JPH07216944A - Water feed control device - Google Patents

Abstract

PURPOSE:To perform proper control of three or more pumps without increasing a cost. CONSTITUTION:A water feeder is constituted to have four pumps 1, 2, 3, and 4 and pump up water through operation of the pumps, and feed water through a water feed pipe 7 to a given place. The water feeder comprises a mass production type low-cost operation control part A to alternately perform individual operation and parallel operation of the pumps 1 and 2 and a mass production type low-cost operation control part B to alternately perform individual operation and parallel operation of the pumps 3 and 4. Meanwhile, a pressure of water in the water feed pipe 7 and a water flow are detected and a detecting result is inputted to a central control part C using a general and low-cost sequence controller on a market. A command is transmitted to the operation control parts A and B by the central control part C so that the number of working pumps 1, 2, 3, and 4 is regulated according to a detecting result of a pressure and a flow rate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water supply control device for a water supply machine having three or more pumps.

[0002]

2. Description of the Related Art As a water supply machine, it has two pumps,
There are alternate parallel models that operate these pumps independently and in parallel. Since this model has a large number of units sold, the control device to be mounted can be manufactured inexpensively by mass-producing a dedicated logic board using a one-chip microcomputer.

[0003]

When the amount of water used on the water receiving side is large, the two pumps may not catch up with the water supply. Therefore, if you install three or more pumps and try to increase or decrease the operating number of these pumps according to the amount of water used,
You have to specially develop a dedicated logic board,
This will increase costs.

The present invention takes the above circumstances into consideration,
The purpose is to avoid cost increase,
An object of the present invention is to provide a water supply control device that can appropriately control three or more pumps.

[0005]

A water supply control device of the present invention has three or more pumps, which sucks water by operating these pumps and sends it to a predetermined place by a water supply pipe, A plurality of operation control units corresponding to each two pumps, controlling independent operation and parallel operation of the corresponding two pumps, a pressure detector for detecting water pressure in the water supply pipe, and water in the water supply pipe. And a central control unit that gives a command to each operation control unit so as to increase or decrease the number of operating pumps according to the detection results of the pressure detector and the flow rate detector.

[0006]

In the water supply control device of the present invention, the pressure and flow rate of water in the water supply pipe are detected, and the detection results are input to the central control unit. The central control unit gives a command to each operation control unit so as to increase or decrease the number of operating pumps according to the detection result.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. First, FIG. 2 shows a water supply device according to the present invention.
Shown in. Four pumps 1, 2, 3 and 4 are provided, and the intake ports of these pumps are respectively connected to the water receiving tank 6 via the water suction pipe 5.
Is communicated within. The water receiving tank 6 contains a liquid such as water.

A water supply pipe 7 is provided at the discharge ports of the pumps 1, 2, 3 and 4.
Is connected, and the water supply pipe 7 is extended to a place where it is necessary to receive water. A pressure tank 8 is connected to a middle portion of the water supply pipe 7. On the water supply pipe 7 between the pressure detector 8 and each pump, a pressure switch 10 as a pressure detector and three flow rate switches 11, 12, 13 as flow rate detectors are attached.

The flow switches 14, 15, 1 which are individual flow rate detectors are connected to the pipes connecting the discharge ports of the pumps and the water supply pipe 7.
6 and 17 are attached respectively. A water receiving tank electrode 18 is provided in the water receiving tank 6.

The water supply controller shown in FIG. 1 is mounted on this water supply machine. The three-phase AC power source 20 has contactor contacts 31a, 31
The drive motor 1M of the pump 1 is connected via a, 31a and a semiconductor switch such as a bidirectional thyristor 33, 33. The power source 20 has contactor contacts 32a, 32a,
Drive motor 2M of pump 2 is connected via 32a and a semiconductor switch such as bidirectional thyristors 34, 34.

A current converter 35 is attached to the energizing path from the bidirectional thyristors 33, 33 to the motor 1M. A current converter 36 is attached to the energization path from the bidirectional thyristors 34, 34 to the motor 2M.

