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spares help to minimize down time if the need appears. The extent of the stock
should be decided based upon the importance of the application, the availability of
the particular spare part and the expertise of the local maintenance personnel.
9.2.2 Periodic part replacement
There is always mechanical wearing when two moving surfaces are in contact
with each other. In electrical machines most of the mechanical wearing occurs
between the rotating shaft and stationary parts. The bearing parts will eventually
wear out and need to be replaced, even if correct greasing is maintained. Other
wearing parts are the seals that are in constant contact with the rotating shaft.
The parts mentioned above make an extensive, but not a complete, list of the
mechanically wearing parts. These parts have an estimated life span, but as
mentioned earlier, their actual durability can vary significantly. For this reason, at
least these parts should be kept in stock. It should also be noted that the
replacement of these parts, due to normal wearing, is not covered by the warranty.
9.2.3 Need of spare parts
Other types of wear occur due to elevated temperatures, electrical disturbances
and chemical reactions. The wear of the diodes in the rectifier bridge is usually
related to abnormal electrical operating conditions. It is usually a slow process,
but it is strongly dependent on the operation conditions of the machines and
system disturbances.
The electrical windings of the ABB machines have good protection against wear,
but only if correct maintenance and operating conditions are followed. The correct
operating temperature must not be exceeded and the windings must be cleaned
from dirt regularly. The winding can also be subjected to accelerated wear due to
a number of electrical disturbances.
9.2.4 Selection of the most suitable spare part package
ABB provides three levels of ready made spare part packages. The personnel best
informed of the machine's operational conditions should select the most suitable
package based on criticality of the application and on the financial risk related to
the duration of downtime and loss of production.
Operational spare parts for commissioning and to ensure usability
These are the most essential spare parts that you should have always available.
Recommended maintenance parts for trouble shooting and scheduled
maintenance
These parts enable should be available while doing medium term maintenance.
These parts also enable fast recovery in case of failure in the most of the
accessories.
Capital spare parts to reduce repair time in case of serious damage
These spare parts are recommended when the machine is a part of essential
processes.
These spare parts enable fast recovery even in case of a serious damage.
9.2.5 Typical recommended spare parts in different sets
Below is presented a general recommendation of the typical spare parts for
different packages. To receive a quotation for specific parts for a specific machine,
please contact the ABB After sales organization.
