Circuit breaker - which to choose

[evalrat]

I haven't scanned all reactions. So sorry if this has already been mentioned. The inrush current of my Rotel RA1592 trips the standard 16A breaker, meaning over 80A inrush. As the normal currents during use stay well below 16A, which corresponds with over 3,5 Kw power delivery. I replaced with 16A C-Law breaker allowing a far greater inrush but guaranties normal protection during normal operation. Only make sure that the wall socket group behind that breaker has no other heavy clients. I personally think that it a crime that audio manufacturers don't install NTC's in front of the power supply as a standard practice. This precaution is standard in every computer power supply.

 

[voodooless]

I replaced with 16A C-Law breaker allowing a far greater inrush but guaranties normal protection during normal operation.

Yup, that seems to be the most reliable and safe solution.

So, if you want one from Conrad with GFCI, check Siemens 5SU13567KK16 or without: Siemens 5SY41167. But there are loads more..

 

[somebodyelse]

Here is an example of a zero-crossing solid state relay

Which is what you want for a resistive load, but for an inductive load like a transformer it will cause near-maximum inrush.
https://sound-au.com/articles/inrush.htm#s4
https://neurochrome.com/pages/the-ultimate-guide-to-soft-start-design
Both point out why you need a bit more than an NTC with most audio amps too. I'm a bit surprised MF didn't include soft start even back then, but standards have tightened over the years. I think it was the early '90s when Quad made it standard rather than an option on the 520f.

 

[roxor]

Yup, that seems to be the most reliable and safe solution.

So, if you want one from Conrad with GFCI, check Siemens 5SU13567KK16 or without: Siemens 5SY41167. But there are loads more..

Thanks,
i want to replace mine which is B-char with the one u posted C-one.

Hopefully the last technical question ... do i need GFCI? Can install / replace CB without GFCI ... somehow without any issues with the one with GFCI? I mean it wont require some complex rewiring?

I can remember that service guy told me that CB with GFCI might also cause the issue... not sure whats the issue of that GFCI extra protection.


thanks

 

[voodooless]

Hopefully the last technical question ... do i need GFCI? Can install / replace CB without GFCI ... somehow without any issues with the one with GFCI? I mean it wont require some complex rewiring?

As I said, many EU countries mandate GFCI for all circuits, so check with your local code. It it mandated, it is likely you already have a GFCI, possible one per phase.

I can remember that service guy told me that CB with GFCI might also cause the issue... not sure whats the issue of that GFCI extra protection.

I doubt it will be an issue.

 

[roxor]

@voodooless

My wall 230V sockets contains 2 cables, ie L and one more cable which is used to bridge N+E,
as per my understanding i wont be able to use CB with GFCI,
in case i want to use the one with GFCI then i need to rewire flat, and each 230V wall socket has to be connected to 3 separate lines ie L, N, E.


appreciate

 

[voodooless]

If your sockets don’t have ground, GFCI is obviously pointless

 

[roxor]

@voodooless
is it okay to use ABB https://new.abb.com/products/2CDS271001R0164/s201m-c16
2CDS271001R0164
instead of the Siemens 5SY41167 you have proposed? They dont sell siemens here

 

[voodooless]

Sure, ABB is top tier equipment. The Siemens one here: https://www.conrad.cz/cs/p/siemens-...-400-v-1753918.html?searchType=SearchRedirect

 

[roxor]

if siemens is worth it i can order from abroad rather then use ABB etc

 

[voodooless]

if siemens is worth it i can order from abroad rather then use ABB etc

It’s not. ABB is fine.

 

[roxor]

appreciate u all for you wisdom and help.

 

[LSPhil]

I have an 800W amplifier with a 600W toroidal transformer. When I had a 16A B-characteristic fuse, I had to insert it every now and then. I changed it to 16A K-characteristic and forgot about the fuses.
At home I have one phase just for me. When my wife is doing laundry and the dishwasher, she only turns it off and I continue listening to my music.

 

[radix]

@voodooless

My wall 230V sockets contains 2 cables, ie L and one more cable which is used to bridge N+E,

MF does say the PSU should be grounded via earth. https://www.musicalfidelity.com/uploads/manuals/English/nvm3.pdf

Are you floating the earth, or is it connected to neutral? It looks like you say it's connected to neutral. Not sure how safe that is, especially if you have other components connected with RCA-style connectors or XLR without ground lift.

 

[NTK]

If your sockets don’t have ground, GFCI is obviously pointless

GFCI works without ground. Go to the frequently asked questions and see "Will a GFCI Work Without a Ground?"

GFCI vs GFI

Brush up on GFCI vs. AFCI, the uses of GFCI circuit breakers and outlets and where GFCI are required.

www.homedepot.com

 

[roxor]

This makes perfect sense, and would explain why it's seemingly quite random for the breaker to trip.

A well designed soft start circuit will often incorporate 'zero crossing' detection - this will ensure that the load is always applied as the mains sine wave passes through zero volts, ensuring there is no sudden large current demand.

I would have thought that such a large power supply would incorporate this - however here in the UK with our typical ring main, the circuit is usually protected by a 32A breaker, and as such large loads like this are rarely an issue - and the amp is a UK design...

@audio_tony

but i am not sure if the assumption was taken in the account,
ie i was powering on only PSU, no so capacitors/ no drain ... and even it tripped CB.


Thanks

 

[roxor]

Are you floating the earth, or is it connected to neutral? It looks like you say it's connected to neutral. Not sure how safe that is, especially if you have other components connected with RCA-style connectors or XLR without ground lift.

argh,.. Its connected to the neutral.

 

[radix]

GFCI works without ground. Go to the frequently asked questions and see "Will a GFCI Work Without a Ground?"

GFCI vs GFI

Brush up on GFCI vs. AFCI, the uses of GFCI circuit breakers and outlets and where GFCI are required.

www.homedepot.com

My understanding is they are even more important when there's not a safety ground. If there's a problem, it's likely YOU who is the alternate path to ground.

 

[voodooless]

GFCI works without ground. Go to the frequently asked questions and see "Will a GFCI Work Without a Ground?"

GFCI vs GFI

Brush up on GFCI vs. AFCI, the uses of GFCI circuit breakers and outlets and where GFCI are required.

www.homedepot.com

Ah, you are absolutely right. So a combination device may still be a possibility. Just note that most are 2 units wide, though there are single unit size ones. I use a 32A-B type one for my car charger from Emat.

 

[radix]

argh,.. Its connected to the neutral.

The pros and cons and safety of using a high-amp electric device that was designed for a safety ground and is using neutral is beyond what I would want to comment on. I know there are ppl on the forum who work with that stuff and know it.