Patent Application
20090038696
The present invention relates to apparatus and methods for preventing persons, animals or things from being injured by the suction exerted on them by water flowing into a drain, in particular that associated with a fluid circulation system in a bathing receptacle such as a swimming pool or spa. Besides its safety function in preventing injury through drain suction acting on a person or thing, the present invention also L controls and prevents damage to water circulation devices, such as pumps, and may be used to control timed operation of water circulation devices.
Various apparatus have been proposed for preventing injury due to drains in fluid-containing vessels, such as pools and spas, including those which sense a pressure change in the conduit extending from the drain to the pump that draws water from the drain and through the conduit. In response to pressure changes indicating an obstruction of the drain, prior art devices exist which reduce vacuum present in the drain-to-pump conduit by, e.g., turning the pump off and/or opening the conduit to the atmosphere. Notwithstanding, there is a need for improved drain safety protection devices that are operational for different types of drain installations, e.g., those on above-ground and below-ground pools and spas, as well as protection devices which do not interfere with the normal operation of fluid circulation systems as are typically encountered in pools and spas, e.g., during the normal cycling of filter/pump systems on and off, during the establishment of prime condition and during speed changes for pumps. Due to laws pertaining to the running of pumps at higher and lower rates of speed to increase economical operation and diminish the use of electricity, it is desirable to have a drain safety protection device that is capable of maintaining safety through speed changes. Further, it is always an objective to improve the reliability and operability of safety equipment, such as drain safety devices.
The limitations of prior art drain safety and pump control devices and methods are addressed by the present invention, which includes a fluid circulation system having a motor-driven pump. A sensor senses operational parameters of the fluid circulation system indicative of the operational state of the pump. A computer receives the output of the sensor and is programmed with a control program and data representing a plurality of criteria values corresponding to a plurality of potential functional states of the pump. The program compares sensor output to the criteria values and selectively generates control output to the pump to control the operation of the pump, thereby defining an intended pump state. The program checks output from the sensor to verify that the actual functional state of the pump is consistent with the intended pump state and terminating pump operation when an inconsistency exists.
In one embodiment of the present invention, the control system features a vent valve communicating with the suction side of the pump. In the event of an inconsistency between the expected and actual functional state of the pump, the vent valve is opened to release vacuum on the suction side of the pump.
In another embodiment of the invention, a priming time criteria is derived from empirical priming time measurements.
In yet another embodiment, pressure criteria pertaining to vacuum/pressure on the suction side of the pump may be adjustable based upon changes in fluid flow resistance through the system.
a-19f are flowcharts illustrating functionality of an embodiment of the present invention.
The controller 48 receives power from a utility supplied power line 52, which extends to a circuit breaker box 54. The controller 48 switches power to the pump 30 on and off via power line 56 and also controls the position of the valves 42,44 via control lines 58, 60. The occlusion of one of the drains 12, 14 or 22, will trigger a change in the vacuum level present in suction conduit 28. A change in vacuum level is sensed by the vacuum sensor 46 and by the controller 48, which can then respond by opening valves 42, 44 to atmosphere and disrupting power to pump 30. In this manner, suction at the drains 12, 14 and 22 is released allowing any obstruction to be cleared. For example, if a swimmer were to become caught on the main drain 12, the resultant release of suction owing to the venting of the suction line 28 to atmosphere and the discontinuance of pumping will allow the swimmer to remove himself from the main drain 12. Besides executing a drain protection safety function, the controller 48 may also be used to control the times when the pump 30 is operated pursuant to a schedule, as well as when the pump 30 is operated at different speeds. On start-up, the pump in some pool/spa installations requires time to establish a prime, viz., the filling of the suction conduit, strainer and pump housing with water. This is normally accomplished by running the pump at high speed. The pump speed (and associated power consumption that is required to prime the pump) is more than that which is required to maintain effective filtration/circulation once prime has been established. Some states have recently passed laws that require pools and spas to have pumps that are operated at two speeds, namely, at high speed to perform certain functions, such as priming and cleaning, and low speed to conduct filtration at a reduced usage of electrical power. The vacuum release system 39 of the present invention monitors for and responds to vacuum anomalies while pump speed changes are executed. The controller 48 has a display 62 and input keys 64 for an operator interface, allowing the operator to read messages presented on the display 62 by the controller and to provide input, such as selecting menu choices, answers and/or values by pressing selected keys. Some pool/spa systems may have a preexisting controller 65 that controls heating, circulation/filtering, cleaning, chlorination, etc. The controller 48 may be connected to a preexisting controller 65 for the purpose of utilizing the scheduling data entered into the controller 65, thereby acting as an intermediary or co-controller.
The return line 36 has a branch 66 which communicates with the inlet of an optional booster pump 68 that is used to increase the pressure of the fluid from the return line 36 to aid in operating a pressure-type pool cleaner 74. Some pools are equipped with automatic cleaners that utilize the return flow of water from the filtration system to drive various pressure cleaner devices. In some pool systems, the filtration/circulation pump 30 is switched to high power to generate a pressurized flow that is effective at driving a pressure cleaner 74. Still other pool systems utilize a booster pump 68 to increase the pressure of the return flow of water to enhance the effectiveness of a pool cleaner 74 during cleaning mode. The vacuum release system 39 of the present invention is capable of monitoring drain occlusion and pump malfunction while pool cleaning is occurring and during the transitions from normal filtration running to cleaning mode and from cleaning mode back to normal filtration. The outlet of the booster pump 68 discharges into conduit 70 that is connected to a flexible hose 72 leading to the cleaner 74. Power to the booster pump 68 via line 75 may be controlled by controller 48, manually, or by controller 65. A stop switch 76 may be provided with the vacuum release system 39 or an existing stop switch 76 may be employed to signal the controller 48 that an emergency shut down has been ordered. The stop switch 76 may be a normally open switch maintaining electrical continuity in a conductive loop. When pressed, continuity is disrupted, signaling an emergency shut-down.
