Thanks for that, i thought as much… my meter is within one of those outside access plastic wall cupboards; build in the era of when someone actually visited the property to read the meter. However; my meter tails go from the cupboard up though the cavity wall, turn 90º to go above the cloakroom ceiling, on for 3 meters, then turn 90º downwards a interior stud wall to the main CU situated in the hallway.
It couldn’t be more awkward 
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I thought that was the case but from viewing recent re-wires (all duly certificated), it seems some sparks are happy to use ‘existing’ conduits et al – and not doing this when adding spurs and akin to existing.
The 450mm “rule” applies to new builds only (England and Wales) and is for accessibility reasons.
For modifying existing builds then I believe it is fine to match the height of existing circuits if desired.
The electrician doing my new CU for my solar said 3m is the maximum length without adding a Circuit Breaker.
Phil
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Yep. That’s the rules.
Internal wiring
• You should ensure that any changes to your own internal wiring comply with the current edition of the Institute of Electrical Engineering (IEE) Wiring Regulations (BS 76711).
• For connection to the metering equipment you should provide 25mm2 double insulated meter tails
for connection into the meter, together with a 16mm2 earth conductor.
• The meter tails between the meter position and your consumer unit should not be longer than 3 metres.
If the length is more than 3 metres, you should install an additional protective device at the nearest
point to the supply inside the customer’s premises, as specified in the current IEE Wiring Regulations
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"For correct mounting height, in the UK refer to Building Regulations Approved Document Part M. which has this to say:
“Wall mounted socket outlets, telephone points and TV sockets
are located between 400mm and 1000mm above the floor, with
a preference for the lower end of the range”
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I have one of these plastic boxes too, the limited area prompts me to consider the requirement for a connection for a car charger in the near future. As a result I have not thought much about a dedicated HiFi supply, in my view the electric car connection is more important.
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Yes this is how the future is looking, i have thought about this too because my meter box is right by the car parking space in front of garage, although i’ve no intention of buying an electric car anything in the foreseeable…
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If you have transformer hum, consider using a DC Blocker.
Although I have a dedicated mains, I started to get transformer hum. Was so loud, you could gear when sitting on the sofa, if you weren’t playing any music. Could be something to with all the EWR infrastructure work in our area.
I tried an IFI DC Blocker which worked very well. Didn’t get rid of all the hum, but you can only hear it now with your ear right next to the amplifier, so a great improvement.
Worth a try?
DG…
This. Two atl units in the main and second room. Minimises or removes hum for me and no degradation in my perceived sound quality.
Update 2 - My sparky came back to me with a price of £755.00 to do the job.
Due to space limitations with where electricity enters our property he is needing to do a bit of a work around by adding a RCBO to our existing consumer unit working separately to the existing breakers. He is then going to fit a new small consumer unit near to where the new un-switched socket will be installed which he assures me will be very neat👍🏻
There are two of them booked to do the job on Monday morning so with any luck the install will go well and I will (fingers crossed🤞🏻) find a noticeable sonic improvement on Monday evening. I will report back with a further update in due course.
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As discussed earlier in this thread, keeping the dedicated wiring well away from the main consumer unit is key. That means splitting the meter tails as well as keeping the earth connection independent.
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Hi Chris,
Many thanks for reminding me of that important part of the install.
I texted the following to my sparky…
- Morning Marcus, I have just had the following comment from a chap who has had a similar install to what I’m looking for “keeping the dedicated wiring well away from the main consumer unit is key. That means splitting the meter tails as well as keeping the earth connection independent.”
Is there anyway we can achieve this objective? Paul*
He then replied…
- Yes we can. I was already going to do that*
So that sounds (no pun intended) promising👍🏻
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You may find a sonic improvement immediately after the install, or it may vary up and down in sound quality for a few hours, days or even weeks.
I’ve read hundreds of reports of people who have installed a dedicated radial, and the majority of them do end up with either a good or a very good increase in sound quality.
Your post of a couple of hours back confused @ChrisSU (per his response) and me. To be 100% clear for you as the client/customer (and which appears to be the case per Marcus-the-sparky’s reply) and assuming you are in the UK(?):
1- Incoming mains power to be split (via Henley (connection) block), with a separate feed to a new hi-fi CU i.e. completely separate from your ‘house CU’ (which is the whole point).
2- H-fi CU to have suitable RCBO, with cables to house sockets after. Sparkies are now tasked with ‘risk evaluating’ the need for a Surge Protection device in CUs nowadays. I’m not clear how these may affect sound quality – you should check.
3- As regards earthing, ideally you want dedicated earthing for the hi-fi CU (which could mean earth rods buried nearby) but this may not be possible depending on the electrical mains & earthing arrangements in your area, plus you will need suitable ground-space to accommodate spikes. This is where employing a qualified sparks is essential.
2- H-fi CU to have suitable RCBO, with cables to house sockets after. Sparkies are now tasked with ‘risk evaluating’ the need for a Surge Protection device in CUs nowadays. I’m not clear how these may affect sound quality – you should check.
It is not a simple as “just a risk assessment”, if the tails or feed go through an external wall then surge protection Must be fitted to comply with latest amendment 2
It’s not unusual to fit a second consumer unit off an RCBO in the main CU, and I understood from your previous post that your sparky was going to do this for your HiFi CU. That is what I would try to avoid, but perhaps I misunderstood what he intends to do.
That is correct, if meter tails are not wholly within a box containing your meter and CU and they are buried in a wall, an unsuspecting homeowner or tradesman might, for example, drill through them, and with no protection on the tails that could be fatal.
Thank you for your replies. I am in the UK.
It is me who really does not understand the in’s & out’s of electrical installations and the particular type to help give my system a sonic uplift.
I was just reposting what Marcus (the spark) sent to me hoping your valuable advice would be forthcoming.
I really appreciate you all taking the time to offer your thoughts to assist me with what I’m trying to achieve.
This forum is amazing👏🏻
I think this additional RCBO unit surge protection is in case of a sudden surge from off the grid, or a lightning strike, either of which maybe a good thing in protecting household electrical appliances that are plugged in and powered up, and this may include the naim audio.
Hi Debs, You recently had a new radial with either SY or CY cable. As the Surge Protector Device is mandatory, I assume you have one. Please could you give us an update on your new radial regarding SQ?
Phil