Circuit breaker - which to choose

[JustJones]

Use an electrician. I belive in the EU, not sure what country you're in, France plug ? Schuko plug ? but the most common are 10 amp or 16 amp breakers. 16 amp should be fine.

And as I said current it randomly tripping 10 and 16a cb

How loud are you listening? You're tripping a breaker before the amps protection kicks in?

Could just be a bad breaker.

 

[roxor]

I had a trippy one, that I replaced.

They don't last forever.

I know, they are max 10y old.
I tried two different circuits both tripping.

So that's why confusion.

And as I said cb have different curves for inrush current so question would be based on what to pick the correct curve..

 

[roxor]

How loud are you listening? You're tripping a breaker before the amps protection kicks in?

Yup
Precisely...just pressing power button and it tripps immediately.

 

[JustJones]

If you've tried more than one breaker and are tripping them perhaps it's the amplifier. Isn't the nu Vista M3 about a 20 year old amp, have you had it checked out?

 

[Doodski]

Yup
Precisely...just pressing power button and it tripps immediately.

Yes, that is a situation where theoretically the transformer inductor draws for a tiny time period infinite current limited only by the source resistance. So that is a nasty current rush that can't be avoided.

 

[roxor]

I am happy to order electrician to replace cb but as I said,
Apart of max ampers...do we need to take into the account while designing whole stuff
The curve of the breakers or it doesn't matter at all?

Thanks

 

[RayDunzl]

cb have different curves for inrush current

MCB Trip Curves - B, C, D, K and Z trip curves- Made easy

Trip curves of MCB's (B, C, D, K and Z curves) tell us about the trip current rating of Miniature Circuit breakers. MCB trip curves

www.electricalclassroom.com

 

[radix]

There may be something wrong with the amp that causes the tripping.

Usually it's because you're on the same branch as something else, like a refrigerator.

That amp is supposed to be 1200 watts, so it should work OK on any standard circuit.

If you do not understand electricity, you really need an electrician to build out the new circuit and get it setup.

 

[roxor]

If you've tried more than one breaker and are tripping them perhaps it's the amplifier. Isn't the nu Vista M3 about a 20 year old amp, have you had it checked out?

It's old correct.

It happening while separate psu is powered on, no amp is attached so it's not about drain by capacitors...

PSU contains only transformathors.
The main mf engineer suggested to use 16a cb with D curve.
But when I asked how he come up to the conclusion that it has to be D curve...
He was not able to answer and said it should not trips any cb and that psu has to be checked....

That's why all my concern and I got lost.

 

[roxor]

Usually it's because you're on the same branch as something else, like a refrigerator.

These circuits, have no refrigerator etc.
Theese were empty circuits.

And only psu of the amp was tested so no capacitors...

 

[roxor]

Yes, that is a situation where theoretically the transformer inductor draws for a tiny time period infinite current limited only by the source resistance. So that is a nasty current rush that can't be avoided.

I got lost, after the..... Infinite current.....
Can't be avoided? In that case whats the fix here?

 

[roxor]

MCB Trip Curves - B, C, D, K and Z trip curves- Made easy

Trip curves of MCB's (B, C, D, K and Z curves) tell us about the trip current rating of Miniature Circuit breakers. MCB trip curves

www.electricalclassroom.com

The selection of cb Curves types has to be done by electrician? Based on what will be attached to the cb?

 

[JSmith]

JSmith

 

[roxor]

Don't wanna do it yourself....
Just want to have at least some understanding what's going on here...

Hence it is necessary to calculate the short circuit current and inrush current before choosing an appropriate MCB rating.

 

[roxor]

Well
I was assuming that MF engineer should know / be able to calculate short circuit current or inrush current... Of the device they were selling...
But apparently they are not able to do that...

 

[RayDunzl]

It happening while separate psu is powered on

What PSU?

Oh. This, I guess:

And only psu of the amp was tested so no capacitors...

"Transformer inrush current is the instantaneous current drawn by the primary winding of the transformer when the transformer is initially energized with the secondary side left open-circuited (no load). The inrush current also referred to as magnetizing inrush current, is transient in nature and exists only for a few milliseconds. The inrush current is two to ten times higher than the standard rated current of the transformer. This article discusses the basic definition of transformer inrush current, its causes, effects, and remedies."

Transformer Inrush Current

Transformer inrush current is the initial current when energized. Learn about its definition, causes, and effects.

tameson.com

 

[MediumRare]

Well
I was assuming that MF engineer should know / be able to calculate short circuit current or inrush current... Of the device they were selling...
But apparently they are not able to do that...

Let’s simplify: there is no possibility that a single amplifier can pull 15A on any curve upon startup unless it is faulty. Even with several components on one circuit (as they should be). Next, it’s highly unlikely you need a separate circuit unless you have an old or very large electric motor on the same circuit. The first thing you need to do os take that amp to a qualified repair person and have them check the amperage drawn v specs.

 

[JustJones]

MCB with class D trip characteristics trips instantaneously when the current flowing through it reaches between Above 10(excluding 10) to 20 times the rated current. Suitable for inductive and motor loads with high starting currents.

If breaker rates at 80% then 16 amp will sustain 12.8 amp and class D trip curve will hold till over 10 times at 128 amps. If your amplifier trips a breaker that can accommodate inrush of minimum 128 amps then I would look at the amplifier not the breaker. That's my guess as to why the engineer said try MCB with class D trip curve, if it trips that then look at the PSU in the amplifier. I assume that's the power supply you're talking about.

He was not able to answer and said it should not trips any cb and that psu has to be checked....

Right there he's telling you that amplifier shouldn't trip any circuit breaker.

 

[Doodski]

Back! @roxor you should draft up a plan/flowchart so that you have a list of to do stuff and get it done. First get that amp checked out so that you know it is not drawing excess current on power ON. Replace the present old CB with a suitable to code new CB and test drive that CB to see if the issue stops occurring. If that issue does not change after these checks and tests then go to the next step. That step is to provide more power for that electrical circuit in the house powering the audio room. You will require a electrician. They will follow code as is by law. Sound good? Does anybody from ASR have anything to add that I missed or made error upon?

 

[roxor]

there is no possibility that a single amplifier can pull 15A on any curve upon startup unless it is faulty.

Check inrush current they said in torroidial transformers it might be 60 times...