JPH04362293A - Water supply device - Google Patents

Abstract

PURPOSE:To prevent the overload operation of an electric motor due to the anomaly of a pump and other causes, in a water supply device equipped with a motor-driven pump and a pressure tank. CONSTITUTION:A water supply device is constituted of a pump 4, electric motor 3 for driving the pump 4, water feeding pipe 9, pressure sensor 8 installed in the water feeding pipe 9, detecting means CT1-CT3 for detecting the loaded state of the electric motor, memory means MPu which memorizes the allowable load rate of the electric motor and the alloable time allowing the operation with this load rate, overload trouble operation display holding part and setting means SW2 and SW3. Accordingly, since the loaded state is directly detected and the pump is brought into stop, the electric motor can be protected surely, and since an operation holding circuit for a protecting circuit is installed, the extinction of signals is prevented even if an electric power source is erroneously cut off, and safety is secured. Further, since the protection characteristic can be set outside if necessary, using performance is improved.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water supply system equipped with an electric pump and a pressure tank, and more particularly to a protection device for a water supply system suitable for use in a system for preventing overload operation of an electric motor due to pump abnormality or other causes.

0002

2. Description of the Related Art Conventionally, waterless operation or overload of a pump has been detected based on the operating current of an electric motor. An example of this type of device is Utility Model Application No. 52-98202. This device uses a contact-equipped ammeter to determine that waterless operation is occurring when a low operating current continues for a certain period of time, and stops the motor. Furthermore, thermal relays (thermal relays) have conventionally been used to protect motors from overload.

0003

[Problems to be Solved by the Invention] The purpose of the above-mentioned prior art is to stop the electric motor when falling into water, but no consideration is given to prevention of falling into water itself or recovery from falling into water. In addition, the overload protection method for motors using thermal relays is bimetallic, so the protective action is slow.
It is not reliable because it uses relay contacts for protection.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a protection device for a water supply device that prevents an electronic (non-contact type) overload failure of the water supply device, and furthermore, once the protection device operates, The purpose is to maintain this state even in the event of a power outage (including a power reset), unless it is reset manually, to ensure safety.

[0005]

[Means for solving the problem] The above purpose is to detect the desired pressure or flow rate of a pump, an electric motor that drives the same, a water supply pipe installed on the pump discharge side, a pressure tank provided therewith, and a water supply system. a means for detecting the load condition of the electric motor (current transformer or wattmeter, etc.), a means for controlling and storing calculations according to a predetermined procedure, and an allowable load factor of the electric motor and operating at this load factor. a storage means for storing the permissible time or a setting means thereof; a clock means for measuring the permissible time; an overload failure operation display section;
Similarly, in a protection device for a water supply device consisting of a control device (microcomputer) having an operation holding section and a reset means,
The above-mentioned load condition is monitored by the above-mentioned control device, and when this device measures the preset allowable load factor for the allowable operating time, it makes an emergency stop of the pump and sends the signal to the overload failure operation display section and holding section. This is achieved by outputting.

[0006]

[Operation] The control device constantly monitors the operating current, and stops the pump if the abnormal current continues for a certain period of time (if necessary, change the time depending on the rate of increase or decrease in the current).

That is, the control/storage calculation processing section stores the pump/motor protection characteristics in advance, and adjusts the protection characteristics as necessary by the motor allowable load factor setting means SW2 and the pump/motor permissible stop operation time setting means. Fix it. moreover,
It is determined whether the value of the input port Pco is "1", and if it is not "1", the pump/motor is considered to be normal and normal operation is performed. A current transformer C serves as a means for detecting the load state of the motor.
Detected by T1 to CT3, when this value exceeds the load factor mentioned above and the operation time mentioned above has elapsed, the input port Pco
Switch to output mode and output "1" data.

Accordingly, the transistor Q of the overload failure operation display and holding section is turned on, the keep relay KS is set, and the light emitting diode LD1 is lit. Furthermore, since the keep relay is set, its contact Sa closes, and the output of the three-state buffer IC1 is "
1”. Next, switch Pco to input mode and read the data here.

As a result, the input from Pco is "1", so the pump and electric motor are brought to an emergency stop.