The controller 148 receives power from a utility supplied power line 152, which extends into a circuit breaker box 154. The controller 148 switches power to the pump 130 on and off via power line 156 and also controls the position of valve 155 via line 158. The occlusion of one of the drains 112 or 122 will trigger a change in the vacuum level present in suction conduit 128. A change in vacuum level is sensed by the vacuum sensor 146 and by the controller 148, which can then respond by opening valve 155 permitting the accumulator 147 to discharge the pressurized fluid contained therein into the suction conduit 128 to pressurize the suction conduit 128 and relieve any vacuum condition that may have previously existed due to an occluded drain. As used herein, the term “fluid” shall have its broadest meaning, encompassing a liquid, such as water, and a gas, such as air. For example, the fluid discharged by the accumulator 147 may include both air and water. The controller 148 also disrupts power to pump 130 to prevent the reestablishment of a vacuum condition in suction conduit 128. In this manner, suction at the drains 112 and 122 is released/reduced allowing any obstruction to be cleared. For example, if a swimmer were to become caught on main drain 112, the resultant release of pressurized fluid from the accumulator 147 into the suction line 128 and the discontinuance of pumping will allow the swimmer to remove himself or herself from the main drain 112. As in the previous embodiment, besides executing a drain protection safety function, the controller 148 may also be used to control the times when the pump 130 is operated pursuant to a schedule, as well as when the pump 130 is operated at different speeds.
Each pool/spa system will have different operating characteristics, e.g., vacuum levels in the suction conduits 28, 128, depending upon many factors, such as pool size, water height above ground level, number and size of drains, conduits, pumps, etc. This is true of normal, unobstructed operation during the various functions performed by the system, as well as during degraded operating mode due to the accumulation of debris in filters and skimmers and when experiencing malfunctions due to obstruction or disconnection of a drain line. The vacuum level in the suction conduits 28, 128 will also vary widely depending upon the functional state that the fluid circulation system is in at any given time: start-up; stabilization; filtration; change of speed; and/or cleaning. As a result, it is necessary to ascertain safe and appropriate vacuum levels for all of the various modes of operation of the circulation system, so that the vacuum release systems 39, 139 are triggered under appropriate circumstances to protect the users and the equipment of the pool/spa system during all phases of operation, while allowing the system to operate in a normal and effective manner.
The upper portion of
Previously, pool/spa owners would manually control the functional state of the circulation systems 10, 110 by, for example, turning the pumps 30, 130, 68 on and off, as necessary. Electro-mechanical timers (a clock which mechanically opens and closes contact points) were then used to automatically turn pumps on and off in accordance with a predetermined schedule. More recently, digital programmable controllers, such as the controller 65, have been utilized to activate pumps and other pool/spa equipment in accordance with a predetermined schedule, which the user enters into the controller 65. The vacuum release systems 39, 139 have the capability of working in conjunction with pool systems that are manually controlled, with electromechanically-timed systems and with digitally controlled systems. More particularly, the vacuum release systems 39, 139 may be utilized on manually controlled circulation systems to convert them to automatic systems, since the vacuum release controllers 48, 148 have timing and scheduling capability, enabling users to schedule the running and speed of the circulation pumps 30, 130, 68 in lieu of turning them on and off manually. Alternatively, the owner of a manual pool/spa system may decline to utilize the timing capabilities of the controllers 48, 148 and continue to run the circulation system manually. In the latter case, the vacuum release systems 39, 139 may be used strictly to monitor vacuum levels to promote user safety and prevent equipment degradation (not for pump scheduling). The vacuum release systems 39, 139 may also be employed with an existing controller which is used to schedule and automatically operate the circulation system.
As can be seen in
There are different methods of ascertaining appropriate and safe levels of vacuum for pool/spa systems during various functional states. One method is to conduct testing on various systems in all possible modes of operation in a laboratory setting to arrive at values with common application. For example, testing may reveal a vacuum level LD that is above all normal operational levels for any system, i.e., the maximum observed level LM plus a tolerance. This high limit LD, may be used as the default criteria for identifying an anomaly, such as an occlusion of the drains 12, 112. This default, high limit-type triggering of vacuum release by the vent valves 42, 44 and/or the accumulator 147 discharge, can be utilized without reference to the particular operational state of the pool/spa system, the identity of the system and/or the scheduling or timing of different functional states. This process of ascertaining a default acceptable vacuum level LD by exercising a pool/spa system and then observing the resultant vacuum levels can also be applied to determine the maximum observed rate of change of vacuum level (slope) SM (either rising or falling) and a default acceptable slope SD for normal safe operation. A default acceptable rate of vacuum change SD can be calculated from the maximum observed rate of change SM by adding a tolerance (see
An alternative and/or supplemental method of ascertaining vacuum level criteria which provides values that are more sensitive to a particular pool/spa system, is to observe and record actual vacuum levels of a given specific pool/spa system during operation, in various states, and then calculate appropriate vacuum ranges and/or high and low limits for the various potential states of that particular pool/spa system. This type of empirical data can be observed and recorded manually and/or automatically captured and/or calculated by the controllers 48, 148. One approach for collecting relevant empirical vacuum level data is to run the system in a state which results in maximum normal vacuum levels, e.g., while utilizing a pool vacuum attached to the skimmer 22.
In the event that the vacuum release systems 39, 139 of the present invention are used as a timer/controller for the pump/circulation systems 10, 110, respectively, and/or works in cooperation with an existing timer/controller, such as the controller 65, time and functional phase-based monitoring of vacuum levels is possible.
Since there is a great likelihood that the second operation of the pump will generate vacuum readings which are somewhat different than the first operation thereof, a more realistic and meaningful comparison would be between the first recorded vacuum levels +/−a tolerance, such that the determination is whether a second reading falls within a range rather than being exactly equal to, less than or greater than a specific value. As shown in
As yet a further alternative, the present invention may continually adjust the priming time criteria based upon sensed empirical data, e.g., to compensate for changing conditions in the system S, S′, such as a filter 34 that provides changing resistance to fluid flow due to debris accumulation/removal and therefore changing amounts of time required to achieve priming. More particularly, the priming time criteria may be adjusted upward and downward based upon the measured time Ts for each occurrence of priming. For example, if the priming time criteria is ascertained by empirically measuring a fifteen second time for priming on a newly installed system and expanded by adding thirty seconds for a first priming time criteria of forty-five seconds, then on a subsequent priming cycle the measured actual time for priming is twenty seconds, the controllers 48, 148 may conclude that priming occurred within an acceptable time. However, the longer measurement (twenty seconds rather than fifteen seconds) may be indicative of a gradual, normal system change, so the controller 48, 148 may add five additional seconds to the priming time criteria (resulting in fifty seconds) to adapt to this change. These incremental changes can be utilized to move the criteria range to accommodate expected changes in function of the system S, S′. The adjustment in priming time criteria implies, however, that a maximum priming time criteria value should be established beyond which no incrementation can be permitted, e.g., representing a maximum limit of time that a pump 30, 130 can be run without achieving prime to avoid damaging the pump 30, 130. For example, using an automatically adjusting priming time approach, a maximum priming time criteria could be set at three minutes. On each priming cycle, after measuring the actual time required for priming, the controller 48, 148 may test to ascertain that the adjustment results in a priming time criteria value less than or equal to three minutes. If so, then the incrementation/adjustment to the priming time criteria is permitted, otherwise, the priming time is set to the maximum, i.e., three minutes. Accordingly, if the time for priming exceeds three minutes, then an error is generated and processed. In addition to adjusting the priming time upward (increasing the priming time criteria), the priming time may be adjusted downwardly, due to a measured priming time that is less than the previously measured priming time. For example, if backwashing of the filter 34, 134 results in a priming time which is ten seconds less than the previously measured priming time, then the priming time criteria can be reduced by ten seconds. One simple formula for calculating the priming time criteria on the next priming cycle is: actual measured time for priming, plus the expansion factor, equals the priming time criteria, but only if the resulting priming time criteria is less than or equal to the maximum possible priming time criteria, otherwise, the priming time criteria equals the maximum possible priming time criteria.
