This invention relates generally to the control of electrical power distribution, and more particularly limiting overheating due to supply voltage reduction, the invention having particular application to electrical equipment associated with operation of pools or spas.
U.S. Pat. No. 5,133,818 discloses operation of a water pump for circulating water to and from a spa or hot tub, the pump driven by an electrical motor from which heat is transferred to the circulating water stream. If the supply voltage to the motor and/or heater appliance drops, electrical current supplied to the motor and/or heater appliance can increase significantly, resulting in risk of electrical overheating and risk of damage to electrical circuitry or components. There is a need for method and means to alleviate these problems, as well as in other applications or systems. There is also need for means to control electrical power delivery to the pump motor and/or heater appliance, as a function of changes in motor and/or heater appliance supply voltage level.
It is a major object of the invention to provide a solution to the above problem or problems. Basically, the method of controlling electrical power delivery, as for example when a motor driven pump and/or heater appliance is operated, includes the steps
It is another object of the invention to provide for controlling electrical power delivery operating to increase or restore electrical power delivery to the motor when a predetermined secondary condition is met, such as operation of a protectionary device, or when proper voltages are re-established. The voltage level monitoring as referred to preferably provides power delivery to the motor and/or heater when a predetermined threshold has been achieved.
Yet another object includes providing control circuitry to perform said sub-paragraph c) controlling. In this regard, voltage level monitoring is typically effected by providing and operating a voltage level monitor at the voltage input side of the motor and/or heater.
The invention is also applicable to systems that do not incorporate the specific spa or hot tub equipment referred to.
In its apparatus aspects the invention includes
Such equipment may include additional pumps, motors, or other electricity using devices.
More generally, apparatus for controlling heating and circulation of a liquid or liquid stream includes:
These and other objects and advantages of the invention, as well as the details of an illustrative embodiment, will be more fully understood from the following specification and drawings, in which:
A pump 14 is driven by an electrical motor 15, to pump water or liquid to body 11, and to receive water or liquid from body 11. Typically, heat generated by motor 15 is transferred to the water or liquid being circulated to the body 11. See for example ducting 16 passing in heat transfer relation to the motor, as by coiling about the motor housing 15a. Accordingly, the motor is electrically operated as a form of useful heater, in conjunction with operation of a spa. A separate independent heater can be employed.
Numeral 17 indicates a water jet at wall 13a, to jet heated water into body 11, and numeral 18 indicates a suction fitting typically at wall 13a, to deliver water from body 11 to line 12b.
The invention contemplates provision of the following:
In the example, such first means may typically include a voltage level monitor 20 at the voltage input side of the system, the power supply line or lines indicated at 21a and 21b. An upstream junction box, or breaker box, or outlet box is indicated at 22. The monitor 20 may comprise a voltage level detector in or at line 21a, or a microprocessor or comparator as seen in
The referenced second means for monitoring the temperature of water in the water body 11, or water flowing to or from the spa, may comprise a temperature level detector 28 seen in
It will be noted that the control system operates to cause opening of voltage level responsive switch 24, irrespective of the open or closed condition of water temperature responsive switch 33, whereby the former dominates or overrides the latter.
The invention, generally, in its method aspects embodies the steps
The invention, generally, in its apparatus aspects concerns means for controlling circulation of a liquid stream, and embodying:
Incoming electrical power is delivered to 23 by line 54 from 22.
Auxiliary lines 55 and 56 deliver electrical power from 23 to auxiliary components 57 and 58, associated with the spa.
Monitor 20 at line 54 operates to assess voltage level, as for example a drop to a threshold below normal level. Control 23 responds to decrease or eliminate power delivery via lines 21b, 53, 55 and 56 to equipment 15, 52, 57 and 58, in the manner as referred to above. Switches for such lines are located at 59.
In
Control components are shown to include the control system 23, electric power monitor 20 and line 21a to control unit 23a, and water temperature monitor 28 and line 31 to control unit 23a. These components remain supplied with electrical power so as to be operable, even though power may at times be cut-off to to other components (pump motor 14, water heater 61, and blower or ozone generator 90). On-off power delivery control switches 92-94 are shown as in series with lines 53, 21b and 91 to the respective other components 52, 14 and 90. Switches are operated by the control unit 23a, as via control line or lines indicated at 93. Power delivery lines to the switches are indicated at 92a, 93a and 94a. The control unit 23a (for example software) operates to control the supply of power to the power consuming components 52, 14, and 90, in response to monitoring at 20 and 28. If monitored voltage level at 20 drops below a predetermined threshold, switches 92-94 are opened, but power delivery to operate 23a, 20 and 28 is not interrupted. Similarly, the control operates to close the switches when full input voltage level is restored. As indicated, provision is made for supply of electrical power to the control components during both maintenance and cut-off of power supply to the power consuming components 52, 14 and 90. This prevents failures (such as control failures), as well as reducing power being consumed during times of heavy external power usage.
Number | Name | Date | Kind |
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5361215 | Tompkins | Nov 1994 | A |
5559720 | Tompkins et al. | Sep 1996 | A |