universal uninterruptible power supply



** The above question simply does not make any sense.
Reversal of the active and neutral conductors is of no consequence in the vast majority of AC powered devices.
The range of AC input voltage and frequency you mention is within the capability of most UPS on the market.
Now, what is you actual question ??
..... Phil
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| |> What would it take in the design of a UPS to make it work correctly and |> safely |> under conditions where the incoming power could have either wire grounded |> or |> neither wire grounded (but there will always be a separate equipment |> grounding |> conductor), and will operate over the nominal voltage range of 200 to 240 |> with |> either 50 or 60 Hz input? | | | ** The above question simply does not make any sense. | | Reversal of the active and neutral conductors is of no consequence in the | vast majority of AC powered devices.
What about "grounded center", where 2 inverters working in sync in the range of 100-120 volts are wired in series, and the grounding connection can be switched between the center and one end?
| The range of AC input voltage and frequency you mention is within the | capability of most UPS on the market.
But what about the ability to safely operate in all electrical systems in the world (at the 200-240 volt configuration in countries like USA and Japan that operate on 100-120 volts L-N with 2 opposiing phase lines which may be 180 degrees apart, or may be 120 degrees apart).
| Now, what is you actual question ??
Same as before: "What would it take ...". I'll refine and specify that the cost, engineering complexity, and safety, would be the focus of that question (which is generally what engineering addresses).
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< snipped-for-privacy@ipal.net Phil Allison |

** A centre grounded ( ie split 120v -0- 120v ) supply poses no problems either.
Sometimes called a "balanced supply" and sold openly to the public.
You are completely clueless.

** Totally NEW question.
(at the 200-240 volt configuration in countries like USA and Japan

** A centre grounded ( ie split 120v -0- 120v ) supply poses no problems either.
You are completely clueless.

** Then yours is STILL an utterly silly question.
For Christ's sake - TELL US what YOU think the safety problem is ??
...... Phil
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| | < snipped-for-privacy@ipal.net | Phil Allison | | |> | |> |> What would it take in the design of a UPS to make it work correctly and |> |> safely |> |> under conditions where the incoming power could have either wire |> grounded |> |> or |> |> neither wire grounded (but there will always be a separate equipment |> |> grounding |> |> conductor), and will operate over the nominal voltage range of 200 to |> 240 |> |> with |> |> either 50 or 60 Hz input? |> | |> | |> | ** The above question simply does not make any sense. |> | |> | Reversal of the active and neutral conductors is of no consequence in |> the |> | vast majority of AC powered devices. |> |> What about "grounded center", where 2 inverters working in sync in the |> range of 100-120 volts are wired in series, | | | ** A centre grounded ( ie split 120v -0- 120v ) supply poses no problems | either. | | Sometimes called a "balanced supply" and sold openly to the public. | | You are completely clueless.
Before I put a the label on you that many other people already have, I will ask you to be specific. Let's see if you really understand this and can actually read what has been posted ... by stating exactly what you think I an clueless about. If you can't state this correctly, then what you are doing is just making personal attacks (which most people will interpret as someone who can't defend what they say in a technical way).
|> | The range of AC input voltage and frequency you mention is within the |> | capability of most UPS on the market. |> |> But what about the ability to safely operate in all electrical systems in |> the world | | ** Totally NEW question.
How is this a new question? You can't see the relation, and thus a basic expansion of, the original question?
| (at the 200-240 volt configuration in countries like USA and Japan |> that operate on 100-120 volts L-N with 2 opposiing phase lines which may |> be |> 180 degrees apart, or may be 120 degrees apart). | | | ** A centre grounded ( ie split 120v -0- 120v ) supply poses no problems | either. | | You are completely clueless.
Before I put a the label on you that many other people already have, I will ask you to be specific. Let's see if you really understand this and can actually read what has been posted ... by stating exactly what you think I an clueless about. If you can't state this correctly, then what you are doing is just making personal attacks (which most people will interpret as someone who can't defend what they say in a technical way).
|> | Now, what is you actual question ?? |> |> Same as before: "What would it take ...". | | | ** Then yours is STILL an utterly silly question. | | For Christ's sake - TELL US what YOU think the safety problem is ??
The safety problems would depend on the specific design. If relays that can, under conditions of failure (e.g. one of them might not make the switch for reasons that might include an open coil) result in an unsafe condition (such as exposing operators to dangerous voltage, or create a fault condition), then it could be (should be) considered unsafe by listing agencies. That can be mitigated by making the design use "double throw" relays that just cannot be in both states at once (though could be in an in between state).
One design idea was to have 2 inverter sections in series, with each of the 3 connections having a relay that could connect that section to ground. But this exposes at least two risks. One is relay operation failure could leave the system ungrounded. Or if latching relays are involved, two could be closed at once (due to an open operation failure) and a fault is created. One way to mitigate that problem is for the control logic to always complete the switching, AND test the continuity state, before activating inverter operations. If supply power is lost, it could come back with different grounding (for example, with Schuko, the plug can be inverted). Now for the grounding of the derived system to be corrected to match, power output has to be briefly shut off (even if for maybe only a cycle or two).
I've thought through quite a number of different design arrangements. Each one has some issue somewhere. Many are issues that safety listing agencies might have big concerns about.
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** Yawnnnnnnn - more absurd gobbledegook.............

