Abstract: A junction box is operable with a gas valve and includes an enclosure having one or more mechanical coupling features arranged to interface with one or more mating features of the gas valve. An electrical terminal strip is disposed within the enclosure and a quick-disconnect electrical connector is disposed on a surface of the enclosure. The quick-disconnect electrical connector is coupled to a mating connector of the gas valve when the mechanical coupling features are interfaced with the mating features of the gas valve. The junction box includes a current carrying element that electrically couples the electrical terminal strip with the quick-disconnect electrical connector. The enclosure includes an opening that facilitates access to at least the electrical terminal strip, and includes one or more access voids disposed to allow electrical wires to enter the enclosure.

Abstract: A junction box is operable with a gas valve and includes an enclosure having one or more mechanical coupling features arranged to interface with one or more mating features of the gas valve. An electrical terminal strip is disposed within the enclosure and a quick-disconnect electrical connector is disposed on a surface of the enclosure. The quick-disconnect electrical connector is coupled to a mating connector of the gas valve when the mechanical coupling features are interfaced with the mating features of the gas valve. The junction box includes a current carrying element that electrically couples the electrical terminal strip with the quick-disconnect electrical connector.

Abstract: A commissioning system incorporates a commissioning station for mounting a controller to be commissioned by the action of loading data into a writable memory of the controller. The station has a label reader for reading a label attached to the controller. Preferably the label is readable by the label reader only when the controller is mounted on the commissioning station. Data encoded in a code pattern on the label specifies commissioning parameters to be loaded into the controller memory. The label reader reads the code pattern and generates a signal encoding the code pattern data. The commissioning system receives this signal and transmits a commissioning signal to the controller encoding the commissioning parameters, which are then loaded into the controller memory. In one embodiment the commissioning station has a configuration that cooperates with the controller to create an access barrier to the label reader scanner surface when the controller is mounted on the station.

Abstract: A system for commissioning a controller accepts a different manual input during each of several different phases of the installation and provides the installer with a different detectable cue during each phase. The installer provides the manual input and then operates a switch indicating the input is present. The system stores the manual input present and advances the system to the next phase, and in a preferred embodiment provides a visible cue identifying each phase. The preferred embodiment uses devices controlled by the controller during normal operation and which also have manual position adjustment or set point selection to provide the manual inputs.

Abstract: A control system for controlling an operating system stores a system parameter such as an ultimate pressure value, for an operating system. The control system allows operation of the operating system only after an initial value of the system parameter has been loaded. In one embodiment, a data generator element intended normally to specify a set point for the operating system, is used to provide the system parameter value as well. The control system provides a grace period after a value of the system parameter has been entered during which the system parameter value can be changed. After the grace period ends, the system parameter value cannot be changed by the operating system manager under normal circumstances. A light source is flashed in various patterns to indicate to personnel which of several different actions available to the control system are occurring.

Abstract: A commissioning system incorporates a commissioning station for mounting a controller to be commissioned by the action of loading data into a writable memory of the controller. The station has a label reader for reading a label attached to the controller. Preferably the label is readable by the label reader only when the controller is mounted on the commissioning station. Data encoded in a code pattern on the label specifies commissioning parameters to be loaded into the controller memory. The label reader reads the code pattern and generates a signal encoding the code pattern data. The commissioning system receives this signal and transmits a commissioning signal to the controller encoding the commissioning parameters, which are then loaded into the controller memory. In one embodiment the commissioning station has a configuration that cooperates with the controller to create an access barrier to the label reader scanner surface when the controller is mounted on the station.

Abstract: A control system for controlling an operating system stores a system parameter such as an ultimate pressure value, for an operating system. The control system allows operation of the operating system only after an initial value of the system parameter has been loaded. In one embodiment, a data generator element intended normally to specify a set point for the operating system, is used to provide the system parameter value as well. The control system provides a grace period after a value of the system parameter has been entered during which the system parameter value can be changed. After the grace period ends, the system parameter value cannot be changed by the operating system manager under normal circumstances. A light source is flashed in various patterns to indicate to personnel which of several different actions available to the control system are occurring.

Abstract: A system for commissioning a controller accepts a different manual input during each of several different phases of the installation and provides the installer with a different detectable cue during each phase. The installer provides the manual input and then operates a switch indicating the input is present. The system stores the manual input present and advances the system to the next phase, and in a preferred embodiment provides a visible cue identifying each phase. The preferred embodiment uses devices controlled by the controller during normal operation and which also have manual position adjustment or set point selection to provide the manual inputs.

Abstract: A local station and a remote station are connected by a single pair of conductors. The local station communicates with the remote station by modulating a power supply within the local station which provides power on the conductor pair for operating the remote station. The remote station modulates its impedance, causing a change in current flow on the conductor pair which the local station can detect. In this way both stations can transmit data to each other at the same time and while the local station is providing operating power to the remote station.