Even when the molded circuit breaker MCB is turned off and then turned on again, the keep relay S remains set for mechanical retention, and its contact Sa remains closed. Therefore, as described above, the output of IC1 is "1" and is in the protective operation state.

When the reset means SW4 is pressed in this state, the reset means is reset, the contact Sa is opened, and the output of the IC1 becomes a high impedance state. The input result of Pco is “1”
”, so normal operation will resume.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 10.

FIGS. 1 and 2 are configuration diagrams of a water supply device according to an embodiment of the present invention.

In FIG. 1, R, S, and T are power supplies, MB is a molded circuit breaker, CT1, CT2, and CT3 are current transformers that detect the current flowing through the main circuit and transform it to an appropriate minute current value.
MC is the coil of the electromagnetic contactor, Mca is its contact, and 3 is the electric motor.

R1 and S are control power sources taken from the secondary side of the molded case circuit breaker MB, SW1 is a switch for switching between automatic operation and stop/manual operation, T is a transformer, and Z is, for example, AC200.
This is a stabilized power supply unit that converts V AC into constant voltage DC (5V) and supplies it.

[0016] PCB is a printed circuit board equipped with a control/memory processing unit, etc., and MPU is a microprocessor generally referred to as a one-chip microcomputer (hereinafter abbreviated as microcomputer), central processing unit, memory, and input/output port PA.
~Built-in PF, A/D converter, etc. Further, B is a clock generator, which is composed of a crystal CL, a resistor R1, and capacitors C3 and C4.

Furthermore, F1 to F3 are interface sections for connecting with the above-mentioned input/output ports, and SW2
SW3 is a setting means for setting the rated current of the motor, and is, for example, an 8-bit dip switch.Similarly, SW3 is a setting means for setting a protection characteristic correction value, and is, for example, an 8-bit dip switch.

The above-mentioned interface F1 is a current transformer C.
The operating current I of the motor 3 detected by T is converted into a DC voltage in order to be input to the analog input ports AN0 to AN2 of the microcomputer, and the value is read and stored in the memory.

PS is a contact point of the pressure switch 8 (FIG. 2), and is connected to the input/output port PA via the interface F2.
Read from 0 and store in memory. Furthermore, the magnetic contactor M is connected from the input/output port PB0 to the interface F3.
Outputs data for ON/OFF control of C.

Further, M is an overload failure operation display and holding section, which includes a keep relay KR, a transistor Q, and a resistor R2.
, R3, R4, diodes D1, D2, light emitting diode LD1, three-state buffer IC1, and reset switch SW4. This reset switch SW4 is for resetting the keep relay KR (mechanical hold), and the buffer IC1 outputs three states: 0, 1, and high impedance.

In FIG. 2, 1 is a water tank, 2 is a water suction pipe,
3 is an electric motor, 4 is a pump, 5 is a gate valve, 6 is a check valve,
7 is a pressure tank having an air reservoir therein, 8 is a pressure switch, 9 is a water supply pipe, and 10 is the control circuit shown in FIG.

FIG. 3 is a diagram showing the pump operation characteristics of the water supply system of this embodiment, with pressure H plotted on the vertical axis and water amount Q plotted on the horizontal axis. In the figure, curve A represents the Q-H characteristic of the pump, curve B represents the load curve or current curve of the motor, P1 represents the starting pressure of the pump, and Q1 represents the amount of water pumped at that time. The pressure switch 8 described above is set to close at P1 and open at return pressure P2. Further, It is the rated current of the motor, and as will be described later, it is set in advance in the memory of the microcomputer or externally set, for example, with a dip switch (not shown).

FIG. 4 shows an example of a protection characteristic diagram of an electric motor.
The vertical axis shows the motor permissible load factor, and the horizontal axis shows the pump motor permissible stop operation time. Curve A is its protective property,
It is stored in the microcomputer's memory in advance as an initial value. When modifying the protection characteristics based on the outside temperature or the like, for example, an arbitrary modification line is provided on the allowable load factor coordinates. This may be stored in a memory in advance, or may be set using a dip switch (not shown).

