Rockwell Automation Publication 7000-UM202D-EN-P - May 2018 183
Appendix C
Preventative Maintenance Schedule
Preventative Maintenance
Checklist
The preventive maintenance activities on the PowerFlex™ 7000 air-cooled drive
can be broken down into two categories:
• Operational maintenance – can be completed while the drive is running.
• Annual maintenance – should be completed during scheduled
downtime.
Refer to the Tools/Parts/Information requirements at the end of this section
for a list of documentation and materials needed to properly complete the
preventive maintenance documents.
Operational Maintenance
This process really involves only one task: changing or cleaning the air filters.
The PowerFlex 7000 drive requires consistent, unrestricted airflow to keep the
power devices cool. The air filter is the main source of blockage in the air path.
The drive will provide an air filter alarm whenever the pressure differential
across the devices drops to a drive-specific level. Referring to the Air Filter
Block parameter, this can be anywhere from 7…17% blocked, depending on the
heatsink and device configuration. This may seem like a small number, but it
takes significant blockage to begin to lower the voltage from the pressure
sensor. The percentage is a measure of voltage drop, and should not be viewed
as a percentage of the opening that is covered. They are not related linearly.
Once you receive an air filter warning, you should immediately make plans to
change or clean the filter. You could still have days or weeks until the drive
reaches an air filter fault, but this is dependent on site-specific particle
conditions.
Annual Maintenance
These maintenance tasks should be performed on an annual basis. These are
recommended tasks, and depending on the installation conditions and
operating conditions, you may find that the interval can be lengthened. For
example, we do not expect that torqued power connections will require
tightening every year. Due to the critical nature of the applications run on MV
drives, the key word is preventive. Investing approximately 8.0 hr/yr on these
tasks is time well spent in adding insurance against unexpected downtime.
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