Synchronization clock

Before the power station could connect to the power grid, its three-phase alternating current had to be synchronized with that of the city power grid. Synchronizing the generators was accomplished by means of synchronization clocks. This power station had three synchronization clocks, including two in the control room and a third one overlooking the main generating floor.

An operator adjusted the phases of the generator, by controlling speed of the turbine shaft, to minimize the phase difference with the power grid. The two systems were synchronized when the needle on the clocks pointed to the 12 o’clock position.