Our testing methods are set by national and international standards. The relevant standards subdivide the instrument transformers into classes, for which the ratio error and phase angle are specified.
The ratio errors are defined by the relative deviation of the measured amplitudes of the current- or voltage vectors from the nominal values. The phase error is the phase angle of the output minus the phase angle of the input, for a sinusoidal input and output at a fixed frequency.
To verify both types of errors, reference standards are necessary, the measuring uncertainty of which is much smaller than those of the devices to be tested.
Series – W
Automatic current and potential transformer test set
Low voltage unit for capacitive voltage divider
Artificial load for voltage and current transformers
Standard current transformer