The electron-cyclotron heating system of the TCV tokamak is being enhanced as part of a major upgrade. Two MW-class dual-frequency gyrotrons will be installed. The first has already been delivered and will be fully commissioned on-site by the end of 2018 while the second is due for delivery in 2019.

This paper describes the electrical integration of these two gyrotrons. The water-cooling system is also described from the electrical point of view. Results of initial measurements on the first gyrotron are described.

Based on long term experience at the Swiss Plasma Center with gyrotrons, giving special emphasis to electromagnetic compatibility, overall electrical design choices will ensure reliable operation of the gyrotrons.