolation point for the new radial needed to be clearly indicated - i.e. if the lounge sockets were isolated via the existing house CU, the Hi-Fi sockets would still be live and this could be a hazard. Appropriate labelling was used to indicated that the new sockets needed to be isolated from the new CU. See pics on my profile page for details. 

Posted on: 12 October 2018 by naim_nymph
james n posted:
ChrisR_EPL posted:

Had a spark round tonight for an estimate; he tells me that unswitched sockets are no longer allowed as there must be a local means of isolation. Googling around it seems to be a grey area in terms of interpreting the regs and their meaning. Anyone had any issue with this?

My electrician's concern was not the unswitched sockets but that the isolation point for the new radial needed to be clearly indicated - i.e. if the lounge sockets were isolated via the existing house CU, the Hi-Fi sockets would still be live and this could be a hazard. Appropriate labelling was used to indicated that the new sockets needed to be isolated from the new CU. See pics on my profile page for details. 

 

I can understand the logic with labelling, although would think in the sanctuary of one's own household the audiophile would be well aware of the electrical arrangement and implications [or should be].

A horrible scenario is when the occupant audiophile nutcase moves away after selling the house with a dedicated audio main remaining in place, and this may or may not having been explained or fully understood by the new purchaser, who may or may not be an audiophile. Then one day the new occupier of the house uses the Hi-Fi socket to plug in the electric lawn mover, and a little while later while mowing the lawn runs over the cable  : P ....well you can see where this is going. I expect 99% of these dedicated audio supplies are disbanded / completely removed when the house is put on the market, but what about the 1% that aren't?

I can see why some electricians get jittery about fitting them : /

Debs

Posted on: 12 October 2018 by Paiste2oo2

Being German I may have misunderstood the last comments. If that's the case pls. excuse me!

Having an unswitched spur does not mean (I hope!!!) the spur is NOT equipped with a security device that switches the spur off in case of a shortcurt (I suspect such a device is called MCB in the UK, we Germans call it "Sicherung" or "Sicherungsautomat").

I was told that an MCB deteriorates the sound and a passive security device should be used instead. It is called "Neozed" and simply melts when there is too much current and disconnects the spur before the house burns down.

Looking into how an MCB works it becomes clear why it affects the sound: it adds an inductive load to the spur with all its nice side effects (AC resistance, phase shift etc.) where a passive Neozed is just a piece of metal that has (almost) no capacitance or inductance.

Looking forward to your comments!

Posted on: 12 October 2018 by ChrisSU
Paiste2oo2 posted:

Being German I may have misunderstood the last comments. If that's the case pls. excuse me!

Having an unswitched spur does not mean (I hope!!!) the spur is NOT equipped with a security device that switches the spur off in case of a shortcurt (I suspect such a device is called MCB in the UK, we Germans call it "Sicherung" or "Sicherungsautomat").

I was told that an MCB deteriorates the sound and a passive security device should be used instead. It is called "Neozed" and simply melts when there is too much current and disconnects the spur before the house burns down.

Looking into how an MCB works it becomes clear why it affects the sound: it adds an inductive load to the spur with all its nice side effects (AC resistance, phase shift etc.) where a passive Neozed is just a piece of metal that has (almost) no capacitance or inductance.

Looking forward to your comments!

The UK regulations require an MCB, or in many situations, an RCD, which is thought be some to be worse still for sound quality. They certainly do not permit the use if an ordinary fuse (i.e. a bit of wire that melts!). Maybe the regulations in Germany are different. 

The meaning of ‘unswitched’ in this conversation is just that there is no switch on the socket. 

Posted on: 12 October 2018 by Huge
Paiste2oo2 posted:
...

It is called "Neozed" and simply melts when there is too much current and disconnects the spur before the house burns down.
...

"Neozed" - otherwise known as a fuse!

Posted on: 12 October 2018 by Paiste2oo2

Thanks for the clarification, Chrissu! AFAIK switches on Sockets are not allowed in Germany (although I've seen some ;-).

A Neozed is not just a wire that melts. It's a precisely defined circuit breaker and comes in different current ratings. They were in widespread use before MCBs become available and look like this:

Mersen 01701.020000 Neozed-Sicherung Sicherungsgröße = D02 20 A 400 V

Posted on: 12 October 2018 by ChrisSU
Paiste2oo2 posted:

Thanks for the clarification, Chrissu! AFAIK switches on Sockets are not allowed in Germany (although I've seen some ;-).

A Neozed is not just a wire that melts. It's a precisely defined circuit breaker and comes in different current ratings. They were in widespread use before MCBs become available and look like this:

Mersen 01701.020000 Neozed-Sicherung Sicherungsgröße = D02 20 A 400 V

Switched sockets are nearly always used in the UK, despite being uncommon in other countries. 

I'm not familiar with Neozeds, so I don't see how they are different from any other fuse? I can't imagine that a UK electrician would be prepared to instal these as an alternative to MCBs, RCDs or RCBOs as seen in domestic consumer units.

Posted on: 12 October 2018 by thebigfredc

These neozeds to me look like they have a fuse wire inside so would work by melting at a particular temperature which equates to a particular amount of current flow.

Stick with an MCB in the UK it could save your life.

Posted on: 12 October 2018 by Richard Dane

Assuming this is a UK installation, could we please stick to discussing only what is approved under current UK Electrical code (Wiring Regs), thank you.