The power source 20 has contactor contacts 51a, 51a,
Drive motor 3M of pump 3 is connected via 51a and a semiconductor switch such as bidirectional thyristor 53. The power source 20 has contactor contacts 52a, 52a, 52
a and a semiconductor switch such as a bidirectional thyristor 5
The drive motor 4M of the pump 4 is connected via 4, 54.

A current converter 55 is attached to the energization path from the bidirectional thyristors 53, 53 to the motor 3M. A current converter 56 is attached to the energization path from the bidirectional thyristors 54, 54 to the motor 4M.

An operation controller A and an operation controller B are connected to the power source 20. The operation control unit A is prepared for an alternating parallel model in which two pumps are alternately operated independently or in parallel, and the number of sales of the same model is large.
It is mass-produced as a dedicated logic board that uses a one-chip microcomputer, and can be manufactured at low cost. The operation control unit B is also the same.

To the operation control unit A, the operation display unit 30, the electromagnetic contactors 31, 32, the bidirectional thyristors 33, 34, and the current converters 35, 36 are connected, and the level sensor 39 is attached. This level sensor 39
It is connected to the water receiving tank electrode 18 of the water receiving tank 6 and detects the liquid level in the water receiving tank 6 through the water receiving tank electrode 18.

The operation control section A has an external interrupt input terminal 4
1, 42, a pressure switch connection terminal 43, flow rate switch connection terminals 44 and 45, and a full water / drought signal output terminal 46.

The pressure switch connection terminal 43 is connected to the pressure switch 10 in the case of the two-pump model, but this is not done because it is the four-pump model. The flow rate switch connection terminal 44 is connected to the flow rate switches 11, 12, and 13 in the case of the two-pump model, but this is not done because it is the four-pump model. The flow rate switch connection terminal 45 is a flow rate switch 1 if it is a two-pump model.
It is for connecting 4 and 15, but it is not done because it is a model of 4 pumps.

To the operation control section B, the operation display section 50, electromagnetic contactors 51 and 52, bidirectional thyristors 53 and 54, and current converters 55 and 56 are connected, and a level sensor 59 is attached. This level sensor 59
It is connected to the water receiving tank electrode 18 of the water receiving tank 6 and detects the liquid level in the water receiving tank 6 through the water receiving tank electrode 18.

The operation control section B has an external interrupt input terminal 6
1, 62, pressure switch connection terminals 63, flow rate switch connection terminals 64 and 65, and full water / drought signal output terminals 66.

The pressure switch connection terminal 53 is connected to the pressure switch 10 in the case of the two-pump model, but this is not done because it is the four-pump model. The flow rate switch connection terminal 54 is connected to the flow rate switches 11, 12, and 13 in the case of the two-pump model, but this is not done because it is the four-pump model. The flow switch connection terminal 55 is the flow switch 1 if it is a two-pump model.
It is for connecting 4 and 15, but it is not done because it is a model of 4 pumps.

On the other hand, a central controller C using a general and inexpensive sequence controller such as a commercially available one is provided.
An external interrupt input terminal 41, a pressure switch connection terminal 43, and flow rate switch connection terminals 44 and 45 of the operation control unit A are connected to the central control unit C by signal lines, and an output terminal of the OR circuit 70 is connected to the central control unit C. Signal line is connected.

An external interrupt input terminal 61, a pressure switch connection terminal 63, and flow rate switch connection terminals 64 and 65 of the operation control unit B are connected to the central control unit C by signal lines, and the OR circuit 70 is connected. The output terminal is connected to the signal line.

The OR circuit 70 is connected at one input end thereof to the water-filling / drought signal output terminal 46 of the operation control unit A, and at the other input end thereof to the water-filling / drought signal output terminal 66 of the operation control unit B, which is provided at the center. The control unit C includes a pressure switch 10, flow rate switches 11, 12, 13 and flow rate switches 14, 1.
5, 16 and 17 are connected.

