House fuse "clicks" off when switching on naim


as a few :slight_smile: might know, I am looking for a 500 DR.

There is a thought which had come up making me nervous a bit.
And its a technical one.
When switching off an on my system I often have no luck in turning it on with the first try.
When switching on the bigger PSUs (555PS / 552PS / 300PS,…) the house fuse “clicks” off (not main fuse - the fuse for the living room only).
I know that these transformers want a lot of electricity when switched on. I experimented a bit with switch-on-order, but no luck. When I first switched on 300 - also living room went dead.
When it is switched on - and I came through with the circle - on all ist fine!

The 500PS has a even bigger transformer - this frightens me a bit, that I even could get him switched on at all with the fuse clicking off every time. The 500PS has a 1.100VA transformer - will this work…

I am no electrician - FAR from that.
I googled that here in Germany 16A fuse is standard and as far as I read no other are allowed.

Is there a dependency between the size of the transformer and my house fuse going off? It has also happened when switching on SC or 135 - but more often with 5552/555.

Thanks for your help on that - any hints will be much appreciated.
Does anyone in Germany or other regions (do not know the local regulations for fuses) know this problem.
Any solutions?

THANKS for your help.

It can happen in the uk. I have a newish NAP250DR, which can cause the same issue.
Best advice is to talk to a local sparky who understands the loads the transformer demands on switch on. A Naim dealer will also be able to suggest a workaround or the name of a likely sparky.
Without a clear understanding of regs in your country, any suggestions would be inappropriate.
Testing of the circuit(s) would be a starting point.

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Do you stagger powering up each unit, or do you switch them all on at once? Firstly, you should do the former, and secondly you shouldn’t be turning them on and off regularly.

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carefully on after the other… I kept them switched all the time…

Do you have those automatic fuses which you pull up manually? Those are if so more sensitive than the old porcelain ones. I believe if these automatic ones have released to many times they become even more sensitive and that the instructions are to change them if so. I also believe there are slow blow versions of those that you might look into. An electrician will help you out :+1: For me the lamps blink when I turn my boxes on including the 500 but I believe it’s more the size of caps that is charged than the size of transformer? My fuse have never blown by turning on naim equipment and I have the older porcelain ones.

That’s completely true.
The Porcelain ones had never blown. I have the newer switched ones.
Called an electrician - there are fuses with a different time lag.
Normally one uses B-characteristic - also you can use C-characteristic which is meant for high current switching on.
Will go for a C fuse for my hifi room. First ask my landlord.
Hopefully the new fuse will not sound different :slight_smile:

The lights on my system also flashes sometimes - but oftenen they complete went off

There are HIFI-fuses available for that position too :slight_smile: Check out “Klangmodul” which is German.

This is quite common and you can fix it by changing the breaker to a type C. It’s a simple replacement job and takes only 5 minutes.


THANKS - I did not know that until an hour ago.

Found it but those seems to be 32A - I think only 16A is allowed …will check

I changed mine to Type C.for this reason. If you then turn things off and on slowly, one by one then things should be okay.

I pulled the plug on my Musicworks G3 and the 500PS feom the socket and it tripped the MCB. I should have turned them off one by one.

It’s basically huge rush of current that type C stops.

But as you say 500PS is a step up in current…

I changed my MCB from 16 amps to 20amps Type C. Easy enough for sparky to change out.

They are available from 10A-32A :+1:

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Would members please be aware that electrical code in the UK is very different to what may be safe and allowable elsewhere (particularly with regard to amperage), so the only safe recommendation here is for the OP to contact a qualified local electrician who will know the relevant code that applies for the area.


I’ve the same three power supplies. They are wired on on a Type C 20 amp RCD circuit off the power board. I always switch them in consecutively and the circuit has never tripped.

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WILL do nothing myself! Only an electrician should and must do this.
THANKS for your comment!
@all: Do not get even near the electric if you are not professional :O)

20A is not allowed in Germany

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Hopefully your electrician will allow a type C breaker which should solve your problem. He will almost certainly use the same 16 Amp rating, as this has to be matched to the circuit it protects regardless of what you intend to plug into it.


hy should he not - I was told this is the standard way but he has to decide. If not… 500 would be a rough ride…

Have you ordered the 500DR yet? :stuck_out_tongue_winking_eye:


Not the first time that substituting a Type C breaker has been mentioned/suggested.

AFAIK… :thinking:

BUT - do check - ideally with a qualified Electrician, local to you… :slightly_smiling_face:

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