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Re: [TCML] Giant Variac For Sale



So, everything seems to be fine! The yellow transformers are ballancing chokes. I first suspected a completely different mode of operation in a way more complex way (as my unit was built like I was talking about), but indeed the 2 x 3 variac stack in this staco system seems to be made for 75kVA.

----- Original Message ----- From: "Chris Boden" <cboden@xxxxxxxxxxxxxxxx> To: "Thomas Shurtz" <whompin105@xxxxxxxxx>; "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
Sent: Thursday, March 31, 2016 3:24 AM
Subject: Re: [TCML] Giant Variac For Sale


Video! Data! Peer Review!
https://youtu.be/XrOZ-jKXr8o

On Wed, Mar 30, 2016 at 1:18 PM, Chris Boden <cboden@xxxxxxxxxxxxxxxx>
wrote:

I think you're the closest to correct in this, and I'm genuinely curious
to figure out just what we've got going on here. This is bugging me. I'm
going to get up-close detailed video of the unit and put it in the
Captain's Blog so that we can all peer review it and figure out just what
this has going on. I figured out what my fundamental error was though.
These are a 208-3ph setup so the variacs are at 120VAC or so. I was
comparing them to the 9 stack triple-triple we have and those are 480VAC.
Of course the kVA was off, the voltage makes a huge difference, and I'm an
idiot.

So, video, data, let's work it through and figure out exactly what we've
got here so that we can put a FAIR price on it. Because as it sits, I think
I'm overcharging.

Of course if you're working with 120VAC Variacs and thinking with a 480VAC
mentality....overcharging is going to be the first problem you have.



On Wed, Mar 30, 2016 at 12:25 PM, Thomas Shurtz via Tesla <
tesla@xxxxxxxxxx> wrote:

It has been interesting to watch this little exchange on the list.  I'm
not going to assume that Chris is trying to mislead anyone, but the point here is that he is advertising a 6-gang variac that comes with some other
goodies that one may or may not be interested in ("who cares?" was the
wording used). If it's a variac stack you are trying to sell, then it's
probably prudent to include the specs for the variac rather than the specs
of the "who cares" unit which it's a component of.  We might be able to
make some assumptions about the variac specs- Staco 5011 series auto
transformers come with a 50 amp fuse they are for 120v input and rated at
7kVA each. The variac stack isn't fused at 50 Amps, so teslalabor's
analysis isn't quite right, but neither is the 75kVA claim made by Chris.
If you can provide some physical measurements of the autotransformers or
check the top of the stack for a nameplate and provide that info, you might
get more success selling this as a variac stack stuck inside of a "who
cares" voltage regulator. BTW - Staco has a part number for the variable transformer listed in the user manual for the voltage regulator (033-7581) but this number doesn't match the part number (031-6954) on the drawing for the 6stack wye configured set of 5011's that I looked at, so that may mean it isn't really made up of 5011's or it could be that it's configured a bit differently for this application and given a unique part number. Best of
luck with the sale.
Thomas
      From: Teslalabor <teslalabor@xxxxxxxxxxx>
 To: Tesla Coil Mailing List <tesla@xxxxxxxxxx>
 Sent: Wednesday, March 30, 2016 10:04 AM
 Subject: Re: [TCML] Giant Variac For Sale

75kVA says the makerplate of what? I only can see a photo of the
makerplate
of the whole unit, which says it is 75kVA.

Makerplate says 75kVA, 208Volts @ 208Amps, so: 208 Volts * 208/sqrt(3)
Amps
* 3 = 75kVA

The variac is fused with 50Amps, you say. That is a maximum power of 18kVA
for the variacs, what makes completely sense to me (maybe even only 9kVA
for
each of the 2 stacks). They are only for controlling the main transformer, and that beast is rated at 75kVA not the little variacs, thats the thing I
am trying to explain to you.



----- Original Message -----
From: "Chris Boden" <cboden@xxxxxxxxxxxxxxxx>
To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
Sent: Wednesday, March 30, 2016 1:50 AM
Subject: Re: [TCML] Giant Variac For Sale


