Liquid level control system for automatic drainage

Abstract

The utility model provides a liquid level control system for automatic drainage, and belongs to the technical field of circuits. A liquid level control system for automatic drainage comprises a three-phase alternating-current power supply, a main switch QS, a fuse FU, a thermal relay FR1, a contactor KM, a water pump and a control loop used for controlling starting and stopping of a three-phase motor M of the water pump, and the three-phase motor M is connected with the three-phase alternating-current power supply through the main switch QS, a main contact of the contactor KM and the fuse FU and used for driving the water pump to drain water. The control loop comprises a normally closed high-water-level float switch, a normally open low-water-level float switch, a start button SB2, a stop button SB1 and a control relay RF; the control relay RF, the stop button SB1, the normally-open low-water-level float switch, the normally-closed high-water-level float switch and a coil of the contactor KM are sequentially connected in series. And the start button SB2 is connected in parallel with the normally-open low-water-level float switch.

Description

Technical Field

[0001] This invention belongs to the field of circuit technology, specifically a liquid level control system for automatic drainage. Background Technology

[0002] In the current production process, wastewater often overflows, polluting the surrounding environment. There is an urgent need to install a liquid level control system that can automatically discharge the internal wastewater when the liquid level exceeds a preset level. Summary of the Invention

[0003] The purpose of this invention is to address the aforementioned problems in existing technologies by proposing a liquid level control system for automatic drainage, which features automatic drainage when the liquid level exceeds a preset value.

[0004] The objective of this utility model can be achieved through the following technical solutions:

[0005] A liquid level control system for automatic drainage includes:

[0006] Three-phase AC power supply, main switch QS, fuse FU, thermal relay FR1, contactor KM, water pump, and control circuit for controlling the start and stop of the three-phase motor M of the water pump.

[0007] The three-phase motor M is connected to the three-phase AC power supply through the main switch QS, the main contacts of the contactor KM, and the fuse FU, and is used to drive the water pump to drain water.

[0008] The control circuit includes a normally closed high-water-level float switch, a normally open low-water-level float switch, a start button SB2, a stop button SB1, and a control relay RF;

[0009] The control relay RF, stop button SB1, normally open low water level float switch, normally closed high water level float switch, and contactor KM coils are connected in series.

[0010] The start button SB2 is connected in parallel with the normally open low water level float switch;

[0011] When the water level exceeds the normally open low water level float switch, the normally open low water level float switch closes, the control circuit is connected, the main contacts of contactor KM are energized and attracted, the motor runs, so that the water pump starts to drain water.

[0012] When the water level drops below the normally open low water level float switch, the normally open low water level float switch opens, cutting off the control circuit. The main contacts of contactor KM are released, and the motor stops running.

[0013] In the above-mentioned liquid level control system for automatic drainage, the normally open low water level float switch is connected in parallel with the auxiliary contact of the contactor KM. The auxiliary contact of the contactor KM is used to connect an indicator light to indicate whether it is in a powered state.

[0014] In the above-mentioned level control system for automatic drainage, the normally closed high-level float switch is connected in series in the control circuit and is used to cut off the control circuit to stop the motor when the water level is high.

[0015] In the above-mentioned level control system for automatic drainage, the control relay RF has the function of cutting off the control circuit when the motor is overloaded.

[0016] In the above-mentioned liquid level control system for automatic drainage, the start button SB2 is a normally open button and the stop button SB1 is a normally closed button. The start button SB2 can forcibly start the control circuit when the normally open low water level float switch is not closed, and the stop button SB1 can forcibly de-energize the control circuit after it is energized.

[0017] In the above-mentioned level control system for automatic drainage, the water pump is a submersible pump.

[0018] Compared with the prior art, this application has the following advantages: Attached Figure Description

[0019] Figure 1 This is the circuit diagram in this application. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] like Figure 1As shown, a liquid level control system for automatic drainage includes: a three-phase AC power supply, a main switch QS, a fuse FU, a thermal relay FR1, a contactor KM, a water pump, and a control circuit for controlling the start and stop of a three-phase motor M of the water pump. The three-phase motor M is connected to the three-phase AC power supply through the main switch QS, the main contacts of the contactor KM, and the fuse FU to drive the water pump for drainage. The control circuit includes a normally closed high-level float switch, a normally open low-level float switch, a start button SB2, a stop button SB1, and a control relay RF. The control relay RF... The stop button SB1, normally open low-level float switch, normally closed high-level float switch, and contactor KM coil are connected in series. The start button SB2 is connected in parallel with the normally open low-level float switch. When the water level exceeds the normally open low-level float switch, the normally open low-level float switch closes, the control circuit is connected, the main contacts of contactor KM are energized and the motor runs, so that the water pump starts to drain water. When the water level drops below the normally open low-level float switch, the normally open low-level float switch opens, the control circuit is cut off, the main contacts of contactor KM are released, and the motor stops running.

[0022] In this application, a three-phase AC power supply provides power to the motor and control circuit. The main switch QS is the main power switch of the system. When closed, the entire circuit is powered on. The fuse FU is for short-circuit protection. When the current is too high, it melts and cuts off the power supply. The thermal relay FR1 is for motor overload protection. When the motor is overloaded, its normally closed contact opens and cuts off the control circuit. The contactor KM includes main contacts (controlling the on and off of the motor power supply) and a coil (controlling the operation of the main contacts). When the coil is energized, the main contacts close and the motor runs. When the coil is de-energized, the main contacts open and the motor stops.

[0023] When the water level is below the low water level, the normally open low water level float switch opens, the normally closed high water level float switch closes, the contactor KM coil is de-energized, the main contacts are in the open state, the motor M does not run, and the water pump stops draining water.

