JP4804786B2 - Water supply equipment - Google Patents

Description

  The present invention relates to a water supply apparatus, and more particularly to a water supply apparatus that supplies water to an apartment house by inverter-controlling a pump.

  For example, in a rotary machine device such as a water supply device, it is widely performed to operate a pump at a variable speed by using an inverter that converts the frequency and voltage of a commercial AC power source into an arbitrary frequency and voltage. Because the inverter can change the rotation speed of the motor that drives the pump arbitrarily, it can be operated at the optimum rotation speed corresponding to the load of the pump, saving energy compared to operating at the rated speed. be able to.

  The inverter of such a water supply apparatus is normally operable in a test operation mode after performing maintenance such as replacement of a pump, and can be operated manually at an arbitrary frequency. During operation in this test operation mode, if water is not used on the secondary side of the water supply device, the internal pressure of the pipe rises to the pump cutoff pressure, which may cause leakage from the pipe joint. . As described above, in the test operation of the inverter of the conventional water supply apparatus, the discharge pressure is increased more than necessary, which may place a burden on the piping. In addition, it was complicated and difficult to perform test operation of other pumps safely while operating other pumps in normal automatic operation.

  The present invention has been made in view of such problems of the prior art, and is to provide a water supply apparatus that can prevent an excessive increase in pipe internal pressure on the secondary side of the water supply apparatus during a test operation. Objective.

  According to one aspect of the present invention, a water supply apparatus is provided that includes a pump, an inverter that variably controls the rotational frequency of the pump, and a control unit that controls the inverter. The control unit controls the rotation frequency of the pump so that the rotation frequency during the test operation of the pump does not rise above a predetermined value.

  With such a configuration, it is possible to suppress an increase in the pipe internal pressure on the secondary side of the water supply apparatus to the pump cutoff pressure during the test operation, and it is possible to prevent the pipe from being excessively stressed.

The control unit sets the maximum rotation frequency during the test operation and the maximum rotation frequency during the automatic operation so that the maximum rotation frequency during the test operation of the pump is lower than the maximum rotation frequency during the automatic operation. To do . Alternatively, the control unit may perform the maximum rotation during the test operation with respect to the maximum rotation frequency during the automatic operation of the pump so that the maximum rotation frequency during the test operation of the pump is lower than the maximum rotation frequency during the automatic operation. Set the frequency value by calculation. Alternatively, the control unit in a test operation of the pump, as discharge pressure of the pump does not rise to the above pressure is set at the time of automatic operation, it restricts the rotation frequency of the pump.

  As described above, according to the present invention, it is possible to prevent an excessive increase in the pipe internal pressure on the secondary side of the water supply apparatus during the test operation.

  Hereinafter, an embodiment of a water supply apparatus according to the present invention will be described in detail with reference to FIGS. 1 to 5. 1 to 5, the same or corresponding components are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a schematic view showing a water supply apparatus 1 according to the first embodiment of the present invention. As shown in FIG. 1, the water supply device 1 includes two water receiving tanks 2, two pumps 3 connected to each water receiving tank 2 through a pipe 10, a motor 4 that drives the pump 3, An inverter 5 that controls the rotation frequency and a control unit 6 that controls various devices including the inverter 5 are provided.

  Each water receiving tank 2 is provided with a water level detector 12 for detecting the water level of the water receiving tank 2 by the electrode rod 12a. The water level detector 12 in the present embodiment detects four liquid level levels (full water, reduced water, return, drought). Tap water is introduced into each water receiving tank 2 through a solenoid valve 16 from a water supply pipe 14 connected to a water main (not shown). The water level detector 12 detects the water level of the water receiving tank 2, and the control unit 6 opens and closes the electromagnetic valve 16 according to the increase or decrease of the water level. With such a configuration, the tap water is once stored in the water receiving tank 2, and the stored water is supplied by the pump 3 to a terminal demand destination such as a house.

  A pipe 18 and a discharge pipe 20 are connected to the discharge side of each pump 3, and the tap water in the water receiving tank 2 is supplied by the pump 3 to a terminal demand destination such as a house. The pipe 18 is provided with a check valve 22 and a flow switch 24, and the output of the flow switch 24 is input to each inverter 5. The check valve 22 is a backflow prevention valve for preventing water from flowing back from the discharge side to the suction side when the pump 3 is stopped, and the flow switch 24 indicates that the amount of water in the pipe 18 has decreased. It is for detection.