Referring again to
The maximum slopes SD and SS are alternative and/or cumulative criteria that may be applied to control the system based on vacuum readings. As with triggering vacuum release based upon a vacuum level criteria, such as LD, an excessive actual slope SA can be ignored for a short time if it falls into a predictable and expected time frame relative to the particular function being executed. Alternatively, the excessive slope SA can trigger vacuum release if using ultra safe criteria SS.
The actual slope SA can be used to indicate the stabilization of a pump (acquisition of prime) such as is illustrated in stabilization region RS in
A similar profile as is exhibited in
After the acquisition of prime, and, if applicable, the setting of the pump speed to low speed for filtering operation, the pumps 30, 130 will continue to run at a given speed for a predetermined time, as determined by the technician and/or user based upon factors such as pool use patterns, exposure to wind borne debris, such as dust and leaves, all of which will vary for each installation. As noted above, the length of operation of the pumps 30, 130 will be determined either manually or by a timer, i.e., either that present in the controllers 48, 148 of the present invention or by another timer/controller, e.g., the controller 65, installed on the pool/spa system. During filtration, the vacuum level in the suction conduits 28, 128 is stabilized and will typically stay within a range of approximately +/−0.5 inches of mercury. Minor variations in vacuum level are common due to the occasional presence of debris, such as leaves on the main drain cover or due to a person passing by or walking on the main drain cover. Because it would not be desirable to shut the system down permanently due to minor variations in vacuum due to predictable and harmless events during normal operation, shutdown is preferably only triggered by a vacuum spike or rate of change that exceeds the selected limit, e.g., LH, LD, SS or SD, and which is predictive of a malfunction, such as occlusion of a drain by a person or an object. Vacuum measurements are taken at about 1000 samples per second and groups of 10-100 consecutive measurements are averaged, yielding a measured average vacuum level adjustable from one hundredth of a second to every one tenth of a second. These measured average vacuum levels are monitored for a rate of change exceeding the selected limit, e.g., SS or SD, such as 40 inches of water per second, which would signal an anomaly and cause the controller to enter the Vacuum Anomaly Detected state. By way of further example, any measured vacuum level exceeding 3.0″ Hg above a vacuum value predetermined as a normal running vacuum LM, will trigger the Vacuum Anomaly Detected state. As noted above, ultra-safe vacuum criteria can be employed and violations of same are considered within the time/function context and auto restart of the pumps 30, 130 a set number of times is employed. Continuous operation of the pumps 30, 130 in filtration mode may be periodically interrupted by a self-test, wherein the solenoid valves 44, 155 are opened to vent the suction conduits 28, 128, respectively, to atmosphere or to the accumulator 147, thereby causing a drop in vacuum level in the suction conduits 28, 128. The motor circuitry of the pumps 30, 130 can also be tested at this time. If the vacuum level does not respond in the expected manner (drops), e.g., greater than or equal to ½″ Hg in response to the opening of the solenoid valves 44, 155, filtration mode is terminated, the event is recorded in an event log, and Vacuum Anomaly Detected mode is entered. Testing can also be initiated by the owner or technician by depressing the “TEST” momentary switch.
Vacuum Anomaly Detected Mode
Upon detection of a vacuum anomaly, the solenoid valves 42, 44, 155 are de-activated within 0.1 seconds, allowing the suction conduits 28, 128 to vent to atmosphere and/or permitting pressurized water stored in the accumulator 147 to enter into the suction line 128. The valves 42, 44, 155 are closed when powered and opened when deactivated. If the solenoid valves 42, 44, 155 are closed in an activated state and opened in a deactivated state, a power failure will result in the opening of the solenoid valves 42, 44, 155. In this manner, an entrapment occurring contemporaneously with a power shutdown, e.g., through a power outage or due to a person pulling the main circuit breaker 54 to the pool in an effort to free someone from a drain, will result in vacuum release. Of course, the alternative setup could be employed, viz., a solenoid valve 42, 44, 155 that is closed when depowered and opened when powered. This alternative may be preferred in systems which are sensitive to the introduction of air, such as those employing DE filters and/or those in which it is difficult to achieve a prime condition. As to the latter, the prime will not be lost by opening the solenoid valve 42, 44, 155, each time the system is shut down.
Upon detection of a vacuum anomaly, power to the pumps 30, 130 could be terminated by the controllers 48, 148, respectively. These actions permit a swimmer/bather to free himself/herself from any drain that they have obstructed. If the vacuum release systems 39, 139 are set to trigger a pump off and vacuum release in response to relatively mild vacuum level changes (ultra-safe mode), after a delay of about thirty seconds, the pump is restarted in Startup mode. The solenoid valve(s) 44, 155 are deactivated periodically during startup to provide a soft start and to warn swimmers of the starting of the pumps 30, 130. The delay on restarting and the soft start provides the swimmer/bather with additional opportunities to get clear of any drains, such as the drains, 12, 14, 112. Each time an anomaly is detected, it is appended to the event log stored in the controllers 48, 148. Before restart, the event log is reviewed by the microprocessor. If the event log contains a given number of vacuum anomaly events within a specific period of time, such as five minutes, then the controllers 48, 148 shut down the circulation systems 10, 110. An alarm may be sounded via speaker 350 (see
The automatic reduction in vacuum level responsive to an excessive rate of vacuum change or excessively high vacuum levels (spikes) by venting the suction conduits 28, 128; or by permitting the accumulator 147 to release; and/or by turning the pump(s) 30, 130, 68 off, may be permanent in the case of a vacuum spike which is totally atypical (higher than LD) and could only be caused by an anomaly, such as complete occlusion of a drain. In such instances, the system may be programmed to shut the pump(s) 30, 130, 68 down until an operator overtly resets the system, e.g., by going through a recovery procedure involving reading and responding to questions and instructions presented on the displays 62, 162.
