Sizing Benshaw VFDs for Use with a Single-Phase Power Source

This Benshaw Application Note provides detailed guidance on how to properly size, configure, and protect Variable Frequency Drives (VFDs) when powered by a single-phase source. It explains the electrical differences from three-phase operation, outlines key precautions, and includes comprehensive selection tables for Benshaw GM2, S, SW, H2, and SG Series drives.

Key Points

  • Single-phase power can safely operate 3-phase VFDs when properly oversized.
  • Derating is required to protect rectifiers and DC link components.
  • Minimum input voltage must be maintained to prevent torque loss.
  • Reference tables included for all Benshaw VFD Series (GM2, S, SW, H2, SG).
  • Expect single-phase input current to be approximately 1.732× higher than three-phase input.
  • Line reactors and proper wiring help manage harmonics and current distortion.
  • EMC filters must be disconnected for single-phase input.
  • Detailed wiring and configuration parameters provided.