  A pressure sensor 26 that detects the discharge pressure of the pump 3 is installed in the discharge pipe 20, and an output signal of the pressure sensor 26 is input to the control unit 6. In addition, a pressure tank 28 is connected to the discharge pipe 20, and when the flow switch 24 detects that the amount of water has decreased, the pressure tank 28 accumulates pressure in order to prevent the pump 3 from shutting down. Then, the operation of the pump 3 can be stopped.

  In this water supply apparatus 1, the rotational speed (rotational frequency) of the pump 3 is variable-speed controlled using the inverter 5 based on output signals from the flow switch 24 and the pressure sensor 26. Generally, the discharge pressure is constant so as to control the rotation speed of the pump 3 so that the pressure signal detected by the pressure sensor 26 matches the set target pressure so that the discharge pressure of the pump 3 becomes constant. Control or estimated terminal pressure constant control for controlling the supply water pressure at the end demand destination to be constant by appropriately changing the target value of the discharge pressure of the pump 3 is performed. According to these controls, the pump 3 is driven at a rotational speed commensurate with the amount of water demand at that time, so energy saving can be achieved.

  When the flow switch 24 is turned on, it is determined that the water is not used and the amount of water is small, and the operation of the pump 3 is stopped. When the use of water is detected due to a decrease in discharge pressure or the like, the pump is restarted. When the pump 3 is stopped when the amount of water is small, the pressure accumulation operation may be performed in which the pump 3 is once accelerated and accumulated in the pressure tank 28 and then the pump 3 is stopped.

  Since the water supply apparatus 1 of this embodiment is provided with a plurality of pumps, when a plurality of units are operated with additional disconnection or when an abnormality of a specific pump 3 or inverter 5 is detected during operation, the other It is possible to continue the water supply by switching the operation to normal pump 3 or inverter 5.

  FIG. 2 is a schematic diagram showing the inverter 5 of FIG. As shown in FIG. 2, the inverter 5 includes a main board 50, an operation panel 52 for setting the inverter 5 (for example, setting acceleration time, deceleration time, etc.), and an I / O board for inputting and outputting various signals. (Input / output substrate) 54.

  The main board 50 includes a rectifier 500 that rectifies AC power input via an earth leakage circuit breaker (Earth Leakage Circuit Breaker: ELB) 56, and switching that converts the power rectified by the rectifier 500 into AC power having a desired frequency. An element (power unit) 501, a communication unit (serial port) 502 that exchanges information with the control unit 6 and other inverters 5 via the serial communication cable 30, and a memory (ROM or rewritable memory) that stores various programs 503, and a CPU 504 that performs an arithmetic control operation based on a program stored in the memory 503.

  The main board 50 converts the electric power input via the leakage breaker 56 into DC power by the rectifier 500 and drives a switching element 501 such as an IGBT (Insulated Gate Bipolar Transistor) to control AC power (control) at a desired frequency. The power is supplied to the motor 4 that drives the pump 3 by converting the power into a frequency corresponding to information sent from the unit 6 via the communication unit 502.

  The memory 503 has a program for controlling the switching element 501, exchanging information via the communication unit 502, and exchanging information with the I / O board 54 and the operation panel 52, and various inverter control and operation control programs. Is remembered. These programs are executed by the CPU 504. Note that the memory 503 and the CPU 504 may be mounted on the same semiconductor chip. Since the memory 503 and the CPU 504 are driven by DC power, the main board 50 of the inverter 5 is provided with a power supply unit 505 that supplies DC power to the main board 50. The power supply unit 505 includes a transformer, a rectifier, a capacitor, and the like. The power supply unit 505 supplies power to the operation panel 52 and the I / O board 54.

  The I / O board 54 includes various input terminals and output terminals that can be freely modified according to the usage application of the inverter 5. In the I / O board 54 shown in FIG. 2, an analog input terminal 540 that receives a signal from a thermistor that is provided in each pump 3 and detects the temperature of the pump 3, and a leakage breaker that is provided on the primary side of the inverter 5. The digital input terminal 541 to which the trip signal of the device 56 and the ON / OFF signal of the flow switch 24 provided on the discharge side of the pump 3 are input, and whether the pump 3 is in operation (pump start / stop) There is provided a digital output terminal 542 for outputting an operation signal which is an ON / OFF signal and a failure signal notifying the failure of the pump 3 or the inverter 5 to the outside of the apparatus.

