Watt - Wattage; Measurement Conditions - Voltech AT5600 User Manual

C H A P T E R 7 – T E S T S
7.31.

WATT - Wattage

Where Used
The Wattage test is a measure of the input power required to energize a
transformer at no load.
A Wattage test is an excellent check on the magnetic quality of the iron core and
the magnetic joints and would typically be used with iron core transformers with
an operating frequency of around 50Hz.
The test measures all losses caused by eddy currents in the core, hysteresis
losses in the core and by the DC resistance of the winding being tested.
It should be noted that if you deploy the WATT test after a MAGI and VOC test,
using the same V/F/Nodes then you will pay no time penalty for the test as the
measurements are already made by the preceding two tests.

Measurement Conditions

During the Wattage test, a constant, user specified AC voltage is applied across
the winding in question. All other windings are held open circuit during this test.
The AT5600 measures the voltage across and current through the winding. The
Wattage is the product of the in-phase components of the current and voltage.
If, in the program, the WATT test follows either a VOC or MAGI test which has the
same test conditions (voltage and frequency), and is applied to the same winding,
then the measurement results from the previous tests can be re-used, saving
program execution time.
The test signal can have a frequency in the range 20Hz to 1.5KHz, and an
amplitude from 1V to 270V, and a power of up to 25W.
Please also see
AT dotNET Editor manual (98-125 2.5.39) for specific advice on programming the
test
10.2.15 for test accuracy specification
AT5600 User Manual 98-119 issue 30
A N D T E S T C O N D I T I O N S
Page 162