The central control unit C increases or decreases the number of operating pumps one by one in accordance with the detection results of the pressure switch 10 and the flow rate switches 11, 12, 13 and the detection results of the level sensors 39, 59 are predetermined. In order to stop the operation of each pump when the value is less than the value,
According to the detection results of 5, 16, and 17 and the operating states of the pumps, the idling of the pumps is detected, and a command is given to the operation control units A and B to stop the operation of the idling pumps.

Next, the operation of the above configuration will be described with reference to FIGS. 3 and 4. First, it is assumed that the automatic display mode is set on the operation display units 30 and 50. When no water is used on the receiving side, all pumps are stopped and the water pressure in the water supply pipe 7 is maintained at P ₂ .

[1] Single Unit Operation (Pump 1) When water is used, the water pressure in the water supply pipe 7 decreases. When this pressure falls below the set value P ₁ , the pressure switch 10 is turned on, and in response thereto, a single activation signal Sa is input from the central control unit C to the pressure switch connection terminal 43 of the operation control unit A. .

Upon receipt of the start signal Sa, the operation control section A energizes the electromagnetic contactor 31 to bring the contactor contacts 31a, 31a, 3 into contact.
1a is turned on and the bidirectional thyristors 33, 3 are turned on.
Turn on 3. As a result, the motor 1M is activated, and the operation of the pump 1 is started. By the operation of one of the pumps 1, water is pumped up from the water suction pipe 5 and sent to the receiving side by the water supply pipe 7.

At this time, the amount of water f ₁ flowing from the pump 1 into the water supply pipe 7 becomes larger than the set value Q ₁ , and the flow rate switch 14 is turned on. By turning on the flow rate switch 14,
The central control unit C inputs a holding signal (logic “1” signal) Ha ₁ to the flow switch connection terminal 44 of the operation control unit A, based on the judgment that the pump 1 is not idling and is functioning normally. . The operation control unit A that has received the hold signal Ha ₁ holds the single operation of the pump 1.

[2] Stop of water supply When the amount of water f ₁ flowing from the pump 1 to the water supply pipe 7 is reduced to the set value Q ₁ or less after the use of water is stopped, the flow rate switch 1
4 turns off.

When the flow rate switch 14 is turned off, the hold signal Ha ₁ input to the flow rate switch connection terminal 44 from the central control section C is released (becomes a logic "0"). When the input of the hold signal Ha ₁ is released, the operation control unit A turns off the bidirectional thyristors 33, 33 to stop the operation of the pump 1.

[3] Single Unit Operation (Pump 2) When water is used again, the water pressure in the water supply pipe 7 decreases. When this pressure falls below the set value P ₁ , the pressure switch 10
Is turned on, and in response thereto, a single activation signal Sa is sent from the central control unit C to the pressure switch connection terminal 43 of the operation control unit A.
Is entered again.

Upon receipt of the start signal Sa, the operation control section A now energizes the electromagnetic contactor 32 to contact the contactor contacts 32a, 32.
a and 32a are turned on, and the bidirectional thyristor 3
Turn on 4, 34. As a result, the motor 2M is activated and the operation of the pump 2 is started. By the operation of one of the pumps 2, water is pumped up from the water suction pipe 5 and sent to the receiving side by the water supply pipe 7.

At this time, the amount of water f ₁ flowing from the pump 2 into the water supply pipe 7 becomes larger than the set value Q ₁ , and the flow rate switch 15 is turned on. By turning on the flow rate switch 15,
The central control unit C inputs the holding signal (logic “1” signal) Ha ₂ to the flow switch connection terminal 45 of the operation control unit A, based on the judgment that the pump 2 is functioning normally without idling. . Upon receiving the hold signal Ha ₂ , the operation control unit A holds the single operation of the pump 2.

[4] Stop of Water Supply After that, when the use of water is finished and the amount of water f ₁ flowing from the pump 2 to the water supply pipe 7 decreases below the set value Q ₁ , the flow rate switch 15 is turned off.