  Further, the I / O board 54 is provided with a dip switch 543, and this dip switch 543 is used for setting an inverter number (pump number) in a water supply apparatus having a plurality of inverters.

  As described above, the I / O board 54 includes input terminals for signals (input signals depending on the pump) required for each pump series, such as the thermistor, the earth leakage breaker 56, the flow switch 24, and the like. Similarly, an output terminal for a signal (an output signal depending on the pump) required for each pump series, such as operation and failure, is also provided. Therefore, it is not necessary to provide these input / output terminals in the control unit 6 as in the prior art, and even when the number of pumps increases, it is not necessary to prepare a separate substrate for inputting / outputting these signals.

  The I / O board 54 and the main board 50 are connected to each other through interfaces 544 and 506. Signals input from the input terminals 540 and 541 of the I / O board 54 are transmitted from the communication unit 502 to the control unit 6 in accordance with a program stored in the memory 503 of the main board 50. Further, a failure signal is output to the outside from the output terminal 542 via the interfaces 506 and 544 based on the determination of the control unit 6 and the CPU 504 of the main board 50.

  As shown in FIG. 2, the operation panel 52 includes an operation changeover switch (operation unit) 520 for selecting test / stop / automatic operation of the pump 3 driven by the inverter 5, a lamp 521 indicating operation / failure, an inverter The minimum number of operation buttons (operation units) 522 necessary for setting 5 is provided. Unlike the operation panel of the conventional inverter, the operation panel 52 does not include a display unit including a liquid crystal display for displaying information related to the inverter 5 or a 7-segment display.

  The operation panel 52 is connected to the I / O board 54 via the interfaces 523 and 545. The operation state of the pump 3 can be switched by switching the operation changeover switch 520, and the operation button 522 is operated to set the inverter 5 (for example, the setting of acceleration time, deceleration time, etc.) and the contents displayed on the display unit. Can be changed (switched). In the present embodiment, the operation panel 52 is formed separately from the main board 50 and connected to the I / O board 54 via the interfaces 523 and 545. It may be formed integrally with the O substrate 54.

  When the operation changeover switch 520 of the operation panel 52 is set to “automatic”, the pump 3 is controlled at a variable speed in accordance with a command from the control unit 6. When the operation changeover switch 520 is set to “stop”, the inverter 5 stops the driving of the pump 3 regardless of the command of the control unit 6. Further, when the operation changeover switch 520 is set to “test”, the inverter 5, the motor 4, and the pump 3 can be manually tested (trial operation). In the water supply apparatus 1, the test operation of the corresponding pump 3 is performed when the apparatus is installed or when the pump 3 or the motor 4 is maintained. In this test operation, it is checked whether or not the device is moving or whether or not the direction of rotation of the pump is correct.

  Since such an operation changeover switch 520 is provided in each inverter 5, when it is desired to forcibly stop or operate an arbitrary pump, the purpose can be easily achieved. When the operation changeover switch 520 is switched to “stop” or “test”, the inverter 5 notifies the control unit 6 that the operation has been switched to the stop state or the test state, and the control unit 6 performs control in consideration of this. It can be performed.

  FIG. 3 is a schematic diagram showing the control unit 6 of FIG. As shown in FIG. 3, the control unit 6 includes a control board 60 that performs signal input / output and device control, and an operation panel 62 that performs various settings.

  The control board 60 includes a communication unit (serial port) 600 connected to the communication unit 502 of the inverter 5, a memory (ROM, flash memory that is a rewritable nonvolatile storage element) 601 storing various programs, And a CPU 602 that performs an arithmetic control operation based on a program stored in the memory 601. Information such as the start / stop of the pump 3, the rotation frequency, the trip of the inverter 5, etc. is exchanged via the communication unit 600. Note that the memory 601 and the CPU 602 may be mounted on the same semiconductor chip.

  The control board 60 has an input terminal 603 to which a signal related to the liquid level of the water receiving tank 2 (an output signal of the water level detector 12) and the like are input, an input terminal 604 to which an output signal from the pressure sensor 26 is input, An output terminal 605 for outputting an output signal to the electromagnetic valve 16 and an output terminal 606 for outputting the state of the water receiving tank 2 (full / low water / drought / failure, etc.) to the outside are provided. As described above, an input signal independent of the pump is input to the input terminals 603 and 604, and an output signal independent of the pump is output from the output terminals 605 and 606. In addition, the control board 60 includes a dip switch 607.