In the situation where the vacuum release systems 39, 139 operate at a more sensitive level, with vacuum change rate and level limits that are anticipated to be exceeded in the course of normal operation, then the controllers 48, 148 may be programmed to automatically restart after a selected delay of, e.g., thirty seconds, for a given number of times until it shuts down permanently and needs to be overtly recovered. For example, if it is anticipated that the vacuum limits SS, LH will be exceeded between 3 and 4 times on start-up, then the controllers 48, 148 can be set to automatically restart the circulation systems 10, 110, respectively, a given number of times, such as five or six times, before shutting down and requiring operator intervention to restart. This cycling through vacuum reduction, delay, and restart can be employed during any phase of operation. For example, during stable filtration, if a user places his/her foot on the drain causing the safe vacuum change rate SS or high limit LH to be exceeded, then the system may be programmed to reduce vacuum by venting or accumulator discharge, shutting the pumps 30, 130 down for a few, e.g. three, seconds (during which time the user's foot is likely to have moved) and restarting. The variations of suction at the drains 12, 14, 112 are likely to remind the user that he/she is standing on a drain, thereby inducing him/her to move. If the condition persists, i.e., the partial blockage continues, the system can continue to try to restart for a given number of times, after which a shutdown requiring operator intervention will occur.
If a low limit LL is utilized as a trigger to shut down the circulation systems 10, 110, then the time that the vacuum level is anticipated to be below that level, e.g., at the beginning of start-up, must be ignored.
A battery 334 driven oscillator 336 feeds a real-time clock 338 to provide a time reference for conducting programmed/scheduled activities, such as pumping/filtration at various speeds, for timing windows of permissible vacuum levels during pump priming and speed change and for time-stamping events recorded in an event log of events that is stored in memory 327 and/or non-volatile flash memory 339. It is preferable for the flash memory 339 to be able to store at least a thousand of the most recent events. Back-up power to the flash memory 339 is provided for the real-time clock 338 by a super capacitor 341. A programmable timer 340 is provided to time events relative to the actual time and has the capacity to schedule, e.g., one to five, separate daily events each day for a week, or the same separate daily events repeated each day.
Three momentary switches 342 are provided to permit the user to enter data into the controllers 48, 148. More particularly, the switch buttons may be labeled “Up & Yes”, “Down & No” and “Menu & O.K. & Test” and can be used to enter answers to questions posed on the display 324, as well as to incrementally change values for date, time and vacuum limits, etc. An LED 344 (
The controller circuit 310 and connections thereto may be housed in a wall-mounted enclosure made from metal and having a grounding lug to which a connection to earth ground is made. The housing may be compartmentalized to contain the high voltage components in one section separate from the low voltage components which are housed in a separate compartment separated by a conductive barrier that is in electrical continuity with the grounded metal housing. In this manner, the high voltages present in the high voltage compartment are prevented from inadvertently contacting low voltage components contained in the other compartment. The high voltage components may be positioned toward the bottom of the housing with the connector terminals pointed downwards to receive the high voltage power lines inserted into the housing from the bottom. The metal housing may be further protected by a clear plastic outer housing which may be hingedly connected to the metal housing to shield the unit from the weather while permitting an operator to view the LCD displays 62, 162 and the LED's 344, 346. During manufacture, the individual circuit components of the controller circuit 310 are tested as they are installed to debug and isolate defective parts. Upon completion of the assembly, the circuit is powered up for a significant time and then tested multiple times to assure proper operation. Having passed assembly and operational testing in the factory, the controller(s) 48, 148 may then be installed at a user's site by an installer/pool technician.
Installation/Setup by Technician
In preparation for installing the present invention in an existing pool/spa/system, any existing check valves are removed from the suction lines, e.g., suction lines 18, 28. Check valves are frequently used to allow pumps, such as the pump 30, that are installed above the water level of the pool/spa to maintain prime after the pump has been turned off. In order for the present system to work effectively, check valves must be removed that would impede venting the suction conduit 28 to atmosphere or delivering a pressurized back flow of water from the accumulator 147. Before connecting electrical power to the system, the housings of the controller 48, 148 would be opened to access the DIP switches 348, which are set to indicate language preference, to indicate whether there is a one or two speed pump, the input voltage for the controller (selected by switch S1 on the PCB board) and other voltage loads, to indicate if a booster pump, such as the pump 68, is present in the system and to indicate whether the vacuum release systems 39, 139 will control the running of the pump(s) 30, 130, 68 on a time schedule or schedules, as applicable, etc. In order to connect the controllers 48, 148 to the power supplies 54, 154, respectively, to the vacuum sensor/transducers 46, 146 and to the pumps 30, 130, 68, the panel protecting the high voltage terminals in the controller housing is removed. The technician can then connect: (1) a remote stop switch, which is normally closed in “run” mode; (2) the terminal pair for a remote alarm relay (normally open—115 volts @5 Amps); a plurality of terminal pairs to pump motor relays (contactors); and the AC power source (115, 208 or 230 VAC). The power cables to the one or two speed pumps 30, 130 and optional booster pump 68 are connected to AC contactor terminals, routed through the bottom of the housing and connected to the respective pump motors. The pump motors are typically rated at up to 1.5 hp at 115 volts or 3 hp at 208 or 230 volts. In the event that a higher power pump is utilized, the contactors can be used in series with the pump motor starters. Each of the motor contactors is controlled by a separate I/O pin of the microprocessor 322. The housings of the controllers 48, 148 are grounded to the electric supply circuit breaker/fuse boxes 54, 154, respectively and also to the bonding system for the pool/spa, if available. The housings can then be reassembled and power to the systems 39, 139 can be turned on. The voltage sensing function of the system is immediately operative and will confirm that suitable voltage is present to power the controllers 48, 148, the solenoid valves 42, 44, 155 and the pumps 30, 130, 68 via a message displayed on the displays 62, 162, respectively.
The controllers 48, 148 have different access classifications, viz., manufacturer, installer/technician and consumer, which allow successively more limited access to controller settings and values. Some settings are accessible to the owner/operator and some are reserved for installer/technicians and factory technicians. Each controller is set for user access when it leaves the factory. Access by technicians can be password protected or require a proprietary sequence of momentary switch depressions or the like.
