JPH10220361A - Pump operation control device for automatic water supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably stop an abnormal pump by a method wherein when during operation, a discharge pressure is reduced to a value lower than a preset value and a time of a timing timer lapses or when a pump operation current is reduced to a value lower than a set value, an alarm is sounded and the pump is brought into a stop. SOLUTION: Flow switches 3-1 and 3-2 are arranged on the discharge sides of two pumps 2-1 and 2-2, respectively, and check valves 5-1 and 5-2 are incorporated in a collecting pipe 4 attached on the discharge sides of the switches 3-1 and 3-2, and a pressure sensor 6 and a pressure tank 7 are connected. A current detecting device is arranged at a control panel 8 to control an automatic water supply device to monitor a current during operation of the pump. When, during operation of the pump, a discharge pressure is below an abnormal reduction detecting value and a set time of a timing timer elapses, an alarm is sounded and the pump is brought into a stop. Or when the operation current of the pump is reduced to a value below a discharge pressure reduction detecting current value, an alarm is sounded and the pump is brought into a stop.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pump operation control device for an automatic water supply device which is capable of detecting abnormalities of a pump and stopping the abnormal pump in an automatic water supply device having a pump which can be operated independently / in parallel. It is about.

[0002]

2. Description of the Related Art In an automatic water supply system having a pump which can be operated independently or in parallel, the discharge pressure of the pump may be abnormally reduced for some reason. In this case, the required pressure cannot be obtained. Instead, the pump may run idle and cause a failure. Conventionally, as a method of detecting this state, there is generally a method of attaching a pressure detecting device such as a pressure switch to a discharge port of each pump to detect a pressure drop during operation of the pump.

[0003]

However, in the conventional method for detecting a pressure drop during the operation of the pump, the water amount-pressure diagram of the pump is normal and the water amount-pressure line of FIG. As shown in FIGS. A1, A2, and A3, when the discharge pressure is equal to or lower than the abnormal pressure drop detection pressure P3, it can be determined that the discharge pressure is abnormal, but in other cases, it cannot be detected. Further, when the cutoff pressure becomes lower than the stop pressure set value P1 as in the water amount-pressure diagram A3, the pump may not be able to stop, and the pump runs idle, causing a failure. In FIG. 1, A1
Is a water volume-pressure diagram when the pump is normal, A2 is a water volume-pressure diagram when the discharge pressure is abnormally low (the pump can be stopped during the shutoff operation), and A3 is a water amount-pressure diagram when the discharge pressure is abnormally low (the cutoff) The pump cannot be stopped during operation).

[0004] The present invention has been made in view of the above points, and when the discharge pressure of the pump abnormally drops for some reason, it is appropriately detected, and the operation of the automatic water supply device capable of stopping the abnormal pump is performed. It is an object to provide a control device.

[0005]

Means for Solving the Problems To solve the above problems, the invention according to claim 1 comprises one or more pumps operating independently, a check valve provided for each pump downstream thereof,
In a single pressure detection device provided downstream of the check valve, a small water amount detection device for stop provided for each pump, and an automatic water supply device equipped with a current detection device that constantly monitors the operation current of each pump, Means for issuing a warning as an abnormally low discharge pressure and stopping the pump when the discharge pressure is equal to or less than a preset pressure and the time of the timer expires during the operation of the pump, and the pump operation current becomes equal to or less than the set value. In this case, a means is provided for issuing an alarm and stopping the pump in the event of the occurrence.

