Yes that's funny or odd
Another rookie question, I would check later but the isolation transformer has two primaries, can I try to connect it that way ? blue/ground & brow/ground?
Voltage will be a little bit higher than 240v....
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Your isolating transformer has dual 115Vac primaries
You have supplies of 127Vac or 220Vac. (+- tolerances)
You can connect the two 115Vac primaries in parallel and connect to your 127Vac supply. This will run the transformer a bit warmer than designed for, especially if your supply voltage goes up a bit. It also means the output is going to be well above 115Vac all the time and when your equipment is drawing low power you are going to have a very high secondary voltage. I don't recommend this connection arrangement. (I'd guess your maximum voltage will be ~132Vac on each secondary, when mains is at 127Vac, giving a total of 264Vac).
The alternative is:
connect the two 115Vac primaries in series to give you a 230Vac isolating transformer.
Connect this to your 220Vac supply.
This will under run the transformer. It will run a little bit cooler. It will also run a bit quieter.
The output voltage will be lower (much lower than the first arrangement). This lower output will allow your own equipment to run a bit cooler and a bit quieter.
When your equipment draws less current the Secondaries will run a bit higher, but will probably never exceed 115Vac.
I recommend this series connected 115Vac primaries connected to the 220Vac supply. (I'd guess your maximum voltage will be ~229Vac)
Finally, note the difference in my predicted MAXIMUM voltages when mains is at 127Vac, 264Vac vs 229Vac
If the mains goes up 5% then these maxima will also go up by 5%.
You have supplies of 127Vac or 220Vac. (+- tolerances)
You can connect the two 115Vac primaries in parallel and connect to your 127Vac supply. This will run the transformer a bit warmer than designed for, especially if your supply voltage goes up a bit. It also means the output is going to be well above 115Vac all the time and when your equipment is drawing low power you are going to have a very high secondary voltage. I don't recommend this connection arrangement. (I'd guess your maximum voltage will be ~132Vac on each secondary, when mains is at 127Vac, giving a total of 264Vac).
The alternative is:
connect the two 115Vac primaries in series to give you a 230Vac isolating transformer.
Connect this to your 220Vac supply.
This will under run the transformer. It will run a little bit cooler. It will also run a bit quieter.
The output voltage will be lower (much lower than the first arrangement). This lower output will allow your own equipment to run a bit cooler and a bit quieter.
When your equipment draws less current the Secondaries will run a bit higher, but will probably never exceed 115Vac.
I recommend this series connected 115Vac primaries connected to the 220Vac supply. (I'd guess your maximum voltage will be ~229Vac)
Finally, note the difference in my predicted MAXIMUM voltages when mains is at 127Vac, 264Vac vs 229Vac
If the mains goes up 5% then these maxima will also go up by 5%.
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Already tried Andrew, the most humming one....I can make a box, filled of sand or any other snake oil, but intrinsically it will always hums.
I would at this point thanks all for your inputs, I've learnt a lot.
SMPS based set up is not an awful things.
I will wait the feedback from my main provider and ask him if I can go back to a mono phase main, but I'm not sure to do that because I've in mind to work on house energy efficiency and of course replace our oil based heating set-up with a heat pump, then a three phase main will be helpful...
I would at this point thanks all for your inputs, I've learnt a lot.
SMPS based set up is not an awful things.
I will wait the feedback from my main provider and ask him if I can go back to a mono phase main, but I'm not sure to do that because I've in mind to work on house energy efficiency and of course replace our oil based heating set-up with a heat pump, then a three phase main will be helpful...
I think, as has been mention a few times, the phasing is not the issue. The supply is probably polluted in some way or over voltage. I understand your frustration. Please don't spend any more money on expensive "fixes". Let us know what they say, don't be fobbed off by them. Might be helpful to get support from your neighbours on that score.
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This thread has drifted into madness, many times.
Everybody (in good faith) trying to follow and answer OP´s original **WROOOONNNNGGGG*** diagnostic that his problem is caused by lack of true neutral, which is *implicit* in his power distribution system.