  In this manner, the control board 60 is provided with input / output terminals (input / output terminals independent of the pump) that do not need to be provided for each pump, such as signals relating to the liquid level of the water receiving tank 2, discharge pressure, and inflow pressure. However, as described above, since the input / output terminals (input / output terminals depending on the pump) necessary for each pump series are provided on the I / O board 54 of the inverter 5, the input / output terminals from the control board 60 are provided. Can be reduced and the size can be reduced. Along with this, cost reduction can be expected.

  The control board 60 executes the control program stored in the memory 601, and determines the start / stop (number of operating units) and operating frequency of each pump 3 based on the conditions set on the operation panel 62 and signals from various sensors. The frequency is determined and transmitted to the inverter 5 to control the rotation frequency of the pump 3. Further, the control board 60 performs control such as stopping the operation of the pump 3 or switching the operation to another pump 3 based on signals from various sensors and a trip signal from the inverter 5.

  Here, when the apparatus is installed and when the pump 3 and the motor 4 are maintained, a test operation (trial operation) of the pump 3 is performed. This test operation is performed by manually switching the operation changeover switch 520 of the operation panel 52 of the inverter 5 to “test”. The rotation frequency of the motor 4 during the test operation can be changed to an arbitrary rotation frequency by an operation button (up / down button) 522 of the operation panel 52. However, when a test operation is performed at a high frequency, the pressure in the secondary side pipe of the water supply device 1 greatly increases when water is not used, and problems such as leakage from the pipe joint occur. .

  In order to avoid such a problem, the maximum operating frequency of the inverter 5 is controlled to be lower during normal operation than during normal operation. Specifically, in the setting of the inverter 5, the maximum operation frequency itself during the test operation is set. Alternatively, the maximum operating frequency during the test operation may be set from the outside as a ratio to the maximum operating frequency during the normal operation, or a constant value for subtracting from the maximum operating frequency during the normal operation. Then, the maximum operation frequency during the test operation is set by a calculation based on a ratio or a constant value set in the inverter 5. By these, it can prevent that the pressure in piping of the secondary side of the water supply apparatus 1 rises excessively.

  Each inverter 5 can freely perform a test operation. That is, any other pump can be test-operated while the other pump is in automatic operation. In this case, since the pressure pressurized by the pump during the test operation is detected by the pressure sensor 26, normal pressure control is performed unless the rotation speed (rotation frequency) of the pump during the test operation is very high. It only has to be. However, when the rotational speed is manually increased beyond such rotational speed, the discharge pressure becomes equal to or higher than the target pressure even when other pumps are stopped. Therefore, the control board 60 controls the inverter 5 in the test operation state so that the rotation speed is not further increased or the rotation speed is decreased when the discharge pressure increases to a target pressure or higher. Can be controlled. That is, the pump 3 can be tested safely and easily by automatically limiting the operating frequency of the pump 3 so that the discharge pressure does not rise above a certain level during the test operation of the pump 3. It becomes like this.

  The memory 601 and the CPU 602 of the control board 60 are driven by receiving DC power from the power supply unit 505 of the main board 50 of the inverter 5. FIG. 4 is a schematic diagram showing a power supply system between the inverter 5 and the control board 60.

  The capacity of the power supply unit 505 of the main board 50 of the inverter 5 is designed on the basis of the power that is a combination of the power required for driving the inverter 5 and the power required for driving the control board 60. As shown in FIGS. 2 and 4, the main board 50 includes a power supply terminal 507 connected to the power supply unit 505, and the power supply terminal 507 is connected to the power supply terminal 608 provided on the control board 60 of the control unit 6. It is connected. In this way, the power supply unit 505 of the main board 50 of the inverter 5 can supply driving power (DC power such as + 5V, + 12V, + 24V) to the control board 60 of the control unit 6.

  In this way, by supplying power for the control board 60 of the control unit 6 from the inverter 5, it is not necessary to separately provide a DC power source for the control board 60. Therefore, the manufacturing cost of the water supply device can be reduced, and the size of the control board 60 can also be reduced. Although development of a stable power supply takes a considerable amount of time and expense, according to the present embodiment, it is only necessary to develop a power supply unit mounted on the inverter, so that the cost of the apparatus can be reduced.