According to a second aspect of the present invention, a plurality of pumps operating in parallel, a check valve provided for each pump downstream thereof, and a single pressure valve provided downstream of the check valve are provided. In an automatic water supply device equipped with a detection device, a small water amount detection device for stop provided for each pump, and a current detection device for constantly monitoring the operation current of each pump, the current value is preset during operation of only the starting pump. When the value becomes equal to or less than the set value, a means for issuing an alarm as an abnormality and stopping the pump, and the current value of the starting pump immediately before the additional operation of the subsequent pump is set to a value equal to or less than the current value determined in relation to the above set value. If there is, the starting pump is determined to be abnormal, a warning is issued and the starting pump is stopped. The current value of one of the pumps is determined in relation to the set value while the pumps are operating in parallel. Preset below the value Means for stopping the starting pump when the time of the timed timer has elapsed, and when the discharge pressure during the parallel operation of the pump is equal to or less than the preset pressure and the time of the preset timed timer has elapsed. It is characterized in that a means for judging a pump having a small current value as abnormal, issuing an alarm and stopping the pump having a small current value is provided.

The invention according to claim 3 is characterized in that one or more pumps operating independently, a check valve provided for each pump downstream thereof, and a single pump provided downstream of the check valve are provided. One pressure detecting device, a discharge pressure adjusting device provided for each pump,
In an automatic water supply device equipped with a current detection device that constantly monitors each pump operation current, if the discharge pressure is below a preset pressure during the operation of the pump and the time of the timed timer has elapsed, the discharge pressure abnormally decreases. Means for issuing an alarm and stopping the pump, and means for issuing an alarm and stopping the pump when the pump operating current falls below a set value.

According to a fourth aspect of the present invention, a plurality of pumps operating in parallel, a check valve provided for each pump on the downstream side thereof, and a single pressure provided on the downstream side of the check valve are provided. In an automatic water supply device having a detecting device, a discharge pressure adjusting device provided for each pump, and a current detecting device for constantly monitoring each pump operating current, a current value is set in advance during operation of only the starting pump. If the current value of the first pump is not more than the current value determined in relation to the above set value, a means for generating an alarm as an abnormality and stopping the pump and stopping the pump when the second pump is additionally operated. Means for determining that the starting pump is abnormal, issuing an alarm and stopping the starting pump, and one of the means during the parallel operation of the pump.
If the current value of the unit has passed the time of the preset timed timer below the current value determined in relation to the set value,
Means for stopping the starting pump, and when the discharge pressure during the parallel operation of the pump is equal to or less than the preset pressure and the time of the preset timer expires, the pump having the small current value is determined to be abnormal. Means for issuing an alarm and stopping a pump having a small current value.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 3 is a diagram showing a configuration example of an automatic water supply device having a pump capable of operating independently / parallelly according to the present invention. In FIG. 3, reference numerals 2-1 and 2-2 denote two pumps mounted on the unit base 1, and pump-stopping low-water-volume detectors are provided on the discharge sides of the pumps 2-1 and 2-2, respectively. Are provided, and the flow switches 3-1 and 3-2 are provided.
A check valve 5-1 and a check valve 5-2 are respectively built in the collecting pipes 4 attached to the discharge side of No. 2, and a single pressure sensor 6 and a pressure tank 7 are connected to the collecting pipes 4. Further, a control panel 8 for controlling the automatic water supply device is provided. The control panel 8 is provided with a current detection device (not shown), and constantly monitors the current during the operation of the pump.

FIG. 1 is a diagram showing the relationship among the water amount, pressure and current characteristics during the isolated operation in the control method of the present invention. In FIG. 1, a curve A1 is a water amount-pressure diagram when the pump is normal, a curve A2 is a water amount-pressure diagram when the discharge pressure is abnormally reduced (the pump can be stopped during the shutoff operation), and a curve A3 is when the discharge pressure is abnormally low. Respectively shows a water amount-pressure diagram (the pump cannot be stopped during the shutoff operation). Further, P1 is a set value of the pump stop pressure, P2 is a set value of the pump start pressure, P3 is a detected value of abnormal discharge pressure drop, and I1 is a normal pump (curve A1).
Pump operating current of the pump driving current value I2 is discharge pressure abnormal drop time (curve A2), the pump operating current of I3 is discharge pressure abnormal drop time (curve A3), I ₀ is the pump before stopping current A value updateable range, I _0a is a predicted current value (initial value) immediately before stopping the pump, I _0b is a current value immediately before stopping the pump, and Ix is a discharge pressure obtained based on a predicted current value I _0a immediately before stopping the pump. The drop detection current value, Q1, is a pump stop small water amount.