When the flow rate switch 15 is turned off, the hold signal Ha ₂ input from the central control section C to the flow rate switch connection terminal 45 is released (becomes a logic "0"). When the input of the hold signal Ha ₂ is released, the operation control unit A turns off the bidirectional thyristors 34, 34 to stop the operation of the pump 2.

As described above, under the control of the operation control unit A based on the command of the central control unit C, the pump 1 and the pump 2 are alternately started and stopped depending on whether or not water is used. The alternating start and stop of the pump 1 and the pump 2 is also performed in the subsequent switching between the one-unit operation and the two-unit operation.

[5] Two-unit operation (Pumps 1 and 2) When one pump 1 or pump 2 is operated, if the water consumption increases and the flow rate f ₂ increases above the set value R ₁ , the flow switch 11 Turn on. At this time, a single activation signal Sa is input from the central control unit C to the pressure switch connection terminal 43 of the operation control unit A.

Upon receipt of the start signal Sa, the operation control section A starts the pump on the operation stop side. For example, if one pump 1 is being operated, the bidirectional thyristors 34, 34 are turned on to start the operation of the pump 2. As a result, the two pumps 1 and 2 are operated.

During operation of the two units, holding signals (logical "1" signals) Ha ₁ and Ha ₂ are input from the central control unit C to the flow switch connection terminals 44 and 45 of the operation control unit A. The operation control unit A which receives the _two holding signals Ha ₁ and Ha ₂
Holds the operation of two pumps 1 and 2.

[6] One unit operation (pump 2) When two units are operated, the amount of water used decreases and the flow rate f ₂ becomes the set value Q ₂
When it is reduced to (<R ₁ ) or less, the flow rate switch 11 is turned off. At this time, the central control unit C stops the pump that was turned on during the previous operation of one unit. For example, if the last single unit operation was the pump 1, the hold signal Ha ₁ is released (it becomes a logic “0”) in order to stop the pump 1.

The operation control unit A, which has released the input of the hold signal Ha ₁ , stops the operation of the pump 1. That is, the operation of two pumps 1 and 2 is switched to the operation of one pump 2. [7] Operation of two units (pumps 1, 2) After that, the amount of water used increases again and the flow rate f ₂ becomes the set value R ₁
When the amount is increased above, the flow rate switch 11 is turned on again.
At this time, a single activation signal Sa is input from the central control unit C to the pressure switch connection terminal 43 of the operation control unit A.

The operation control section A which receives the start signal Sa starts the pump on the operation stop side. For example, if the operation of the single pump 2 is being executed, the operation of the pump 1 is started. As a result, the operation of one pump 2 is restored to the operation of two pumps 1 and 2.

[8] Three-unit operation (pumps 1, 2, 3) The amount of water used further increases, and water supply may not catch up with two-unit operation of the pumps 1, 2.

When the flow rate f ₂ increases above the set value R ₂ ,
The flow rate switch 12 is turned on (the flow rate switch 11 is on and the flow rate switch 13 is off). At this time, from the central control unit C to the pressure switch connection terminal 6 of one operation control unit B
A single activation signal Sa is input to 3.

Upon receipt of the start signal Sa, the operation control section B energizes the electromagnetic contactor 51 to contact the contactor contacts 51a, 51a, 5a.
1a is turned on and the bidirectional thyristors 53 and 5 are turned on.
Turn on 3. As a result, the motor 3M is started and the operation of the pump 3 is newly started, and the operation of the three pumps 1, 2 and 3 is started.

At this time, the amount of water f ₁ flowing from the pump 3 into the water supply pipe 7 becomes larger than the set value Q ₁ , and the flow rate switch 16 is turned on. By turning on the flow rate switch 16,
The central control unit C inputs the holding signal (logic “1” signal) Hb ₁ to the flow switch connection terminal 64 of the operation control unit B, based on the judgment that the pump 3 is functioning normally without idling. . The operation control unit B that has received the hold signal Hb ₁ holds the operation of the pump 3.

