Power supply monitoring protection circuit

Abstract

The utility model provides a power supply monitoring protection circuit. The power supply monitoring protection circuit comprises a circuit breaker QF, a contactor KM1, a contactor KM2, a contactor KM3, a thermal relay FR, a fuse FU1, a fuse FU2, a motor M, a fuse FU, a stop button SB1, a start button SB2, a relay KA, an operation indicating lamp HR1, an operation indicating lamp HR2, a stop indicating lamp HG1 and a stop indicating lamp HG2. According to the utility model, the conditions of motor burnout and abnormal shutdown of operation equipment caused by motor power supply phase loss due to circuit breaker or power supply abnormity can be avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of power supply monitoring and protection, in particular to a power supply monitoring and protection circuit. Background Art

[0002] In any chemical industry, the main power of the production process is provided by on-site motors. Therefore, the smooth operation of the motors is directly related to the stability of the production equipment. Every year, production enterprises are frequently affected by motor failures, among which motor burnouts due to power supply abnormalities account for a large proportion. The traditional motor control circuit is protected by thermal relays, which are protected according to the temperature characteristic curve of the thermal element and have an inverse time limit. They cannot provide timely protection against power supply abnormalities, resulting in motor burnouts.

[0003] The primary circuit of a low-voltage motor is often composed of a circuit breaker, a contactor, and a thermal relay. The secondary circuit is connected in series to the control circuit using the auxiliary point of the thermal relay (normally closed). During long-term equipment operation, equipment maintenance frequently causes power outages and power supply, or line failures, which can lead to phase loss in the motor power supply. Phase loss causes the motor current to increase instantly. The thermal protection element requires a certain time limit to operate according to the temperature characteristic curve, and the thermal protection responds slowly, failing to protect the equipment in time, ultimately leading to motor burnout and abnormal shutdown of the operating equipment. For the chemical industry, the risk to the process is relatively high after the vehicle jumps. Utility Model Content

[0004] The utility model provides a power supply monitoring protection circuit to prevent the circuit breaker or power supply abnormality from causing a phase loss in the power supply of the motor, resulting in the burning of the motor and the abnormal stopping of the running equipment.

[0005] The embodiment of this specification discloses a power supply monitoring protection circuit, including a circuit breaker QF, a contactor KM1, a contactor KM2, a contactor KM3, a thermal relay FR, a fuse FU1, a fuse FU2, a motor M, a fuse FU, a stop button SB1, a start button SB2, a relay KA, a running indicator light HR1, a running indicator light HR2, a stop indicator light HG1 and a stop indicator light HG2;

[0006] The three phases at one end of the circuit breaker QF are respectively connected to external live wires, and the three phases at the other end of the circuit breaker QF are connected to one end of the coil of the thermal relay FR through the normally open main contact KM11 of the contactor KM1, and the other end of the coil of the thermal relay FR is connected to the motor M, one end of the fuse FU1 is connected to the first phase of the other end of the circuit breaker QF, the other end of the fuse FU1 is connected to one end of the coil of the contactor KM2, the other end of the coil of the contactor KM2 is connected to one end of the coil of the contactor KM3 and the second phase of the other end of the circuit breaker QF, the other end of the coil of the contactor KM3 is connected to one end of the fuse FU2, and the other end of the fuse FU2 is connected to the third phase of the other end of the circuit breaker QF;

[0007] One end of the fuse FU is connected to an external live wire, and the other end of the fuse FU is connected to one end of the normally closed contact KA1 of the relay KA, one end of the normally closed contact KM21 of the contactor KM2, one end of the normally closed contact KM31 of the contactor KM3, one end of the normally open auxiliary contact KM13 of the contactor KM1 and one end of the normally closed auxiliary contact KM14 of the contactor KM1. The other end of the normally closed contact KA1 of the relay KA is connected in series with the normally closed contact FR1 of the thermal relay FR, the stop button SB1, the start button SB2 and the coil of the contactor KM1, and the neutral line is connected externally after the series connection; the normally open auxiliary contact KM12 of the contactor KM1 is connected to the start button SB2 and the start button SB3. The button SB2 is connected in parallel, the other end of the normally closed contact KM21 is connected to the other end of the normally closed contact KM31 and one end of the coil of the relay KA, the other end of the coil of the relay KA is connected to the neutral wire, the other end of the normally open auxiliary contact KM13 is connected to one end of the operation indicator light HR1 and one end of the operation indicator light HR2, the other end of the operation indicator light HR1 and the other end of the operation indicator light HR2 are both connected to the neutral wire, the other end of the normally closed auxiliary contact KM14 is connected to one end of the stop indicator light HG1 and one end of the stop indicator light HG2, the other end of the stop indicator light HG1 and the other end of the stop indicator light HG2 are both connected to the neutral wire.