When the pressure sensor 6 detects a preset starting pressure set value P2, one of the two pumps 2-1 and 2-2 is started. When the amount of water used decreases, the pressure sensor 6 detects the stop pressure set value P1, and when any of the flow switches 3-1 and 3-2 detects the pump stop small water amount Q1, the pump that has been started is stopped. .

FIG. 2 is a diagram showing the relationship between the amount of water, the pressure and the current characteristics during the parallel operation in the control method of the present invention. In FIG. 2, a curve A1a is a water amount-pressure diagram for one pump when the pumps are operating normally in parallel, a curve A1b is a water amount-pressure diagram for two pumps when the pumps are operating normally in parallel, and a curve A2 is parallel. Water volume-pressure diagram of the abnormal pump when one pump is operating and the pressure is abnormally lowered (the pump can be stopped during the shutoff operation), and the curve A3 indicates the case where one pump is discharged and the abnormal pressure decreases during the parallel operation of the pumps. The water volume-pressure diagram of the abnormal pump (the pump cannot be stopped during the shutoff operation) is shown.

Further, P1 is a set value of the stop pressure of the pump, P
2 is a pump starting pressure set value, P3 is a discharge pressure abnormal drop detection value, I1 is a pump operating current value when the pump is normal (curve A1a), and I2 is a discharge pressure abnormal drop (curve A2).
Pump operating current of the pump driving current value I3 is discharge pressure abnormal drop time (curve A3), I ₀ is the current value updatable range immediately before the pump is stopped, I _0a current predicted value of the immediately preceding pump stop (Initial value ), I _0b is the current value immediately before stopping the pump, I1a
Is the current value immediately before the additional pump is started when the initial pump is normal (curve A1a), I2b is the current value immediately before the additional pump is started when the advanced pump discharges and the pressure is abnormally reduced (curve A2), I3c Is the current value immediately before the additional pump is started, and Ix is the pressure drop detection current value obtained on the basis of the predicted current value I _0a immediately before the pump is stopped, when the first pump discharges and the abnormal pressure is abnormal when the abnormal pump (curve A3) is used. , Q1 are pump stoppage small water amounts.

When the pressure sensor 6 detects the starting pressure set value P2 again while the first pump, for example, the pump 2-1, is operating, the second pump, for example, the pump 2-2 is additionally started. Thereafter, when the amount of water used decreases and the pressure sensor 6 detects the stop pressure set value P1, the starting pump 2-1 stops, and further, the amount of water used decreases, and the pressure sensor 6 decreases the stop pressure set value P1. When the flow is detected again and the flow switch 3-2 detects the pump stop small water amount Q1, the subsequent pump 2-2
Also stop.

In the automatic water supply device, the current characteristics of the pump to be used are confirmed in advance, and the current predicted value (initial value) I _0a immediately before the pump is stopped is predicted and set (for example, the rated current of the motor used). 60%). The predicted current predicted value I _0a is used as the initial value of the current value immediately before the pump is stopped, and the current value can be updated immediately before the pump is stopped. Within the range I ₀ ), the current value is updated to the current value I _0b immediately before the actual stop of the pump (for example, at power-on and when an abnormality is detected, the current value is initialized to the predicted current value I _0a immediately before the stop of the pump). The current value I _0b immediately before the pump is stopped is compared every time the pump is stopped, and the minimum value is updated.

With the above settings, the pump is automatically operated. Hereinafter, the case where the single operation and the parallel operation are set will be described.