  In the present embodiment, as shown in FIG. 4, the power supply terminal 507 of each inverter 5 is directly connected to the power supply terminal 608 of the control board 60. For this reason, the power supply unit 505 of the inverter 5 is provided with a backflow prevention mechanism (not shown) such as a diode so that the power of a certain inverter does not flow back to other inverters.

  In the present embodiment, power can be supplied from the plurality of inverters 5 to the control board 60 of the control unit 6. That is, since the power supply units 505 of the plurality of inverters 5 are connected in parallel to the control board 60, even if a certain inverter cannot supply power due to a trip of the leakage breaker 56 or the like, Sufficient power can be supplied to the control board 60 by the inverter. As described above, the configuration according to the present embodiment has a backup function of normally continuing the operation of the control board 60 and preventing the operation of the water supply apparatus 1 from being stopped. Supply can be stabilized. In addition, when the number of inverters is increased, it is only necessary to increase the number of inverters of the same type as that of the existing inverter, so that the number of inverters can be easily increased or decreased.

  Although not shown in the sense of reducing the number of power supplies, a power supply unit may be provided on the control board 60 and DC power may be supplied from the power supply unit to each inverter 5. Alternatively, a power supply unit may be provided separately from the inverter 5 and the control board 60, and DC power may be supplied from the power supply unit to the inverter 5 and the control board 60. In such a case, since the apparatus stops when the power supply unit does not operate normally, the above-described backup function cannot be realized. Further, when considering the addition of the inverter, it is necessary to use a power supply unit having a sufficient capacity or to add a power supply unit in accordance with the addition of the inverter.

  As shown in FIG. 3, the operation panel 62 of the control unit 6 displays a lamp 620 that indicates the state of the device, an operation button 622 that sets operating conditions such as a target pressure of the water supply device 1, and information related to the device. Display unit 624 including a liquid crystal display, a 7-segment display, and the like. An operation button 622 is used to select an operation mode and set operation conditions. The display unit 624 displays parameters of the apparatus being operated.

  As described above, the operation panel 52 of each inverter 5 is not provided with a display unit unlike the operation panel of the conventional inverter. Information on the inverter 5 such as current and operating frequency is displayed on a display unit 624 provided on the operation panel 62 of the control unit 6. That is, when the operation button 522 of the operation panel 52 of the inverter 5 is pressed, information regarding the inverter 5 is displayed on the display unit 624 on the operation panel 62 of the control unit 6. In this case, the display unit 624 may be switched by pressing any one of the operation buttons 522, or a display switching button may be provided in the operation button 522.

  Thus, according to this embodiment, since it is not necessary to provide a display unit such as a liquid crystal in the inverter 5, the cost of the apparatus can be reduced. In addition, since the display unit is provided in the control unit 6 in an integrated manner, the operator can easily understand the display contents, and the operability can be improved.

  On the other hand, since the minimum necessary operation buttons 522 remain on the operation panel 52 of the inverter 5, the display can be switched by an operation on the operation panel 52 of the inverter 5. Therefore, the display switching operation is simplified as compared with the case where the display is switched by the operation on the operation panel 62 of the control unit 6, and the operation panel 62 of the control unit 6 is also provided when the pump 3 and the inverter 5 are increased or decreased. There is no need to change the structure of the display unit 624. In addition, when the operation for display may be somewhat complicated, it is good also as displaying the information of each inverter 5 by switching a display by operation in the operation panel 62 of the control part 6. FIG.

  In addition to the function of displaying information related to the inverter 5 described above, the operation panel 62 of the control unit 6 selectively displays discharge pressure, inflow pressure, and the like during operation of the water supply apparatus 1 by operating the operation button 622. It has a function that can. Further, the operation condition such as the target pressure of the water supply apparatus 1 can be set by operating the operation button 622. The operation panel 62 is provided with an alarm buzzer, and the alarm content is displayed on the display unit 624 when an alarm is issued.

  FIG. 5 is a schematic diagram showing a water supply apparatus 101 according to the second embodiment of the present invention. A water supply apparatus 101 shown in FIG. 5 is a direct connection type water supply apparatus that directly connects the pump 3 to the water main pipe 102 and supplies water using the pressure of the water main pipe 102. In this water supply apparatus 101, a suction side pressure sensor 103 for detecting the water pressure of the water main pipe 102 is provided in the suction pipe 104, and this output is input to the control unit 6. The suction pipe 104 is provided with a backflow prevention device 105.

