A monitoring system for a heating, ventilation, and air conditioning (HVAC) system of a building includes a monitoring device installed at the building, a monitoring server located remotely from the building, and a review server. The monitoring device measures an aggregate current supplied to components of the HVAC system and transmits current data based on the measured aggregate current. The monitoring server receives the transmitted current data and, based on the received current data, assesses whether failures have occurred in first and second components of the HVAC components. The monitoring server generates a first advisory in response to determining that the failure has occurred in the first component. The review server provides the first advisory to a technician for review and, in response to the technician verifying that the failure has occurred, transmits a first alert.

/pdf/hvac-system-remote-monitoring-and-diagnosis-4g4e28ij0c.pdf

Hvac system remote monitoring and diagnosis

A monitoring system for a heating, ventilation, and air conditioning (HVAC) system of a residence includes a monitoring device installed at the residence and a server located remotely from the residence. The monitoring device measures an aggregate current supplied to a plurality of components of the HVAC system and transmits current data based on the measured aggregate current. The server receives the transmitted current data and, based on the received current, assesses whether a failure has occurred in a first component of the plurality of components of the HVAC system and assesses whether a failure has occurred in a second component of the plurality of components of the HVAC system.

Residential solutions hvac monitoring and diagnosis

A system and method for managing energy consumption of a building system includes a source of actual energy consumption data (430), a source of actual weather data (440), and a database (420) correlating discrete weather data values with expected energy consumption values for at least one component of the building system. A computer accesses the actual weather data, actual energy consumption data (430) and database (420), wherein the computer compares (450) the expected energy consumption values with actual energy consumption data and generates an output (470) based on the comparison. The expected energy consumption values are generated for the discrete weather data values using an energy consumption model that functionally relates discrete weather data values and design information for the buiding system component.

Model-based alarming

A system and method for monitoring the food product and refrigeration system performance of a remote location includes a management center in communication with a remote location through a communication network. The management center receives performance information of the refrigeration system at a remote location. The management center employs software modules to analyze the performance information, diagnose system conditions, and provide alarms for food safety and quality issues, refrigeration system component failure, and indicate maintenance conditions.

System for remote refrigeration monitoring and diagnostics

An environmental control system for conditioning air in a vehicle compartment, such as an aircraft cabin. Cool expanded higher-pressure air from a turbine is mixed with recirculated warmer, lower pressure air from the compartment. The air is mixed and recirculated by a jet pump which includes an inlet section, an outlet section, a diffuser section and a mixing section. The mixing section includes a plurality of separate mixing chambers. The diffuser section includes diffusers for receiving mixed gases from each of the mixing chambers. The outlet section receives the mixed gases which are then conveyed to the compartment. The inlet section includes for each of the mixing chambers, a primary nozzle for introducing the higher-pressure air into a respective mixing chamber, and a secondary nozzle for introducing the lower pressure air to a respective mixing chamber.

Environmental control system

The control system of the invention regulates a centrifugal compressor having inlet guide vanes adjustable as one means for varying the compressor capacity A variable speed motor is connected to drive the compressor, and provides another means for regulating the compressor capacity The control system regulates the motor speed alone over one portion of the load variation curve, and regulates the motor speed jointly with the inlet guide vane opening over another portion of the load variation curve, to achieve the most energy-efficient operating condition while avoiding the surge condition This optimum control path is realized by utilizing a signal which is a measure of the compressor head value Compressor surge or instability is avoided by deriving a critical Mach number (speed indication) for any given operating condition, as a function of the compressor head and vane position, and preventing the motor speed from going below that Mach number under the specific operating conditions The control system of the invention is useful both with existing equipment, by way of retrofit, and with newly manufactured and installed equipment

Control system for regulating large capacity rotating machinery

The logic control system of the invention regulates the frequency of operation of an inverter which drives an electric motor, and also regulates the level of the d-c bus voltage supplied to the inverter. This is accomplished by sensing the level of the bus voltage and the level of the current supplied to the motor, and comparing the sensed values to a reference or set point signal. The motor drives a compressor, and a capacity control system cooperates with the logic control system in the regulation of the compressor. The capacity control system provides signals, such as start/stop and inverter set point, to the logic control system to assist in regulating operation of the inverter which drives the compressor. In particular the logic control system includes a reference conductor on which a basic reference control signal is developed for use in controlling both the amplitude and the frequency of the a-c energy supplied by the inverter to the motor.

Logic control system for inverter-driven motor

Semiconductor apparatus (600) for mounting and cooling disc type semiconductor devices (602, 604). The apparatus includes two disc type semiconductor devices each having a pole face thereof in contact with a first terminal bar (606), that bar in turn being in contact, through thermally conductive electrical insulation, with a water-­cooled plate (610). The opposite pole face of each disc device is in electrical and thermal contact with a first surface of a respec­tive metallic block (632, 634). A second surface of each block, opposing the first face, is in electrical conductive contact with a second terminal bar (630). A compressive mounting force is applied across the first and second terminal bars to appropriately compress the disc devices. Each metallic block is sized to absorb a substantial portion of the disc device junction heat generated during a tran­sient portion of a duty cycle, such as may correspond to the starting of a motor.

System for mounting and cooling power semiconductor devices

A three-phase rectifier circuit is connected to provide a d-c output voltage as a function of the three-phase energy passed to the rectifier circuit. This energy is reduced in amplitude over a voltage divider circuit and passed through an optically-coupled detector circuit to provide a control signal indicating the presence of energy on all phase conductors of the supply line. If a fuse blows in one line, or if the power on that line is interrupted for any reason, the ripple content of the rectified voltage increases. This is sensed by a detector circuit to energize an alarm and/or interrupt the main power bus to the load.

Phase failure detection circuit for multi-phase systems

An improved temperature control system for centrifugal compressors in refrigeration equipment for elimination of ''''droop'''' associated with proportional position control is disclosed using a two thermistor temperature sensing unit for sensing both the temperature and the rate and direction of change of the temperature of the chilled liquid from the evaporator and for producing a change in the pre-rotation vane setting. The rate and direction of change of temperature is obtained by comparing a fast and a slow temperature signal in a summing amplifier to control a pulse width modulator that modulates a sawtooth generator to control a vane motor through appropriate logic. The fast temperature signal is also compared with a unit cycling thermostat reference signal in a Schmitt Trigger to de-energize the compressor when that temperature signal reaches the reference level. The fast temperature signal is also used to drive a recorder.

Dean King Norbeck

Papers

Control system for regulating large capacity rotating machinery

Logic control system for inverter-driven motor

System for mounting and cooling power semiconductor devices

Phase failure detection circuit for multi-phase systems

Temperature control system for centrifugal liquid chilling machines