At the end of the range of wind power gearboxes with a capacity of up to 14 MW, these gearboxes are subjected to a test run. During this test run, the gearboxes must first be tempered via the oil supply, and in the further course of the up to 3-day test run, the gearboxes are cooled by the oil. For this purpose, the gearboxes are permanently rinsed with fresh oil and the oil is reprocessed in the oil center.

Particular attention is paid to the observance of strict oil cleanliness classes as they have a very high impact on the lifetime of such transmissions.