JPS58130942A - Control device for hot-water reserving type electric water heater - Google Patents

Abstract

PURPOSE:To reduce heat dissipating loss and improve power transmission efficiency by a method wherein the necessary conducting time of electric power supplied to a heating body is operated by detecting feed water temperature and the amount of heat of the hot-water remaining in a hot-water reserving tank and the necessary conducting time is contrived so as to be completed at a time when the conduction of midnight electric power is finished. CONSTITUTION:The temperature of water fed into the hot-water reserving tank is detected by a feed water temperature sensor 6 while the amount of heat to be reserved is operated in an operator 7 from the detected value of the sensor 6 and the capacity of the hot-water reserving tank. The amount of heat of the hot-water remaining in the hot-water reserving tank is detected by the detecting unit 8 for the amount of heat of the remaining hot-water while the necessary conducting time is operated in the operator 9 from a difference between the amounts of heat detected by the operator 7 and the unit 8. The conduction of electric power supplied to the heating body 2 is controlled in a timer unit 10 so that the necessary conducting time, obtained by the operator 9, has been completed at the time when the supply of the midnight electric power is finished. The high-temperature hot-water, raised in the temperature thereof, will not be left for a long period of time and the heat dissipating loss may be reduced. Further, the electric power is supplied in the later half of the time band for supplying the midnight electric power, therefore, the power transmission efficiency may be improved.