Having gained access, the technician can then communicate commands and settings to the microprocessor 322 by depressing the momentary switches 342 in conjunction with and in response to the display of prompts from the microprocessor 322 displayed on, for example, the displays 62, 162. The technician can set the initial parameters for the particular installation, including: the value corresponding to a default high vacuum spike criteria LD which would indicate an occlusion; the value for ultra-safe vacuum level LH during filtration; and the delay before restart is attempted. The priming time criteria may also be set/calculated at this point. In appropriate cases, the installing technician will exercise all of the pool and spa functions, such as, priming, filtering, speed changes, etc., and observe and record the timing and vacuum levels associated with those functional states. Alternatively, the controllers 48, 148 can automatically capture this data as the circulation systems 10, 110 are exercised. The technician may exercise these systems by following written instructions or by following cues displayed on the displays 62, 162. The technician would then exit custom set-up mode and enable pump protection from abnormal AC voltages. A data display mode would then be entered which dynamically displays operational parameters based upon sensed empirical sensor readings/values, such a vacuum readings in the suction conduit 28. These are typically expressed in inches of mercury.
Besides controller setup, the technician can perform certain maintenance tasks, as well as all the user functions that are available in user mode. The controllers 48, 148 automatically shut down pump operation when technician mode is entered. One of the special functions available only in technician mode is to override shutdown due to excessively high vacuum readings. This shutdown override is sometimes necessary to clear obstructions, such as leaves, that may at times clog the drains 12, 14, 112 that could not otherwise be conveniently removed. Of course, during override, the technician must be certain that the pool/spa is not being used by any persons.
User Preference Selection—Setup/Maintenance
The user can perform the following at any time via the operator interface (input keys 64 and display 62): initiate a self-test; set the real-time clock 338, and schedule events to be executed in the future programmatically, such as the schedule of pump operation, viz., times for turning the pumps 30, 130 on and off, for running them at high and low speed and for turning the booster pump 68 on and off for cleaning purposes. The technician can also view the most recent events that have been logged into the event log and step back sequentially to view prior events. The user can review the recorded log of errors that have occurred and respond to any questions posed by the controller 48, 148. Responding to certain questions may be required before the controller will permit access to certain functions or effecting selected settings.
In
a-f show a flow chart 700 of the operation of an exemplary embodiment of the present invention. The system, e.g., 400 or 500, including the controller thereof 410, 510 is powered ON 710. (For purposes of simplicity of illustration, the system 400 will be referred to in describing the functionality expressed in the flowchart 700. It should be understood that any of the embodiments disclosed herein could utilize this same functionality.) The controller 410 may be powered ON in different contexts, e.g., after manufacture for testing, in the course of installing the system at a residence, by the owner of a pool/spa to input his/her preferences for operating the pool/spa, by the owner during maintenance, for first use of his pool/spa after being shutdown, for maintenance by the owner, by technicians, etc. The context in which the controller 410 is powered ON 710 is determined by operator input, switch settings, and/or states in the system 400 that indicate the context. After power is applied, the controller 410 (programmatically in the microprocessor, e.g., 322) conducts an internal test 712 to determine if “initial start is enabled”. This state is initialized to the negative, i.e., the system does not start immediately upon turning the power ON 700, to provide the operator with control over the system 400, i.e., to send power to the pumps, e.g., 412, etc. only when the operator has determined that he/she is ready and it is safe to do so. The operator is queried 714, “Initial Start Now?”. If any other key is pressed or if no key is pressed in response, then the controller will idle indefinitely without applying power to the pumps (starting). If the “Y” key is depressed to indicate “Yes”, then the operator is queried 718, “Disable Start Delay?”. If the “Y” key is depressed within a given opportunity time, e.g., five seconds, then the initial start delay is disabled (by setting an internal flag or variable value). The consequence of disabling the start delay will be that system 400 will immediately implement controlled functioning upon applying power 700 to the controller 410 in the future.
At step 726, the controller 410 internally checks to see if DIP switch 5 is “ON” to indicate that the context of powering up 710 is in the manufacturing environment, e.g., pursuant to testing the functioning of the controller 410. If so, then such testing is conducted 728. The manufacturing tests would involve applying inputs to the controller 410 and ascertaining that the controller responds with the correct outputs/responses. For example, known vacuum levels may be applied to the controller (through the solenoid valve to the vacuum sensor) to see if the controller responds appropriately thereto, e.g., shutting off power to the pump when the vacuum level exceeds a preselected threshold, as shall be described further below and as previously described above. Similarly, the power supply can be varied, e.g., via a vacuum to ascertain that the controller 410 responds appropriately to such variations, e.g., responding to a low power condition with the appropriate warning messages and shutting power to the pump off. The controller 410 can also be checked to confirm that it outputs the proper messages making up the operator interface and responds appropriately to operator input.
In the event that the manufacturing context is not applicable at step 726, then the controller (via the display 444 thereof) displays 730 the message “Hayward Pool Products, Inc.” or similar introductory messages identifying the manufacturer or otherwise communicating with the operator. This is followed by displaying 732 the date and time. In the eventuality 734 that the operator wishes to clean the pool/spa e.g., by using a pool vacuum, the operator can so signify by simultaneously pressing the “Menu” and “N” keys. Note that checking 734 whether the operator wants to clean the pool or not is not necessarily a overt query posed to the operator via the display 444, but rather is initiated by the operator pressing an improbable combination of keys on the operator interface to indicate that cleaning the pool is desired. In this manner, inadvertent selection of this option is avoided and the selection may be made only by someone who has learned how to operate the controller, e.g., by reading the manual or by receiving operating instructions from a technician or other knowledgeable person. In the event that the operator of the pool/spa (be that the owner, a technician or installer) indicates that they want to clean the pool/spa, the Clean Pool Function is invoked 736. The Clean Pool Function allows the pump, e.g., 412, to be operated at high speed and also allows the booster pump, e.g., 68 to be operated without monitoring the vacuum level. This is permitted because the process of vacuuming/cleaning may cause the vacuum level to spike in the normal course thereof. In order to permit vacuuming/cleaning of the pool/spa, vacuum monitoring must be overridden for a time. Before entering this unmonitored mode, the operator is warned 738 on the display 444 that the pump is about to be operated in unprotected (no vacuum monitoring) mode and that the pool must be cleared of all persons. The controller then queries the operator 740 to determine if the pool has been cleared. If the answer is “Yes”, unmonitored operation of the pump 742 is performed. Pool cleaning mode will not begin until the operator indicates the pool is cleared of swimmers. Upon such indication, unmonitored operation persists for a given time, whereupon unmonitored operation comes to an end based upon the expiration of a predetermined time window, e.g., a given number of minutes, which can be determined by factory set defaults, or alternatively, this may be a variable set by the installer or the pool owner upon installation/reinstallation. As with operation of the controller 410 generally, all operational states are recorded in an operational log (in non-volatile memory or media).
