PDT (Pig) failure modes

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Dave Hartwick by way of Terry Fritz <twftesla-at-qwest-dot-net>" <ddhartwick-at-earthlink-dot-net>

[Since there is great sensitivity to this issue, henceforth I shall refer to
them as PDTs: Pole Distribution Transformer.]

Guys,
I drained the oil and pulled the core--which isn't really a core but is the
actual xfmr--from the tank. Of course, upon examination, nothing was
obviously wrong. It is apparent from the construction of these things that
all but the most superficial malfunctions are fixable by the common Joe
Coiler.

What is truly a mystery about this thing is that it either works perfectly,
or acts like there is a crowbar dead short across the primary. I can be
fiddling around with it, maybe measuring something or feeding very low
voltage to it and boom--it wakes up again and will fire at full power, then
will just quit again.

How is this possible? I cannot envision a mechanism that would result in
this. I'm thinking failure is usually going take the form of charring and/or
tracking and subsequent progressive shorting that does not exhibit what
amounts to a sort of Binary behavior: on or off.

Well, at this point, I'm tentatively pronouncing Ariel dead. I'm going to
call T&R to see if they can supply a replacement core so that I can perform
transplant surgery.
Dave H