Single-Phase Motor Wiring and Setup
WORKING PRINCIPLES OF A SINGLE-PHASE MOTOR:
- A Single-Phase Motor generally has a Main Winding (U1/U2), Auxiliary Winding (Z1/Z2), Running Capacitor, Starting Capacitor and Centrifugal Switch.
- If the Single-Phase (220VAC) Motor direction needs to be reversed, it requires swopping the U1 and U2 (or Z1/Z2) wires.
- The Starting Capacitor value is generally larger than the Running Capacitor, which can increase the starting torque. The Starting Capacitor will be disconnected through the Centrifugal Switch when the mechanical speed reaches a certain value. Some light-load Single-Phase Motors do not have a Starting Capacitor.
DRIVE WIRING:
- Input: AC 220V is connected to any two phases of R, S, and T of the Drive (preferably R and T).
- Output: The output is connected according to the specific mode selection as described below.
SINGLE-PHASE MOTOR WIRING AND DRIVE SETUP:
VSDs have 2 modes for driving a Single-Phase Motor:
- Single-Phase Mode (FE-03=1): The Motor needs to be connected to the Drive output terminals U and V (which generally connects to the main winding of the motor U1/U2) – this is similar to using the Single-Phase Motor connected to a normal Single-Phase power supply. In this mode, forward and reverse rotation of the motor cannot be controlled by the Drive (Motor wiring needs to be reversed to reverse the rotation). The wiring in this mode must be connected to the U and V terminals of the Drive, otherwise the display current is abnormal/incorrect. If the motor has a Starting Capacitor, the Starting Capacitor can be removed, which can reduce the starting current and increase the speed range.
- Three-Phase Mode (FE-03=2): Similar to a Three-Phase Asynchronous Motor, the main windings of the Single-Phase Motor (generally U1/U2) needs to be connected to the Drive output terminals U and V, and the secondary winding of the motor (generally Z1/Z2) is connected to the W output terminal of the Drive. This mode requires the removal of all capacitors, which allows for full-range speed control and for a high starting torque, but lower high-speed torque. This mode allows for forward and reverse rotation of the Motor via the Drive controls.
For both modes, set the rated parameters of the motor (rated voltage, rated frequency, rated current). Low-frequency torque can be increased by modifying the VF curve or increasing the torque boost.
Please Note: The Reverse function (when using Three-Phase Mode) is only possible while PV Mode is switched off. This can be changed momentarily (when using the drive in PV mode) as described in the FAQ entry HERE.