> Each coil of this variac is fused at 50A, what was yours at? The
> makerplate
> says 75kVA, and it's Staco....I believe them.
>
> On Tue, Mar 29, 2016 at 1:08 PM, Teslalabor <teslalabor@xxxxxxxxxxx>
> wrote:
>
>> :-)))) Very funny. Yes, the small potentiometer knob is used to
fine-tune
>> the regulation range, with this you only can change the output >> voltage
in
>> a
>> range of lets say 200-216 Volts.
>> I know this because I bought exactly such an unit like yours some >> years >> ago for a big pile of money. I also thought "wow, very cool >> variac..."
>> The end of the story was, that there was only a very small (3-phase)
>> variac with some kVA's inside, which (when I remember corectly)
>> controlled
>> in combination with another (small) 3 phase transformer the VERY big
>> 3-phase load-transformer inside the housing. BTW, please don't ask >> me,
>> how
>> this works...
>> I could be wrong but I'm pretty sure that your unit works in the same
>> way... At least you should take this into consideration instead of >> only
>> rely on size-comparisons with another variacs.
>>
>> ----- Original Message ----- From: "Chris Boden"
>> <cboden@xxxxxxxxxxxxxxxx>
>> To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
>> Sent: Tuesday, March 29, 2016 6:06 PM
>>
>> Subject: Re: [TCML] Giant Variac For Sale
>>
>>
>> The output is adjustable (it's the little knob under the meter) and
has a
>>> considerable range. I don't know it's full range as I haven't tested
>>> this
>>> unit. We got them for the stacks, and then leapfrogged past them in
our
>>> upgrade cycle in building the new lab. That's why we're selling >>> these.
>>>
>>> The variac, pulled from the cabinet, will actually handle a 75kVA >>> load >>> just fine. I know this because it's a slightly smaller version of >>> the
>>> one
>>> I
>>> use every day in our High Voltage lab as our main power supply. >>> There
>>> are
>>> dozens, if not hundreds of videos of my demonstrating it's use in
front
>>> of
>>> thousands of people. You yourself are welcome to come here and >>> measure
>>> the
>>> output capacity and compare it yourself. Of course I suggest you
bring a
>>> NIST traceable, calibrated measurement set. If you wish to do this, >>> I
>>> would
>>> be happy to provide a complete camera crew and live audience to
publish
>>> your results if you have any doubt as to the veracity of my claims.
>>>
>>> It's only a voltage regulator if you keep it intact and use it as
such.
>>> Anyone interested on here would likely autopsy it for its component
>>> pieces.
>>> The transformer inside, aside from being "damn big" I know nothing
>>> about.
>>> Though it would make one hell of a boat anchor or a great core for a
>>> reactive ballast.
>>>
>>>
>>> On Tue, Mar 29, 2016 at 11:25 AM, Teslalabor >>> <teslalabor@xxxxxxxxxxx>
>>> wrote:
>>>
>>> Okay! I was little bit confused because of the additional "large
>>>> transformer" you mentioned. What I was talking about, are units
similar
>>>> to
>>>> yours, used for automatic "voltage stabilisation". They >>>> automatically
>>>> adjust line voltage within a range of +/- some percent. These units
>>>> consist
>>>> of small variacs + big transformer, which takes the load.
>>>> But anyway, you should check the namplate carefully. It says INPUT >>>> is
>>>> 166-229 Volts and OUTPUT is fixed at 208 / 120 Volts.
>>>> So this means, this unit can NOT regulate Voltage between 0 - 208
>>>> Volts!
>>>> Is stabilizes the Output Voltage @ 208 Volts, whereas Input voltage
can
>>>> be
>>>> anything between 166-229 Volts.
>>>> So this is not a 75kVA Variac Mr. Boden...
>>>>
>>>> ----- Original Message ----- From: "Chris Boden" <
>>>> cboden@xxxxxxxxxxxxxxxx>
>>>> To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
>>>> Sent: Tuesday, March 29, 2016 4:39 PM
>>>> Subject: Re: [TCML] Giant Variac For Sale
>>>>
>>>>
>>>>
>>>> If you check the pics, this is not a small variac. ;) It's a >>>> 6-stack
>>>>
>>>>> (triple-double) of the standard big toroids with balancing chokes.
>>>>> It's
>>>>> one
>>>>> size smaller than our 100kVA variac and will certainly handle the
>>>>> load.
>>>>> Check the pics, the stack fills up half of that cabinet.
>>>>>
>>>>> On Tue, Mar 29, 2016 at 3:45 AM, Teslalabor >>>>> <teslalabor@xxxxxxxxxxx
>
>>>>> wrote:
>>>>>
>>>>> Nice! I also had such an big automatic voltage regulator some time
>>>>> ago.
>>>>>
>>>>>> "Problem" is: I don't remember how it works but the variac itself
>>>>>> (which
>>>>>> would be interesting for TC use) is only a relatively small one,
