Jeffrey J Simon

US Patent:

7208909, Apr 24, 2007

Filed:

Jul 29, 2005

Appl. No.:

11/192650

Inventors:

Jeffrey J. Simon - Germantown WI, US

Assignee:

Rockwell Automation Technologies, Inc. - Mayfield Heights OH

International Classification:

H02P 1/26

US Classification:

318778, 318430, 318434, 388903

Abstract:

A circuit for inhibiting a protection device of a motor includes first, second, and third comparators and an inhibit signal generator. The first comparator is operable to determine if a motor current signal associated with the motor exceeds a starting threshold to identify a starting state of the motor. The second comparator is operable to determine if the motor current signal exceeds an inrush threshold to identify a transition from the starting state to an inrush state of the motor. The third comparator is operable to determine if the motor current signal falls below a running threshold to identify a transition from the inrush state to a running state of the motor. The inhibit signal generator is operable to deassert an inhibit signal for inhibiting the protection device responsive to the third comparator identifying the running state.