>In alt.engineering.electrical Tzortzakakis Dimitrios wrote:

>| A shame that Tesla won the infamous "battle" and we don't have DC:-() But
>| then, we would be having a power plant at each neighborhood, instead of the
>| 300 MW ones.

>And the latter make easy terrorism targets, too.

> In alt.engineering.electrical Tzortzakakis Dimitrios wrote:
>
> | A shame that Tesla won the infamous "battle" and we don't have DC:-() But
> | then, we would be having a power plant at each neighborhood, instead of the
> | 300 MW ones.
>
> And the latter make easy terrorism targets, too.
>
>
> | I know, I know, my answer was a bit provocative:-) And of course there are
> | DC regulators.... You're talking about DC generators;the one a 300 MW uses
> | for excitation is 220 V, 1000 A DC and probably shunt field. I have seen
> | here in some machine shops the old type welding generator, which is a 3
> | phase induction motor coupled to (usually) a compound field DC generator,
> | which provides the welding current. The modern ones are, maybe, not larger
> | than a shoe box and powered by a higher wattage 230 V 16 A receptacle.
> | (Usual receptacles are 230 V 10 A;16 A for washing machines, dryers and the
> | like).
> ...

>In alt.engineering.electrical Michael Moroney world.std.spaamtrap.com> wrote:

>| Are the load tap generators configured make-before-break?
>| Break-before-make would mean a (very short) power outage every activation
>| but make-before-break would mean a momentarily short-circuited winding and
>| the break would involve interrupting a large short circuit current.

>I wonder how much regulation could be managed through the use of variable
>leakage inductance in the transformer windings.

>| Certainly modern ones likely use thyristors and zero crossing detectors.

>With zero crossing detection, then the switching is not happening on all phases
>at the same time.

> "daestrom" NO_SPAM_HEREtwcny.rr.com> writes:
>
>

>>P.S. In the US, a 'tap-changer' may be built for either for unloaded or
>>loaded operation. The 'unloaded' type can not be stepped to another tap
>>while there is load on the unit (although it can still be energized).
>>It's
>>switch contacts cannot interrupt load though, so if you try to move it
>>while
>>loaded, you can burn up the tap-changer. The classic 'load-tap-changer'
>>is
>>actually several switches that are controlled in a precise sequence to
>>shift
>>the load from one tap of the transformer to another while not interrupting
>>the load current.

>

>>P.P.S. Load tap changers typically have a significant time-delay built
>>into ...

> In alt.engineering.electrical Michael Moroney
> world.std.spaamtrap.com> wrote:
>
> | Are the load tap generators configured make-before-break?
> | Break-before-make would mean a (very short) power outage every
> activation
> | but make-before-break would mean a momentarily short-circuited winding
> and
> | the break would involve interrupting a large short circuit current.
>
> I wonder how much regulation could be managed through the use of variable
> leakage inductance in the transformer windings.
>

>
> ? "daestrom" NO_SPAM_HEREtwcny.rr.com> ?????? ??? ??????
> news:482725ae$0$30509$4c368faf@roadrunner.com...

>> P.S. In the US, a 'tap-changer' may be built for either for unloaded or
>> loaded operation. The 'unloaded' type can not be stepped to another tap
>> while there is load on the unit (although it can still be energized).
>> It's switch contacts cannot interrupt load though, so if you try to move
>> it while loaded, you can burn up the tap-changer. The classic
>> 'load-tap-changer' is actually several switches that are controlled in a
>> precise sequence to shift the load from one tap of the transformer to
>> another while not interrupting the load current.
>>
>> P.P.S. Load tap changers typically have a significant time-delay built
>> into the controls so they do not 'hunt' or respond to short drops in
>> voltage such as starting a large load. 15 seconds to several minutes is
>> typical. So even with load-tap-changers, starting a single load that is
>> a high percentage of the system capacity will *still* result in a voltage ...

>
> You don't use 400 V for anything heavy duty like an oven?

> I'm a little confused about a 230 volt circuit. In what part of the
> world does the utility supply 230v?