[9] Two-unit operation (pumps 1, 2) When three units are operated, the amount of water used decreases and the flow rate f ₂ becomes the set value Q ₃
When it is reduced to (<R ₂ ) or less, the flow rate switch 12 is turned off. At this time, the hold signal Hb ₁ input from the central control unit C to the flow switch connection terminal 64 is released (becomes a logic “0”).

When the input of the hold signal Hb ₁ is released, the operation control unit B stops the pump 3 and switches the operation of the three pumps 1, 2, 3 to the operation of the two pumps 1, 2. [10] Three units operation (pumps 1, 2, 4) After that, the amount of water used increases again and the flow rate f ₂ becomes the set value R ₂
When the amount is increased above, the flow rate switch 12 is turned on again.
At this time, a single activation signal Sa is input from the central control unit C to the pressure switch connection terminal 63 of the operation control unit B.

Upon receipt of the start signal Sa, the operation control section B energizes the electromagnetic contactor 52 to contact the contactor contacts 52a, 52a, 5a.
2a is turned on and the bidirectional thyristors 54, 5 are turned on.
Turn on 4. As a result, the motor 4M is started and the operation of the pump 4 is newly started, and the operation of the three pumps 1, 2, 4 is performed.

At this time, the amount of water f ₁ flowing from the pump 4 into the water supply pipe 7 becomes larger than the set value Q ₁ , and the flow rate switch 17 is turned on. By turning on the flow rate switch 17,
The central control unit C inputs the holding signal (logic “1” signal) Hb ₂ to the flow switch connection terminal 65 of the operation control unit B, when it is judged that the pump 4 is not idling and is functioning normally. . The operation control unit B that has received the hold signal Hb ₂ holds the operation of the pump 4.

In this way, switching between the two-unit operation and the three-unit operation is performed while the pump 3 and the pump 4 are repeatedly started and stopped alternately. [11] Four-unit operation (pumps 1, 2, 3, 4) When the amount of water used further increases and the flow rate f ₂ increases above the set value R ₃ , the flow rate switch 13 turns on (the flow rate switches 11 and 12 also on). At this time, a single activation signal Sa is input from the central control unit C to the pressure switch connection terminal 63 of the operation control unit B.

Upon receipt of the start signal Sa, the operation control section B starts the pump on the operation stop side. For example, if three pumps 1, 2, and 4 are in operation, the operation of the pump 3 is started. As a result, the operation of the three pumps 1, 2, 4 is switched to the operation of the four pumps 1, 2, 3, 4.

During operation of the four units, holding signals (logic "1" signals) Hb ₁ and Hb ₂ are input from the central control unit C to the flow switch connection terminals 64 and 65 of the operation control unit B. The operation control unit B which has received these two holding signals Hb ₁ and Hb ₂
Holds the operation of the pumps 3 and 4.

[12] Three-unit operation (pumps 1, 2, 3) When four units are operated, the amount of water used decreases and the flow rate f ₂ becomes the set value Q ₄
When it is reduced to (<R ₃ ) or less, the flow rate switch 13 is turned off. At this time, the central control unit C stops the pumps that have been turned on during the last operation of the three vehicles. For example, if the last three units were operated by pumps 1, 2 and 4, the hold signal Hb ₂ is released to stop the pump 4 (logic “0”).
Will be).

The operation control section B, which has released the input of the hold signal Hb ₂ , stops the operation of the pump 4. That is, the operation of the four pumps 1, 2, 3, 4 is switched to the operation of the three pumps 1, 2, 3.

In this way, by increasing or decreasing the number of pumps 1, 2, 3, 4 operated one by one according to the amount of water used on the water receiving side, it is possible to supply water over a wide range from a small amount to a large amount.