[In Case of Set to Single Operation] The operation in the single operation will be described with reference to FIGS. 1 and 4. FIG. 4 is a diagram showing a flow at the time of the isolated operation in the control method of the present invention. It is determined whether or not the discharge-side pressure detected by the pressure sensor 6 is equal to or less than the starting pressure set value P2 (step ST2).
1) If the discharge side pressure is equal to or less than the starting pressure set value P2, the pump starts (step ST2). If the discharge pressure decreases for any reason during the operation of the pump, the discharge pressure is set to a value equal to or less than a predetermined abnormal drop detection value P3 (for example, 80% of the starting pressure set value P2). It is determined whether or not the set time (for example, 7 seconds) of the timed timer has elapsed (step ST3). If the set time has elapsed while the discharge pressure is equal to or lower than the abnormally low detection pressure P3, the discharge pressure is abnormal. As detection of the decrease, an alarm is issued and the pump is stopped (step ST4).

If the current value has decreased due to a decrease in the discharge pressure during operation in step ST2 due to any cause, and if the abnormal discharge pressure detection value P3 has not been detected in step ST3, the operating current value of the pump There pump stop just before the current predicted values for (initial value) I _0a, it can be determined that the abnormal discharge pressure drop detected current value Ix (e.g.,
And 50% of I _0a) to determine less if it (step ST5), discharged as a pressure abnormality drop detection discharge if: the pressure drop detected current value Ix, stops the pump with issuing an alarm (Step ST4).

If no abnormal decrease in the discharge pressure is detected, the discharge pressure is set to a preset stop pressure set value P1.
It is determined whether or not the above is the case (step ST6). If it is determined that the discharge pressure is equal to or higher than the stop pressure set value P1, it is next determined whether or not the flow switch detects the pump stop small water amount Q1 (step ST6). ST7) If the pump stop small water amount Q1 is detected, the current value I _0b immediately before the pump is stopped is updated (step ST8), and the pump is stopped (step ST8).
9).

If the discharge pressure drops for some reason during the operation of the pump alone as described above, the discharge pressure detected by the pressure sensor 6 is determined to be a predetermined abnormality, and the discharge pressure is abnormally lowered. When the detected value is equal to or less than P3, when a preset time period elapses, it is determined that an abnormality has occurred, an alarm is issued, the pump is stopped, and a current prediction value (initial value) I _0a immediately before the pump is stopped during pump operation. Not only the discharge pressure but also the abnormality of the current value is detected so that when the discharge pressure drop detection current value Ix, which can be judged as abnormal, is determined to be abnormal or less, an alarm is issued and the pump is stopped. As a result, not only is the discharge pressure abnormal drop detection value P3 or less that can be determined to be abnormal, but also the discharge pressure abnormal drop detection value P3 when the discharge pressure abnormal drop occurs (curves A2 and A3). It can also be detected abnormality of the pressure range exceeding.

[When Parallel Operation is Set] The operation during the parallel operation will be described with reference to FIGS. 2, 5 and 6. In addition,
FIG. 5 and FIG. 6 are diagrams showing the flow at the time of parallel operation in the control method of the present invention, and are connected to FIG. 5 and FIG. 6 respectively. It is determined whether or not the discharge side pressure detected by the pressure sensor 6 is equal to or lower than the starting pressure set value P2 (step ST10). If the discharge side pressure is equal to or lower than the starting pressure set value P2, the starting pump is started (step ST11), and the starting is started. If the current value decreases due to a decrease in the discharge pressure for some reason during the operation of the pump alone, it is determined that the current value of the starting pump is abnormal with respect to the current predicted value (initial value) I _0a immediately before the pump stops. The discharge current drop detection current value Ix (for example,
And 50% of I _0a) was in a determination of whether the following (Step ST12), discharged in the following cases the pressure drop detected current value Ix discharge starter pump pressure abnormality drop detection, starting with issuing an alarm The pump is stopped (step ST13).

As described above, when the operating current value is equal to or less than the discharge pressure drop detection current value Ix, it is determined that there is an abnormality, and an alarm is issued and the pump is stopped. Since the pressure decreases and the discharge pressure becomes equal to or less than the starting pressure set value P2 before the abnormality is determined, the subsequent pump is additionally started and the discharge pressure increases.