** You clearly have no clue of the difference between supply neutral and safety ground.
Go away - IMBECILE.
...... Phil
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| |> | ** Then yours is STILL an utterly silly question. |> | |> | For Christ's sake - TELL US what YOU think the safety problem is |> ?? |> |> |> The safety problems would depend on the specific design. If relays that |> can, |> under conditions of failure (e.g. one of them might not make the switch |> for |> reasons that might include an open coil) result in an unsafe condition |> (such |> as exposing operators to dangerous voltage, or create a fault condition), |> then |> it could be (should be) considered unsafe by listing agencies. That can |> be |> mitigated by making the design use "double throw" relays that just cannot |> be |> in both states at once (though could be in an in between state). | | | ** Yawnnnnnnn - more absurd gobbledegook.............
So, basically, you really were doing nothing but making personal attacks.
|> One design idea was to have 2 inverter sections in series, with each of |> the |> 3 connections having a relay that could connect that section to ground. | | | ** You clearly have no clue of the difference between supply neutral and | safety ground.
I sure do. But do you? Given your failure to explain yourself, it is now clear that you do not believe your own knowledge to be defensible.
| Go away - IMBECILE.
Not a chance.
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** Yaaaaawnnnnnnn - more ABSURD gobbledegook......

** You clearly have no clue of the difference between supply neutral and safety ground.
Go away - IMBECILE.

** No you do not.
Cos you keep referring to neutral as "ground".
AC supply conductors are NOT and CANNOT be linked to "ground" inside any appliance.
FUCKWIT !!
..... Phil
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| |
| |> ** Then yours is STILL an utterly silly question. |> |> For Christ's sake - TELL US what YOU think the safety problem is |> ?? |> |> |> The safety problems would depend on the specific design. If relays that |> can, |> under conditions of failure (e.g. one of them might not make the switch |> for |> reasons that might include an open coil) result in an unsafe condition |> (such |> as exposing operators to dangerous voltage, or create a fault condition), |> then |> it could be (should be) considered unsafe by listing agencies. That can |> be |> mitigated by making the design use "double throw" relays that just cannot |> be |> in both states at once (though could be in an in between state). | | | ** Yaaaaawnnnnnnn - more ABSURD gobbledegook......
| | |> One design idea was to have 2 inverter sections in series, with each of |> the |> 3 connections having a relay that could connect that section to ground. | | | ** You clearly have no clue of the difference between supply neutral and | safety ground. | | Go away - IMBECILE.
Normally I don't call people names. But in this case, you are earning it.
|> I sure do. | | | ** No you do not. | | Cos you keep referring to neutral as "ground".
Get your clue now;
Not all electrical systems have a neutral by its exact definition. A neutral conductor carries the imbalance current from 2 or more current carrying conductors. In a 2 wire system, there is no actual neutral since there is no imbalance. Where a 2 wire branch circuit is connected to a multi-wire system, one of the wires is usually (but not always) connected to that system's neutral. That wire often gets referred to as the neutral. The referral is conventional and the meaning is understood but by the definition it is not correct. The correct term is "groundED conductor".
There is a separate groundING conductor. In the case of a separately derived system, a groundED conductor (whether it is a neutral or not) is derived by bonding it to the groundING conductor.
A UPS with a bypass poses an interesting challenge. When it switched to bypass mode, it cannot be a separately derived system. The groundED conductor is pass through as a groundED conductor. The groundING conductor is not to be connected to any current carrying conductor in this case.
When the UPS is NOT switched to bypass mode, there are two ways it can be operating. One way is as a separately derived system. This is like an isolation transformer. The groundING conductor is connected to the conductor intended to be grounded, or in the case of an American style 240V circuit, the groundING conductor is connected to the point between two 120V isolated sources, whether or not that point is carried out as a neutral conductor, or not. For single ended 240V systems like that used in Australia, the groundING conductor is connected to the proper output conductor. For reversable single ended 240V systems like that used in Germany, the groundING conductor is connected to whichever output conductor is serving as the groundED conductor (which MAY be changed as a result of reversing the groundED relationship of the source supply).
The UPS could also be operated in a mode like an autotransformer. This mode would require (at least by American safety standards) the groundED conductor be supplied and passed through, and all other conductors be related to it.
The UPS could also be operated floating.
Whether the latter two operating modes are legal, or could practically be made legal, under various safety codes, is a big issue. I believe in limited cases this can be done under American electrical codes. But such setups would be more complex and probably preclude universal use on non-American systems.
| AC supply conductors are NOT and CANNOT be linked to "ground" inside any | appliance.
Read above.
I suggest you do some googling for "seperately derived system" and also for "autotransformer" (or "auto transformer" or "auto-transformer" as the term is often spelled that way in many places). Then do some learning on how the groundING and groundED conductors can be used. Pay particular attention to how the groundING and groundED conductors must be kept separate from each other.
| FUCKWIT !!
Then you need to find the nearest mental health services clinic and make an appointment to seek some care for your attitude and anti-social problems.
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On 7 Feb 2009 05:40:18 GMT, snipped-for-privacy@ipal.net wrote:

How in hell can "2 opposing phase lines"..."be 120 degrees apart"?

