Problem with new Hi-cap2

First, Naim PSUs are intended to be left on all the time for optimum performance, so regular switching on shouldn’t be necessary.
As already mentioned, these relatively heavy duty PSUs briefly have a big inrush current when switched on. This is what can trip a circuit breaker, especially if it has been specified for relatively lightweight domestic use. Changing the breaker to a correctly selected Type C version will almost certainly solve this issue if it’s permissable under your local electrical regulations.

Order 13A breakers instead of 10A. Since I changed they stopped going off. After going off even the first time Miniature circuit breakers can have degraded
(I use type C)


I have three HiCaps, one recent HCDR & 2 x Olives which dont trip my circuit breaker, neither does the NAP200 we own. The power inrush for a HC is not that high, input power rated at just 40VA so it may be an idea to swap the power lead or try another socket.

Its best policy to leave Naim equipment permanently switched on, unless theres good reason not to ie thunderstorms etc.

Naim perform extensive QA/QC, both on individual components prior and during assembly as well as finished products.

I have had the power trip using a furutech mains plug on 555PS, and standard Naim plugs on an Olive hicap.

It’s not uncommon and nothing major to worry about. If it trips while it’s on rather than when plugging in or powering up, that’s a different matter.

If the system is powered up most of the time other than lightning strikes it shouldn’t cause too much distress.

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It comes down to luck of the draw, when the switch contacts close and where the 50Hz or 60Hz mains supply is in its cycle. The highest current would occur in a transformer circuit when the rate of change in the primary voltage is at its highest, ( i.e. at zero crossing point).

I turn my system on and off every time I use it, (shock horror) and operate my system from a type B 32A MCB protected circuit. I have managed to trip my circuit breaker twice in 5 years.

As Dan says its not uncommon.


Why are you turning it on and off? Turn it on, leave it on unless you need to turn off the whole system.

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Actually I don’t like to leave a unit on and leave the house except the refrigerator and I was not aware of inrush current that is create by this unit( I was guessing something but wasn’t sur ) , but from now on I’ll leave it on.
Thanks to all of you for your help


I live in Switzerland and have the same issue with a 10A domestic mains system. I have tripped the CB on occasions on power up and got around it by swapping around some of the MCBs (an electrician mate did it - mains can bite and you might only get one chance to get it wrong!). In the old days, you had slow blow fuses that tolerated an overcurrent during a transitory period, but the modern MCBs can be sensitive and twitchy. One of mine was worse than the others, guess the brand and age is a factor here.
Now my biggest concern is a 2.2kW kettle that seems to take an age compared to a UK 3kW one when I fancy a cuppa.

A 2.2Kw kettle is right on the limit for a 10A MCB.

Yup, pesky little MCBs! :0)

My first property used bare fuse wire protection, I did begin to wonder whether it was at all effective in terms of its safety.

But I only boil a cup’s worth of water :joy:

Your kettle does not ‘know’ that though!


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