Posted on: 13 October 2018 by Mr Happy

Either fuses or mcbs are perfectly safe and comply with BS7671 electrical regs.

Posted on: 13 October 2018 by ChrisSU
Mr Happy posted:

Either fuses or mcbs are perfectly safe and comply with BS7671 electrical regs.

So if I wanted to use a good old fashioned fuse box instead of a modern consumer unit with MCBs, possibly also RCD protected, for a dedicated circuit for the hifi, it would conform to the UK regs?! In the context of this discussion, that appears to be what you’re saying, which sounds unlikely to me. 

Posted on: 13 October 2018 by Mike-B

Rewirable fuse boxes are not illegal as such,  but any audio-nut who thinks it can be done might find that buying a new fused consumer unit to replace a CB type might prove a bit of a challenge - you can't buy them anymore.   Re legality;  you may be required to replace a rewirable fuse box if other work is undertaken to ensure that the whole system is brought into line with current regulations.

Posted on: 13 October 2018 by count.d

My hifi spur goes from a dedicated 100a Wirelex rewireable carrier without mcb/rcd. It was fitted when I had all my house electrics done (with rdc/mcb) in 2006 and was fully in line with regulations. Don't know if the law has changed since.

 

Posted on: 13 October 2018 by Mike-B

Looking around www - it looks like BS7671 17th edition effective from 1 July 2008 has the change / addition that 30mA RCDs (residual earth leakage current) are required for socket outlets.    (This is for new installs & additions) 

Posted on: 13 October 2018 by nigelb
Mike-B posted:

Looking around www - it looks like BS7671 17th edition effective from 1 July 2008 has the change / addition that 30mA RCDs (residual earth leakage current) are required for socket outlets.    (This is for new installs & additions) 

Mike, you've gotta get out more.

Posted on: 13 October 2018 by Mr Happy
ChrisSU posted:
Mr Happy posted:

Either fuses or mcbs are perfectly safe and comply with BS7671 electrical regs.

So if I wanted to use a good old fashioned fuse box instead of a modern consumer unit with MCBs, possibly also RCD protected, for a dedicated circuit for the hifi, it would conform to the UK regs?! In the context of this discussion, that appears to be what you’re saying, which sounds unlikely to me. 

As mentioned above an rcd is now required in most cases but yes you can use fuses of bs 1361 type. The old rewirable bs 3036 type are no longer available but that is not what I was suggesting anyway, and if they are installed in an existing circuit then the circuit has different rating characteristics to account for the fuse type.

Posted on: 13 October 2018 by Mike-B
nigelb posted:
Mike-B posted:

Looking around www - it looks like BS7671 17th edition effective from 1 July 2008 has the change / addition that 30mA RCDs (residual earth leakage current) are required for socket outlets.    (This is for new installs & additions) 

Mike, you've gotta get out more.

Funny you should say that Nigel, just wot Mrs Mike sez.

Posted on: 01 November 2018 by Docv

electrician coming next week 

Posted on: 08 November 2018 by Docv

Spurs installing tomorrow...spark ok with new earth arrangement and unswitched single MK sockets (decided to stick with 2 singles and run all the power cables off a Russ Andrews power block).

Slight? issue is that spark will not use 10mm cable...will only work with 6mm...I’m getting 2 of these.

I have waited so long I caved in...at least I will have a dedicated hifi supply ????

 

Posted on: 08 November 2018 by Japtimscarlet

Can fully understand him not wanting to use 10mm wire

It really is meant for heavy duty applications like electric shower and the like ...too much agg trying to cram it into a single socket!!!

Posted on: 08 November 2018 by Mr Happy

Its not that difficult, it needs to be properly formed to the correct position before trying to connect it. An electrician should be able to easily do this, although the labour charge may be a bit higher as it takes a bit longer to do. The uplift in sound makes it easily worth a few more quid. 

When you first switch on you may have mixed feelings but things get better over about six weeks of burn in. After around six weeks you wont believe the difference.

Posted on: 08 November 2018 by Japtimscarlet

I've just had a nice uplift in sound by changing the fuse in my four way hydra

Figured that as all four units ( S'cap 250 and XPS and core) were all coming through one fuse ...it would make sense to upgrade that one fuse.... And it did !!

Posted on: 08 November 2018 by ChrisSU

Installing 10mm is certainly more of a faff than 6mm or less, and different electricians will vary in their attitude to installing something that is, depending on the individual installation, more or less awkward for them. Mine was happy to oblige, but it's hard to argue when you are asking for 10mm to be rammed into the back of a socket that was really only designed for 2.5mm.

Posted on: 09 November 2018 by Popeye

That’s annoying, it definitely can be done with 10mm. Mine is and my electrician didn’t make any reference to it, just said it’s a bit fiddly that’s all. 

Posted on: 09 November 2018 by hungryhalibut
Docv posted:

Spurs installing tomorrow...spark ok with new earth arrangement and unswitched single MK sockets (decided to stick with 2 singles and run all the power cables off a Russ Andrews power block).

Slight? issue is that spark will not use 10mm cable...will only work with 6mm...I’m getting 2 of these.

I have waited so long I caved in...at least I will have a dedicated hifi supply ????

 

I’d say a single 10mmor the job is off.