[0024] When the water level reaches the low water level, the normally open low water level float switch closes due to buoyancy. At this time, the water level has not exceeded the upper limit of the normally closed high water level float switch, so the normally closed high water level float switch remains closed. The contactor KM coil is energized, the main contacts close, the motor M runs, and the water pump starts to drain water.

[0025] As the water pump drains water, the water level drops below the low water level. The normally open low water level float switch opens, interrupting the control circuit path. The contactor KM coil is de-energized, the main contacts open, the motor M stops running, the water pump stops draining water, and the system returns to its initial state, waiting for the water level to rise to the low water level again before restarting.

[0026] In the event of a malfunctioning low water level float switch, the start button SB2 can be manually closed to start the water pump, or the stop button SB1 can be opened to cut off the power to the water pump.

[0027] The entire system automatically monitors the water level by controlling the on / off state of the float switch, and works with the contactor to enable the water pump to automatically drain water without human intervention. At the same time, it ensures safe operation through high water level protection, thermal relays, and fuses.

[0028] Specifically, the normally open low water level float switch is connected in parallel with the auxiliary contact of contactor KM. The auxiliary contact of contactor KM is used to connect an indicator light to indicate whether it is in a powered state.

[0029] In this automatic drainage level control system, the normally open low-level float switch is connected in parallel with the auxiliary contact of contactor KM, and the auxiliary contact also serves as the indicator light control signal, improving the system's practicality and reliability. Operators can directly observe the indicator light to determine whether the water pump is running.

[0030] The auxiliary contacts and the main contacts of the contactor are linked – when the main contacts are closed (the water pump is running), the auxiliary contacts close simultaneously and the indicator light illuminates; when the main contacts are open (the water pump stops), the auxiliary contacts open simultaneously and the indicator light goes out.

[0031] Specifically, the normally closed high-water-level float switch is connected in series in the control circuit and is used to cut off the control circuit to stop the motor when the water level is high.

[0032] Connecting a normally closed high-water-level float switch in series in the control circuit and cutting off the circuit to stop the motor when the water level is high is a typical safety protection mechanism in automatic drainage systems. Its advantages are concentrated in three aspects: safety, reliability, and automation adaptability.

[0033] When the water level exceeds the preset high limit, the float switch changes from "normally closed" to "open" due to buoyancy, directly cutting off the current path of the control circuit. This process does not rely on any intermediate logic and has an extremely fast response speed. It can force the contactor to lose power at the moment the water level is about to overflow, causing the motor to stop running and fundamentally avoiding water immersion, equipment damage, or safety accidents.

[0034] Specifically, the control relay RF has the function of cutting off the control circuit when the motor is overloaded.

[0035] Specifically, the start button SB2 is a normally open button, and the stop button SB1 is a normally closed button. The start button SB2 can force the start of the control circuit when the normally open low water level float switch is not closed, and the stop button SB1 can force the power off after the control circuit is energized.

[0036] Specifically, the water pump is a submersible pump.

[0037] It should be noted that all directional indications in the embodiments of the present invention, such as up, down, left, right, front, back, etc., are only used to explain the relative positional relationship and movement of the components in a specific posture, as shown in the attached figure. If the specific posture changes, the directional indication will also change accordingly.

[0038] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Meanwhile, the word "and / or" throughout the text means including three solutions; for example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies A and B. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0039] All of the above components are general standard parts or components known to those skilled in the art. Their structure and principles can be learned by those skilled in the art through technical manuals or conventional experimental methods.

[0040] The specific embodiments described herein are merely illustrative examples of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to replace them, without departing from this utility model or exceeding the scope defined by the appended claims.

Claims

1. A liquid level control system for automatic drainage, characterized in that, include: Three-phase AC power supply, main switch QS, fuse FU, thermal relay FR1, contactor KM, water pump, and control circuit for controlling the start and stop of the three-phase motor M of the water pump. The three-phase motor M is connected to the three-phase AC power supply through the main switch QS, the main contacts of the contactor KM, and the fuse FU, and is used to drive the water pump to drain water. The control circuit includes a normally closed high-water-level float switch, a normally open low-water-level float switch, a start button SB2, a stop button SB1, and a control relay RF; The control relay RF, stop button SB1, normally open low water level float switch, normally closed high water level float switch, and contactor KM coils are connected in series. The start button SB2 is connected in parallel with the normally open low water level float switch; When the water level exceeds the normally open low water level float switch, the normally open low water level float switch closes, the control circuit is connected, the main contacts of contactor KM are energized and attracted, the motor runs, so that the water pump starts to drain water. When the water level drops below the normally open low water level float switch, the normally open low water level float switch opens, cutting off the control circuit. The main contacts of contactor KM are released, and the motor stops running.

2. The liquid level control system for automatic drainage according to claim 1, characterized in that, The normally open low water level float switch is connected in parallel with the auxiliary contact of the contactor KM. The auxiliary contact of the contactor KM is used to connect an indicator light to indicate whether the circuit is energized.

3. The liquid level control system for automatic drainage according to claim 1, characterized in that, The normally closed high-water-level float switch is connected in series in the control circuit and is used to cut off the control circuit to stop the motor when the water level is high.

4. The liquid level control system for automatic drainage according to claim 1, characterized in that, The control relay RF has the function of cutting off the control circuit when the motor is overloaded.

5. The liquid level control system for automatic drainage according to claim 1, characterized in that, The start button SB2 is a normally open button, and the stop button SB1 is a normally closed button. The start button SB2 can force the start of the control circuit when the normally open low water level float switch is not closed, and the stop button SB1 can force the power off after the control circuit is energized.

6. The liquid level control system for automatic drainage according to claim 1, characterized in that, The water pump is a submersible pump.

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