The Trane Company

American Standard Inc.

Trane International Inc.

Robert E Krocker

James F Saunders

Paul C Rentmeester

Thomas J Clanin

Robert M Swanson

Tony J Wood

Merle A Renaud

Terence D Baier

Michael W Murry

Brian S Junk

Patrick J Wilson

Kirk W Johnson

A system for servicing a computer controlled machine comprising: a computer controlled machine including a device operable to perform a function, a controller controlling the operation of that device, and a data access port for transferring data and commands from the controller; and a service tool operably connected to the data access port, the service tool including a remote communications capability, a computer, and diagnostics and graphing software; and an expert observer system operably linked to the remote communications capability of the service tool and including historical machine data, machine sales information, software revisions for the controller, additional diagnostics software, and an expert observer capable of providing a mentor capability to the operator of a service tool.

HVAC service tool with internet capability

The determination as to whether an operational compressor in a multiple-screw compressor water chiller is fully loaded is made by sending a relatively long duration test pulse to the load solenoid of the compressor. If the compressor is fully loaded, no measurable change in the current drawn by the compressor motor will be measured since no slide valve movement will have occurred and no additional load will have been placed on the compressor. If, however, the compressor is not fully loaded at the time the test pulse is sent, the compressor slide valve will move to load the compressor to an extent such that a reliably measurable change in compressor motor current draw occurs.

Method and apparatus for determining full load condition in a screw

A microcomputer based fault detector for identifying a phase reversal, a phase loss, and a power loss in three-phase circuits. A microcomputer samples a pattern of timing signals generated in response to three current transformers associated with each of the three phases. The changing pattern of timing signals represent the phase relationship of each of the three phases. The sampling rate of the microcomputer is synchronized to the alternating current in each of the three phases by an interrupt signal indirectly generated by one of the phases. In the absence of current in this interrupt generating phase, a backup interrupt, internal to the microcomputer, is enabled which directs the microcomputer to determine if the absence of the first interrupt is due to a phase loss or a power loss. Either interrupt prompts the microcomputer to sample the pattern of signals and compare it to a predetermined pattern. By counting any deviant patterns and classifying them as characteristic of either a phase reversal, phase loss, or power loss, the microcomputer identifies the specific fault as the occurrence of a predetermined number of deviant patterns within a classification.

Fault detector for a three-phase alternating current supply

A thermostat used to control a temperature conditioning system to heat or cool a comfort zone to a heating setpoint and a cooling setpoint. The thermostat is microcomputer based and includes both a digital keypad and display for setpoint entry by an operator. Control means in the thermostat automatically insure that at least a predetermined minimum offset is maintained between the heating and cooling setpoints stored in memory, and the control means are further operative to adjust one of the setpoints if the operator enters a value for the other setpoint that is in error.

Auto changeover thermostat with means for handling temperature entry

A control and method for defrosting the outdoor heat exchanger of an air source heat pump. A defrost cycle is initiated when ice and frost have accumulated on the outdoor heat exchanger sufficiently such that, as a function of the indoor temperature of a comfort zone, the maximum permissible heat transfer degradation at which the efficiency and reliability of the temperature conditioning system are optimized, has occurred. Heat transfer degradation is determined from the outdoor ambient air temperature and the temperature of either the outdoor heat exchanger, or the compressor suction line. If the temperature of the outdoor heat exchanger or the suction line is less than a predetermined value, a deferred defrost cycle is initiated wherein the defrost cycle starts after a fixed time interval has elapsed. The defrost cycle is terminated when the relative tempratures of the outdoor heat exchanger and the outdoor ambient air indicate that sufficient frost is melted from the heat exchanger to insure adequate time between successive defrost cycles for optimizing the efficiency and reliability of the system, or after a predetermined time interval has elapsed, whichever condition occurs first.

Control and method for defrosting a heat pump outdoor heat exchanger

Apparatus and method for controlling a temperature conditioning system in which a plurality of stages of temperature conditioning apparatus may be selectively energized to meet a temperature conditioning demand in a comfort zone into which the flow of temperature conditioned air is varied in response to temperature therein. Control means are operative to determine the differential temperature of the return air and the supply air and to energize and de-energize stages of temperature conditioning in response thereto. Means are provided to measure the outdoor ambient temperature, thereby enabling the control means to determine the heating capacity of an ambient air source heat pump relative to the outdoor ambient air temperature, and to energize and de-energize heating stages as appropriate, to meet heating demand.

Apparatus and method for controlling a variable air volume temperature

A control and method for defrosting the outdoor heat exchanger of an air source heat pump. A defrost cycle is initiated when ice and frost have accumulated on the outdoor heat exchanger sufficiently such that, as a function of the indoor temperature of a comfort zone, the maximum permissible heat transfer degradation at which the efficiency and reliability of the temperature conditioning system are optimized, has occurred. Heat transfer degradation is determined from the outdoor ambient air temperature and the temperature of either the outdoor heat exchanger, or the compressor suction line. If the temperature of the outdoor heat exchanger or the suction line is less than a predetermined value, a deferred defrost cycle is initiated wherein the defrost cycle starts after a fixed time interval has elapsed. The defrost cycle is terminated when the relative temperatures of the outdoor heat exchanger and the outdoor ambient air indicate that sufficient frost is melted from the heat exchanger to insure adequate time between successive defrost cycles for optimizing the efficiency and reliability of the system, or after a predetermined time interval has elapsed, whichever condition occurs first.

Apparatus and method for controlling one or more electrically powered devices. A control for a temperature conditioning system is shown which is operative to monitor the electrical current supplied to component devices, i.e., compressors, auxiliary heating elements, indoor fan, and outdoor fan; and to cause an indicator means to indicate that one or more of the devices has failed to operate in a manner consistent with the controlled status of the system. If a failure is detected, control means are operative to lock out one or more of the devices from operation.

Current monitoring control for electrically powered devices

Method and apparatus are disclosed for controlling and selectively setting back the comfort condition, such as temperature, within a conditioned zone utilizing a system which includes both preferred and back-up conditioning means, the former exhibiting more favorable energy consumption characteristics than the latter. The system is operable in both a normal mode, and in an economy mode during which the comfort condition is permitted to degrade toward an economy level during a setback period of predetermined duration. Selective operation of the preferred and back-up conditioning means is effected in order to minimize energy consumption during both modes and especially during the time that the comfort condition is restored to the normal level from the economy level. In a preferred embodiment, the preferred conditioning means comprise an electrically operated heat pump of the vapor compression type and the back-up conditioning means comprise electrical resistance-type heating means. A second aspect of the present invention involves the provision of a system which includes a refrigeration system for cooling a conditioned zone in conjunction with economizer means for supplying cool ambient air to the conditioned zone during those times when it is available and wherein operation thereof is effected in both normal and economy cooling modes so as to minimize the overall energy consumption of the system.

Growing community of inventors

Stoddard, WI, United States of America

Robert E Krocker