Tap changers

Members of Preis group develop and produce a diverse and wide range of off load tap changers which are in compliance with EN 60214.

Each produced tap changer is mechanically tested according to EN 60214-1 Point 7.3.1.

Types of tap changers

Tap changer series PDR 1 and 2 are used depending at the type (up to 36kV and 63A) in distribution transformers in one, two or three phase application. Depending on the technical requirements there are holders in different lengths available: 50, 70, 90 and 130 mm (a distance between the tank cover and the centre of the copper tubes).

The tap changer knobs exposed to the environment are made of a high-class plastic (modified PA6.6). A knob made of aluminium is also available as a special construction.

The tap changer series PDZ is used depending at the type (up to 36kV and 120A) in distribution transformers in one, two or three phase application.

The distance between the tank cover and the centre of the copper tubes is freely selectable by the customer. Please, specify this measurement in the inquiry or order.
The tap changer knobs exposed to the environment are made of aluminium.

The tap changer series PDM is used depending at the type (up to 36kV and 150A) in transformers in one, two or three phase application.

Depending on the technical requirements there are holders in different lengths available: 91 and 131mm (a distance between the tank cover and the centre of the copper tubes).

The steel parts are standardly made of mild steel and zinc plated. As a special design these parts are also available in stainless steel.

Internal and external tests

 The type changer type PDR was successfully tested according to IEC EN 60214-1 by the accredited testing laboratory CESI including following tests:

  • Temperature rise test of contacts
  • Short circuit current test
  • Separate source AC withstand voltage test
  • Against earth
  • Between the phases
  • Between two close-by contacts
  • Lighting impulse test

Each produced tap changer is mechanically tested according to EN 60214-1 Point 7.3.1.

  • Butterfly Wells
  • Oil level indicators

Further information about our range of tap changers can be found in our download area.