Extended storage of motors • Note that the service life of the lubricant in the ball bearings is reduced by 10% per year after the first year of storage. • You should re-lubricate the lubrication devices on motors that have been in stor- age for longer than 5 years before startup. Observe the information on the motor lubricant plate. • Check whether the motor has absorbed moisture as a result of being stored for a long time. Measure the insulation resistance for this purpose (measuring voltage 500 V). The insulation resistance (see the following figure) varies greatly depending on the temperature. The motor must be dried if the insulation resistance is insuffi- cient.