Standard Voltage Transformers

EPRO Gallspach GmbH’s Standard voltage transformers are used in the industry since decades. They are internationally well known for maximum reliability and accuracy. 

As the devices are purely inductive. Properly handled, the lifetime is up to 30 years and more without any accuracy drift or any changes. International calibration and metrological institutes as PTB Germany, INMETRO Brazil, VMI Vietnam among many others are using these devices as national standard. In the private sector these devices are used in the labs of various manufacturers of instrument transformers and transformers and others.


The Standard voltage transformers are available as single pole and double pole execution from 1kV up to 800/√3kV in various models. The smallest models up to 6kV are dry insulated, starting from 15kV the models are oil insulated and the larger models are designed in a cascade execution.


The model NVRD 40 is a special execution, some people call it the most accurate standard voltage transformer in the world for 40 kV so it is not by chance that this device is used with a lot of private and governmental calibration units. A big variety of the standard voltage transformers are also available in mobile execution for testing on site and transport in a truck. This mobile (outdoor) execution can be distinguished from the other devices by the light grey silicone rips on the outside. All devices offer a very wide range of 40-120%. This means in this percentage of rated voltage EPRO can guarantee the maximum accuracy of the devices.


Please see an overview of the available models here at the product data sheets. Please always consider that the mentioned datasheets are examples. Any customers request considering tappings on the primary side, different voltages on the secondary, operation frequencies of 50 and 60 Hz and other wishes can be fulfilled.