Therefore, the discharge pressure is set to the starting pressure set value P2.
In the following, it is determined whether or not a preset time set by a timed timer has elapsed (step ST14). When the discharge pressure is equal to or less than the starting pressure set value P2 and the set time has elapsed, the subsequent pump is started. (Step ST15), it is determined whether or not the operating current value of the leading pump immediately before the subsequent pump is additionally started is equal to or less than the predicted current value (initial value) I _0a immediately before the pump is stopped or the current value I _0b immediately before the pump is stopped. (Step ST16), the predicted current value (initial value) I immediately before the pump stops.
_0a or the current value I _0b immediately before the stop of the pump, the start pump is stopped and the start pump is stopped (step ST
13).

When the discharge pressure decreases in one of the pumps during the parallel operation, the operating water amounts of the two pumps become uneven, and the operating current value of the pumps in which the discharge pressure decreases decreases. . The operating time of one of the two pumps is equal to or less than the current predicted value (initial value) I _0a immediately before the pump is stopped or the current value I _0b immediately before the pump is stopped. It is determined whether or not 10 seconds have elapsed (step ST17). The operating current value of one of the two pumps is the current predicted value (initial value) I _0a immediately before the pump is stopped or the current value immediately before the pump is stopped. If the set time has elapsed at the current value I _0b or less, the starting pump is stopped (step ST18).

At this time, if the normal pump is the starting pump, the required discharge pressure cannot be obtained with one subsequent pump of the abnormal pump, so that the discharge pressure detected by the pressure sensor 6 is equal to the starting pressure set value. It is determined whether the set time has elapsed at P2 or less (step ST14). If the discharge pressure has elapsed at the start pressure set value P2 or less and the set time has elapsed, the normal starter pump once stopped is additionally started as a late pump. (Step ST15).

It is determined whether the operating current value of the abnormal advanced pump immediately before the addition of the normal late pump is equal to or less than the predicted current value (initial value) I _0a immediately before the pump is stopped or the current value I _0b immediately before the pump is stopped. It is determined (step ST16), and when the current value is less than the predicted current value (initial value) I _0a immediately before the stop of the pump or the current value I _0b immediately before the stop of the pump, an alarm is issued as detection of an abnormal drop in the discharge pressure of the starting pump, and The abnormal pump serving as the starting pump is stopped (step ST13).

If the abnormal pump is the starting pump, the abnormal pump is stopped and the normal starting pump 1 is stopped.
When the discharge time detected by the pressure sensor 6 due to the increase in the amount of water and the set time has elapsed at the starting pressure set value P2 or less in step ST14, the abnormal pump is additionally started as a late pump and operated in parallel. (Step ST15).

In step ST16, the operating current value of the normal preceding pump immediately before the addition of the abnormal pump that has become the later pump is the current predicted value (initial value) I immediately before the pump is stopped.
_0a or the current value I _0b immediately before the pump stops,
When the set time has elapsed while the operation current value of the abnormal pump which has become the late pump is equal to or less than the current predicted value (initial value) I _0a immediately before the pump stop or the current value I _0b immediately before the pump stop in step ST17, the normal start The pump stops (step ST18). In the step ST14, the required discharge pressure was not obtained with one subsequent pump which is an abnormal pump, and the discharge pressure detected by the pressure sensor 6 passed the set time at the starting pressure set value P2 or less, and the pump was stopped once. The first pump of the pump is additionally started as the second pump (step ST15).

When the operating current value of the abnormal pump which has become the preceding pump immediately before the addition of the subsequent pump of the normal pump is less than or equal to the predicted current value (initial value) I _0a immediately before the pump is stopped or the current value I _0b immediately before the pump is stopped. It is determined whether or not there is (step S
T16), the operating current value of the abnormal pump that became the first pump immediately before the additional pump is additionally started is the current predicted value (initial value) I _0a immediately before the pump stopped or the current value I immediately before the pump stopped.
If it is _0b or less, an alarm is issued and the abnormal pump that has become the initial pump is stopped as the initial pump discharge pressure abnormal drop detection (step ST13).

