AU2120399A - Flow monitor and pump over-ride appliance - Google Patents

Description

P/00/011 28/5/91 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Name of Applicant: Actual Inventor Address for service is: GREGORY MICHAEL WHITMEE Gregory Michael Whitmee WRAY ASSOCIATES 239 Adelaide Terrace Perth, WA 6000 Attorney code: WR Invention Title: Flow Monitor and Pump Over-Ride Appliance Details of Associated Provisional Application No: PP2892 The following statement is a full description of this invention, including the best method of performing it known to me:- -2- The present invention relates to the field of reticulation and irrigation of gardens and lawns.

The invention is particularly directed toward domestic/home installations of garden lawn watering, where a bore is sunk and water is pumped to water lawns and gardens.

It is often the case in some installations that water from the pump is conveyed and distributed by gate valves, and the user manually selects which zone is to be watered. In other cases, the reticulation is automated, with solenoid controlled valves under the control of a reticulation controller/timer distributing water from the pump to a number of watering zones.

0. There is a problem which can occur with such pump supplied reticulation systems, when the pump is left to run against a closed head (ie with no discharge of water). This can occur when the user inadvertently leaves gate valves closed, or if there is a failure in a solenoid valve or the reticulation controller. In this situation, damage will occur to the pump.

Another problem which can occur is where there is failure of the one way valve or valves that maintain the pump in primed condition. If this occurs, the fluid head between the pump and the one way valve will drain away, leaving the pump to run without any water. In this situation, if watering occurs at a time when it is not observed, it can be some time before the problem is identified (usually when lawns and plants are dying through lack of water), by which time damage has occurred to the pump.

While there are commercial solutions to this problem, they are not usually adopted by domestic users, probably due to the requirement for specialised knowledge and skill in order to put them into effect. One commercial solution to the problem of excess water pressure brought about by a failed solenoid valve or the like has been to locate a pressure sensing switch in the water supply line -3from the pump, and include suitable circuit elements to cause the pump to be shut down when an over-pressure condition is sensed. However, since this requires hard wiring of some circuit elements to the electrical mains, the services of a registered electrician are required.

It is an object of this invention to provide a "plug-in" appliance to protect pumps from damage due to no-flow, caused either by pumping against a closed head, or leakage of priming-head from the pump.

It is a further object that the plug in appliance be for pumps of the type which are wired to a mains plug, to be plugged into a mains plug receptacle, of either a single phase type or a three phase type.

It is yet a further object that the invention be suitable for use in a pumping system which supplies either one watering zone, or two or more watering zones with either manual gate valves or automatically controlled solenoid valves.

Throughout the specification, unless the context requires otherwise, the word 15 "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

S• In accordance with the invention there is provided a pump controller having an electrical mains connector plug of the type to be plugged into an electrical mains outlet, an electrical mains connector socket of the type to receive an electrical mains plug of a pump or leading to a pump; input means to receive a control signal from fluid flow detection means, said control signal being indicative of a flow state of fluid in proximity to said fluid flow detection means; timing means contained within a housing and associated with said input means; and switching means contained within said housing and associated with said -4timing means, said switching means being provided for selectively electrically disconnecting current carrying conductors in said connector plug and said connector socket to interrupt power to said connector socket; whereby if said control signal indicates a lack of fluid flow for a predetermined period of time while said pump is actuated, said timing means provides a signal to cause said switching means to interrupt power to said connector socket and deactivate said pump.

While the input means is electrically isolated from current carrying conductors in said connector plug and said connector socket, this does not preclude one conductor of said input means being electrically connected to the mains earth connector in the connector plug. The mains earth connector in the connector plug will normally be connected to the mains earth connector in the connector t socket.

to In one preferred arrangement, the input means will usually be two conductors, 15 one being for a signal feed, and the other being for a signal return. In this arrangement the input means can connect to a proximity sensor in the fluid flow detection means. However, it will be appreciated that alternative arrangements may prove equally suitable.

