A service connection for controlling a water sluice gate driver for a water sluice gate in a hydroelectric power plant, wherein the water sluice gate drive has an asynchronous machine having a fan brake, the service connection comprising:
- a first control phase element for a normal operation, and a second control phase element for an emergency operation, wherein
- the second control phase element is designed to operate the asynchronous machine in a generative island operation in a self-actuating manner, wherein a rotating field is generated in the self-actuating manner having at least a first stage of load resistors for at least one of a first control and adjustment control stage and a second stage of load resistors for at least one of a second control and adjustment control stage.