Further, when the discharge pressures of both pumps decrease during the parallel operation, the discharge pressure is set to a preset discharge pressure abnormal drop detection value P3 (for example, 80% of the starting pressure). In the following, it is determined whether or not a preset time (e.g., 7 seconds) of a timed timer has elapsed (step ST19), and the set time is determined when the discharge pressure is equal to or less than the discharge abnormal pressure detection value P3 or less. If the elapsed time has elapsed, a warning is issued and the abnormal pump with the smaller operating current value is stopped (step ST20) to detect abnormal drop in the discharge pressure of the pump with the smaller operating current value, and the operation is started independently.

If no abnormal decrease in the discharge pressure is detected during the parallel operation, it is determined whether or not the discharge pressure is equal to or higher than a preset stop pressure set value P1 (step ST).
21) If the stop pressure is determined to be equal to or higher than the set pressure P1, the starting pump is stopped (step ST18), and it is determined whether or not the discharge pressure is equal to or lower than the start pressure set value P2 (step ST14). When the set time has elapsed without being below the value P2, the discharge pressure is again reduced to the stop pressure set value P1.
It is determined whether or not this is the case (step ST22). If it is determined that the stop pressure is equal to or more than the stop pressure set value P1, then the flow switch (3-1 or 3-2) detects whether or not the pump stop small water amount Q1 has been detected. Is determined (step ST23), and when the pump stop small water amount Q1 is detected, the current value I _0b immediately before the pump stop is updated (step ST24), and the pump is stopped (step ST25).

As described above, if the discharge pressure drop detection current value Ix which can be determined to be abnormal, which is obtained from the current predicted value (initial value) I _0a immediately before the pump is stopped during the advanced pump operation, is reduced to the initial value. pump abnormality as the distal onset pump is stopped with issuing an alarm, further current I1a Advance pump immediately before the subsequent pump adds start, I2b, I3c current predicted value immediately before the pump is stopped (initial value) I _0a or pump stop Also when the current value is immediately lower than the current value I _0b , it is determined that the starting pump is abnormal, an alarm is issued, and the starting pump is stopped.

If the discharge pressure during the parallel operation is equal to or less than the preset discharge pressure abnormal drop detection value P3 and the time of the preset timer expires, it is determined that the pump having the small current value is abnormal. Then, an alarm is issued and the pump having a small current value is stopped.

During the parallel operation, when the current value of one of the units is equal to or less than the current value I _0b or I _0a immediately before the pump is stopped and the time of the preset timer expires, the starting pump is stopped. Since it is detected as an abnormality at the time of additional start, even in the case of parallel operation, by detecting an abnormality of the pressure and current value, one of the pumps in the parallel operation discharges together with the abnormal pressure detection value that can be judged as abnormal To detect an abnormality in the pressure range exceeding the abnormal discharge pressure detection value P3 in the case of an abnormal pump when the pressure is abnormally reduced (the pump can be stopped during the cutoff operation of the curve A2, and the pump cannot be stopped during the shutoff operation of the curve A3). Can be.

In the above-described embodiment, an example in which a flow switch is used as the pump stoppage small water amount detection device is shown. However, a device employing a constant discharge pressure control method using a pressure reducing valve instead of the flow switch may be used. It is possible to achieve the same effect.

[0036]

As described above, according to the present invention,
In an automatic water supply system equipped with a pump capable of independent / parallel operation, the discharge pressure and the operating current are constantly monitored, and if the discharge pressure decreases for any reason, the pump operation is performed due to a change in the amount of water used. Even if the amount of water changes, an excellent effect can be obtained in that it is possible to prevent failure due to idle operation by detecting an abnormality appropriately and stopping the abnormal pump.

[0037]

[Brief description of the drawings]

FIG. 1 is a diagram showing a flow rate of a single operation in a control method according to the present invention;
FIG. 4 is a diagram illustrating a relationship between pressure and current characteristics.

