Help with a radial!

Hi Folks,

I don’t particularly want to go over old ground but I have a golden opportunity to install a dedicated radial supply to my 500 series Naim system.
May I ask you folks who have experience with this particular install to ask for a shopping list of the components to purchase. Currently I have laid a 10mm2 mains cable from my MK unstitched wall socket to my existing CU. I have trawled the forums for the components to purchase however to no avail, I am aware of the revised 18th regs so RCD are frowned upon, which leads me to choose between RCB or RCBO. I have just recently printed off the latest Radial schematic from this forum. May I ask what rating does the RCB, RCBO need to be? B or C type? What make and model of CU do need to purchase, reading the forums Hagar seem to be popular, is the garage type acceptable or does it have to be a domestic type?
As you can see Im at my wits end with decisions on equipment selection and my time is running out as I have a joiner coming to my home to lay hard wood flooring very soon!!!
I would greatly appreciate any advice from you folks that have already had success in this install.
Just to reiterate my desperation!, type, make and model of CU, type make, model and rating of the RCB, RCBO’s. I am of course using two single 100A single pole Henley blocks.

Kindest Regards


FYI. I’m getting a new radial circuit installed next week and the Electrician is installing Hager 30Amp Type C RCBOs. Also a Hager six way domestic CU is being fitted as I am having three radial circuits fitted with 6mm2 twin and earth.

Hope that this helps

Good evening DiggyGun,

Of course this is a great help and steers me in the right direction, I thank you greatly for your swift reply, thanks.
Im guessing I can purchase a 2 was CU?

Don’t forget that you also need to fit a main switch in the CU, which itself is two MCBs wide.

Most small consumer units are 4-way, which gives you 2 slots for the DP switch, one for the breaker on the dedicated circuit, plus a spare.

A Type C breaker prevents nuisance tripping when you turn on your big PSUs. Your electrician will probably not allow a regular MCB as generally recommended if local regs require an RCD.

It was quite a long time ago when Hager were recommended. They are now part of a much larger global company, and a consumer unit you buy now is unlikely to be built in the same continent, never mind to the same spec as they were back then. They are probably fine though. Mine is MK, and that works well too.

Hi ChrisSU,

Thanks for the advice its appreciated, If I were to purchase an MK consumer unit it is a wise move to also purchase MK breakers? If at all possible if I were to purchase a 2 way is it advisable to accompany the CU with MK breakers? and what rating of an RCBO for my single radial?
So many questions Im sorry but Im bewildered with this new challenge!

Thanks ChrisSU

Mine has an MK MCB in it. If you use a different brand it may not fit, but your electrician should know that.

@neil67 great that you are asking the questions, but are you in the UK and do you have a qualified electrician installing and registering your new circuit?

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Yes of course, my apologies for not being informative! I am in the UK and have a qualified electrician awaiting instruction

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Nice one. It will be interesting to hear what improvement you get over your current setup. I would have thought your existing radial circuit would give you the better part of an improvement, compared to a separate CU, but it certainly makes sense to do it while you have the opportunity, as these things can be quiet a cheap upgrade - relatively speaking. Good luck

Hi Neil.

Just out of interest if you have an electrician carrying out the work one would of thought that he/she would know what materials to obtain to meet your requirements.
Kind Regards.


A lot a Electricians are not aware of what Audiophiles want as the spec is well over the normal requirements for a radial circuit. For example, mine said that cable is for cooker circuits.

It’s often hard to find services that want to go beyond their more common work. If/when you do find them, keep hold of them :blush:

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I ran a single 10mm cable and a single 6mm cable, from a dedicated consumer unit.
These went to a single socket that I use for the 500dr and my multi block, that I fixed into the wall, rather than have it lose on the floor.
The 6mm goes to the single, the 10mm the multi, works very well

Hi GD,

Absolutely Im gonna jump at the chance, fortunately I will be able to carry out an A and B comparison between the existing house circuit and the new dedicated radial. I will keep you posted!!


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Hi Roger,

Im hoping after explaining to the electrician what my needs are he/she will understand and give appropriate advice on the hardware however it would be advantageous to learn what other audiophiles have installed with regard to CU and the type of breakers so as I have an idea of the components which are acceptable for the best sound quality.

Thanks Roger for your reply.

Evening Dunc,

Thats a very good setup indeed and a great idea to feed your 500DR independently from your other equipment, unfortunately Im not able to install such a main like yours so I will be running all my DR supplies from my one radial however I have to say living in a very small village in rural Scotland I have found the mains to be pretty clean, my Superline does not suffer to noise pollution at all.
Though Im looking forward to getting the radial installed.

Thanks Dunc for your reply

Hi Again DG,

Would you mind telling me if its possible the model number of the Hager CU you have chosen as your dedicated hifi CU as I have spoken to several suppliers regarding a 2 way Hager CU for my needs.
According to the sparky I have coming the RCBO of your choice is adequate for my install too however with several 2 way Hager CU’s to choose from I was wondering what model you are using, of course I will run this past my sparky to be sure its comparable with my plan.

Thanks again GD

I use the same hager one russ Andrews recommend, but from my local electrical outlet, and at a substantial price difference.
Try your 500 on a different supply if you can to the rest off your gear, as i found it to be better like this

Hopefully you only have one socket as 2 x 10mm cables in the terminal and back box is something no electrician will thank you for having him install…