In a preferred arrangement, the fluid flow detection means may comprise an element suspended in the fluid flow pathway, whereby the fluid flow state is indicated by measurement of deflection of the element from a rest position.

Preferably the fluid flow detection means comprises an element hingedly suspended from or near an edge thereof, within a pipe member in such a manner so as to at least partially occlude the cross section of the pipe member; the planar element being connected to a permanent magnet, whereby on flow of sufficient fluid within said pipe member, said element is deflected, causing displacement of the permanent magnet, there also being provided magnetic sensing means, to interact with the magnetic field of said magnet, the magnetic sensor means being interfaced with said input means.

Preferably the magnetic sensing means is located in a position so that it responds to said permanent magnet, when said element is hingedly deflected a sufficient extent commensurate with a flow rate sufficient to prevent damage being caused to the pump.

Preferably said magnetic sensing means comprises a reed switch, whose leads are connected to said input means.

Typically the switching means may be a relay, with the timing means being 10 connected to the coil thereof. However, the switching means may be entirely electronic, for example utilising triacs, however, care would need to be taken to provide suitable electrical isolation to any exposed wiring of the input means, to minimise the risk of electric shock.

Preferably said connector plug is connected to said housing by a length of 15 electrical mains flex, and said switching means is contained within said housing.

a Preferably, in addition, or as an alternative, said connector socket is connected said housing by a length of electrical mains flex.

Preferably, the entire pump controller including the pipe member with it associated parts, and the housing and parts contained therein, are provided as an integral unit.

Preferably the housing includes means for preventing ingress of water, such a grommets or the like around cable entry points.

The invention will be described in the following description of one specific embodiment thereof, in which: Figure 1 is a view of the pump controller according to the embodiment, -6including a cross-section view through the housing thereof; and Figure 2 is a wiring diagram of the pump controller.

Referring to figure 1 the pump controller is shown. The pump controller includes a housing 11, and has a one metre length of electrical mains flex 13 extending from the housing 11 and connecting to an electrical mains connector plug 15 of the typical three pin variety. Extending from the opposite end of the housing 11 is a further one metre length of electrical mains flex 17 connecting to an electrical mains connector socket 19 also of the typical three pin variety.

Attached to the housing, at the base thereof is fluid flow detection means, which comprises the following parts. A tube member 21 extends from the base of the :housing 11 down to a pipe member 23, and is in fluid communication therewith.

There is no fluid communication from the tube member 21 to the interior of the housing 11, the connection between these two members being sealed.

Contained within the pipe member is an element in the form of a disk 25 which is 15 hingedly mounted to the interior of the pipe member 23 about a hinge 27, so as to be moveable under the influence of the flow of fluid in the pipe member 23. A spring 28 formed of 0.5mm stainless steel wire having two opposed arms joined by 6 turns wound around the pin (not shown) of the hinge 27, provides bias to *.--.return the disk 25 to locate in the fluid flow pathway. The disk 25 presents its 20 cross-sectional area across the fluid flow pathway within the pipe member, so as to be deflectable thereby, against the bias exerted by the spring 28. The normal direction of flow of fluid within the pipe member 23 is indicated by arrows 29.

It will be understood that in an alternative embodiment, the spring 28 may be omitted. Where the spring 28 is not utilised, the disk 25 would need to be constructed more heavily so that it will fall under its own weight in situations where the flow rate is insufficient. A material such as brass should prove suitable for construction of the disk 25. It will be understood that when the spring 28 is omitted, the orientation of the housing 11 is more critical, as the disk must be able to fall under gravity, in situations where there is no flow. It can -7be advantageous to omit the spring 28, particularly in a situation where the water being pumped might give rise to corrosion or calcification problems.

