Hi Coiler,David and Stefan,
I´m at the TCML a long time ago,but mostly as a reading member.
you don´t need big variacs to control your pole pig.
There is a device called "phase shift controller"with thyristors.
I drive my 15kVA TC with this devices,here we have 400V/50Hz,but it works also at 240V/60Hz.
for 3 phase 95Amps the weight will be less than 15kg,the most weight is the heatsink for the Thyristormodules.!
It´s used two control galvanic bath,windmills,transformers and very large motors in ships and so on.
You can get thyristor-powerblocks over 500A.
You should take thyristors with a voltage rating 3-4times the supply voltage.
for example TT150N16 (150A/1600V).
but you need a current limiter also.I´ve tried an electronic current-regulator,but it´s not fast enough.
best regards
alex
-----Original-Nachricht-----
Betreff: Re: [TCML] 30kVA 3-Phase Variac
Datum: Wed, 10 Sep 2014 16:31:33 +0200
Von: "Teslalabor" <teslalabor@xxxxxxxxxxx>
An: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
Hi David,
it was "a little of nothing".
This variac was used in a theatre for dimming nearly hundred light bulbs.
Because the bulbs wasted a lot of (expensive) energy, the whole system was
replaced by LED systems, so the variac was not needed any more. So I took
the opportunity :-)
Yes, this variac is called a "columnar variac". Here in germany we have both
types, also the circular shaped units. I have another columnar variac, which
I will use in my current DC resonant project. This isn't even an
autotransformer, it has separated primary and secondary coils:
https://www.youtube.com/watch?v=5EKyaMFbCP4
And here is another circular shaped high power 3-phase variac in my variac
collection: It makes 0-440V @ 32Amps per phase (24kVA) and of course can
also be pushed far behind this powerlevel
https://www.youtube.com/watch?v=798JN1ZgHq4
Regards,
Stefan
----- Original Message -----
From: "David Rieben" <drieben@xxxxxxx>
To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
Sent: Tuesday, September 09, 2014 7:08 PM
Subject: Re: [TCML] 30kVA 3-Phase Variac
> Wow! Nice find. Did you have to come off a king's ransom to score this
> beauty or were your able to get it for "a little of nothing"?
> I see it's linear, as opposed to the more common circular shaped style (at
> least here in the US they are).
>
> David
>
>
> On Tuesday, September 9, 2014 6:31 AM, Teslalabor <teslalabor@xxxxxxxxxxx>
> wrote:
>
>
>
> Hi all,
>
> just wanted to show you my new 0-400V high-power variac, made a video of
> it.
> It's a motor driven 3-phase variac with a power rating of 30kVA. It has a
> nameplate rating of 45A per phase and can make twice the power for 2
> minutes
> (90Amps per phase, 60kVA).
> 2x2 Contactors per phase and so it even has balancing chokes between each
> pair of contactors on each phase. The contact-surface below them is silver
> coated, so it has a dark colour.
>
> Video: https://www.youtube.com/watch?v=U5No4VBoM9A
>
> Regards,
> Stefan
>
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