[0008] The embodiments of this specification can at least achieve the following beneficial effects:

[0009] In case of abnormal power supply to the motor or phase loss of the circuit breaker, the equipment can be protected in time, which compensates for the slow response speed of the thermal relay, avoids burning the motor due to phase loss, and reduces maintenance costs. The contactor is used to realize the phase loss monitoring function. When any phase of the power supply is missing, the auxiliary contact (normally closed) of the contactor corresponding to the contactor power failure is turned on, and the KA relay is energized to assist the normally closed contact to disconnect the control circuit, thereby realizing the protection function of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0011] Figure 1 It is a partial schematic diagram of a power supply monitoring and protection circuit involved in some embodiments of the present utility model.

[0012] Figure 2 It is another partial schematic diagram of the power monitoring protection circuit involved in some embodiments of the present utility model. DETAILED DESCRIPTION

[0013] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the embodiments of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0014] In the description of the embodiments of the present invention, it should be understood that the terms "length", "vertical", "horizontal", "top", "bottom", etc. indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present invention.

[0015] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present utility model, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0016] In the embodiments of the present utility model, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present utility model can be understood according to specific circumstances.

[0017] In the embodiments of the present utility model, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through another feature between them. Moreover, the first feature being "above", "above" and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature includes the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0018] The disclosure below provides many different embodiments or examples for realizing different structures of the embodiments of the present utility model. In order to simplify the disclosure of the embodiments of the present utility model, the components and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the embodiments of the present utility model. In addition, the embodiments of the present utility model can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed.

[0019] The embodiments of the present utility model are described in detail below with reference to the accompanying drawings.

[0020] like Figure 1 and Figure 2 As shown, the embodiment of this specification discloses a power supply monitoring protection circuit, including a circuit breaker QF, a contactor KM1, a contactor KM2, a contactor KM3, a thermal relay FR, a fuse FU1, a fuse FU2, a motor M, a fuse FU, a stop button SB1, a start button SB2, a relay KA, a running indicator light HR1, a running indicator light HR2, a stop indicator light HG1 and a stop indicator light HG2;

[0021] The three phases at one end of the circuit breaker QF are respectively connected to external live wires (L1, L2, L3), the three phases at the other end of the circuit breaker QF are connected to one end of the coil of the thermal relay FR through the normally open main contact KM11 of the contactor KM1, the other end of the coil of the thermal relay FR is connected to the motor M, one end of the fuse FU1 is connected to the first phase of the other end of the circuit breaker QF, the other end of the fuse FU1 is connected to one end of the coil of the contactor KM2, the other end of the coil of the contactor KM2 is connected to one end of the coil of the contactor KM3 and the second phase of the other end of the circuit breaker QF, the other end of the coil of the contactor KM3 is connected to one end of the fuse FU2, and the other end of the fuse FU2 is connected to the third phase of the other end of the circuit breaker QF;

[0022] One end of the fuse FU is connected to an external live wire (L3), and the other end of the fuse FU is connected to one end of the normally closed contact KA1 of the relay KA, one end of the normally closed contact KM21 of the contactor KM2, one end of the normally closed contact KM31 of the contactor KM3, one end of the normally open auxiliary contact KM13 of the contactor KM1 and one end of the normally closed auxiliary contact KM14 of the contactor KM1. The other end of the normally closed contact KA1 of the relay KA is connected in series with the normally closed contact FR1 of the thermal relay FR, the stop button SB1, the start button SB2 and the coil of the contactor KM1, and the neutral line (N) is connected externally after the series connection; the normally open auxiliary contact KM12 of the contactor KM1 is connected in series with the normally closed contact FR1 of the thermal relay FR, the stop button SB1, the start button SB2 and the coil of the contactor KM1. The start button SB2 is connected in parallel, the other end of the normally closed contact KM21 is connected to the other end of the normally closed contact KM31 and one end of the coil of the relay KA, the other end of the coil of the relay KA is connected to the neutral wire, the other end of the normally open auxiliary contact KM13 is connected to one end of the running indicator light HR1 and one end of the running indicator light HR2, the other end of the running indicator light HR1 and the other end of the running indicator light HR2 are both connected to the neutral wire, the other end of the normally closed auxiliary contact KM14 is connected to one end of the stop indicator light HG1 and one end of the stop indicator light HG2, the other end of the stop indicator light HG1 and the other end of the stop indicator light HG2 are both connected to the neutral wire.