Also forming part of the fluid flow detection means is a narrower diameter tube member 31, which is mounted to the base of the housing 11, concentrically within the tube member 21. The narrower diameter tube member 31 slidingly receives a permanent magnet 33, which is coupled to the disk 25, by connecting rods 35 and about hinge pins 37. As the disk 25 is deflected by the flow of fluid, the permanent magnet 33 slides along the tube member 31, toward the housing 11. When fluid flow ceases, the disk 25 will return to a rest position under the 10 bias of the spring 28, resulting in the magnet 33 sliding along the tube member 31, away from the housing 11. The magnet 33 interacts with magnetic sensing .:means in the form of a reed switch 39, whose terminals are connected to input means in the remainder of the circuitry contained within the housing 11. The reed switch 39 is located in the base of the housing 11, proximal to and substantially aligned with the narrower diameter tube member 31. The reed "'*switch 39 is actuated when the permanent magnet 33 is located toward the housing. Thus the reed switch 39 being actuated corresponds to there being sufficient flow within the pipe member 23.

The housing also includes timing means in the form of a timer circuit 41, and 20 switching means in the form of a relay 43. A step down transformer 45 is provided to derive 24 VAC from the mains, to provide low voltage to power the timer circuit 41 and the relay 43. The reed switch is an ADEMCO T M model 944WH. The timer 41 is a 24VAC electronic timer SAIA T M The relay 43 is an OMRONTM 24VAC coil, 16 amperes contacts, and is mounted on an octal base.

It will be understood that alternative sourced parts will be capable of performing the function of the pump controller.

The lengths of mains flex 13 and 17 each have their entry points to the housing sealed by grommets 47. The housing 11 has a lid 49, secured by screws 51, -8and includes a seal (not shown) under the lid 49. The seal and grommets 47 act to waterproof the housing 11.

The reed switch 39 has a pair of leads 53 which in effect form input means, receiving a control signal from the fluid flow detection means of which the reed switch 39 forms a part, as discussed above. The timer circuit 41 is associated with the input means, and the relay 43. The circuitry is best understood by referring to the discussion of its operation, which follows.

The pump controller is electrically connected with its electrical mains connector ,,socket 19 connected to the electrical mains plug of the pump, and with its electrical mains connector plug 15 plugged into the supply from the pump *.controller or pump starter or pump start relay, the latter which may be built according to the applicant's invention titled "Pump Start Appliance", the subject a provisional application lodged in Australia on 2 April 1998. The pipe member 23 is located in the fluid outlet from the pump in the reticulation system.

The input means 53 (and hence the reed switch 39) is connected in parallel with normally closed contacts 55 of the timer 41. The timer 41 is of the type that when powered maintains the contacts 55 closed for sufficient time (typically to 30 seconds) for the pump to establish flow in the pipe member 23, after which the contacts 55 in the timer 41 are opened. Either the contacts 55 of the timer 41 or the reed switch 39 make a circuit which supplies 24 VAC from the transformer 45 (once power is supplied to the electrical mains connector plug to energise the coil 57 of relay 43, and so cause the contacts 59 of the relay 43 to close, supplying power to the electrical mains connector socket 19 (and hence the pump). Initially, the circuit to the coil 57 of the relay 43 is made by the contacts 55 of the timer 41. After the predetermined time of 30 seconds the contacts 55 of the timer are opened. If normal water flow is established in the pipe member 23, the circuit to the coil 57 of the relay 43 is maintained by the closed contacts (not shown) in the reed switch 39. Thus it will be appreciated that should there be no fluid flow in the pipe member (and hence from the pump) -9after the predetermined time of 30 seconds, or should that fluid flow cease, the circuit to the coil 57 of the relay 43 will be broken (since the contacts in the reed switch 39 will be open).

The lengths of mains flex 13 and 17 each have three cores for active 61, neutral 63, and earth 65, wired in conventional manner to the plug 15 and socket 19 respectively. In the housing 11, the earth wires 65 are joined, while the active wires 61 and neutral wires 63 are connected (ie active to active and neutral to neutral) through respective switch contacts 55a and 55b of the relay 43.

It will be understood that the pump controller of the invention will provide 10 protection to the pump in circumstances where there is no flow of water due to either the loss of head from the pump (where a one way valve has failed to maintain the pump in primed condition), or where a valve has not opened, and the pump is working against a closed head.

