The purpose of this thesis was to create a layout-driven 3D-assembly of current transformer assemblies. The thesis was made for the Transformers unit of ABB located in Vaasa. The layout driven 3D-assembly would decrease the time of designing. In addition, a manual for the use of the layout-driven assembly was made. The manual includes also a standardization of the designing of the current transformer assemblies.

The work began with the Needs Analysis in which the characteristics of the layout were defined. The layout-driven assembly was created with Pro ENGINEER Wildfire 4.0 designing software. Top-Down-techniques and programming were used.

The manual for the use of the layout-driven 3D-assembly was written in English. Different methods were used to clarify the format of the manual. The standardization of the designing of the current transformer assemblies facilitates the designing.

The result of the thesis is a flexible 3D-assembly of current transformer assemblies which allows the building of 3D-models of all the common current transformer assemblies easily. The manual which is written in English helps the introduction of the current transformer layout in the other transformer factories of ABB.