In particular, the mass-production type inexpensive operation control units A and B for alternately operating the two pumps independently and in parallel are used as they are, and a general and inexpensive sequence controller such as those on the market is used. Since the central control unit C controls centrally, it is not necessary to specially develop a dedicated logic board, only the program processing of the sequence controller is required, and therefore four pumps can be properly used without increasing the cost. Can be controlled.

Moreover, since there are two operation control units A and B equipped with microcomputers, even if the microcomputer of one operation control unit runs out of control, water supply can be continued by the other operation control unit. As a result, there is no need to worry about running out of water, ensuring high reliability.

When the sequence controller, which is the central control unit C, runs out of control, the output signal of the pressure switch 10 and the flow rate switches 11, 12, 13, 14, 1 are output.
The water supply can be continued by directly inputting the output signals of 5, 16, and 17 to the operation control unit A or the operation control unit B.

[13] Failure of bidirectional thyristor Despite the fact that the operation control section A has given the ON signal to the bidirectional thyristors 33, 33,
33 may not turn on. In this case, the current converter 3
Since the detection current of 5 becomes zero, the operation control unit A determines that the bidirectional thyristors 33, 33 have a failure in the open mode, and displays the fact on the operation display unit 30.
For safety, the electromagnetic contactor 31 is deactivated and the contactor contact 31
a, 31a, 31a are turned off.

Despite the off timing of the bidirectional thyristors 33, 33, the bidirectional thyristor 3
3,33 may stay on. In this case, since the detected current of the current converter 35 becomes larger than zero, the operation control unit A determines that the bidirectional thyristors 33, 33 have a short-circuit mode failure, and displays the fact on the operation display unit 30. At the same time, the electromagnetic contactor 31 is deenergized and the motor 1M
Forcibly shut off the power supply to.

The same function is provided in the operation control unit A for the failure of the bidirectional thyristors 34, 34. Also, the bidirectional thyristors 53, 53, 54, 54
The same function is installed in the operation control unit B for the failure of.

[14] Drought in the water receiving tank 6 The amount of water in the water receiving tank 6 is detected by the level sensor 39 on the side of the operation control unit A and the level sensor 59 on the side of the operation control unit B via the water receiving tank electrode 18. It

When the detection results of the level sensors 39 and 59 decrease below a predetermined value, the operation control units A and B cause the electromagnetic contactor 3 to operate.
1, 32, 51, 52 are forcibly deactivated, pump 1,
Immediately stop operations 2, 3, and 4. At the same time, the operation control units A and B send a drought detection signal to the central control unit C from the full water / drought signal output terminals 46 and 66.

The central control unit C, which has received the drought detection signal, suspends the control of the operation control units A and B. When the drought is eliminated and the detection results of the level sensors 39, 59 return to a predetermined value or higher, the operation control units A, B cause the pumps 1, 2, 3, to pump.
The operation control of 4 is restarted and the drought detection signal is released.

After the input of the drought detection signal is released, the central control unit C restarts the control of the operation control units A and B. [15] Idling of Pump When the central control unit C issues a start signal for operating the pump 1 and the flow rate switch 14 does not turn on even after a predetermined time has passed, the pump 1 is idling. The determination is made and an abnormal stop signal for the pump 1 is sent to the external interrupt input terminal 41 of the operation control unit A.

The central control unit C determines that the pump 2 is idling when the flow rate switch 15 does not turn on even after a predetermined time elapses after the activation signal for operating the pump 2 is issued. An abnormal stop signal for the pump 2 is sent to the external interrupt input terminal 41 of the operation control unit A.

The central control unit C determines that the pump 3 is idling when the flow rate switch 16 does not turn on even after a predetermined time elapses after the activation signal for operating the pump 3 is issued. An abnormal stop signal for the pump 3 is sent to the external interrupt input terminal 61 of the operation control unit B.

The central control unit C determines that the pump 4 is idling when the flow rate switch 17 does not turn on even after a lapse of a predetermined time after issuing a start signal for operating the pump 4. An abnormal stop signal for the pump 4 is sent to the external interrupt input terminal 61 of the operation control unit B.