Assuming that cleaning mode has been skipped or completed, the controller 410 then queries 744 if the operator wishes to set the Time and Date. If so, the Time and Date functions 746 are executed, which are conventional, such as would be encountered in setting the time and date on any modern appliance or clock. The controller then ascertains if Timer event setting has been enabled (by setting DIP switch 4 “On” previously, e.g., during installation. If so, the operator is queried 748 if they want to Set Timer Events. If the operator indicates “Yes”, the Timer Events Function is invoked 750. The Timer Events are used to control the ON and OFF times of the filter pump, e.g., 30, the booster pump, e.g., 68, and the high and low settings of two-speed pumps, e.g., 30. The timed events may be scheduled for daily execution (every day of the week has the same schedule of events) or each day of the week can be assigned a custom schedule, which may or may not be the same as another day of the week, e.g., to accommodate the individual's preferences and schedule of usage of the pool/spa. DIP switch, flags or other variable settings with values assigned on set-up or installation can be used to indicate the presence of two speed pumps and/or booster pumps in the system. Alternatively, the controller can sense on the wiring connections thereto to ascertain the presence of specific equipment configurations. The Set Timer Events Function 750 steps through each device to ascertain from operator input when the devices should be turned ON and OFF each day of the week.
After the Timer Events query 748 and/or execution of the Set Timer Events Function 750, the controller checks to ascertain if the operator wishes to enter pool tech mode 752. This indication from the operator is not in response to a query posed by the controller, rather, the checking is done without messaging the operator via the display, e.g., 444. More particularly, if the operator, of his own incentive, wishes to enter Pool Tech Mode and is aware of the combination of key depressions that are required, then Pool Tech Mode may be so indicated. It should be appreciated that any improbable combination of key depressions may be used as a secret code to invoke certain functions and that the secret code can be shared with a limited number of qualified persons to prevent unqualified persons from accessing certain functions that could otherwise be conducted. In
Another Custom Installation function is to zero the vacuum sensor. The sensor is initialized to zero at the factory and therefore reflects a zero value for the specific atmospheric pressure at the factory. In the event the system 400 is installed at a significantly different elevation, then the difference in atmospheric pressure or due to the static pressure of the water when the pump sensor is below the water level, may result in pressure effects attributable thereto rather than directly attributable to operation in a pool spa system. Accordingly, the present invention permits re-zeroing the vacuum sensor. The power supply voltage level (115/208/230 VAC) may also be set.
Because the time required for priming the pump will vary for the particular installation, e.g., due to the length of the suction conduit 424 and/or the other lines leading from the drains and the elevation of the pump relative to the water level, the controller 410 during Custom Installation Functions 754 permits the amount of time allocated to achieve prime to be adjusted during the custom install procedure. In addition to adjusting the time allotted to prime the pump before indicating an error condition, the threshold vacuum value used to ascertain if priming is occurring without a critical defect in the lines (break in the line which admits air or other water/air leak, such as an improperly installed strainer lid, that would lead to dry running of the pump) may also be adjusted. Once again, because the vacuum levels experienced during priming will vary for specific installations, normal priming vacuum levels for one installation may be significantly higher or lower than for other installations, hence the threshold indicating critical failure needs to be adjusted up or down based upon empirical values observed by the technician. The default vacuum threshold for priming is initially set to 30% of the vacuum level observed during stabilized operation of the circulation system. Unless the particular installation experiences difficulty in priming, the 30% default value should not be changed. Further, because an acceptable time for priming will also vary among different systems, the priming time criteria may also be based upon empirical measurements of same, either by the technician or automatically by the controller. As described more fully above, the controller may expand the time and update the priming time criteria based upon observed priming times.
Given that the vacuum conditions during stable running will change depending upon changing conditions within the filter (as the filter accumulates dirt, it will present more resistance to the filtration flow resulting in lower vacuum values.) A stable running low threshold is therefore useful to provide a window of operability without indicating an error condition that triggers shutdown of the circulation system. As noted above, in addition to monitoring for high vacuum conditions indicating blockage of a drain, the controller 410 also monitors for low vacuum conditions which could indicate a line break such that the pump(s) may be protected from run-dry conditions by depowering the pump. This low vacuum monitoring uses values appropriate to the stage of operation that the system is in, e.g., priming or stable running. In stable running, the low vacuum threshold is set by default at 60% of the normal, unimpeded stable running vacuum level. As noted above, because each pool/spa installation will vary, e.g., in the type of filter employed, i.e., DE, sand, cartridge, the size of the filter, the amount of debris loading due to environmental effects, the stable running low threshold may need to be adjusted. This can be done as part of the Custom Install Functions 754 based upon the vacuum levels noted empirically (by the installation technician or a trouble shooter who has come to resolve the frequent shut-down of the system).
When the system is first installed and the pump is run, the controller, e.g., 410 recognizes when the pump 412 achieves a stable condition and records the vacuum level associated with that stable run condition. In the event that the first recorded stable run vacuum level was not representative of the actual stable running, e.g., due to an anomaly, such as an air leak due to an improperly installed strainer basket lid, then the Custom Installation Functions permit the technician to reset the stable vacuum level after the correction of the condition leading to the anomaly.
If the operator pressed “Y” in response to query 752, then the Pool Tech Mode Functions 756 are enabled. The time and date are displayed 758. If Pool Tech Mode was selected at decision 752 and the controller 410 is in Active Pool Tech Mode 760, the Pool Tech Mode functions are presented to the operator via specific messages 762. These messages and functions would include a query to the operator as to whether a two-speed pump is installed and if so, to double check that the dip switch settings are appropriate for a two speed pump. The operator is then queried if the drain cover(s) are installed. If not, the system must be powered down before it will restart. If the drain cover(s) are installed, the operator is queried as to whether he/she would like to manipulate the data log, which is a log of all events retained in the memory of the controller. The event log can be used by the technician to identify and correct problems in the system. After completing the desired Custom Installation Functions and/or the Pool Tech Mode Functions, such as setting the high vacuum level, the operator may terminate Pool Tech mode by pressing “OK/MENU”.
