Abb Inc.

Dennis Tyczkowski

Douglas W Karraker

Kalyan P Gokhale

Donald J Truettner

Alpo Vallinmaki

Jeffrey A Brunner

A motor bypass is controlled by a digital signal processor (DSP) with embedded control software that allows fault detection and annunciation, serial communications between both a variable frequency drive (VFD) and a bypass controller and the bypass controller and a host computer. The use of the DSP and embedded control software further allows for contactor coil control to provide fault tolerant operation as well as fault condition detection and annunciation to the user.

AC motor bypass with fault annunciation, serial communication and fault tolerant coil control

A system for use in ac to ac or dc to ac power conversion equipment to detect faults in an inverter when the inverter is in a high impedance mode. The system detects ground faults or cross wiring conditions by converting the inverter outputs to digital signals and evaluating the frequencies of the resulting signals. The system keeps the inverter in the high impedance mode until after it has been determined that neither of the described abnormal statuses exist. The system tests for both of the abnormal statuses on power up and thereafter tests only for a ground fault whenever the inverter switches are disabled.

Growing community of inventors

Franklin, WI, United States of America

Dennis Tyczkowski