Upon receipt of the abnormal stop signal, the operation control unit A stops the operation of the corresponding pump and displays the fact on the operation display unit 30. In the above embodiment, the case where the number of pumps is four has been described as an example, but the number of pumps is not limited, and the same can be performed with five pumps, six pumps or more. Also, an electromagnetic contactor and a bidirectional thyristor were used as means for opening and closing the energization path to the motor.
Other devices such as a relay may be used as long as they have similar functions.

[0071]

As described above, according to the present invention, the pressure and flow rate of water in the water supply pipe are respectively detected, and the detection results are input to the central control unit, and the central control unit responds to the detection results respectively. Since the configuration is such that a command is given to each operation control unit in order to increase or decrease the number of pumps to be operated, it is possible to provide a water supply control device that can appropriately control three or more pumps without increasing costs.

[Brief description of drawings]

FIG. 1 is a block diagram of a control circuit according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a water supply device according to the embodiment.

FIG. 3 is a diagram showing a mutual relationship among a change in the number of operating pumps, a water pressure, and a water flow rate in the example.

FIG. 4 is a flowchart for explaining the operation of the embodiment.

[Explanation of symbols]

1, 2, 3, 4, ... Pump, 7 ... Water supply pipe, 8 ... Pressure tank, 10 ... Pressure switch (pressure detector), 11, 12,
13 ... Flow rate switch (flow rate detector), 14, 15, 1
6, 17 ... Flow rate switch (individual flow rate detector), A, B ...
Operation control unit, C ... Central control unit, 31, 32, 51, 52
... electromagnetic contactor, 33, 34, 53, 54 ... bidirectional thyristor.

Claims (3)

[Claims] 1. A water dispenser having three or more pumps, which sucks water by operating these pumps and sends it to a predetermined place through a water supply pipe, which corresponds to two pumps of each of the pumps. A plurality of operation control units that control the independent operation and parallel operation of the two pumps, a pressure detector that detects the pressure of water in the water supply pipe, and a flow rate detector that detects the flow rate of water in the water supply pipe. , A central control unit for giving a command to each of the operation control units in order to increase or decrease the number of operating pumps according to the detection results of the pressure detector and the flow rate detector, apparatus. 2. A water supply machine having three or more pumps, which sucks water from a water receiving tank by the operation of these pumps and sends it to a predetermined place through a water supply pipe, which corresponds to two pumps each. However, a plurality of operation control units that control the independent operation and the parallel operation of the corresponding two pumps, a pressure detector that detects the pressure of water in the water supply pipe, and a flow rate that detects the flow rate of water in the water supply pipe. A detector, a level sensor for detecting the liquid level in the water receiving tank, and to increase or decrease the operating number of each pump according to the detection results of the pressure detector and the flow rate detector, and of the level sensor. A water supply control device comprising: a central control unit that gives a command to each of the operation control units so as to stop the operation of each of the pumps when the detection result is equal to or less than a predetermined value. 3. A water dispenser having three or more pumps, sucking water from a water receiving tank by operating these pumps, and sending it to a predetermined place through a water supply pipe, corresponding to two of each of the pumps. However, a plurality of operation control units that control the independent operation and the parallel operation of the corresponding two pumps, a pressure detector that detects the pressure of water in the water supply pipe, and a flow rate that detects the flow rate of water in the water supply pipe. A detector, a level sensor that detects the liquid level in the water receiving tank, a plurality of individual flow rate detectors that individually detect the flow rate of water from each of the pumps to the water supply pipe, the pressure detector and the In order to increase or decrease the operating number of each pump according to the detection result of the flow rate detector, and to stop the operation of each pump when the detection result of the level sensor is a predetermined value or less, and the individual flow rate detection A central control unit that gives a command to each operation control unit in order to detect the idling of the pump according to the detection result of the pump and the operating state of each pump and stop the operation of the idling pump. Characteristic water supply control device.