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AssigneeBorg-Warner Corporation
InventorsJacob E. Shaffer, Jr., Joseph F. Picarello
Estimating the term…
A control system for an electric water heater operatively associated with an external heat source, such as a heat pump. The water heater includes a water storage tank provided with an electric tank heating unit having a tank thermostat which closes in response to water temperature in the tank, allowing a flow of current through the tank heating unit so as to turn it on to heat the water, and which opens when the tank thermostat has been satisfied, interrupting the current flow so as to turn the tank heating unit off. The control system as responsive to the initial current surge through the tank heating unit when the tank thermostat closes to (1) interrupt the current flow to the tank heating unit so as to maintain the heating unit off and (2) to turn on the external heat source and maintain it on until the tank thermostat opens. The initial current surge cleans the contacts of the tank thermostat by burning off any insulating oxide residues which may have formed on them. The control system includes means responsive to abnormal conditions which would prevent the external heat source from heating water effectively for (1) turning off the external heat source and turning on the tank heating unit and (2) maintaining the external heat source off and the tank heating unit on until the tank thermostat is satisfied.
A control system for a water heater operatively associated with an external heat source, said water heater including a water storage tank and an electric tank heating unit, said tank heating unit having at least one tank thermostat responsive to water temperature in said tank, said tank thermostat closing when there is a demand for hot water in said tank thereby allowing a current to flow through said tank heating unit so as to turn it on and opening when the demand has been satisfied thereby interrupting the current flow through said tank heating unit so as to turn it off, said control system comprising means responsive to an initial current surge through said tank heating unit when said tank thermostat closes both for interrupting the current flow so as to maintain said tank heating unit off and for turning said external heat source on, the initial current surge cleaning the contacts of said tank thermostat by burning off any residue thereon.
Dependencies are inferred from the claim text.