So crazy ideas have been considered, such as grounding one phase/grounding "half a phase"/isolation transformers/"regenerating AC"/going DC/using a motor generator/potting humming toroids in tar and sand/etc.
I´m certain I´m missing a couple.
BACK TO THE ORIGINAL PROBLEM (just to recover some sanity):
Ok, that´s what you have , no way to change that unless you move; although very outdated, distribution company will not change that, based on a minor quibble (in their eyes) by a very minor user (no insult, plain statistics says that you probably are less than 0,1% of their customer base)
IF that were your only problem, and you wanted to correct it for whatever reason, *that* individual point can be corrected, and a prper solution has been offered, and I *think* you are already using it: a 1:1 220V:220V transformer, primary connected phase to phase, secondary ground to (new, ground referenced) phase.
What you asked for in the thread title
and doing that should happily close this thread.
Sadly, although you have successfully done what you asked for, you have not solved your problem (yet), which actually is:
Repeat it please? So we are certain which is the problem?
Ok, now that we agree (hopefully) , let´s adress it without preconceptions.
To begin with, let´s abandon the theory/poor diagnostic thatit is caused by lack of true ground, because you have just proven it is not the case .... as I read it you got true phase+grounf through you isolation transformer and have NOT solved the case.
To boot, your isolation transformer IS a toroid too, so even if you had solved amp transformer hum/buzz, you would still have new hum/buzzin in the new one.
As in: if Aspirin gives you headache, taking more Aspirin to cure it won´t help , and I hope the analogy makes the problem clear.
Many have pointed to the real cause of the problem; mains waveform distortion/assymmetry .
Which *might* be solved by:
* mains waveform rectification/regeneration. Technically possible, but complex/expensive enough (not that it can´t be done) to make it impractical.
* moving . Hey ... sort of drastic, but if the problem annoys you so much ...... )
* this one has not been suggested but is not crazier than others: use a real long power cord . Meaning: IF (maybe) there´s good/conventional 220V power nearby, you might ask for (or run it yourself) a special wire to bring it to your home.
Quite illegal but technically possible. BUT ..... if waveform is as distorted as yours, it won´t solve the real problem anyway.
Now to the real solution to the real problem: ditch the toroids, replace them with same spec EI transformers, which will NOT buzz.
Crazy? .... think again.
Way less crazy than many of the alternative solutions, which to boot were not so, since they did not address the real problem, which, to repeat it again, is NOT a lack of true ground as you diagnosed on your own but toroid intolerance to dirty unbalanced mains waveforms.
Everybody (in good faith) trying to follow and answer OP´s original **WROOOONNNNGGGG*** diagnostic that his problem is caused by lack of true neutral, which is *implicit* in his power distribution system.
So crazy ideas have been considered, such as grounding one phase/grounding "half a phase"/isolation transformers/"regenerating AC"/going DC/using a motor generator/potting humming toroids in tar and sand/etc.
I´m certain I´m missing a couple.
BACK TO THE ORIGINAL PROBLEM (just to recover some sanity):
I´d add: no neutral.
Ok, that´s what you have , no way to change that unless you move; although very outdated, distribution company will not change that, based on a minor quibble (in their eyes) by a very minor user (no insult, plain statistics says that you probably are less than 0,1% of their customer base)
Yup, that´s what you have.
IF that were your only problem, and you wanted to correct it for whatever reason, *that* individual point can be corrected, and a prper solution has been offered, and I *think* you are already using it: a 1:1 220V:220V transformer, primary connected phase to phase, secondary ground to (new, ground referenced) phase.
What you asked for in the thread title
and doing that should happily close this thread.Sadly, although you have successfully done what you asked for, you have not solved your problem (yet), which actually is:
Repeat it please? So we are certain which is the problem?
Ok, now that we agree (hopefully) , let´s adress it without preconceptions.
