Rockwell Automation 7000A PowerFlex Medium Voltage AC Drive (A Frame) - ForGe Control - Manual (Page 165)

Rockwell Automation Publication 7000A-UM200C-EN-P - June 2014 165
Appendix
C
Preventative Maintenance Schedule
Preventative Maintenance
Checklist The preventive maintenance activities on the PowerFlex 7000 Air-Cooled Drive
(“A” Frame or “B” Frame) 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 drives require 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 heat
sink 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 should 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.