PFIFFNER can carry out power frequency withstand tests up to a test voltage of 700kV, incl. partial discharge measurement. Lightning impulse withstand test voltages up to 1550kV are possible.
Before leaving the factory, every instrument transformer is subjected to routine tests. In the medium and high-voltage area, freedom from partial discharge under high voltage loading is measured, among other things. In this case, our internal test procedures are more stringent in part than those required by standards. Detailed measurements are made on every instrument transformer: the results are documented and their conformity to standards is reviewed.
Instrument transformers which are used for billing, i.e. for the commercial measurement of electricity, may only then be used if they have been calibrated at a test facility recognised by the state. Our test facilities are the only test site in Switzerland accredited by the state for instrument transformers testing and high-voltage tests. Verification is documented by means of a test stamp and a calibration certificate is provided. The costs for verification are billed in accordance with officially defined charges.