[Milsurplus] Mystery Transformer #2

[patrick jankowiak]

Here we go again..

I have uncovered another large transformer of about 120-130 LBs (nor
weighed yet), which is slightly larger than the BC-610 plate
transformer, and it has the number "S570" stamped on the primary side
end bell. 


Primary has a black fibrous plastic or phenolic terminal board, with
the following arrangement:
Where "@" are the terminal bolts:

     __________________________________
     |                                 |
     |  115v                     199V  |
     |   @                         @   |
     |              @                  |
     | 2 @          1              @ 3 |
     |              @                  |
     |   @                         @   |
     |  +/-                       230V |
     |_________________________________|
     

The secondary terminals are 1" long, 1" diameter brown ceramic
insulators which are at the lower left corner of the other end bell,
if the secondary side is facing you. The terminals have a stamping:
2850-0-2850. The insulators are not exactly cylindrical, but have
circumferential grooves in them.

The unit is gray in color, and the frame surrounding the core is a
thick casting with feet like the BC610's transformer, with the
sheetmetal end bells bolted to this. A long external bolt from one end
bell across the core to the other, at each of four corners, holds the
whole thing together.

Anyone have an idea what this one might be from? 

Thanks in advance, 
Patrick