Tests

BEZ TRANSFORMÁTORY a.s. product portfolio is fully type tested in compliance with IEC 60076 and its subchapters in accredited independent laboratory to fulfill the latest technical requirements of applications and installations.

Routine tests

To be able to declare high level of quality for each individual distribution transformer, it is necessary to check and measure all products which are dispatched from our factory to the customer. High level of quality is verified by routine tests, which consist of:

  • measurement of winding insulation resistance
  • winding turn ratio measurement
  • vector group detection
  • winding resistance measurement with direct current
  • separate source voltage withstand test
  • inducted over-voltage withstand test
  • no-load losses measurement, no-load current measurement
  • load losses, load impedance voltage
  • measurement of partial discharges

Note: Routine test are performed according to relevant standards according to which the transformer was made. Customer requirements for different testing procedure require individual approach and verification by development team and testing laboratory.

Type tests

Type test of the transformer is carried out to verify and prove the quality of a transformer design and to confirm its technical performance according to the requirements of the relevant standards. Our product portfolio is standardly type tested by following tests procedures:

  • noise level test
  • lighting impulse test
  • temperature rise test
  • no-load current and current measurement at 90% and 110% of rated voltage

Special tests

Special tests could be part of the type test procedure in the sense of IEC standard, such as Short-circuit withstand test. Other special test, which are not standardly required by the standard can be performed after agreement between customer and BEZ TRANSFORMÁTORY a.s.

  • special electrical strength tests
  • measurement of warming of the warmest winding point (hot-spot)
  • dissipation factor and windings capacitance