  In embodiment mentioned above, although the example which applied the inverter 5 to the water supply apparatus 1 was demonstrated, it is not restricted to this. The inverter 5 can be applied to various devices other than the water supply device simply by changing the operation panel 52 and the I / O board 54 of the inverter 5 to appropriate ones and rewriting the program in the memory 503. Therefore, the present invention can be applied to various devices without changing the hardware configuration of the main board 50 of the inverter 5, and thus the cost of the device can be reduced.

  A device for controlling the frequency of the power source for driving the DC brushless motor is often called a driver. However, the driver is also an induction motor in that the AC power source is rectified to obtain a desired frequency power by a switching element. It is the same as the inverter for driving. Therefore, you may drive a DC brushless motor using the inverter of the structure mentioned above. When a DC brushless motor is used, a motor rotation signal or current signal may be input to the I / O board 54 of the inverter 5.

  Needless to say, the number of the water receiving tank 2, the pump 3, the motor 4, the inverter 5, the control unit 6, the control board 60, and the like is not limited to the illustrated one. Further, the communication between the communication unit 502 of the inverter 5 and the communication unit 600 of the control board 60 can be performed not only by serial communication but also wirelessly. Moreover, although the water supply apparatus was demonstrated to the example in the above-mentioned embodiment, this invention is not limited to a water supply apparatus. For example, the present invention can be applied to an inverter used in a rotary machine device such as a fan or a compressor that requires rotational speed control. In other words, the present invention can be applied to various devices using a fan or a compressor by changing the pressure sensor to a device that detects the load of the device such as a temperature sensor by using the pump as a fan or a compressor.

  Although one embodiment of the present invention has been described so far, it is needless to say that the present invention is not limited to the above-described embodiment, and may be implemented in various forms within the scope of the technical idea.

It is the schematic which shows the water supply apparatus in the 1st Embodiment of this invention. It is the schematic which shows the inverter of FIG. It is the schematic which shows the control part of FIG. It is the schematic which shows the power supply system between the inverter of FIG. 2, and the control board of FIG. It is the schematic which shows the water supply apparatus in the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,101 Water supply apparatus 2 Water receiving tank 3 Pump 4 Motor 5 Inverter 6 Control part 10 Piping 12 Water level detector 14 Water supply pipe 16 Solenoid valve 18 Piping 20 Discharge pipe 22 Check valve 24 Flow switch 26, 103 Pressure sensor 28 Pressure tank 30 Serial Communication cable 50 Main board 52, 62 Operation panel 54 I / O board (input / output board)
56 Earth leakage breaker 60 Control board 102 Water main pipe 104 Suction pipe 105 Backflow prevention device 500 Rectifier 501 Switching element (power section)
502,600 Communication unit 503,601 Memory 504,602 CPU
505 Power supply unit 506, 523, 544, 545 Interface 507, 608 Power supply terminal 520 Operation switch 521, 620 Lamp 522, 622 Operation button 540, 541, 603, 604 Input terminal 542, 605, 606 Output terminal 543, 607 Dip Switch 624 display

Claims (4)

A pump,
An inverter that variably controls the rotation frequency of the pump;
A control unit for controlling the inverter;
With
The control unit controls the rotation frequency of the pump so that the rotation frequency during the test operation of the pump does not exceed a predetermined value, and the maximum rotation frequency during the test operation of the pump is the maximum rotation frequency during automatic operation. to be lower than the feed water system you and sets the maximum rotation frequency of the maximum rotation frequency and the automatic operation during the test run. A pump,
An inverter that variably controls the rotation frequency of the pump;
A control unit for controlling the inverter;
With
The control unit controls the rotation frequency of the pump so that the rotation frequency during the test operation of the pump does not exceed a predetermined value, and the maximum rotation frequency during the test operation of the pump is the maximum rotation frequency during automatic operation. to be lower than the feed water system the value of the maximum rotation frequency during the test run for the maximum rotation frequency of the automatic operation of the pump you and sets by calculation. A pump,
An inverter that variably controls the rotation frequency of the pump;
A control unit for controlling the inverter;
With
The control unit controls the rotation frequency of the pump so that the rotation frequency during the test operation of the pump does not exceed a predetermined value , and the discharge pressure of the pump is set during the automatic operation during the test operation of the pump. and so it does not rise above the pressure feed water system you and limits the rotation frequency of the pump.   The water supply device according to any one of claims 1 to 3, wherein the inverter includes an operation unit for selecting the test operation or the automatic operation.

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