How should Variable Frequency Drives (VFDs) be evaluated during balancing?

How should Variable Frequency Drives (VFDs) be evaluated during balancing?

• A. They should be ignored during balancing.
• B. Verify that VFDs respond correctly to speed commands, maintain commanded CFM across operating ranges, and display correct status.
• C. They should always run at full speed during testing.
• D. They should be replaced with fixed-speed drives if any issue.

Answer: (B)