Mains power: how to recreate a phase?

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As it has been discussed earlier in this thread it all seem to be down to distorted AC waveform in your power network. This can't be fixed by just playing with AC reference. Even if you would get your phase-neutral pair but AC waveform is as bad as before you'll still have the same problem.
 
May be a simple, properly rated isolation transformer can be used to make a cleaner AC supply to your audio setup, but this simply shifts the buzz/hum problem to the location of the isolation transformer.

Done and you're right again, the isolation transformer hums a lot.
And yes it seems to bring some more ( in term of quieter background).
I also measure the output of the balanced toroids, **** in>**** out
 
Naca5, you must be very frustrated by now. All this good advice and nowhere near to a solution. How about starting over?

What equipment are you using? How is it connected? Have you tested it elsewhere? Do your neighbours have the same problem? Show us some photos and schematics. What have you tried already? Where does the isolation transformer fit into all of this?
 
Naca5, you must be very frustrated by now. All this good advice and nowhere near to a solution. How about starting over?

What equipment are you using? How is it connected? Have you tested it elsewhere? Do your neighbours have the same problem? Show us some photos and schematics. What have you tried already? Where does the isolation transformer fit into all of this?


Thanks for your support Mark,
Yes it's frustrating, and yes this is a standard main over here.
Even the fridge is humming ;-)
About set-up , it is of course the consequence of that and I use where I can small power hungry devices or SMPS. (T-amp, passive preamp....)

The power isolation was fitted from wall plug (1000VA),
DC killer on each humming,

The only working filter device I tested was :
-overpriced (more than 1500 eur)
-noisy (fans)

Small humming are ok, but when we talk about amp (F5 or so) that become frustrating.
Using T-amp on battery is an alternative, but you know, t-amp on high efficiency driver are not the quieter amp on earth.

Finally, yes I tried my stuff in another country (living at the border ;-) and yes no hum.
 
You have an older distribution system with 230V between phases and no explicit neutral.
Between any of the mains sides and the ground you should measure ~132V (be careful doing that measurement).
Your mains might also be unbalanced and polluted, but that's an entirely different story

This just means that he has DELTA type connection as pointed earlier by Elvee. If you do the transformation to "Y" type connection then the protective earth will appear as the middle conductor and thus measures 220/sqrt(3) VAC to any phase in the triplet.

That is absolutely correct for a three phase system. There is 120 degrees between each phase. 1/sin(120) x 110 = 127.

What is a bit more bothersome is that a transformer rated for 240 volts at 60 Hz should be fine at 200 Volts at 50 Hz. Not so even at 220 volts. However if it is rated for 220 volts at 60 Hz it will start saturating at 183 volts.

As your transformer is seeing 220 volts from what appears to be a proper service the issue is most likely one of how the transformer is rated.

From what you have shown it does not look like delta. It is two legs of a Y with centre is ground.
looks like all four of you agree.
 
Thanks for your support Mark,
Yes it's frustrating, and yes this is a standard main over here.
Even the fridge is humming ;-)
About set-up , it is of course the consequence of that and I use where I can small power hungry devices or SMPS. (T-amp, passive preamp....)

The power isolation was fitted from wall plug (1000VA),
DC killer on each humming,

The only working filter device I tested was :
-overpriced (more than 1500 eur)
-noisy (fans)

Small humming are ok, but when we talk about amp (F5 or so) that become frustrating.
Using T-amp on battery is an alternative, but you know, t-amp on high efficiency driver are not the quieter amp on earth.

Finally, yes I tried my stuff in another country (living at the border ;-) and yes no hum.

clearly a power utility supply issue....why not talk to them and get advice, they should know and you as a costumer has the right to a good service...
 
> Neutral is referenced to earth

No!

A Neutral combines two circuits so their currents cancel.

There is no electrical reason it has anything to do with ground. (Edison invented neutral but didn't ground it for the longest time.)

As has been said, about every electric supply system (larger than Edison's first) "must" earth their supply somewhere. And usually in a way which minimizes the maximum to-ground voltage on any leg of the supply. In systems which use a Neutral, this is commonly (not inevitably) the Neutral.

Naca5 has 3-phase wYe power. The PE is not for power, only safety. All loads are fed across *two hot legs*. All three legs "neutral" their adjoining currents. This looks very odd to my eyes, but should work fine. Adding an isolation transformer does no more than what the equipments' internal transformers already do, as he showed. I do not think it is the source of all his loads humming.
 
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