Example:
The following is an example of a transformer prepared for a Heat Run testing, utilizing a WR-14
and a WR50, having the following nameplate:
HV:
66KV, 78.8A
LV:
11KV, 473A
At the moment that the source providing power to the transformer to heat it up is switched off,
press the Timer on both Winding Resistance meters. This will set the base start time. Connect the
measuring cables from the WR14 to the high voltage side of the transformer and connect the
measuring cables from the WR50 to the corresponding
winding of the low voltage side.
Start the measurement on the high voltage side first with the WR14 set for interval mode and a
Current range of approximately 7A
After the current is flowing on the high voltage side, Start the measurement on the low voltage side
with the WR50 set for interval mode and with a current range of 40A.
After the results are obtained, stop the current on the low voltage side first (WR50) and then stop
the current on the high voltage side (WR14).
Now you can analyze the test results with the optional heat run test software to calculate the
cooling curve. A description of this software can be found in chapter 7.2 Heat Run Test Software on
page 80. Or you may export the results on a computer and analyze the data with our Software “T-
Base Pro”.
22 See chapter F Measuring high- and low-voltage-side in series on page 125.
23 Ensure that the test current does not exceed 10% of the rated winding current; this could cause erroneous reading due to heating in
the windings.
Instruction Manual Winding Resistance Meter
Type WR100 / WR50 / WR14
Page 129 of 139
WR14
WR50
HV-Side
1
Start Timer
2
Start Measurement
5
Stop Measurement
LV-Side
1
Start Timer
3
Start Measurement
4
Stop Measurement