In this embodiment, the 300% point is shown as the protection correction line. The initial setting value of SW3 is t3, but if this is changed to t3', the point shifts from 00 to 01, and curve A becomes curve B.

5 to 10 are flowcharts showing the operating procedure of the control device shown in FIG. 1 according to the embodiment of the present invention.
The operation of the water supply device will be explained in detail with reference to this drawing.

In FIG. 1, when the wiring breaker MB is turned on, the microcomputer power is turned on in the order of T→Z, starts operation, and first, the stack pointer at step 501 in FIG.
Perform initial settings for input/output ports, timer interrupts, analog interrupts, etc.

In step 502, the protection characteristic shown in FIG. 4 is stored in the memory as a curve A, for example, as a function. Further, as described above, the data of the setting means SW2, SW3 is read out from the memories MSW2, MSW3 in which the data are stored, and the curve A is corrected. Then, for example, 1.3 times, 2.0 times, 3.0 times, and 6.0 times are calculated based on the data of switch SW2 that sets the rated value of the motor load factor, and the results are stored in the memories MSW4 to MSW7. The allowable stop operation time is calculated using the modified function at a load factor of 13.
Automatically set by substituting values of 0%, 200%, 300%, and 600% and finding an inverse function.

As a result, t1, t2, t3, and t4 are stored in memories MTIME0 to MTIME6. And 5
In step 02, a soft timer (for example, 100 ms) is executed to prepare for timer and analog interrupt processing.

For example, if the timer interrupt period is set to 20 ms at the time of initial setting, a timer interrupt occurs during soft timer processing, and the processing shown in FIG. 6 is executed. That is 6
In step 02, analog interrupts are prohibited from occurring, and in step 603, the data of SW2 and SW3 described above are read and stored in, for example, memories MSW2 and MSW3.

In step 604, SW1 shown in FIG.
A subroutine for PS determination is called to determine the position of SW1 and whether the pressure switch PS is ON or OFF. This result is stored in the memories MSW1 and MSW2 as follows, for example. MSW1: OOH...manual FFH...automatic MSW2:OOH...OFF FFH...ON Similarly, in step 605, the pump shown in Figures 9 and 10
A subroutine is executed to check the load factor and operating time of the motor and determine whether it is an overload failure or normal.

In FIGS. 9 and 10, in step 902, the input/output port Pco is set to input mode. and,
In step 903, it is determined whether Pco is "1". If it is "1", it means that there is an abnormality, and the process jumps to step 914, where FFH (meaning of abnormality) is set in the memory MNGP.

If it is not "1", proceed to step 904, find the minimum value of the current value detected by the current transformers CT1 to CT3 in this step and to step 910, Since it is not 00H due to other stray capacitances, it is set to 10H here to give a margin). If it is smaller than this, it means an open phase (any of the three phases), so the duration of this state is counted in step 910.

For example, as will be described later, a memory MTIMF (8 bits) is prepared as a flag for starting and stopping the timer. Naturally, this value is set to 00H in the initial setting. Here, bo is set to "1" to start the open phase operation timer MTIME0. 606-60 in Figure 6
In step 8, this flag bo bit is checked to see if it is "1" and counted down (step 607).

That is, this timer has an interrupt period (in this example, 2
0ms). Therefore, timer M
TIME0 to MTIME6 are composed of 2-byte memory.

In step 911, it is determined whether the countdown result is "0". If it is "0", it means that the open phase operation has passed for a predetermined time, so in step 912 the input/output port Pco is switched to output mode, and in step 913 "1" is output to the input/output port Pco, and the memory Set FFH to MNGP, 917-91
Exit this loop through 8 steps.

[0036] If the above loop is not passed, 91
Proceed to step 5 and determine if there is a reverse phase or overload. 915
The data of the current passing through the step is transferred to the A register, and the load factor is 13% at the 916th step (memory MSW4
It is determined whether it is smaller or larger than the value (incl. If it is larger, the process advances to step 919 (FIG. 10), where it is determined whether the load factor is greater than or equal to 200%. If it is smaller, a timer is started in step 920 to measure the operating time at that load factor.