To begin with, let´s abandon the theory/poor diagnostic thatit is caused by lack of true ground, because you have just proven it is not the case .... as I read it you got true phase+grounf through you isolation transformer and have NOT solved the case.
To boot, your isolation transformer IS a toroid too, so even if you had solved amp transformer hum/buzz, you would still have new hum/buzzin in the new one.
As in: if Aspirin gives you headache, taking more Aspirin to cure it won´t help
, and I hope the analogy makes the problem clear.Many have pointed to the real cause of the problem; mains waveform distortion/assymmetry .
Which *might* be solved by:
* mains waveform rectification/regeneration. Technically possible, but complex/expensive enough (not that it can´t be done) to make it impractical.
* moving . Hey ... sort of drastic, but if the problem annoys you so much ...... )
* this one has not been suggested but is not crazier than others: use a real long power cord . Meaning: IF (maybe) there´s good/conventional 220V power nearby, you might ask for (or run it yourself) a special wire to bring it to your home.
Quite illegal but technically possible. BUT ..... if waveform is as distorted as yours, it won´t solve the real problem anyway.
Now to the real solution to the real problem: ditch the toroids, replace them with same spec EI transformers, which will NOT buzz.
Crazy? .... think again.
Way less crazy than many of the alternative solutions, which to boot were not so, since they did not address the real problem, which, to repeat it again, is NOT a lack of true ground as you diagnosed on your own but toroid intolerance to dirty unbalanced mains waveforms.
> What is confusing is that the neutral (blue) is really a phase
I said days ago the colors are odd compared to current EU custom; however colors have been changed before and are not always followed in the field. Never Trust Wire Colors!!
> and that ground (green/yellow) is both neutral and ground.
The green is NOT a Neutral! It is only Protective Earth.
Where is it written that a power company must give you a Neutral? I agree that no-neutral is very unusual, but I see no need to demand it.
Taking the 127V from phase to PE would be as illegal as me getting 120V phase to Green. Yes, the lamp would light. No, you are not supposed to put load current on a PE. A further fault in the PE network would make ALL his appliance cases LIVE. Do not do that.
Also his is a 220V country so there would not be 127V loads.
The multiple 115V windings on his isolation transformer should be wired 230V:230V to extract a separately-derived power source; all applicable rules should be followed on the secondary side. (Rules for sep-derived sources much too technical and messy for forum discussion.)
I said days ago the colors are odd compared to current EU custom; however colors have been changed before and are not always followed in the field. Never Trust Wire Colors!!
> and that ground (green/yellow) is both neutral and ground.
The green is NOT a Neutral! It is only Protective Earth.
Where is it written that a power company must give you a Neutral? I agree that no-neutral is very unusual, but I see no need to demand it.
Taking the 127V from phase to PE would be as illegal as me getting 120V phase to Green. Yes, the lamp would light. No, you are not supposed to put load current on a PE. A further fault in the PE network would make ALL his appliance cases LIVE. Do not do that.
Also his is a 220V country so there would not be 127V loads.
The multiple 115V windings on his isolation transformer should be wired 230V:230V to extract a separately-derived power source; all applicable rules should be followed on the secondary side. (Rules for sep-derived sources much too technical and messy for forum discussion.)
The neutral is the mid connection of the Y. (XYZ of each transformer coil). Here it is connected to ground. If one of your clever neighbours plugs in a 110V device, using the ground as neutral.
Can't speak for the rest of the EU but this form of power supply s not allowed in the Netherlands.
Can't speak for the rest of the EU but this form of power supply s not allowed in the Netherlands.
in a delta system, XY, YZ, and ZX are single phases that can be used individually, no neutral, protective earth can be used here....
in a wye system, single phases are XN, YN and ZN, the neutral is common to all three phase arms......
the two systems are distinct with each other...
neutral is very close to 0 volts but is not always the case....
in a wye system, single phases are XN, YN and ZN, the neutral is common to all three phase arms......
the two systems are distinct with each other...
neutral is very close to 0 volts but is not always the case....
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