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Preventive Maintenance
3ADW000488R0101 DCS880 Service manual e a
Annual preventive maintenance
The following actions have to take place:
−
Check the cooling fans of units H1 … H8.
The lifetime of the cooling fan is about 30,000 … 100,000 hours depending on the converter type, the usage
of the DCS and the environmental conditions (e.g. temperature). Fan failure can be predicted by means of
increasing noise from its bearings and a gradual rise of the heatsink temperature. If the DCS operates in a
critical part of the process it is recommended to replace the fan once the above mentioned symptoms
appear.
−
Check the cooling air pressure switch of units H7 and H8.
Actions:
−
Make sure electrical safety is performed.
−
Open the module's door and hold it in position to prevent any movement.
−
Repeat it with the cabinet’s door.
−
Start the drive.
−
The air pressure switch is ok when the converter is either switched off by 5080 Drive fan acknowledge
or shows warning A518 Drive fan acknowledge - see 20.38 Drive fan acknowledge source.
Crosscheck this result with the module’s door closed.
Attention:
Do not reach into the fan. Negligence to this warning can cause injury.
−
Check for tightness of unit stacks H6 … H8.
The thyristors together with the heatsinks are stacked. The proper stack torque is shown by the torque
indication spring:
The correct torque has to be checked the following way:
