Re: x-ray transformer questions

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

Original poster: "Jack Vandam" <snotoir7674g-at-mindspring-dot-com> 

Hi David,

Thanks for your response.  I was able to locate an x-ray repair tech a year
or so ago who told me that all of the "X" input connections were for
filament input; the "G" was ground; "MA" for meter or ground if not used for
meter; and "A/AA" input to the transformer primary.  What I don't know, as
you pointed out, is what phase this transformer is (I lost my x-ray tech
contact).  I'm going to take a wild guess that it's single phase because of
the input configuration, but that's why I asked here because I am uncertain.

I've also guessed that the one conductor and three conductor high voltage
outputs feature +hv out for single, -hv out for one of the three with the
other two for filament.  Again, this is a big guess.  I've been tempted to
energize it at low voltage and to try and find out for sure, but only if I
have no other alternative.

Jack

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Saturday, September 25, 2004 1:48 PM
Subject: Re: x-ray transformer questions


 > Original poster: "David Rieben" <drieben-at-midsouth.rr-dot-com>
 >
 > ----- Original Message -----
 > From: "Tesla list" <tesla-at-pupman-dot-com>
 > To: <tesla-at-pupman-dot-com>
 > Sent: Friday, September 24, 2004 7:52 PM
 > Subject: x-ray transformer questions
 >
 >
 >  > Original poster: "Jack Vandam" <snotoir7674g-at-mindspring-dot-com>
 >
 >
 > Hi Jack,
 >
 > Since I have some limited experience with x-ray transformers, I'll
 > try to answer what I can....
 >
 >  > Hello all once again,
 >  >
 >  > Tonight's questions concern a Westinghouse x-ray transformer.  There
are
 > two
 >  > things I'm wondering about with this unit: its specs and input/ output
 >  > information.
 >  >
 >  > Here's what's on the label:
 >  > cycles 50/60
 >  > wiring 3D 8939
 >  > style 981928
 >  > Volts AC, KVA, and Amps are all blank.
 >  > Under the word "Westinghouse", there are the following tiny numbers:
 > 36233-D
 >
 > I can't really tell much from these part numbers and finding matches
 > for GE part #s is no easy task.
 >
 >  > Can anyone figure out the complete specs with this info?
 >  >
 >  > Now for the input connections:
 >  > XFL, XFC, XFS, G, MA, A, AA
 >
 >  > Input hookup info?
 >  >
 >
 > I think the "X" inputs are probably the main primary inputs for
 > this transformer. Do you know if it's 3-phase? "G" is most likley
 > ground and I'm not sure what the "M" electrodes are but they're
 > probably inputs to the filament transformers inside.
 >
 >
 >  > And, finally, there are two high voltage recessed terminals.  One has a
 >  > single center conductor; the other side has three (their purpose?).
The
 >  > diameter of the sockets is 1.25".  I did manage to obtain some high
 > voltage
 >  > cable at one point, but the end diameters are too large.  I'm
considering
 >  > making new ends out of epoxy or if I could obtain the correct size
cable
 >  > economically, I would go with that.
 >
 > That seems a little strange as all of the x-ray trannies that i've seen
have
 > three conductor pins in each of the recessed high voltage terminals. Some
 > of the sub-100 kV transformers only have one recessed high voltage
 > terminal but would still have the three electrodes inside. The two extra
 > electrodes are for the low filament voltage. Sometimes, cable with
 > the male terminlas that match and fit the female recessed terminlas
 > of the transformer can be found on ebay but these cables would be
 > quite expensive if purchased retail.
 >  >
 >  > Dimensions are about 13.5x17x15 inches and it must weigh at least 250
lbs
 > I
 >  > would guess.  Not sure what I'm going to use it for, but my purpose
right
 >  > now is to just find out about it and get it going, using an appropriate
 >  > variac for current limiting of course.
 >
 > At this size, which is rather small for an x-ray tranny BTW, I'd guess
 > that it's rated around 125 kVp -at- 300 mA, give or take. To properly
 > current limit it, you will need a reactive ballast in addition to the
variac
 > to be able to push it up to near its maximum rated voltage. X-ray
 > trannies, just like pole pigs and plate transformers, are not current
 > limited and can draw a tremendous current if fired up without
 > proper input ballasting.
 >
 > You'd need to remove the internal diode sticks if you want
 > to use it for a Jacob's ladder.
 >  >
 >  > If anyone has any info on this or a similar unit, I would appreciate
your
 >  > sharing of it.
 >  >
 >  > Thanks,
 >  > Jack
 >  >
 >  >
 >
 > David Rieben
 >
 >