On
If the test 766 is Negative, then the controller 410 checks 770 if the timer indicates a RUN condition/If not, messages pertaining to time scheduled events are displayed 772, such as, identifying the next timed event and when it is to occur, as well as indicating to the operator that they may press MENU for other options. The controller 410 monitors if MENU has been pressed 774. If so, control returns to connection point “A” on
When the timer indicates RUN at decision 770, an AC Voltage test is conducted 776 wherein the controller 410 ascertains whether the voltage level is within an operable range, i.e., not too high due to a surge or too low due to a brown-out or other power interruption. If the voltage is out of range as tested at decision 778, control passes to connection point “E” on
In addition, before power is applied to a pump, e.g., 412, the vacuum level present in the suction conduit 424 is checked. Depending upon how many pumps are installed in the pool/spa system and how many are running, a specific pre-running vacuum level can be expected. For example, in the case of pool with a single pump 412, the pre-running vacuum level should be nil. If the pre-running vacuum level is not at the expected level, e.g., in a pool with one pump 412, if the vacuum level is greater than nil, then this may be interpreted as an indication that the pump 412 is already unexpectedly running. If the pump 412 is unexpectedly running, then this is likely an indication that some portion of the system that controls the running of the pump 412 is malfunctioning. One example of a malfunction which would cause unexpected pump running would be a motor contactor (relay) which is stuck in the “ON” position, e.g., due to the welding of the contacts (points) thereof. In the event that an unexpected vacuum value is detected which is attributable to an unexpectedly running pump, then this anomaly is recorded and error processing is invoked starting at connector “E” in
During start-up, the controller continually tests 782 to verify that the high vacuum limit is not exceeded, which would indicate a malfunction, such as the occlusion of a drain, thus protecting swimmers from becoming trapped on a drain. A low vacuum threshold is also optionally tested at this time, as set at step 754, to prevent the pump 412 from running in a dry state. In addition to monitoring vacuum levels, the time to achieve prime condition may also be monitored and compared to the priming time criteria. If errors are encountered, the nature of the error is recorded and error processing is continued at connector “E” in
If no errors are encountered, the Stabilization Function 784 is performed. While the pump 412 is running, the vacuum sensor 435 continually monitors the vacuum level reporting it to the controller 410 and the controller 410 continually verifies 786 that the High Vacuum Limit is not exceeded. As the pump 412 becomes fully primed, the vacuum experienced by the vacuum sensor 435 should stabilize. This stabilization allows Vacuum Window Parameters to be set 788. The Vacuum Window is a tolerance range of vacuum variation centered around the actual experienced vacuum level empirically determined at stabilization. Given this empirical value, the vacuum window may then be set to be in a range (+/−) of this actual reading (average reading), e.g., +/−3″ Hg. As a result, the Vacuum window is a tighter range of acceptable vacuum levels than that between the High and Low Vacuum Limits and is centered on the actual operating vacuum levels present in the running pool/spa system after stabilization.
Optionally, the present invention may continually adjust the Vacuum Window in a manner similar to the way the priming time criteria is interactively adjusted based upon sensed empirical data, e.g., to compensate for changing conditions in the system S, S′, such as a filter 34 that provides changing resistance to fluid flow due to debris accumulation/removal and therefore results in changing levels of vacuum for associated operational states. More particularly, the Vacuum Window may be adjusted upward and downward based upon the measured vacuum for any operational state. For example, if the vacuum during stabilized running in filtration mode is empirically measured to be X on a newly installed system and expanded by a tolerance of +/−3″ Hg, resulting in a Vacuum Window of X+/−3″Hg, then measured to be X-1″Hg on a subsequent cycle in the same operational mode, the controller 48, 148 would interpret that the measured vacuum level X-1″ Hg falls within the acceptable range of X+/−3″ Hg. However, because the measured vacuum level is 1″ Hg less than the previously measured level, the controller may recalculate the vacuum window to be (X-1″ Hg)+/−3″ Hg. These incremental changes can be utilized to move the vacuum window to accommodate expected changes in function of the system S, S′. The adjustment in the vacuum window implies, however, that a maximum and minimum should be established beyond which no incrementation/decrementation can be permitted.
Having established the Vacuum Window Parameters 788, the controller 410 then executes Run Mode 790. When the system is in Run Mode 790, vacuum measurements are taken at about 1000 samples per second and averaged, yielding a test vacuum value every hundredth of a second. This average value may then be compared 794 to the vacuum window calculated in step 788 to determine if it is within an acceptable range. If not, vacuum anomaly processing is conducted (connector “E”). Besides monitoring vacuum levels, the power input voltage is also monitored 792 to ascertain if it remains in an acceptable range. If not, error processing is conducted (see connector “E”).
The operation of the spare switch, e.g., 431 (if applicable) is also monitored. In the event that a spare switch 431 has been operated (decision 796), the state of the spare switch is tested 798, i.e., to see if it is presently OFF. If the spare switch is OFF, the controller records that state (Reset Spare Switch Operation 800) and turns the pump(s) controlled by the spare switch OFF 810. When the pumps. e.g. 412, are turned OFF, a corresponding reduction in vacuum should result. If not, then this would be an indicator of loss of control over the running of the pump 412, e.g., due to a malfunctioning contactor (relay) as in the case of welded contact points. The systems therefore tests the vacuum level 811 to verify vacuum reduction due to pump shut-down. If the expected change in vacuum levels does not occur, then this error is recorded and control is passed to connector “E” in
For embodiments of the present invention utilizing a vacuum conduit, such as 430 that extends to the controller 410 and to a vacuum sensor 435 therein, the present invention preferably includes a vacuum monitoring function that verifies that the vacuum conduit 430 is not plugged with debris or kinked and therefore obscuring the actual state of vacuum present in the suction conduit 424. More particularly, vacuum levels established in vacuum conduit 430 and vacuum tube 462 are sensed by vacuum sensor 435. These levels change depending upon the state of the pump 412, the obstruction of drains, e.g., 112, etc. In addition, there are small fluctuations in the vacuum level that are present even after stabilization. If the vacuum conduit becomes obstructed, e.g., plugged with debris or kinked, then the portion of the vacuum conduit 430 between the obstruction and the vacuum sensor 435 becomes sealed/isolated from the vacuum levels present in the suction conduit 424. As a result, the sealed/isolated portion of the vacuum conduit 430 will retain the vacuum level that was present therein when the obstruction occurred and therefore the sensor will not be effective in detecting changing vacuum conditions in the suction conduit 424. Of course, this type of occlusion would frustrate the operation and purpose of the vacuum release system 400.