Abstract: A power controller has upstream and downstream switches in series connection to provide redundant switching for power supplied from a power source to a load. A switch operating system closes the switch closer to the load first (downstream) and then the switch closer to the source (upstream). The operating system conditions closing the downstream switch on absence of power voltage on an upstream power terminal of the downstream switch. A preferred embodiment of the operating system performs a number of real time status checks during the connection process to assure that power voltage is properly absent and present at switch terminals during the stages of the connection process. This operating system guards against supplying power to the load if either the upstream or downstream switch's pair of contacts are welded at the time the connection process starts.

Abstract: A controller, having a microprocessor, a control potentiometer and a monitor interface circuit connected between the microprocessor and the potentiometer, operates to monitor the control potentiometer and monitor interface circuit for failures. The potentiometer along with its wiring terminals and its wiper are monitored for faults. In addition the monitor interface circuit itself is tested so that either a fault in the potentiometer or a fault in the monitor interface circuit will be detected. The monitoring includes three tests performed from time to time. First, voltages across the full potentiometer are measured and compared to a voltage determined at initial installation or commissioning. The measured voltage is compared against limits to detect whether the measured voltage is inside or outside the limits. Second, the voltage across the wiper selected portion of the control potentiometer is measured and compared against a threshold to detect a fault.

Abstract: A safety circuit for monitoring computer hardware that can create an unsafe condition if a failure occurs. The circuit includes a microprocessor, a keyword decoder, and a dynamic safety relay drive circuit. The microprocessor runs a set of internal tests which create a keyword made up of a series of bits. A particular series of bits indicates the desired operation of the microprocessor. On alternate generations of the keyword one bit in the series is inverted. The keyword decoder receives the keywords and output a "true" signal if the keyword indicates the desired operation of the microprocessor, and "false" signal if the keyword indicates otherwise. The output of the keyword decoder is transmitted to the dynamic safety relay drive circuit, and this signal will keep the circuit energized as long as its alternating. The position of the bit which is inverted is rotated through the keyword so that different bit paths through the keyword decoder may be tested.

Abstract: Apparatus and method for sensing the operating condition of a burner temperature as the indicating variable. When the operating status is stable, the flue temperature should be nearly identical to that when the system was known to be in proper condition. During a time when the system is known to be in proper operating condition, the flue temperature is recorded during stable operation for a number of different firing rates. When identical or similar firing rates occur at a later time and operation is stable, the operating flue temperature is compared with the current flue temperature, and if substantially different, an operation status signal is set to a state indicating this change in operating condition.

Abstract: A method and apparatus control firing rate in a heating system to compensate for thermal mass characteristics of the heating system. The thermal mass characteristics of the heating system are derived from heating system identification information. A weighted control response factor is selected which is representative of load characteristics of a load type affecting firing rate control and which is representative of desired control tightness. The firing rate is varied, based on the weighted control response factor and the thermal characteristics, to match the heating system, the load type being controlled and the desired control tightness for optimum control.

Abstract: A burner control system has a microprocessor for testing parameters of operation and for indicating deviations from a preset range for each. The sensors monitoring the parameters provide their outputs as analog voltages to analog to digital (A/D) converters which provide the parameters in digital form. Tests using preset voltage standards increase the likelihood of A/D converter accuracy. In addition, as operating conditions for the burner change, different preset ranges are used for each sensor output when testing them so as to provide maximum confidence of proper burner operation.

Abstract: Damper position of a damper in a heating system is monitored. The damper is movable between end positions in response to movement of a motor shaft. The motor shaft moves in response to a movement request signal. A shaft position signal is received by a position detector and has a value representative of position of the motor shaft. When the damper reaches an end position, it is determined whether the value of the shaft position signal is within a predetermined tolerance. If it is outside of the tolerance, then the system is shut down as unreliable; otherwise, the shaft position signal is recalibrated to maintain accuracy.

Abstract: A boiler control system utilizing a microcomputer, a memory, and a firing rate control scheme provides a boiler with a more responsive control arrangement. This improved response is accomplished by the firing rate control converting the desired pressure setpoint to a computed temperature, and then establishing a computed pressure band for control of the boiler.

Abstract: An automatic firing rate control mode arrangement is provided as a method of operation within a flame safeguard sequencer. The system uses proportional control squared, an integration which reflects the past load history to determine the present load, and further has a constant which relates the rate of change of pressure with respect to time in order to make more responsive the normal load control operation. The system is also capable of on-off control that will hold the system in low fire to allow for stabilization, and to avoid thermal shock to a boiler.

Abstract: An energy transfer network is used to ensure reliable operation of a low water sensing system for a boiler. The energy transfer network provides a sufficient time interval to make sure that wave action and boiling within the boiler do not simulate the loss of water. The energy transfer network is structured to be discharged in the event water actually drops below an appropriate level. The energy transfer network provides for the continuous presence of water so that boiling action does not simulate an artificially high (presence of) water level.

Abstract: A positive voltage supply is connected to a circuit having a single capacitor and depletion-type field-effect transistor to create a reliable timer. The capacitor is initially charged upon the opening of a control switch without creating a timed output across the drain-source terminals of the field-effect transistor. The closing of the switch reverses the bias of the single capacitor to the gate-source connections of the field-effect transistor to thereby create a fixed and reliable timed interval.