In step 921, it is determined whether the timer is counted down and has reached "0". If it is not 0, the process passes through steps 917 to 918 and exits from this loop. If it is 0, the process advances to step 912 and the above-described operation is executed.

[0038] Although the explanation is omitted, when the load factor is 300% and 600%,
%, the same operation is performed by the processing from step 922 onwards. By executing the above processing, timer interrupt 61 in Figure 6 is created.
Enable interrupts and exit in 5 steps. Therefore, an analog interrupt is executed next.

In FIG. 7, in step 703, the load current is detected by CT1 to CT3, and the load current is detected by the memories MAN0 to MAN.
Store in 2.

After executing the soft timer process in step 503, the process proceeds to step 504, where it is determined whether SW1 is closed to the K side. If it is closed to the K side, the data in the memory MSW1 is FFH, so the process advances to the next step 505. If not closed, 504 steps are “automatic”
Repeat execution until it is set to (K side). moreover,
In step 505, it is determined whether the contacts of the pressure switch PS are closed. When it is closed, the data in the memory MSW2 is FFH. Therefore, if it is FFH, proceed to the next step 507. Data in memory MSW2 is FF
If not H, the process returns to step 504 and is executed again from here.

As described above, in step 507, in the timer interrupt processing, the load current of the motor is detected, and based on the relationship between the predetermined load factor and operating time, it is determined whether an overload failure state has occurred. If it is in an overload failure state, the memory NGP data is set to 00H, so if this NGP data is 00H, jump to step 506 and issue a pump stop command. and do not start the pump. If it is FFH, the next 50
Start the pump in 8 steps.

Next, in step 509, the pressure switch is turned OFF.
It is determined whether F is on, and if it is on, the process returns to step 507 and the pump continues to operate. if,
During this loop, in the above-mentioned timer interrupt processing, if overload is detected and memory NGP is set to 00H, 5
The process advances to step 06, where the pump comes to an emergency stop. Thereafter, the process returns to step 504, and the subsequent processes are executed and repeated until the value in the memory NGP is reset to FFH.

Even if the power supply is reset by mistake in this state, the keep relay KP shown in FIG. 1 is set and its contact sa is closed, as described above.
The value input from the input port Pco is "1", and the overload failure state is maintained. If the reset switch SW4 is pressed in this state, the reset coil R is excited, the contact sa is opened, the input of the input/output port Pco becomes a high impedance state, and the overload fault is reset. Next, if the determination result in step 509 is that the pressure switch is OFF and the data of MSW2 is "0", the process proceeds to step 510, and the pump is stopped. Then, the process returns to step 503, and the above-described operations are repeated.

Next, other embodiments of the present invention are shown in FIGS. 11 to 13.
This is explained by: In this embodiment, the water supply device includes a plurality of pumps each driven by an electric motor, a detection means for detecting the load state of the electric motor, and a load factor of the electric motor is calculated based on the output of the detection means. A protective means is provided that performs a protective operation on the motor based on the protective characteristics determined by the relationship between the load factor and the allowable operating time, and the protective means temporarily stops the operation of the pump when an abnormality occurs and switches to the other pump. The system is configured so that it can be operated with

In this embodiment, electric motors are connected to pump 1 and pump 2, respectively, and the electric currents of the electric motors of pump 1 and pump 2 are connected to CT1, CT2, CT3, and CT, respectively.
4, the controller as a protection means calculates the load factor based on this output as shown in Figure 13, and the protection is determined by the relationship between this load factor and the permissible operation time determined by the preset rated current. The motor protection operation is performed based on the characteristics.

As shown in FIG. 12, this protection operation involves a retry operation, that is, an operation in which the operation of the pump is temporarily stopped before it completely goes down, and then the operation is switched to the other pump. If this happens three times, it will be considered an abnormality and an emergency stop will be performed.

[0047] This makes it possible to electrically detect overload and water drop to protect the motor.

As a safety measure, as in the above embodiment, once the protection device is activated, the pump is rendered inoperable unless it is manually reset, and this state is maintained even if the power is turned off.

