Rockwell Automation 6012DB PowerFlex Medium Voltage Variable Frequency Drive - Manual (Page 80)

80 Rockwell Automation Publication 6000-UM001B-EN-P - October 2014
Chapter 5 Preventative Maintenance and Component Replacement
Medium Voltage Testing
Medium voltage insulation resistance (IR) or dielectric withstanding voltage
(megger) tests should not be used to check solid-state control equipment. When
meggering electrical equipment, such as transformers or motors, solid-state
devices must be bypassed before performing the test. Even though no damage
may be readily apparent after a megger test, the solid-state devices are degraded
and repeated application of high voltage can lead to failure.
Maintenance after a Fault Condition
Opening of the short circuit protective device (such as fuses or circuit breakers)
in a properly coordinated motor branch circuit is an indication of a fault
condition in excess of operating overload. Such conditions can cause damage to
medium voltage motor control equipment. Before restoring power, the fault
condition must be corrected and any necessary repairs or replacements must be
made to restore the medium voltage motor control equipment to good working
order. Refer to NEMA Standards Publication No. ICS-2, Part ICS2-302 for
procedures. Use only replacement parts and devices recommended by Rockwell
Automation to maintain the integrity of the equipment. Ensure the parts are
properly matched to the model, series and revision level of the equipment. After
maintenance or repair of the equipment, always test the control system for proper
functioning under controlled conditions (that avoid hazards in the event of a
control malfunction). For additional information, refer to NEMA ICS 1.3,
PREVENTIVE MAINTENANCE OF INDUSTRIAL CONTROL AND
SYSTEMS EQUIPMENT, published by the National Electrical Manufacturers
Association, and NFPA70B, ELECTRICAL EQUIPMENT
MAINTENANCE, published by the National Fire Protection Association.
Final Report A complete, detailed report on all steps in the Preventive Maintenance
procedures should be recorded to identify changes.
A detailed description of all adjustments and measurements that were taken
during the process must be recorded (Interlock Adjustments, Loose Connections,
Voltage Readings, Megger Results, Parameters, etc.).