FIG. 2 shows the amount of water during parallel operation in the control method of the present invention;
FIG. 4 is a diagram illustrating a relationship between pressure and current characteristics.

FIG. 3 is a diagram showing a configuration example of an automatic water supply device capable of operating independently / parallelly according to the present invention.

FIG. 4 is a diagram showing a flow at the time of isolated operation in the control method of the present invention.

FIG. 5 is a diagram showing a flow at the time of parallel operation in the control method of the present invention.

FIG. 6 is a diagram showing a flow at the time of parallel operation in the control method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Unit base 2-1 Pump 2-2 Pump 3-1 Flow switch 3-2 Flow switch 4 Collecting pipe 5-1 Check valve 5-2 Check valve 6 Pressure sensor 7 Pressure tank 8 Control panel

Claims (4)

[Claims] 1. One or more pumps operating independently, a check valve provided downstream for each pump, a single pressure detection device provided downstream of the check valve, and a pump In the automatic water supply device equipped with a small water amount detection device for stop provided in the above and a current detection device for constantly monitoring the operation current of each pump, the discharge pressure during the pump operation is equal to or less than a preset pressure, and a timed timer is used. Means are provided that, when the time has elapsed, a means for issuing a warning as the discharge pressure is abnormally low and stopping the pump, and a means for issuing a warning and stopping the pump when the pump operating current falls below the set value. A pump operation control device for an automatic water supply device. 2. A plurality of pumps operating in parallel, a check valve provided for each pump downstream thereof, a single pressure detecting device provided downstream of the check valve, and a pump provided for each pump. In an automatic water supply device equipped with a stoppage small water amount detection device and a current detection device that constantly monitors the operation current of each pump, when the current value becomes equal to or less than a preset value during operation of only the starting pump, Means for issuing an alarm as an abnormality and stopping the pump, and when the current value of the starting pump immediately before the additional operation of the subsequent pump is less than or equal to the current value set in relation to the above set value, the starting pump will be abnormal. Means for issuing an alarm and stopping the starting pump, and a timed timer which is set in advance when the current value of one of the pumps is equal to or less than the current value determined in relation to the set value while the pumps are operating in parallel. Time has passed Means to stop the starting pump, and if the discharge pressure is equal to or less than the preset pressure while the pumps are operating in parallel and the time of the preset timed timer has elapsed, the pump with the small current value is abnormal. And a means for issuing an alarm and stopping a pump having a small current value. 3. One or more pumps operating independently, a non-return valve provided for each pump downstream thereof, a single pressure detecting device provided downstream of the non-return valve, In the automatic water supply device equipped with a discharge pressure adjusting device provided in the above and a current detection device which constantly monitors each pump operation current, the discharge pressure during the pump operation is equal to or less than a preset pressure and the time of the timed timer If the pump operation current has become equal to or less than a set value, a means for issuing a warning and stopping the pump when the discharge pressure is abnormally low is provided. Pump operation control device of automatic water supply system. 4. A plurality of pumps operating in parallel, a check valve provided for each pump downstream thereof, a single pressure detection device provided downstream of the check valve, and a pump provided for each pump. In an automatic water supply system equipped with a discharge pressure adjustment device and a current detection device that constantly monitors the operation current of each pump, if the current value falls below a preset value during operation of only the starting pump, abnormal Means for issuing an alarm and stopping the pump; and, when the current value of the starting pump immediately before the additional operation of the subsequent pump is equal to or less than the current value determined in relation to the above set value, the starting pump is regarded as abnormal. Means for judging, issuing an alarm and stopping the starting pump, and a timer for setting a timed timer which is set in advance when the current value of one of the pumps is equal to or less than the current value determined in relation to the set value while the pumps are operating in parallel. When time has passed In this case, the means for stopping the starting pump and the pump having a small current value when the discharge pressure is equal to or less than the preset pressure and the time of the preset timer expires during the parallel operation of the pumps are abnormal. And a means for issuing a warning and stopping a pump having a small current value.