History of middle voltage section

Serial numbers 1 -12: The first transformers produced from RITZ:
12 Bushing and Bar Type Current Transformers for 30 kV were supplied to HEW (Hamburgische Elektrizitätswerke).


Within this timeframe a base program for Middle Voltage Transformers from 10 kV to 30 kV was developed.

Bushing-type Current Transformers were further developed.

1953 –1959
Bushing-type Current Transformers were developed for Outdoor Application.

Indoor Voltage Transformers were further developed in small oil volume as well as a dry method design with only small variances (as in the year 1950).

Outdoor Voltage Transformers received an Oil Paper Insulation.

1960 –1969
In the 1960s RITZ changed over from producing Porcelain-insulated Transformers to Cast Resin Insulated Transformers.

To begin with, Indoor Support-type Current Transformers were manufactured in a big design with cast resin insulation

1969 –1970
Current Transformers for 50 000 A, Series 30

At the same time the in-house production of a high current testing device gave RITZ order for a Precision Instrument Transformer for 50 000 A for a high power testing facility in Leningrad.

1970 –1979
Cast resin insulation is now established in the whole Medium Voltage division

Support-type Current Transformers for Outdoor

A complete program with different sizes from series 10 to 45 fulfils practically all demands on accuracy, achievement and performance for measuring and protective purposes.

Bushing-type Current Transformers for Indoor

Bar or Single-wire Bar-type Current Transformers series 10 to 30

In the course of the further development, the Instrument Transformer received flat cast iron flanges with an integrated secondary terminal box

As in the first run in the 1960’s there are four slim model designs rated for nominal currents up to 2500 A and a thicker model design for higher core requests and also rated for nominal currents up to 3000 A.

Voltage Transformers for Indoor

As in the resin encapsulation, the large design was also produced now next to the small design. As for the Current Transformers a narrow DIN design was supplemented into the program

Damping inductance device against ferroresonance

Single-pole Insulated Voltage Transformers in an insulated net can be destroyed in certain switching operations through relaxation oscillations

1980 – 1989
In the 1980’s the possibilities of the cast resin insulation in the transformer construction were further used.

The standard types required more resources in addition to the vacuum casting process therefore the introduction of the pressure gelation technology was developed. Further uses for Instrument Transformers arrived, for example for the railways, for SF6-switchgears for the measuring of direct current component in the networks.

from 1990 onwards
RITZ developed to one of the leading companies for Instrument Transformers.

Apart from the Medium Voltage division there are also divisions such as Low Voltage, High Voltage and Electronic Sensor Technology.

Especially in the Instrument Transformer division, a large amount of design and electrical dimensioning fulfils all requirements of the client.

The takeover of WTW in Wirges in Westerwald Germany and the Instrument Transformer department of TuR in Dresden required the mastering of new tasks, especially the reaching of an intentional synergy effect.