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| On 7 Feb 2009 05:40:18 GMT, snipped-for-privacy@ipal.net wrote: |
|>|
|>| |>|> What would it take in the design of a UPS to make it work correctly and |>|> safely |>|> under conditions where the incoming power could have either wire grounded |>|> or |>|> neither wire grounded (but there will always be a separate equipment |>|> grounding |>|> conductor), and will operate over the nominal voltage range of 200 to 240 |>|> with |>|> either 50 or 60 Hz input? |>| |>| |>| ** The above question simply does not make any sense. |>| |>| Reversal of the active and neutral conductors is of no consequence in the |>| vast majority of AC powered devices. |> |>What about "grounded center", where 2 inverters working in sync in the |>range of 100-120 volts are wired in series, and the grounding connection |>can be switched between the center and one end? |> |> |>| The range of AC input voltage and frequency you mention is within the |>| capability of most UPS on the market. |> |>But what about the ability to safely operate in all electrical systems in |>the world (at the 200-240 volt configuration in countries like USA and Japan |>that operate on 100-120 volts L-N with 2 opposiing phase lines which may be |>180 degrees apart, or may be 120 degrees apart). | | How in hell can "2 opposing phase lines"..."be 120 degrees apart"?
Source supply is 2 phases taken from a 3 phase system, such as 208Y/120 as found in USA and Canada, or 220Y/127 as found in Mexico. In Mexico, it is more common to have 120 degree phasing than to have 180 degree phasing.
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snipped-for-privacy@ipal.net says...>

The "2 opposing phase line" still have a 180 degree relationship to each other, moron. Two lines *CANNOT* be 120 degrees from each other. <sheesh>
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|> Source supply is 2 phases taken from a 3 phase system, such as 208Y/120 as |> found in USA and Canada, or 220Y/127 as found in Mexico. In Mexico, it is |> more common to have 120 degree phasing than to have 180 degree phasing. | | The "2 opposing phase line" still have a 180 degree relationship to | each other, moron. Two lines *CANNOT* be 120 degrees from each | other. <sheesh>
So you really have THAT narrow of an electrical power engineering experience level? Sheesh. I guess I will have to dismiss *EVERYTHING* you post as from someone who simply does not have much experience in power systems. Maybe you don't even have any.
I actually have worked with equipment connected to lines that actually are 120 degrees apart from each other. Theese were 120 volts relative to ground and had a voltage difference of 208 volts between each other. The NEC even has specific rules for this kind of system (so there are a LOT of other electrical engineers and electricians that have plenty of experience with these kinds of systems). For example NEC 310.15(B)(4)(b) which says that this kind of system requires including the neutral conductor in conductor counts for derating purposes, since it will carry current even when both of the 120 degrees-apart current carrying conductors have equal resistive loads at PF 1.
I would suggest you stay away from these kinds of systems. But if you deny they even exist, then I'll have to suggest you stay away from all power systems since your ability to recognize what you are dealing with is in major doubt. You wouldn't know you are dealing with a 120 degree system if you believe it cannot exist. And that makes you a danger around electrical power wiring of those kinds of systems.
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Phil Howard KA9WGN is a RABID NUTTER

** More INSANE SHITE !!!!

** Still that does not make them " opposing phase "
The criticism was about CORRECT TERMINOLOGY
YOU FUCKWIT DAMN
RADIO HAM
MORON !!!!!!!!
...... Phil
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** FUCK OFF
YOU ASININE RADIO HAM IMBECILE !!!
..... Phil
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krw wrote:

Phil is quite correct. You are wrong. Phil is clearly referring to a 3 wire system which can have voltages measured with respect to the neutral' Then the two "hots" can be 180 degrees apart (120/240), or 120 degrees apart (120/208 or277/480 or...) as in practical systems or whatever relationship that one can use (i.e. 2 legs of any n (n>1) phase star system.
In the case of a two conductor line, "phase" is meaningless as you have only one voltage which is always in phase with itself (not 180 degrees apart)- regardless of the assumed polarity (it is meaningful for voltage and current). Phase implies a relationship between two quantities.
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wrote:

No, I am not.

That may be what he's referring to but that is *NOT* what he said. It takes three points to define a plane. A 120 degree angle don't fit on a line.

It takes three points define a plane.
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krw wrote:

a) If you had read the thread in context, the reference to neutral is there.
b)In the case of two "lines"(as referred to electrically-i.e. conductors), - there is only a single voltage between them- You can assume a polarity of one "line" with respect to the other but you cannot define a phase of the voltage with respect to itself.
c)This has nothing to do with planes and "lines" in the geometrical sense.
d)Admittedly the wording could be changed to eliminate the word "line" but the usage is common and the meaning is clear.
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