The "fuse" is turning the electricity off

I have recently bought a used stereo. Equipment:
Naim XP5 XS
Naim SuperCap
Naim NAP 300 + 300 DS
Naim NAC252
Naim NDX2
Premier Power Plant regenerator
Audiovector SR6

All power cables goes into the Premier Power Plant regenerator and that goes to a Supra that then goes into the “wall” (sorry for my bad english here). The problem is that when I turn the equiptment on it seems to overload and the fuse releases and electricity dies.

Is this normal? Hence that these hi end stereo equipment needs so much electricity so a “normal room in a normal house” cant supply the electricity needed? I guess that I need to call an electrician - just want to hear if you have experienced the same thing!


I suggest that you are experiencing what is known as “inrush current”.
When an electrical equipment is powered up there is a brief moment, tens of milliseconds, when the unit will demand more current from the mains than the “quiescent” current drawn under “normal operation” when the equipment has stabilised. This inrush “spike” can be several times the rated current draw, and can cause your house circuit breakers to trip.

In days of yore, the solution was to fit “slow blow” fuses; latterly you can get an electrician to change the circuit breaker from the usual Type B to a Type C.

I presume you are switching on “one at a time”? If so, which unit causes the trip?

Yes! And it seems that when I turn on the last piece- the Naim NAP 300 + 300 DS that is when the fuse turns off the electricity. So that seems to give the “final push”

First thing is to not power it all on together, switch each unit on one at a time.
I guess you are not living in UK, so maybe best have a local electrician check out your fuse or circuit breaker amp ratings are suitable according to your countries regulations.
You need slow blow fuse or CB reaction suitable for an inductive load.

Have a look at my lengthy thread here:

Should apply to your situation as well.

Turn off all other consumers on the circuit and power on the power amp first.

No, it is not the total power consumption of the stereo, it is the high inrush causing the circuit breaker to trip.

Thanks! I live in Sweden

I now managed to get it to work again. I swtiched everything off and then started with the NAP NAP 300 + 300 DS. I guess that is the “strongest” electricity consumer. So now it works, thanks for the help! Another question - we have had some thunderstorms over Stockholm during the last weeks. Should I always disconnect my equipment then or is it some kind of “lightning protector” that I can connect so I still can have the stereo turned on?

Received wisdom is that, if in doubt, disconnect electrical items entirely from the mains, not just power down.

I live in Germany and have a “fast” circuit breaker as well (as this is the usual default in apartments). Occasionally turning on the 300 also triggers the breaker.

Whether this happens is pure luck because the size of the inrush current depends on the exact point of the mains power AC cycle when you press the 300’s power button.

As others have suggested, having an electrician fit a slow breaker should cure it. I’m not bothered though because it happens maybe once out of ten tries. Then I flip the breaker switch and it usually works on the next try.

It’s what I learned recently from the thread on thunderstorms I opened. I thought precedently that switching off items was enough.

There is no way to get full protection from a lightning strike.
The best & by far the cheapest is to disconnect from electrical power, FM/TV antenna & broadband/phone.
However, even in a disconnected state, it’s still possible to incur damage from the electromagnetic pulse from a nearby strike - its happened to me - & that is the value & purpose of your domestic contents insurance.

The power amp should be turned on last, and turned off first. Once the source and preamp have been turned on they are using very little power when not in use and will not affect nuisance tripping from the power amp.

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True in principle, but if the 300 in-rush trips the breaker often, then you turn on the streamer PS, then the streamer, then the SC - and then everything goes off again when you turn on the 300. This gets old fast. In this case, I would also turn on the 300 first as the only downside is some popping from the pre.

That’s a fair point, but a Type C breaker would take care that and allow the switch on/switch off convention to be observed.

Sure, it’s just a matter of how often you turn it off etc. and what’s most convenient. Of course a C breaker takes care of it, but if you need it like 5 times a year, may or may not be worth it

It reminds the day I sold my 300 dr to a guy on EBay. When he wanted to switch it on , all the home electricity was off. He thought first that I have sold him a nap 300 dr non working. Hopefully his dealer advised him to try another wall plug. It worked. If not he would have returned my 300 dr.

Power your amp first sometimes this happens i had the same issue with my xps i just keep spare fuses .

I live in the Netherlands and I used to have the same problem, circuit breaker C16 should solve the problem … talk to the electrician.