In order to detect and prevent any negative consequences from vacuum conduit 430 occlusion, the present invention monitors the vacuum level for a sustained, unchanging vacuum level, i.e., a static vacuum level, which would be indicative of vacuum conduit 430 occlusion. A static or constant vacuum level would be indicative of occlusion because even in stabilized running, there is a constant fluctuation in vacuum level during normal operation. The present invention therefore compares the vacuum level taken at successive intervals and ascertains if there is an abnormal constancy. If the vacuum level appears static, then the vent valve 458 is triggered exposing the vacuum conduit 430 to atmospheric pressure or to the pressure developed in the accumulator 537. In addition, the pump 412 may be cycled ON/OFF. These action(s) are intended to purge the vacuum conduit 430 of clogs. Upon sensing abnormal constancy in the vacuum conduit 430 and triggering the vacuum reduction response, the error event is recorded. The system 400 then resets the vent valve 458 to a non-venting position and/or restarts the pump 412. Vacuum level is rechecked to ascertain normal fluctuations in vacuum. If the vacuum remains constant, error processing is conducted at connector “E” wherein a check 823 for failed sensor test is made and if present, the pump 412 is turned OFF 825, the vacuum is released 827 by opening the vent valve, an error message is displayed 829 indicating that the vacuum conduit 430 is blocked, the alarm is turned on 831 and control passes via connector F to wait for intervention by a human operator. The system 400 requires overt operator intervention to restart, such as by answering queries concerning the state of the vacuum conduit 430.
If, at decision 796 on
e depicts error processing. As described above, a failed sensor test 823, results in turning the pumps OFF 825, releasing vacuum 827, posting an error message 829, and turning the alarm ON 831. If the error was not due to a failed sensor test, then the controller ascertains 839 if the error was due to an identified loss of pump control, e.g., as indicated by an unexpected vacuum level after turning a pump ON or OFF. If so, the vacuum is released 841 by opening the vent valve, alarms are turned ON 843, an error message is posted 845, and a loop of checking 847 for menu key depression is entered. Once a menu key is pressed indicating the intervention of a human operator, Alarms are turned OFF 854. In the event that the error was not due to a previously identified loss of pump control, verification 838 that all pumps are turned OFF is conducted, e.g., by turning the pumps OFF and ascertaining 849 a drop in vacuum levels, which in the typical case would be to nil. This assumes that the vent valve is positioned or is repositioned to measure vacuum for test 849. Alternatively, the OFF/ON state of the pumps could be ascertained by measuring the electrical values associated with the pump, e.g., the amount of current passing through the pump motor circuit. Methodology for analyzing pump function based upon electrical measurements is known in the art, e.g., as disclosed in U.S. Pat. No. 4,473,338 to Garmong. A well-known expedient to electrically ascertain whether a motor is running is to measure the electrical current draw of the motor. As before, if the expected vacuum levels indicate lack of motor response, the processing associated with loss of pump control, as determined at step 839, can be conducted, i.e., steps 841, 843, 845, 847, etc.
If the pumps are successfully turned OFF 838 as indicated by the appropriate low vacuum 849, then the vacuum in the suction conduit 424, is released 840, i.e., by repositioning the vacuum solenoid valve 458 to expose the suction conduit 424 to atmosphere or to the pressurized fluid in the accumulator 537, as applicable. The controller 410 then checks 842 to see if the error is a Hard Stop Error (High Vacuum/vacuum spike, a given number of consecutive errors, a given number of failed attempts to achieve stabilization/prime). If so, the alarm(s), e.g., 427 are turned ON 844. After three seconds, the vacuum solenoid valve 458 is repositioned 846 to prevent further venting of the suction conduit 424 and/or exposure of the suction conduit 424 to pressurized fluid from the accumulator 537. The controller then checks 848 to see if the Hard Stop was due to the depression of the Stop Switch 429 (Panic button). If so, the alarm(s) are turned OFF 850. If the Stop Switch 429 was not pressed, the controller 410 ascertains 852 if the Menu Key has been depressed. If so, the Alarm(s) are turned OFF 854. If not, the controller 410 pauses for a predetermined time, e.g., ten minutes, during which time the alarm(s), e.g., 427 are sounding. At the end of the pause, the alarm(s) are turned OFF 858.
Returning to decision 842, if the error was not a Hard Stop Error, the controller 410 verifies 860 that the Stop Switch 429 has not been pushed. If it has, the alarm(s), e.g., 427 are turned ON 862 and then there is a predetermined delay period 864, e.g. three seconds, during which time venting to atmosphere/reverse flow from the accumulator 537 is occurring to reduce the vacuum level at the drains, e.g., 12, 14 (
Besides the various queries that are described above, the controller 410 also displays informational messages pertaining to the operational state of the system, error messages, etc., such as: “Calibrating”, “Starting Pump”, “Stabilizing”, “Monitoring”, “Stop Switch” (If the Stop Switch is depressed it needs to be reset before the system will resume operation.), “S/Vent Error” (Sensor/Solenoid Venting error—This may occur due to the clogging of the vent 432), “No Stabilization”, “Self Test”, “Over Window Vacuum”, Under Window Vacuum”, “High Vacuum Alert”, “System Won't Stabilize”, “Too Many Sensor Solenoid Errors or No Prime”, “Loss of Motor Control—Relay Stuck Open/Closed”, etc.
In responding to vacuum anomalies characteristic of drain occlusion, the present invention provides for vacuum reduction via venting or reverse pressurized flow in conjunction with pump shut down. The present invention recognizes that it may be preferable in many pool/spa installations for the venting and/or reverse flow to be limited to a relatively short time period, e.g., three seconds. This brief time period is adequate to reduce vacuum at any drain to allow a swimmer to escape drain entrapment. Because the present invention contemplates use of a narrow window of acceptable vacuum levels to provide an enhanced sensitivity to vacuum changes, it is more likely to interpret vacuum levels outside the acceptable window as errors and therefore trigger vacuum reduction and pump shutdown. Due to this enhanced sensitivity, the present invention provides adequate vacuum reduction to allow a swimmer's escape, but without losing the pump's prime and/or interrupting filtration media stability through the introduction of air into the filter system, e.g., 34. After exceeding a predetermined number of vacuum releases and restarts, the system requires operator intervention, e.g., by interacting with the controller 410, e.g., by answering questions posed by the controller, which would indicate the pool spa system is safe to use before the controller 410 will allow restarting. Furthermore, the controller 48, 148, 410, 510 of the present invention provides for a selected number of automatic restarts under circumstances which are due to transient non-threatening vacuum variations.
It should be understood that the embodiments described herein are merely exemplary and that a person skilled in the art may make many variations and modifications without departing from the spirit and scope of the invention. For example, the present invention has been described above in reference to swimming pools and spas, but could be applied to fountains, water features, water park areas, or other installations where water is pumped into a receptacle and is subsequently drained there from. All such variations and modifications are intended to be included within the scope of the present invention.
This application is a continuation-in-part of U.S. patent application Ser. No. 11/601,588, filed Nov. 17, 2006, entitled Drain Safety and Pump Control Device, which claims the benefit of U.S. Provisional Patent Application No. 60/817,473, filed on Jun. 29, 2006, the disclosures of which are incorporated herein by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| 60817473 | Jun 2006 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 11601588 | Nov 2006 | US |
| Child | 12163126 | US |
