|> ** 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
|> under conditions of failure (e.g. one of them might not make the switch
|> reasons that might include an open coil) result in an unsafe condition
|> as exposing operators to dangerous voltage, or create a fault condition),
|> it could be (should be) considered unsafe by listing agencies. That can
|> mitigated by making the design use "double throw" relays that just cannot
|> 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
|> 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
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
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
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
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
| 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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