An electrical power distribution control system configured to issue a demand response signal to cut power to a plurality of electrical power consuming loads within an electrical power distribution network to reduce a peak power demand within an electrical power grid during a peak power demand. Unlike conventional demand response systems, the controller in each consumer residence includes both a distributed control based on the ability to track individual 24 hour usage patterns and selectively delay the demand response signal on individual resistive heating loads based on usage patterns for the purpose of reducing a likelihood of consumers experiencing effects of the reduced peak power demand.

A heating assembly for a water heater may include a base, a first electric heating element secured to the base, and a second electric heating element secured to the base. The second electric heating element is electrically isolated from the first electric heating element. The first and second electric heating elements are independently switchable to provide a first heat rating of the heating assembly and a second heat rating higher than the first heat rating. A water heater assembly may include a tank defining a chamber for holding a volume of water, and the heating assembly coupled to the tank. The water heater assembly may include a second heating assembly, and may further include a controller configured to control the first and second heating assemblies to provide heating at same or different heat ratings.

A heating assembly for a water heater may include a base, a first electric heating element secured to the base, and a second electric heating element secured to the base. The second electric heating element is electrically isolated from the first electric heating element. The first and second electric heating elements are independently switchable to provide a first heat rating of the heating assembly and a second heat rating higher than the first heat rating. A water heater assembly may include a tank defining a chamber for holding a volume of water, and the heating assembly coupled to the tank. The water heater assembly may include a second heating assembly, and may further include a controller configured to control the first and second heating assemblies to provide heating at same or different heat ratings.

A water heater that includes a cylindrical storage tank and at least one heating element, is modeled using a one-dimensional model that includes: a vertical stack of disks representing the water volume in the cylindrical storage tank, and a stack of annular segments surrounding the vertical stack of disks. Various temperature measurements are determined via resistance calculations of the at least one heating element. The stack of annular segments represents the cylindrical wall of the cylindrical storage tank. The one-dimensional model may be used by a condition-based maintenance system comprising an electronic data processing device configured to detect a failure mode present in the water heater based on an output of the water heating model component. Some illustrative failure modes include insulation disturbance, heating element failure, excessive sediment buildup, or a drip tube rupture.

Embodiments of this disclosure provide a method and apparatus for determining a fault of a heating device and an electric water heater. When the heating device includes at least two heating units in an operating state parallelly arranged on branches of a same phase line and the heating unit include a heating element and a switch controlling the heating element, the method includes: acquiring a main circuit current value of the phase line when the operating state of the heating units is not changed, and determining that a fault occurs in a heating element in at least one heating unit when the main circuit current value is not greater than a first current value; and acquiring a variation value of the main circuit current value caused by turning on/off the switch, and determining that a fault occurs in a heating element controlled by the switch when the variation value of the main circuit current value is not greater than a preset variation value. With the embodiments of this disclosure, diagnosis of faults in a plurality of heating elements in the heating device may be achieved at a low cost and high reliability.

Embodiments of this disclosure provide a method and apparatus for determining a fault of a heating device and an electric water heater. When the heating device includes at least two heating units in an operating state parallelly arranged on branches of a same phase line and the heating unit include a heating element and a switch controlling the heating element, the method includes: acquiring a main circuit current value of the phase line when the operating state of the heating units is not changed, and determining that a fault occurs in a heating element in at least one heating unit when the main circuit current value is not greater than a first current value; and acquiring a variation value of the main circuit current value caused by turning on/off the switch, and determining that a fault occurs in a heating element controlled by the switch when the variation value of the main circuit current value is not greater than a preset variation value. With the embodiments of this disclosure, diagnosis of faults in a plurality of heating elements in the heating device may be achieved at a low cost and high reliability.

A water heater that includes a cylindrical storage tank, at least one heating element, and at least one temperature sensor is modeled using a one-dimensional model that includes: a vertical stack of disks representing the water volume in the cylindrical storage tank, and a stack of annular segments surrounding the vertical stack of disks. The stack of annular segments represents the cylindrical wall of the cylindrical storage tank. The one-dimensional model may be used by a condition-based maintenance system comprising an electronic data processing device configured to detect a failure mode present in the water heater based on an output of the water heating model component. Some illustrative failure modes include insulation disturbance, heating element failure, excessive sediment buildup, or a drip tube rupture.

An electronic module housing having a rounded stylized dog-bone-type shape and an equatorial partial light bar. The shape provides a view of parts of the light bar from many locations. The controller circuitry can detect a malfunction among one or more of a plurality of current-drawing components by detecting that the total cumulative current drawing by all the components falls outside a predetermined nominal range.

In accordance with the principals of the present invention, a furnace unit adapted to be installed in-line with a fuel source of a furnace modulates natural gas or propane to reduce fuel consumption, minimize temperature overshoot, and reduce furnace short cycling. A modulator is contained with the furnace unit. The modulator is in gaseous communication with the in-line gas fuel source. A furnace sensor senses furnace criteria related to the operation of the furnace. A microcontroller receives from the furnace sensor furnace criteria and controls the modulator based on the furnace criteria. In a further aspect of the invention, an environmental sensor can be provided to sense environmental criteria related to the operation of the furnace. In a further aspect of the invention, a base unit in electrical communication with the furnace unit can be provided, the base unit determining energy consumption usage and savings. This Abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims

This invention relates in general to a renewable energy water heating system and method for residential and commercial applications. The heating system has a renewable energy source providing a DC electric current and a controller connected to the renewable energy source. The water heater is connected to the controller, the water heater having a water storage tank and at least one heating element for heating water in the tank responsive to an electric current supplied thereto. The controller modulates and switches the DC electric current to produce a converted output to provide the electric current to the at least one heating element to heat the water.