Insulation pipe step-up transformers


This type of transformer is realized inside an insulating pipe with metal covers. The top cover is connected to the output of high voltage and the lower cover is connected to ground and basement. On the top cover is present the high voltage electrode.
This type of transformer is only for indoor.
The insulation pipe transformers are designed for not-continuous operation (normally 5 'ON - 15' OFF), but it is possible to upgrade to continuous operation with the addition of an external oil cooling unit.
Between the low voltage and the high voltage windings is present an electrostatic screen which ensures a perfect electrical insulation in the event of failure of the object under test.
All insulation pipe transformers are Corona free and so recommended for PD test.
The insulation pipe construction is strongly recommended for transformers cascade solution, because the upper stages will be positioned directly on the lower one. This solution allows to reduce the space occupied by the testing system.

The main benefits of these transformers are the following:

  • very low work Induction to ensure a perfect sine waveform, with low harmonic distortion on the test circuit
  • Different cooling possibilities of:
    o ONAN
    o ONAF
  • Possibility to insert an additional winding to feed a cascade transformer
  • Possibility to include a pneumatic earthing system of HV pole.
  • Possibility to modify the transformer design to decrease or increase the impedance voltage (if possible), according to customer request.
  • Possibility to choose different moving systems:
    o VulkollanĀ® wheels
    o Rails
    o Air cushions



  1. Without condensation
  2. For different sea level heights installation is necessary to reduce accordingly the max working voltage




For higher voltage will be installed cascade transformers

On request, we can quote transformers with different rated power and voltage.