[0023] Contactor KM2 / KM3 is used for phase loss monitoring, and relay KA is used for phase loss protection, in which: when the power supply is normal, circuit breaker QF is closed, the coil of contactor KM2 and the coil of contactor KM3 are energized, the normally closed contact KM21 and the normally closed contact KM31 are disconnected, relay KA is in a de-energized state, the normally closed contact KA1 is turned on, after pressing the start button SB2, the coil of contactor KM1 is energized, the normally open main contact KM11 is closed, and the motor M starts and runs normally.

[0024] When the running equipment loses phase due to abnormal phase loss of circuit breaker QF or power supply, one of the coils KM2 and KM3 loses power or both lose power, the normally closed contacts KM21 and KM31 are connected, the coil of relay KA is energized, the normally closed contact KA1 is disconnected, the coil of contactor KM1 is de-energized, the normally open main contact KM11 is disconnected, and the motor M stops running, thus protecting the equipment in time to avoid burning of the motor due to phase loss.

[0025] When the running equipment is overloaded, the current increases and the thermistor element of the thermal relay FR is activated, the normally closed contact FR1 is disconnected, the coil of the contactor KM1 is de-energized, the normally open main contact KM11 is disconnected, and the motor M stops running.

[0026] The above embodiments describe multiple specific implementations of the present invention, but those skilled in the art should understand that various changes or modifications can be made to these implementations without departing from the principles and essence of the present invention, but these changes and modifications are all within the scope of protection of the present invention.

Claims

1. A power supply monitoring and protection circuit, characterized in that: It includes circuit breaker QF, contactor KM1, contactor KM2, contactor KM3, thermal relay FR, fuse FU1, fuse FU2, motor M, fuse FU, stop button SB1, start button SB2, relay KA, running indicator light HR1, running indicator light HR2, stop indicator light HG1 and stop indicator light HG2; The three phases at one end of the circuit breaker QF are respectively connected to external live wires, and the three phases at the other end of the circuit breaker QF are connected to one end of the coil of the thermal relay FR through the normally open main contact KM11 of the contactor KM1, and the other end of the coil of the thermal relay FR is connected to the motor M, one end of the fuse FU1 is connected to the first phase of the other end of the circuit breaker QF, the other end of the fuse FU1 is connected to one end of the coil of the contactor KM2, the other end of the coil of the contactor KM2 is connected to one end of the coil of the contactor KM3 and the second phase of the other end of the circuit breaker QF, the other end of the coil of the contactor KM3 is connected to one end of the fuse FU2, and the other end of the fuse FU2 is connected to the third phase of the other end of the circuit breaker QF; One end of the fuse FU is connected to an external live wire, and the other end of the fuse FU is connected to one end of the normally closed contact KA1 of the relay KA, one end of the normally closed contact KM21 of the contactor KM2, one end of the normally closed contact KM31 of the contactor KM3, one end of the normally open auxiliary contact KM13 of the contactor KM1 and one end of the normally closed auxiliary contact KM14 of the contactor KM1. The other end of the normally closed contact KA1 of the relay KA is connected in series with the normally closed contact FR1 of the thermal relay FR, the stop button SB1, the start button SB2 and the coil of the contactor KM1, and the neutral line is connected externally after the series connection; the normally open auxiliary contact KM12 of the contactor KM1 is connected to the start button SB2 and the start button SB3. The button SB2 is connected in parallel, the other end of the normally closed contact KM21 is connected to the other end of the normally closed contact KM31 and one end of the coil of the relay KA, the other end of the coil of the relay KA is connected to the neutral wire, the other end of the normally open auxiliary contact KM13 is connected to one end of the operation indicator light HR1 and one end of the operation indicator light HR2, the other end of the operation indicator light HR1 and the other end of the operation indicator light HR2 are both connected to the neutral wire, the other end of the normally closed auxiliary contact KM14 is connected to one end of the stop indicator light HG1 and one end of the stop indicator light HG2, the other end of the stop indicator light HG1 and the other end of the stop indicator light HG2 are both connected to the neutral wire.

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