
Dutchi Motors B.V.
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DMA2 & DM1 Mounting & Maintenance Instructions
Page 7 of 8
22-5-2006
DM1 280 2 6314 C3 / NU314 6314 C3 70 / 70
DM1 280 4 / 6 / 8 6317 C3 / NU317 6317 C3 85 / 85
DM1 315 2 6317 C3 / NU317 6317 C3 85 / 85
DM1 315 4 / 6 / 8 6319 C3 / NU319 6319 C3 95 / 95
DM1 355 2 6317 C3 / NU317 6317 C3 85 / 85
DM1 355 4 / 6 / 8 6322 C3 / NU322 6320 C3 110 / 100
DM1 400 2 6317 C3 / NU317 6317 C3 85 / 85
DM1 400 4 / 6 / 8 6326 C3 / NU326 6326 C3 130 / 130
DM1 450 2 6317 C3 / NU317 6317 C3 85 / 85
DM1 450 4 / 6 / 8 6328 C3 / NU328 6328 C3 140 / 140
9 GREASE INTERVAL FOR BEARINGS
By the term “greasing interval” we mean the number of working hours after which the
bearing lubricant has to be replaced.
Electric motors have such a wide range of application that they must cope with many
adverse conditions as for instance dust, moisture, vibration, temperature, chemicals,
marine atmosphere and of course, the mounting position and loading of the driven
machine.
Generally we can say lubrication life is a product of time, speed and the bearing size. Due
to the impact of all these factors, it is practically impossible to determine any exact values
that are valid under all circumstances. Nevertheless it is necessary to provide at least some
guidelines concerning greasing to the user.
Under normal load and environmental conditions the quality of the grease ensures proper
operation of the motor for about 10000 service hours with 2-pole designs and 20000
service hours with multi pole designs. If not otherwise agreed upon the grease need not
be refilled during this period. Nevertheless the condition of the grease filling should be
occasionally checked also within the said lubricating intervals.
The stated service hours are only current under operation with rated speed. For
relubrication thoroughly clean the bearings with a suitable solvent and use the same or
substitute grades specified by the motor manufacturer. Bear in mind, however, that the
bearings should be filled only up to about 2/3 of their free space as a complete filling of
the bearings and bearing covers results in an increased bearing temperature and therefore
in increased wear. For bearings with relubrication facility regrease at the grease fitting
with the motor running according to the grease amount required for the motor in case.
The relubrication intervals should be looked up in the following table:
A chemically aggressive environment, extreme moistness, strong vibrations, high or low
ambient temperatures are not normal circumstances and such conditions must be taken
into account.
Construction size Two pole motors Four-pole and multi-pole motors
80 up to and including 400 2 000 hours 4 000 hours