Re: [TCML] Re: Tar

[DC Cox <resonance@xxxxxxxxxxxx>]

Run 1 kVA into the core with the two HV leads shorted to ground.  Then, very
slowly admit the oil with a syphon setup while increasing the input power to
2 kVA.  Use a small dia tube so the filling process takes 3-4 hours.  The
hot core, with slow filling, will slowly drive out the bubbles.

Let the filled tank set for 2-3 days.  Unshort the HV sec leads, and then
very slowly put input into the xmfr core using a series reactor to limit any
high currents (a slow trip 5 A. circuit breaker would also fill the bill).
Bring the potential up slowly as a "healing" process may be necessary to get
to full potential.

I usually run them at 20% for 30 minutes, then increase by 20% every 30
minutes until I'm at full output potential.

Pop in a series 5 kVA power reactor, and enjoy your wild climbing arc.

Dr. Resonance




On Tue, Jan 20, 2009 at 7:30 PM, Bob Arenella <rja12@xxxxxxxxxxx> wrote:

> Hi all,
>                    Been lurking here for a good while. This subject brings
> up some questions about an X-Ray transformer that I'm about to put back
> together. Typical 125 KV xfmr, core strapped to brackets that are bolted to
> the cover. I've got new Shell Diala A oil. The xfmr has been out of oil for
> about 1.5 years. I'll assume I can't just put it back together, add oil &
> let 'er rip.
>
>                    My questions are: How can I apply vacuum to this thing
> so there are no air pockets in the windings? I don't think the cover will
> hold vacuum. Just how much vacuum does one need to accomplish this? I see
> some small, inexpensive pumps on eBay that are rated at 3-5 CFM & will draw
> 30" Hg. would something like that fill the bill? Would the vacuum pump used
> to service auto AC systems work?
>
>                    A friend suggested heating up the core to about 140 F &
> just lowering it into the much cooler oil. I don't want to ruin this thing
> the first time I fire it up. Any & all suggestions greatly appreciated !!
>
> Thank you,
> Bob A
> ----- Original Message ----- From: "Russell L Thornton" <
> Russell.L.Thornton@xxxxxxxx>
> To: <tesla@xxxxxxxxxx>
> Sent: Tuesday, January 20, 2009 9:38 AM
> Subject: [TCML] Re: Tar
>
>
> Ed,
>> The high voltage transformers that are filled with oil are subjected to
>> vacuum to pull the air out of all the
>> little crannies.  I would expect that wax and tar, being less fluid, would
>> especially need this procedure to
>> be sure there are no pockets of air.  With the heat requirements you are
>> looking at a more complex setup.
>> You may want to consider the oil again and maybe change your container.
>> Just my 2 cents soon to be 1 cent.
>> Russell at the Cape...Go Delta!
>>
>>
>>
>> Message: 3
>>> Date: Sat, 17 Jan 2009 15:42:10 -0800
>>> From: Ed Phillips <evp@xxxxxxxxxxx>
>>> Subject: [TCML] TAR
>>> To: Tesla Coil Mailing List <tesla@xxxxxxxxxx>
>>> Message-ID: <49726CD2.508@xxxxxxxxxxx>
>>> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>>>
>>>  Does anyone know where to get the type of black "tar" used to pot
>>> transformers?  Does anyone know the actual temperature at which it's
>>> poured into the transformers?  Did a web search but got nowhere and
>>> suspect that roofing tar or pitch probably isn't suitable.  I want to
>>> pot a couple of GMHEI transformers in a cylinder to simulate the
>>> secondary of a "spark coil" and don't want to mess with oil or the
>>> like.  Paraffin wax doesn't work, at least for me, because of too many
>>> bubbles - I've tried pretty hard to get rid of them [with the exception
>>> of vacuum] without much luck.
>>>
>>> Ed
>>>
>> _______________________________________________
>> Tesla mailing list
>> Tesla@xxxxxxxxxxxxxx
>> http://www.pupman.com/mailman/listinfo/tesla
>>
>
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxxxxxx
> http://www.pupman.com/mailman/listinfo/tesla
>
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla