Guess what guys! I pulled apart my transformer tonight and found a tiny burn mark on the outer wrap of HV side. I opened the paper it was right next to the end and there is one tiny little dot on one wrap of wire. What I found out happened was when this transformer got its bushing hit by a fork lift it shifted the core and it was sitting on the tank and it burned a small dot through the paper and was grounding onto the can. A good couple of coats of electrical varnish should fix it right up... man I’m so happy good end to a Friday!
Sent from my iPhone
> On Jan 4, 2019, at 8:32 AM, Tedd Dillard <tedd.dillard@xxxxxxxxx> wrote:
>
> Tyler,
> Two things you mentioned indicate that your defect may not be too serious.
> You said that there was debris floating on the surface if the oil in the
> can.
> This suggesy to me that the fault may be above the oil level as fault
> products would seem to be heaver than the oil and sink.
> Also you mentioned that one of the bushings had been replaced. My long
> history of working on things tells me that very often the cause of the
> problem was the last time it was worked on.
> Replacing the bushing is a simple task but still must be done right.
> On the subject of pole transformers for sale there is a company about 20
> miles northwest of Orlando in Zellwood that is licensed to recycle
> transformers.
> They sell them for $7.00 dollars per kva.
> I got my 10 kva for $70.00 dollars.
> The name of the company is TRC America. You should find them on Google and
> Google Maps.
> Phone 407-703-8577.
> Teddy
>
>> On Jan 4, 2019 9:02 AM, "David Rieben" <drieben@xxxxxxx> wrote:
>>
>> Tyler,
>>
>> Wow! Although $700 may be a decent deal for a 25 kVA pig these days, it
>> ain’t cheap at all, at least not to me! Especially when it dies on you so
>> soon after the purchase! Can you provide any details on the capacitor that
>> you were using (uFd, kV rating) and whether you were placing the capacitor
>> in parallel with the Jacobs ladder rails or in series between the
>> transformer bushings and the Jacobs ladder rails?
>>
>> Like I said, I have let the magic smoke out of a couple of smaller
>> transformers in the past by simply seriesing the hv output of the pole
>> pig’s bushings through a capacitor. I found that if the capacitance was in
>> the correct range, it would form a near resonance with the transformer’s hv
>> output and allow the power arc to drawn out to several feet before
>> breaking, as opposed to mostly 12” to 18”, at best, before breaking without
>> the capacitor. I should mention that my ballast allows about 100 amps to be
>> drawn when shorted across a 240 volt AC source and when I applied the line
>> voltage to my transformer, it would draw upwards of around 80 to 90 amps
>> (w/out the capacitor). Also, with the correct sized capacitor, the power
>> arc is much louder and the current draw INCREASES (and can momentarily peg
>> out my 150 amp ammeter, through my same ballast!) with increased arc
>> length, as opposed to DECREASING current draw with arc length increase
>> without the capacitor!
>>
>> Your experience, as well as my past experiences with a smaller (5 kVA)
>> pole pig and a 3 kVA PT, is starting to make me reconsider this practice
>> (google “arczilla”) with my own 25 kVA, 14.4 kV transformer! Maybe the
>> ferro-resonance that Jan mentioned is what’s happening here and may not be
>> healthy practice for any pole transformer?
>>
>> David
>>
>>
>>
>> Sent from my iPhone
>>
>>> On Jan 3, 2019, at 2:29 PM, Terry Oxandale <toxandale@xxxxxxxxxxxxx>
>> wrote:
>>>
>>> I know we would see static charges develop during oil filtering/filling,
>> but these were very short-lived changes, but still enough to get your
>> attention.
>>> On Thursday, January 3, 2019, 1:07:31 PM CST, Teslalabor <
>> teslalabor@xxxxxxxxxxx> wrote:
>>>
>>> How should this be possible? If there is any tiny charge, it surely is
>>> not dangerous?
>>>
>>>
>>>> Be sure to ground all terminals for a few minutes before disassembling.
>> Some of these can hold a charge for a long time.
>>>>
>>>> Sent from my iPhone
>>>>
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