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Here pig pig pig

Coilers,
 Well I am in possession of my pig!  No - it didn't weigh a mere 125 lbs 
as advertised.  The true weight is 300 lbs + 25 for the pallet it was 
strapped to!

 I am now famous at work for having a pole transformer delivered to the 
loading dock!  I came back with my pickup and grabbed it (lined up the 
powered loading elevator with the bed of the truck and pushed it in 
using a pallet jack).

 Just tonight I completed welding a cable winch onto the end of my boom 
arm - and was able to use said instrument to get the transformer off the 
truck, onto the ground. :)

 The transformer appears to be BRAND NEW - no rust, white paint, the 
wire lugs are tight down and don't appear to have ever clamped a cable.  
The can is roughly 16 inches in diameter and 28 inches tall.  The input 
insulator is over a foot long which places the top of the insulator at 
about 41 inches off the ground!  It isn't small or portable and is not 
quite what I expected.

 Total bill was $94 + $70 s/h.  Not a bad deal.  I will get the relevant 
addresses/URLs for anyone else interested in adopting such an electric 
animal.  I also have yet to pursue those mini-pigs in the local scrap 
yard.

 There is no top access plate so I don't think it has a tap switch.  I 
can take the entire top off (including the input bushing) which I will  
do to inspect the insides.

 There is what appears to be a pressure blow-off port at the top of the 
can. (a spring-loaded pull-ring)  

 It contains the traditional three lugs for 120-0-120 connection, and 
the '0', or neutral lug is also bussed to the case of the transformer 
(this is removable).  There is also a separate lug welded right to the 
case.

 I'm going to have to find some sort of wheeled platform for this thing 
to sit on.  Either that or I'll put wheels on the pallet and call it 
done!!

 I was thinking about how to power the darn thing...  I have a 240 v 28 
amp variac and various limiting devices (including a welder).  But the 
problem is that if I use the variac - what becomes of the neutral 
connection on the pig?  I can't connect it to the neutral bus - since if 
I did - then one 120 volt primary of the pig would always see a full 120 
volts (from N to Hot).  Also - since I have only one HV output and the 
other side is connected to the case - I'd really need to keep the case 
grounded and connected to neutral.  The only solution I see is to use an 
isolation transformer between the variac and the pig.  This should allow 
me to tie the pig's N to system N/ground, and power the pig's 12v lugs 
off the isolation transformer.

 It just so happens that I have a 20 amp 240v toroidal 1:1 isolation 
transformer!

 Does anyone think I should break the pig's N-to-case link, tie the 
pig's case to a good RF ground, and then tie the pig's N to the power 
neutral?  I think that might be the best plan.

 Oh - I depotted our 37 amp line filter which the tesla coil killed.  It 
is hard to tell but it looks like the RF arc'd from one hot wire, 
through the potting tar, to the case.  That tar just barely became soft 
at 350 degrees (in a toaster oven).  I would think that the heat time to 
depot a large neon would be at least 12 hrs since this 4x3x1 inch filter 
took over 2 hrs to melt and there wasn't any iron to heat either!

More later.  Comments invited.

-Bill

 

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