Patent Number: 7,272,302

Title: PSC motor system for use in HVAC applications with field adjustment and fail-safe capabilities

Abstract: A field-adjustable motor control system includes a motor, an inverter coupled to provide energization to the motor, a controller coupled to the inverter, and a field adjustment circuit that provides field adjustment signals to the controller. The controller provides signals to control the output of the inverter in response to received input control signals and field adjustment signals. The input control signals define the controller's operating state that corresponds to a desired system operating state. The field adjustment signals and input control signals define a desired output parameter of the inverter for an operating state. In certain embodiments, fail-safe circuitry is also provided that includes a relay receiving controller signals. The relay's input is coupled to a line power and to the inverter output. The relay's output is coupled to the motor. If the controller fails, the relay couples the line power to the motor.

Inventors: Woodward; Arthur E (Manchester, MO), Shahi; Prakash B (St Louis, MO), Furmanek; Ralph D (Wildwood, MO)

Assignee: Emerson Electric Co.

International Classification: H02P 7/06 (20060101)

Expiration Date: 2019-09-18 0:00:00