[0049]

[Effects of the Invention] Since the present invention is constructed as described above, the load condition of the motor is detected and the pump is stopped, so that not only can the pump motor be reliably protected, but also the protection circuit Since it is mechanically held when activated, it is safe and will not be reset accidentally. Furthermore, the protection characteristics can be modified by external settings depending on the surrounding environment and usage conditions, which has the effect of improving usability.

[Brief explanation of the drawing]

FIG. 1 is a control circuit diagram of a water supply device in one embodiment of the present invention.

FIG. 2 is a system diagram of the water supply device of this embodiment.

FIG. 3 is an operational characteristic diagram of the pump of this embodiment.

FIG. 4 is a diagram showing protection characteristics of an example of an electric motor.

FIG. 5 is a flowchart showing the control procedure of the control circuit of the water supply device of the present embodiment.

FIG. 6 is a flowchart showing the control procedure of the control circuit of the water supply device of the present embodiment.

FIG. 7 is a flowchart showing a control procedure of the control circuit of the water supply device of the present embodiment.

FIG. 8 is a flowchart showing a control procedure of the control circuit of the water supply device of the present embodiment.

FIG. 9 is a flowchart showing a control procedure of the control circuit of the water supply device of the present embodiment.

FIG. 10 is a flowchart showing a control procedure of the control circuit of the water supply device of this embodiment.

FIG. 11 is a block diagram showing the configuration of a second embodiment of the present invention.

FIG. 12 is a diagram showing the operating range of this embodiment.

FIG. 13 is a flowchart showing the operation flow of this embodiment.

[Explanation of symbols]

Claims (6)

[Claims] Claims: 1. A pump, an electric motor for driving the pump, a water supply pipe connected to the discharge side of the pump, a pressure detection means provided on the water supply pipe, and a water supply system based on a signal from the pressure detection means. A water supply device comprising a control means for controlling the operation of the electric motor according to a predetermined order according to a variation in the amount of water, a detection means for detecting a load state of the electric motor, an allowable load factor of the electric motor, and a control means for controlling the operation of the electric motor according to a predetermined order according to a variation in the amount of water. It has a storage means for storing a permissible operating time, and a timing means for measuring the permissible operating time, and when the operating current of the motor exceeds the permissible operating time at the permissible load factor, the control means detects an overload of the motor. A water supply device characterized in that the electric motor is stopped by predicting a failure. 2. The water supply device according to claim 1, further comprising setting means that allows external setting of the allowable load factor and the allowable time of the electric motor. 3. The control means includes a microcomputer;
2. The water supply system according to claim 1, further comprising means for holding an overload failure operation, means for resetting the overload failure operation, and means for displaying an overload failure operation. 4. The overload failure operation holding means is connected to a data bus connected to one of the input/output ports of the microcomputer, and the control means determines whether or not there is an overload failure of the electric motor. 4. The water supply device according to claim 3, wherein the input/output ports are selectively switched to either an output mode or an input mode. 5. A pump, an electric motor for driving the pump, a water supply pipe connected to the discharge side of the pump, a pressure detection means provided on the water supply pipe, and a water supply system based on a signal from the pressure detection means. A water supply device comprising a control means for controlling the operation of the electric motor according to a predetermined order according to a variation in the amount of water, a detection means for detecting a load state of the electric motor, an allowable load factor of the electric motor, and a control means for controlling the operation of the electric motor according to a predetermined order according to a variation in the amount of water. storage means for storing protective characteristics determined in relation to the permissible time for operation at this load factor;
It has a timing means for measuring the permissible operating time, and a setting means for setting the rated load value and permissible time of the motor, and an arbitrary point of the load factor of the protective characteristic is predetermined as a set reference point, and the above-mentioned A water supply device characterized in that the above characteristics can be modified based on the set value of the rated load setting means. 6. A plurality of pumps each driven by an electric motor, a detection means for detecting a load state of the electric motor, a load factor of the electric motor based on the output of the detection means, and a load factor of the electric motor. The motor is equipped with a protective means that performs a protective operation for the motor based on a protective characteristic determined by the relationship between the pump and the allowable operating time, and the protective means temporarily stops operation of the pump when an abnormality occurs, and then switches to the other pump and resumes operation. A water supply device configured to perform.