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I have a voltage converter from 220V to 110V. The line-neutral output voltage is as expected, but neutral-earth is 220V.
Would this be considered "valid" in any context? What are the implications for grounded devices?
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You have neutral and hot reversed at the input.
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What are the implications to devices?
And BTW, can this happen with isolated transformers?
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It can present a risk as some switches only isolate live side. For example many light switches.
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What are the implications to devices?
And BTW, can this happen with isolated transformers?
To hell with devices------it can zap you!
It looks like what you have is an auto-transformer.
If you swap Neutral & Active on them,you will get just the situation you report.
An isolated transformer,or more correctly "isolating transformer" has a secondary winding which is electrically isolated from the primary,so that neither side of the secondary winding is connected to Active,Neutral,or Earth.
An auto-transformer,on the other hand,is just one winding ,connected between Active & Neutral of the higher voltage (in your case,220v) source.
To get 110v ,the winding is tapped (in this case,a centre tap),& the 110v device being powered is meant to be connected between the Neutral end of the winding & the tap.
If your Neutral & Active are inverted at the transformer input,they stay inverted at the output. -
Please define precisely what you mean by "voltage converter"?
There are several very different things that could bear that label (assuming it is even correct).
"neutral-earth is 220V" is a DISASTER OF THE HIGHEST MAGNITUDE!
Forget about connecting ANYTHING to this abortion until it is fixed!
It is impossible to overstate how terrible this is!
It is NOT VALID in ANY context! -
vk6zgo: Never mind me, I can take it.
I just wonder what are some possible side effects to grounded devices that are connected, during normal and fault conditions.
I mistakenly assumed this was an isolation transformer because it's a laminated core type, but it does indeed seem to be an autotransformer. But can't you get similar results from an isolation transformer, line/neutral at 110V/220V above earth, depending on what output taps you use?
Richard: It's just a laminated transformer in a box, with a switch and a fuse. It was a bit surprising to see non-0V there because it's constructed cleanly enough.
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I agree with vk6zgo that it sounds like you have an autotransformer and not a proper isolated full transformer.
You guys in 220V-land apparently have the notion that both sides are "hot" so you have no idea which side is 0V.
Which is fine as long as you are using equipment designed to handle that safely. Including a proper isolated transformer.
But when you try to use 110V equipment with proper 3-pin mains plugs, neutral is expected to be essentially zero.
Using a conversion solution that delivers "neutral" at 220V is quite possibly LETHAL. I would either fix it or toss it.
Your very life is at risk here, IMHO. This is not something to be trifled with. -
Neutral is supposed to be at 0V here as well. Or what do you mean by both sides hot?
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There was a previous discussion here where it was revealed that in Nordic countries (at least, if not elsewhere), they treat BOTH sides as "hot", and only the green-wire safety ground can be relied on to be zero volts. If you have only good, modern, double-insulated appliances then it is probably safe. But when you start fooling around converting to 110V and using legacy 110V loads, you can easily have a deadly combination.
Since you have not revealed WHERE you are on the planet, we have no clue what "here" means. -
That's odd, assuming by default non-0V at both sides. Do you remember what thread it was?
What do you mean by legacy loads?
Well, here in the general sense of non-110V. Or so I thought.
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A lot of countries in the EU have mainsplugs that are symmetrical. Meaning that you can plug them in a socket both ways, result is that both leads can be phase or hot (220V) or neutral (0V) relative to ground earth.
So if you use an autotransformer you have to be aware of this. -
vk6zgo: Never mind me, I can take it.
I just wonder what are some possible side effects to grounded devices that are connected, during normal and fault conditions.
I mistakenly assumed this was an isolation transformer because it's a laminated core type, but it does indeed seem to be an autotransformer. But can't you get similar results from an isolation transformer, line/neutral at 110V/220V above earth, depending on what output taps you use?
Richard: It's just a laminated transformer in a box, with a switch and a fuse. It was a bit surprising to see non-0V there because it's constructed cleanly enough.
110V devices usually treat both sides of the Mains as if they were 110V w.r.t Earth,just in case the wall socket is incorrectly wired with Live (hot) & Neutral transposed.
If the "Neutral" connection is 220V w.r.t Earth,the insulation between it & Earth may be insufficient.
In countries where there is no convention as to which pin on the Mains socket is the Neutral one,this is always a possibility with an auto-transformer.
With an isolation ( two winding) transformer,the only connection between the primary & secondary is the varying magnetic field.
The only voltage available on the secondary of a 220V to 110V isolation transformer is 110V between the two ends of the secondary winding. -
I would be tempted to open the case then cut any wires joining primary to secondary. If this is impossible (everything wound in one go) then the common connection between input and output MUST be connected to neutral.
I wonder why plugging this in did not trip your circuit breaker? -
Postscript:
This is something that the French and British have done correctly, their plugs can only be inserted into the socket one way.
C'est la vie -
The 2 prong Europlug can be plugged in both ways, but the outlet itself still has an official line/neutral sidedness.
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There was a previous discussion here where it was revealed that in Nordic countries (at least, if not elsewhere), they treat BOTH sides as "hot", and only the green-wire safety ground can be relied on to be zero volts.
All sane standards operate this way. The difference is that certain countries have centre-tapped earth, not a neutral conductor.
Green, FYI, is no longer the colour of ground in the majority of countries.I wonder why plugging this in did not trip your circuit breaker?
I'm not entirely sure you understand how a circuit breaker operates. -
I'm not entirely sure you understand how a circuit breaker operates.
It should trip if its a GFCI, should it not? -
I'm not entirely sure you understand how a circuit breaker operates.
It should trip if its a GFCI, should it not?
Why would it? -
The 2 prong Europlug can be plugged in both ways, but the outlet itself still has an official line/neutral sidedness.
AFAIK this is NOT defined in my country. The rule of thumb is to use the left connector (looking from the outside) as hot since most people are right handed they would choose to insert a nail for instance in the right hole (children) but this is nowhere defined AFAIK. -
Interesting. What do you see in practice in the outlets in your house?
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In practice you see who connected the outlet
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The 2 prong Europlug can be plugged in both ways, but the outlet itself still has an official line/neutral sidedness.
I haven't heard of that, but even if true the plugs are symmetric so it wouldn't matter for device you plug in. I think this would only be relevant in a country like France where the outlet accepts both europlug and a polarized grounded outlet. I am pretty sure that in at least the Netherlands, whatever convention may exist is not followed reliably.
These days the only thing polarization really matters for is Edison light sockets where the neutral conductor is exposed. Most other devices are required to be isolated and/or grounded, so there should be no more danger of coming into contact with neutral than hot. They do at least keep live and neutral identified for fixed wiring, so at least permanently wired lighting fixtures should be connected with the correct polarity. -
These days the only thing polarization really matters for is Edison light sockets where the neutral conductor is exposed. Most other devices are required to be isolated and/or grounded, so there should be no more danger of coming into contact with neutral than hot. They do at least keep live and neutral identified for fixed wiring, so at least permanently wired lighting fixtures should be connected with the correct polarity.
Yes, exactly so. But if you are in 230-volt land and messing around with 110V auto-transformers and undisclosed loads of indeterminate safety, this could be a lethal problem. -
I'm not entirely sure you understand how a circuit breaker operates.
It should trip if its a GFCI, should it not?
Why would it?
Whoops, I thought the ground and neutral were reversed, not the hot and neutral.