Industrial Engineer · phase 9 of 16
Input Voltage / Phase
AC supply voltage and phase configuration for which the drive is designed.
The Explain card
- Plain English
- The input rating says what supply the drive is built for, such as 480 volts three phase or 240 volts single phase. The rectifier, the bus and the ratings all assume it.
- Example
- A drive rated 380 to 480 volts three phase is fed from a 480 volt plant supply. The same drive on 240 volts would run, badly, with a bus far too low for the motor.
- Why it matters
- A single phase drive fed three phase or a 240 volt drive fed 480 volts is destroyed at power up. The tolerance band on the nameplate is the real limit, and a plant that sags below it trips drives on undervoltage.
- Hook
- Read the plate before the disconnect closes.
Where it sits in the deck
Phase 9: VFD Ratings, Sizing, and Motor Data
Nameplate arithmetic, where the currents, voltages and duty ratings decide whether a drive can actually run the motor you bolted it to.
