Copeland Corporation

Therm-o-disc, Incorporated

Emerson Climate Technologies Gmbh

Hank E Millet

Hung M Pham

Vijay O Bahel

Mickey F Hickey

Gregory P Herroon

Gerald L Greschl

Jean-Luc M Caillat

Wayne R Warner

Nagaraj Jayanth

Bernd D Zimmermann

Richard E Welch

Natarajan Rajendran

David Reynolds

William W McCroskey

Charles H Culp, Iii

Suresh Shivashankar

Birchard M Taylor

Gregroy P Herroon

Joseph B Niemann

A compressor includes a motor protector which stops the compressor's motor when it senses an out of specification condition. A diagnostic system monitors the status of the motor protector. The diagnostic system includes logic circuitry that diagnoses the type of problem the compressor is having based upon the running times and status of the motor in conjunction with the times and status of the motor protector.

Compressor diagnostic system

An improved liquid level sensor is disclosed which provides a reliable and simple device for accurately determining the level of a liquid within a vessel. The sensor of the present invention utilizes a plurality of thermocouples grouped in pairs with the pairs being spaced along a line extending generally in the direction in which the liquid level may vary. A first thermocouple of each pair is located in relatively close thermal proximity to an electrically powered heater and the second of each pair of thermocouples is spaced away from the heater. The thermocouples are connected in series and produce a signal directly indicative of the level of the liquid along the sensor. Additionally, a pressure sensing circuit may also be incorporated with the liquid level sensor.

Liquid level sensor

A compressor protection and control subsystem for a rotary compressor provides temperature pressure, mis-wiring and vibrational protection for the scroll machine. The vibrational protection comprises a vibration sensor which is integrated on the circuit board of the protection and control subsystem. The vibration sensor, in conjunction with at least one timer, monitors the vibrations of the scroll machine and will shut down the machine when excess vibrations are sensed over a prespecified period of time. The temperature system monitors operating temperature conditions the pressure system monitors operating pressures and the mis-wiring system monitors the power supplied to the compressor. Once an undesirable characteristic is identified, the operation of the scroll machine is stopped. These protection systems are integrated into a single subsystem which identifies the reason of shutting off the scroll machine in order to simplify repairs needed. The subsystem incorporates a gateway and/or a serial peripheral interface in order to communicate with a central operating and control system.

Compressor with control and protection system

A protection system for a scroll machine provides temperature, mis-wiring and vibrational protection for the scroll machine. The vibrational protection comprises a vibration sensor which is integrated on the circuit board of the protection system. The vibration sensor, in conjunction with at least one timer, monitors the vibrations of the scroll machine and will shut down the machine when excess vibrations are sensed over a prespecified period of time. The temperature system monitors operating temperature conditions and the mis-wiring system monitors the power supplied to the compressor. Once an undesirable characteristic is identified, the operation of the scroll machine is stopped. These protection systems are integrated into a single module which identifies the reason of shutting off the scroll machine in order to simplify repairs needed.

Compressor with protection module

Compressor discharge temperature, ambient outdoor air temperature and thermal load are used as control parameters for controlling the expansion valve setting and indoor fan speed. Diagnostics monitor a feedback signal from the fan motor to detect fan over-speed and increased speed due to decreased air flow caused by a dirty indoor air filter. Discharge pressure of the compressor is monitored to detect a blocked outdoor fan. The difference between actual and optimum compressor discharge temperatures and suction pressure of the compressor are monitored to detect a stuck-closed expansion valve or low refrigerant charge. Compressor 'short-cycling' is limited to prevent reduced reliability of the compressor. The difference between compressor discharge temperature and outdoor coil temperature is measured before and after startup to detect compressor failure.

Diagnostics for a heating and cooling system

The microprocessor-based HVAC control system detects sensor faults by comparing thermistor readings with predetermined extreme values, indicative of sensor fault. The system automatically selects the appropriate combination of automatic/preset modes of operating key system components such as the expansion valve, the demand defrost system and the indoor fan speed control system. With a view towards minimizing any negative impact on system performance and reliability in the event of sensor malfunction.

Heat pump motor optimization and sensor fault detection

Compressor discharge temperature, ambient outdoor air temperature and thermal load are used as control parameters for controlling the expansion valve setting and the indoor fan speed. In a variable capacity system the thermal load parameter also controls the compressor capacity. Thermal load is measured by an integrating procedure that increments or decrements an accumulated demand counter value used as an indication of thermal load on the system. The counter value is incremented and decremented based on the room temperature and thermostat setpoint. These same parameters are also used in the overcharge/undercharge diagnostic system.

Heating and cooling system with variable capacity compressor

Liquid refrigerant temperature, measured by a sensor adjacent the flow control device, provides multiple diverse pieces of information which are used to control the indoor fan speed. liquid refrigerant temperature is used as an indication of outdoor air temperature and is also used as an indication of whether the compressor is operational or not.

Forced air heat exchanging system with variable fan speed control

The blocked fan or obstructed airflow condition is detected by measuring the difference between outdoor air temperature and outdoor exchanger coil temperature. If a very high difference is detected, or if no decrease in the difference is achieved after termination of the defrost cycle, and if either of these conditions persists over a plurality of defrost cycles, then the blocked condition is declared. The diagnostic system can be integrated in an existing demand defrost cycle and is capable of detecting blocked conditions attributable to foreign matter such as leaves, paper and debris which cannot be cleared by defrosting.

Blocked fan detection system for heat pump

The control system employs multiple, distributed architechure, processors in the indoor unit, the outdoor unit and optionally the thermostat unit. The overall system control functions are distributed across the processors, which communicate with one another over a communications link, employing a messaging system which allows sensor values to be obtained locally and transmitted to the other processors. The processors communicate to automatically refresh or update information during times when it will not degrade performance of critical functions.

Microprocessor-based control system for heat pump having distributed

A blocked fan or obstructed airflow condition is detected by measuring the difference between outdoor air temperature and outdoor exchanger coil temperature. If a very high difference is detected, or if no decrease in the difference is achieved after termination of the defrost cycle, and if either of these conditions persists over a plurality of defrost cycles, then the blocked condition is declared. The diagnostic system can be integrated in an existing demand defrost cycle and is capable of detecting blocked conditions attributable to foreign matter such as leaves, paper and debris which cannot be cleared by defrosting.

The refrigeration control software periodically checks for overcharge and undercharge conditions by placing the expansion valve at a predetermined setting, based on measured environmental temperature. While the expansion valve is at the predetermined setting a series of compressor discharge temperature readings are taken to obtain an average reading and this average reading is compared with a reference value. An undercharge condition is declared when the average reading is greater than the reference value and an overcharged condition is declared when the average reading is less than the reference value.

Overcharge-undercharge diagnostic system for air conditioner controller

A microprocessor based control system for controlling frost accumulation on the outdoor evaporator coil of a heat pumping system during normal heat mode operations. A demand defrost concept is implemented to increase efficiency and maximize time intervals between defrost cycles by initiating the defrost cycle only when an optimal maximum amount of frost has accumulated on the coil. The control system also facilitates monitoring of the rate of frost accumulation to make the outdoor coil conditions less favorable to frost buildup.

Growing community of inventors

Piqua, OH, United States of America

Hank E Millet