More on those illumination/photocopier transformers.

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

Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>

Some data and analysis on leakage inductance, etc. for those GE
transformers can be found at 
http://home.earthlink-dot-net/~jimlux/hv/xfmrex1.htm 

I have copied it below.. What I left off that page was that the
measurements were done at 60 Hz (an egregious chauvinism, I know) note the
13.5 ohms of reactance... that's about 35 mH at 60 Hz

The active power measurements were done with a conventional "spinning disk"
type of watt meter.

I haven't worked out measurement procedures for measuring the mutual
inductances and leakage reactances with the three windings.  This might be
interesting, because there's only one set of magnetic shunts (between the
HV winding and the two low voltage windings, as I recall).

If one of you theoreticians knows, or would like to work out, how to do all
the measurements (comparable to the usual shorted and open tests) for a
three winding transformer with signficant leakage reactance, I'd love to
add it to my web.




Example Transformer Measurements and Calculations

This page has some actual measurements and calculations on GE Type 5021G10
transformer, which was originally intended for an illumination power supply
for a copier. It has a lot of leakage reactance to
limit the current. The nominal specs are 120V input, 4500V output, 400mA
short circuit output current. This transformer is interesting because it
has a third winding, nominally 600V, for connecting a
capacitor for power factor correction. At rated output, this transformer
draws about 8.5Amps, i.e. about 1kVA

Open Circuit Tests

     Primary Voltage: 118V 
     Primary Current: 5A 
     Active Power to Primary: 69.6W 
     Secondary Voltage: 4415 

Short Circuit Tests

     Primary Voltage: 68V 
     Primary Current: 5A 
     Active Power: 40.7W 

Calculated:

Reactive Power 585.9 Vars

Magnetizing Circuit R: 200 + j23.76 Ohms

Series equivalent: 1.628+j13.5 Ohms