>>>>>> maybe
>>>>>> 10kVA or less. The main power (75kVA in your case) comes from the
big
>>>>>> standard 3-phase transformer, which is controlled via the small
>>>>>> variac
>>>>>> +
>>>>>> controll transformer.
>>>>>> Maybe you should add an info to your auction, that this is NOT a
>>>>>> 75kVA
>>>>>> variac, this could lead to some confusion and you could get some
>>>>>> trouble
>>>>>> otherwise :-)
>>>>>>
>>>>>>
>>>>>> ----- Original Message ----- From: "Chris Boden" <
>>>>>> cboden@xxxxxxxxxxxxxxxx>
>>>>>> To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
>>>>>> Sent: Tuesday, March 29, 2016 1:21 AM
>>>>>> Subject: [TCML] Giant Variac For Sale
>>>>>>
>>>>>>
>>>>>> If anyone is interested in a massive 6-stack variac, we have one
for
>>>>>> sale.
>>>>>>
>>>>>> http://www.ebay.com/itm/222067908245
>>>>>>> This happens to also include a solid cabinet with a large
>>>>>>> transformer
>>>>>>> and
>>>>>>> some control circuitry. The unit actually works, but who cares,
it's
>>>>>>> a
>>>>>>> giant 6-stack variac :)
>>>>>>>
>>>>>>> And a matching massive switch as well
>>>>>>> http://www.ebay.com/itm/-/322055321777
>>>>>>> --
>>>>>>>
>>>>>>> Chris Boden
>>>>>>> President
>>>>>>> The Geek Group National Science Center
>>>>>>> www.thegeekgroup.org
>>>>>>> We Build Awesome
>>>>>>>
>>>>>>> --
>>>>>>>
>>>>>>>
>>>>>>> This email may contain confidential and privileged material for
the
>>>>>>> sole
>>>>>>> use of the intended recipient. Any review or distribution by
others
>>>>>>> is
>>>>>>> strictly prohibited. If you are not the intended recipient >>>>>>> please
>>>>>>> contact
>>>>>>> the sender and delete all copies.
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> Tesla mailing list
>>>>>>> Tesla@xxxxxxxxxx
>>>>>>> http://www.pupman.com/mailman/listinfo/tesla
>>>>>>>
>>>>>>>
>>>>>>> _______________________________________________
>>>>>> Tesla mailing list
>>>>>> Tesla@xxxxxxxxxx
>>>>>> http://www.pupman.com/mailman/listinfo/tesla
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>> --
>>>>>
>>>>> Chris Boden
>>>>> President
>>>>> The Geek Group National Science Center
>>>>> www.thegeekgroup.org
>>>>> We Build Awesome
>>>>>
>>>>> --
>>>>>
>>>>>
>>>>> This email may contain confidential and privileged material for >>>>> the
>>>>> sole
>>>>> use of the intended recipient. Any review or distribution by >>>>> others
is
>>>>> strictly prohibited. If you are not the intended recipient please
>>>>> contact
>>>>> the sender and delete all copies.
>>>>>
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>>>>> Tesla mailing list
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>>>>> http://www.pupman.com/mailman/listinfo/tesla
>>>>>
>>>>>
>>>> _______________________________________________
>>>> Tesla mailing list
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>>>>
>>>>
>>>
>>>
>>> --
>>>
>>> Chris Boden
>>> President
>>> The Geek Group National Science Center
>>> www.thegeekgroup.org
>>> We Build Awesome
>>>
>>> --
>>>
>>>
>>> This email may contain confidential and privileged material for the
sole
>>> use of the intended recipient. Any review or distribution by others >>> is
>>> strictly prohibited. If you are not the intended recipient please
>>> contact
>>> the sender and delete all copies.
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>>
>> _______________________________________________
>> Tesla mailing list
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>> http://www.pupman.com/mailman/listinfo/tesla
>>
>
>
>
> --
>
> Chris Boden
> President
> The Geek Group National Science Center
> www.thegeekgroup.org
> We Build Awesome
>
> --
>
>
> This email may contain confidential and privileged material for the > sole
> use of the intended recipient. Any review or distribution by others is
> strictly prohibited. If you are not the intended recipient please
contact
> the sender and delete all copies.
>
> _______________________________________________
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--

Chris Boden
President
The Geek Group National Science Center
www.thegeekgroup.org
We Build Awesome




--

Chris Boden
President
The Geek Group National Science Center
www.thegeekgroup.org
We Build Awesome

--


This email may contain confidential and privileged material for the sole
use of the intended recipient. Any review or distribution by others is
strictly prohibited. If you are not the intended recipient please contact
the sender and delete all copies.

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