The pump controller of the invention provides an off the shelf appliance that can be purchased by a consumer or reticulation installer, and does not require the on-site services of an electrician.

It will be understood that various changes and modifications may be made to the embodiment described herein, without departing from the spirit and scope of the invention. For example, the pump controller may be used to control a three phase pump. In such an embodiment, it would be necessary to use three phase plugs and sockets, and utilise a relay (or equivalent circuit) able to switch all phases.

In yet a further embodiment, the transformer 45 may be replaced by a feed from the pump start output of a reticulation controller, so that the pump controller doubles as a pump start interface device and non-flow protection device.

Claims (9)

1. A pump controller having an electrical mains connector plug of the type to be plugged into an electrical mains outlet, an electrical mains connector socket of the type to receive an electrical mains plug of a pump or leading to a pump; input means to receive a control signal from fluid flow detection means, said control signal being indicative of a flow state of fluid in proximity to said fluid flow detection means; timing means contained within a housing and associated with said input S• 10 means; and switching means contained within said housing and associated with said timing means, said switching means being provided for selectively ~electrically disconnecting current carrying conductors in said connector plug and said connector socket to interrupt power to said connector socket; whereby if said control signal indicates a lack of fluid flow for a predetermined period of time while said pump is actuated, said timing means provides a signal to cause said switching means to interrupt power to said connector socket and deactivate said pump.

2. A pump controller as claimed in claim 1 wherein the input means comprises 20 two conductors, one being for a signal feed and the other being for a signal return, said two conductors being for connection to a proximity sensor in the fluid flow detection means.

3. A pump controller as claimed in claim 1 or 2 wherein the fluid flow detection means may comprise an element suspended in the fluid flow pathway, whereby the fluid flow state is indicated by measurement of deflection of the element from a rest position.

4. A pump controller as claimed in claim 3 as dependent from claim 1 wherein the fluid flow detection means comprises an element hingedly suspended -11- from or near an edge thereof, within a pipe member in such a manner so as to at least partially occlude the cross section of the pipe member; the planar element being connected to a permanent magnet, whereby on flow of sufficient fluid within said pipe member, said element is deflected, causing displacement of the permanent magnet, and wherein a proximity sensor comprising magnetic sensing means is provided to interact with the magnetic field of said magnet, the magnetic sensor means being interfaced with said input means. A pump controller as claimed in claim 4 wherein the magnetic sensing means is located in a position so that it responds to said permanent magnet, when said element is hingedly deflected a sufficient extent commensurate o: with a flow rate sufficient to prevent damage being caused to the pump.

9.. .9o 9 °9 S6. A pump controller as claimed in claim 4 or 5 wherein said magnetic sensing *means comprises a reed switch, whose leads are connected to said input means. 99 9. 7. A pump controller as claimed in any one of the preceding claims wherein the *9*9 switching means comprises a relay, with the timing means being connected to the coil thereof. 8. A pump controller as claimed in any one of the preceding claims wherein said connector plug is connected to said housing by a length of electrical mains flex, and said switching means is contained within said housing. 9. A pump controller as claimed in any one of the preceding claims wherein said connector socket is connected to said housing by a length of electrical mains flex.

10. A pump controller as claimed in claim 8 or claim 9 wherein the entire pump controller including the pipe member with its associated parts, and the housing and parts contained therein, are provided as an integral unit. -12-

11. A pump controller as claimed in any one of claims 8, 9, or 10 wherein the housing includes means for preventing ingress of water, such a grommets or the like around cable entry points.

12. A pump controller as claimed in any one of the preceding claims wherein said switching means is associated with a second input means for connection to a low voltage pump start output of a reticulation controller, so that said pump controller functions as a pump start interface device and non- flow protection device.

13. A pump controller substantially as herein described, with reference to the 10 drawings. Dated this SIXTEENTH day of MARCH 1999. *4 •GREGORY MICHAEL WHITMEE Applicant Wray Associates Perth, Western Australia Patent Attorneys for the Applicant