My XPS DR or any other Naim component has never tripped my 32 amp Type B MCB. However my XPS DR has blown it’s internal fuse from time to time through switching on, same as the light bulb comment mentioned above. The solution - ordered a few spare fuses of the correct rating from my Naim dealer. Store fuses in a safe and dry place. Leave the unit on for long periods. No big deal - unless you’ve put a lot of time and attention into building your Fraim rack and your XPS DR is on the bottom shelf. Solution - replace old fuse with a new one regardless, before building your Fraim. Now that is a light bulb moment! 
1 Like
Lots of talk about changing MCBs from type B to type C.
In the UK you have to check that the earth loop impedance of your circuit is low enough for a type C MCB to disconnect in time to be compliant with the IET Regs. Unless you are familiar with the regs, methods of calculation and measurement I would think that this is a job for an electrician.
3 Likes
Well said.
I will also add - you cannot assume the competence of other forum users & to advise diving into a consumer unit without mention of safe isolation/proving dead procedures seems a bit reckless.
Leave it to the professionals.
Regards
Neil.
3 Likes
It’s too bad there are not a few technical guidelines and pre-requisites from Naim and their experience with this, so that customers can discuss with a decent qualified electrician in order to see the work required to achieve an acceptable suppy to the equipment.
Maybe this could be added as a FAQ. That way avoiding people talking about these issues so frequently. I don’t want to go down the “analogs” comparisons route, but I would simply expect clearer guidelines and requirements to achieve the best from our systems.
FWIW, I am convinced that the reasons for all the ups and downs with my setup in Germany is excessive performance variability probably due to a very poor earthing. A 1970s house where the cables and fuse boxes that have never been changed or even brought up to current standards. Yes I have installed a dedicated spur, but the supply and earthing from the street are as before.
1 Like
In the UK you can ask a suitably qualified electrician to carry out out an Electrical Installation Condition Report,(EICR), this will tell you if your Installation meets your local regulations which in the UK are the IET wiring regulations or BS7671. I am sure that Germany has a similar arrangement as both Uk and German electrical regs are derived from the same International regulatory documents.
I would expect Naim and other manufacturers to make equipment that complies with the necessary appliance standards, and of course it is no accident that if your supply complies with the electricity standards and your appliance complies with its standards that the two will work happily together. This is why we have standards.
Naim and other manufactures cannot reasonably be expected to legislate for their equipment being operated outside of the design standards. It is quite possible that many domestic electrical installations through out the UK (for example) do not comply. And I have heard of examples where the local electricity board, (district network operator, DNO) has run their systems at higher voltages than they should be in some places, to ‘sweat their assets’. Tut tut!
Yes I’m well aware of the standards. We checked all this out recently in my late mother’s place in 2019 just down the road from where you live actually.
I suppose you are right that we can’t really ask more of Naim than to deliver something that meets the specification to operate within certain tolerances whilst maintaining certain standards.
Thank you for your answer though.
2 Likes
A 32 amp Type B MCB is considerably higher than most people will have. Mine were mostly 20 amp for my UK power sockets and my electrician changed it to a type C to prevent it tripping when turning on my XPS and also, on occasion, 3 x 250’s in quick succession.
Naim have in the past provided a loose guideline for UK installations. Unfortunately code can differ markedly across the world, so a blanket recommendation isn’t really possible. What’s more, code requirement change regularly so the only specific advice that can be given is to consult with a qualified electrician who’s fully conversant with the electrical code for where you live.
2 Likes
Yes I see something to that effect in the user manuals with a clause that there were no guarantees to such solutions improving the situation. I don’t remember the exact phrasing.
This is possibly accounting for variability of the age and quality of the wiring/earthing of peoples homes.
It would be interesting though if we tried to make the environment in which the system is as best as we can get by getting a decent substation/isolation transformer prior to supplying the building. The best possible earthing system like multiple spikes underneath a basement foundation and possibly a faraday cage to reduce the impact of the RF soup. The latter was done by a colleague because his wife is very sensitive. In the end i am left convinced that my cheapy chrome bumper system has most of these elements and sounds amazingly good and consistent without the cat chasing it’s tail scenario that i have with the main system in Germany. There is really only one way to find out.
On the subject of equipment/system design, i can only speak generally here. The ‘disturbances’ affecting a system performance have significantly changed since the 1980s, especially for cities and wonder how these aspects are considered in terms of evolving designs. My favourite examples are the sensitivity of k boards in an olive 52 and superline where it was clearly heard radio broadcasts prior to putting a record on. Usually solved using an RF choke around the interconnect. My linto phonostage has absolutely no issues in that respect but I’m sure some will say yes but it is rather boring musically though 
Thanks in any case for the reply and clarification.
I untangled my power chords and was able to put the XPS directly into a wall socket rather than to put it into a power strip together with my amp (and other stuff like TV etc.). After being away for a week the XPS was powered down, but I was able to turn it on without having the fuse triggered. Seems to be a problem of too many devices put into a daisy chain, so powering the XPS directly from a wall socket works well. Nevertheless I will contact a electrician to install a dedicated spur if possible.
1 Like
Sparky will install a dedicated spur and a C type mcb next month. Looking forward to even more improved sound then.
1 Like
I guess I will have a Gigawatt G-16A fitted. Anyone experience with this? Any recommendations reg. an in wall cable?
Fully agree!
Powering mine up pops the breaker nearly every time!! I found that I have to switch everything off and then turn on the source, pre and finally power amp… I have to leave a gap between switching them on… it’s in my converted garage so only got a 16amp breaker…
Pain in the ar*e thou !!
It’s the best MCB you can get for audio. A no brainer. 
1 Like
Even Munich has its issues, this from the exhibitor information!
“Fuses at the room
Each room has two power circuits, each 3 KW (each wall has its own circuits). We have installed so called fast fuses (FI) and that is, why some electronic with huge power consumption while switching on, results sometimes in “black out”. On request, we offer to change the fast fuses (FI) on both circuits into slower alternative.”
1 Like
Sparky has left the building. After installing a dedicated line with a GigaWatt G-16A Circuit Breaker on one end and a Phonosophie wall socket at the other end the problem is solved. I can now happily turn the XPS on and off. Unfortunately the hum is still there, but I know that this problem is based on other issues. For now I put the XPS inside my lowboard and will try to dampen the space around the power supply. Case closed.
4 Likes
This topic was automatically closed 60 days after the last reply. New replies are no longer allowed.