Hamilton Standard Controls, Inc.

Michael T Grunden

Eugene P Mierzwinski

Stephen E Youtz

An integrated electronic control arrangement is disclosed in the illustrative environment of burner such as in a gas-fired furnace. The control incorporates a self-test feature which shuts down the furnace in the event of any one of a number of possible sensed faults. Self-testing occurs automatically before an attempt at ignition and during furnace operation. Proper functioning of the sensor which senses for induced air flow through the burner combustion chamber is tested prior to enabling a fan which causes that induced air flow. Air flow is confirmed by sending to and receiving back from the sensor a sequence of pulses. Should air flow not be sensed during a combustion period, combustion is terminated. A flame sensor is provided for determining the presence of a flame in the combustion chamber. During times when a flame should be present, pulse sequences are sent to and received back from the flame sensor to confirm that a flame is present. When it is known that no flame is present, if sent pulses are received back, a fault has occurred and the system locks out. If, at any time, any pulses are received when none were sent the system also locks out.

Integrated furnace control having ignition switch diagnostics

An integrated electronic control arrangement is disclosed in the illustrative environment of a gas-fired furnace. The control incororates a self-test feature which shuts down the furnace and displays a diagnostic fault code in the event of any one of a number of possible sensed faults. Self-testing occurs automatically before an attempt at ignition and during furnace operation. The self-test may also be initiated manually at any time the furnace is not operating. The control accepts digital information on daily temperature setback, weekend temperature setback and vacation setback in any one of several preset schedules and preset setback increments. The control has a multipurpose display for selectively showing component indicative failure codes, temperature setback schedules, time of day, and day of the week.

Growing community of inventors

Fort Wayne, IN, United States of America

Michael T Grunden