A remote control system for operating electrical loads, particularly in multi-unit lodging establishments such as hotels, motels and the like, includes a power sensing circuit for deenergizing the loads when the power supplied varies beyond predetermined limits in voltage or phase, a restart circuit for sequentially reenergizing the loads with the time between reenergization of loads on successive buses being dependent upon the period of time the loads were deenergized in order not to produce an overload by simultaneous load operation under peak demand conditions, a start-up circuit for controlling the cycle period of the loads in accordance with outdoor temperature in order to provide efficient freeze protection and temperature maintenance, an excess manual switching circuit for comparing the number of loads presently energized with the number of loads energized at a predetermined prior time plus a preset number representing the maximum number of loads desired to be energized over the predetermined period of time such that if the number of presently energized loads exceeds the desired number of energized loads over the predetermined time no additional loads can be manually switched on-line until the number of presently energized loads is reduced below the desired number of energized loads thereby increasing electrical efficiency.
An energy demand controller having a sensor for measuring the instantaneous power being delivered to a building, a thumb wheel switch for preselecting a power limit for use in the building, and circuitry for comparing the instantaneous power to the power limit and to switch off power to various heating zones within the building in order to maintain the instantaneous power below the preselected power limit. The control circuitry includes a cycling circuit only operative when the instantaneous power exceeds the measured power to deactivate a sufficient number of heater circuits in order to drop the instantaneous power below the preselected power limit for a predetermined time interval only. At the end of the predetermined time period, the deactivated heater circuits are turned back on. If the instantaneous power still exceeds the preselected power limit, then other zone heaters of sufficient number are likewise deactivated in a second predetermined time interval. As long as the instantaneous power exceeds the preselected power limit when the predetermined time intervals terminate, the heater circuits, in similar fashion, will be cyclically turned off and on so that heat loss in any given area is minimized. When all heater circuits within the predetermined time interval are deactivated, and the instantaneous power still exceeds the power limit, then the hot water heater is deactivated. If the instantaneous power still exceeds the preselected power limit, an alarm will then sound to inform the inhabitant of the building to either increase the preselected power limit or to deactivate other electrical circuits within the building.
A system and method is disclosed for intelligent power management of actuators such as those used in papermaking. Multiple power supply units are connected to a common power bus. The power bus is connected at predetermined locations to a communications bus. The communications bus is connected in series with all of the actuators. The actuators are arranged in predetermined groups. A computing device determines if electrical power can be supplied to some or all of the actuators that are requesting simultaneous movement and if there is insufficient power for all such actuators the computing device issues permission for actuators to move based on a preselected criteria.
A power controller for a powered device such as a heating/air conditioning unit that monitors and controls the supply of power to an individual heating/air conditioning unit and shuts off power to the powered device when the voltage level of the power supplied to the unit falls outside a predetermined range. The power controller also transmits telephonic alarms and receives touch tone commands over telephone lines. The power controller may be equipped with a device for sensing the presence of a fire.
A PC computer monitors the energy, power, voltage, and current consumed at a plurality of local stations placed behind the electrical meter of the utility company for individual billing of the local users, a bidirectional communication line being used therebetween. A command from the PC computer causes at each station the power, voltage, current and totalized energy to be stored, and thereafter the PC computer derives individually the results for separate estimations and central billing.
A data processing system includes as part of its power circuits, a number of converter circuits, each coupled to a different one of the power supply units which are to provide different voltages for distribution and use throughout the system. Each of the power supply circuits furnish a 24 volt dc power confidence signal to a central ac power input entry panel which applies the power confidence signals to the converter circuits. Each converter circuit includes an optically coupled isolator circuit which converts the 24 volt dc signal to a noise free low voltage logic level suitable for utilization by the low level high speed logic circuits included within the system. The output noise free low voltages provided by the converter circuits are in turn applied to a corresponding number of confidence input lines of a system interface unit which includes a plurality of ports, each port connected to a different module within the data processing system. The states of the low voltage logical level signals are stored in a status register. When the operating system determines that a unit is inoperative due to a power supply unit failure, it can logically disconnect the port having a module having the failure. Additionally, one of the converter circuits provides a second output signal which is used to enable the clock circuits during system power up only after the system has been placed in a known state.
