American Standard Inc.

Rolf M Hanson

Dennis R Dorman

Robert M Swanson

Jeffrey A Moore

Lunxi Peter Xia

Michael G Lunacek

Nels R Ebbesen

Dwayne L Johnson

Walter Earhart, Jr

An apparatus and method for soft-starting a three-phase motor for connection to a three-phase power source for driving a three-phase motor. Soft-start provides a way to reduce the amount of starting torque and current during starting conditions. First, second, and third conductors are connected between a three-phase power source and a three-phase motor. A power contactor interrupts and provides current along the three conductors. A phase-shifting element for shifting the phase of the power signal normally outputted from the first conductor to match the phase of the power signal normally outputted from the third conductor is connected between the first and third conductors. A switching apparatus having first and second switch elements is connected between the phase-shifting element and the third conductor. When the first switch element is closed, current flows from the first conductor to the motor via the phase-shifting element. When the second switch element is open, no current flows from the third conductor to the motor directly. In this mode, the motor is running on single-phase power. When the states of the first and second switch elements are flip-flopped, the motor runs on three-phase power. The first and second switch elements' states are controlled by a control element which energizes the switching apparatus upon the occurrence of a triggering event.

Apparatus and method for soft-starting a three-phase motor

A device for monitoring and modulating the admission of fresh air into a building. The device comprises a housing; a sensor associated with the housing and operable to measure airflow through the housing; and a damper including at least two damper blades. Each damper blade includes a shaft rotatably attached to the housing at least at a first shaft end. The shaft is located on the surface of the damper blade so as to divide the surface into first and second substantially equal areas.

Fresh air flor modulation device

Fresh air flow modulation device

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Holmen, WI, United States of America

Rolf M Hanson