Control circuit for judging fault of circuit board of soft starter

Abstract

The utility model discloses a control circuit for judging faults of a circuit board of a soft starter. The control circuit comprises a first branch circuit, a second branch circuit and a third branch circuit, the first branch comprises a normally open contact of a circuit breaker QF, a normally open contact of a first intermediate relay KA1 and a first indicating lamp HL1 which are sequentially connected in series, and the first indicating lamp HL1 is connected in parallel with a normally open contact of a second intermediate relay KA2 and a second indicating lamp HL2 which are sequentially connected in series; the second indicator lamp HL2 is connected in parallel with a normally open contact of a third intermediate relay KA3 and a third indicator lamp HL3 which are sequentially connected in series, and the third indicator lamp HL3 is connected in parallel with a normally closed contact of a fourth intermediate relay KA4 and a fourth indicator lamp HL4 which are sequentially connected in series; the third indicator lamp HL3 is also connected in parallel with a normally open contact of a fourth intermediate relay KA4, a normally closed contact of a main control contactor KM and a coil of a fifth intermediate relay KA5 which are sequentially connected in series, and a fifth indicator lamp HL5 is connected in parallel between the normally closed contact of the main control contactor KM and the coil of the fifth intermediate relay KA5.

Description

Technical Field

[0001] The utility model relates to the technical field of circuit control, and particularly relates to a control circuit for judging the faults of a soft starter circuit board. Background Art

[0002] A soft starter is mainly a motor control device integrating soft start, soft stop, light load energy saving and multi-functional protection, which can start the motor smoothly without impact during the whole starting process, and can adjust various parameters during the starting process according to the characteristics of the motor load, such as current limiting value, starting time, etc.

[0003] When the soft starter is used in an environment with a large amount of coal dust for a long time, a large amount of coal dust will be deposited in the circuit board of the soft starter. Since the coal dust is conductive, it will cause the current limiting resistor in the circuit board to burn out or short circuit, resulting in false alarms (input phase loss) of the soft starter, misleading the direction of fault finding, low maintenance efficiency, and seriously affecting production. How to accurately judge the accuracy of the reported faults will be the key to finding problems. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a control circuit for judging the faults of a soft starter circuit board.

[0005] The utility model is implemented by the following technical solutions: a control circuit for judging the faults of a soft starter circuit board, which includes a main circuit and a control circuit;

[0006] The control circuit includes a first branch, a second branch, and a third branch;

[0007] The first branch includes the normally open contact of a circuit breaker QF, the normally open contact of a first intermediate relay KA1, and a first indicator light HL1, which are sequentially connected in series. The first indicator light HL1 is connected in parallel with the normally open contact of a second intermediate relay KA2 and a second indicator light HL2, which are sequentially connected in series. The second indicator light HL2 is connected in parallel with the normally open contact of a third intermediate relay KA3 and a third indicator light HL3, which are sequentially connected in series. The third indicator light HL3 is connected in parallel with the normally closed contact of a fourth intermediate relay KA4 and a fourth indicator light HL4, which are sequentially connected in series. The third indicator light HL3 is also connected in parallel with the normally open contact of a fourth intermediate relay KA4, the normally closed contact of a main control contactor KM, and the coil of a fifth intermediate relay KA5. A fifth indicator light HL5 is connected in parallel between the normally closed contact of the main control contactor KM and the coil of the fifth intermediate relay KA5;

[0008] The second branch includes a fault dry contact J of the soft starter and the coil of a fourth intermediate relay KA4, which are sequentially connected in series. The coil of the fourth intermediate relay KA4 is connected in parallel with a sixth indicator light HL6;

[0009] The third branch includes a normally-closed contact of a thermal relay FR, a stop button SB1, a normally-open contact of a fifth intermediate relay KA5, and a coil of a main control contactor KM, which are arranged in series in sequence. The normally-open contact of the fifth intermediate relay KA5 is connected in parallel with the normally-open contact of the main control contactor KM.

[0010] Further, the main circuit includes a three-phase power supply, a normally-open contact of a circuit breaker QF, a normally-open contact of a main circuit relay KM, a thermal relay FR, and a motor M, which are arranged in series in sequence. A first intermediate relay KA1 is connected between the A phase of the three-phase power supply and the neutral line, a second intermediate relay KA2 is connected between the B phase of the three-phase power supply and the neutral line, and a third intermediate relay KA3 is connected between the C phase of the three-phase power supply and the neutral line.

[0011] Advantages of the present utility model: With the cooperation of the first branch, the second branch, and the third branch, the fault direction can be quickly found, the maintenance efficiency is improved, and the smooth progress of production is ensured. The function of the first branch is to detect the three-phase power supply and accurately judge the phase loss situation of the three-phase power supply. At the same time, under the action of the second branch, the abnormal situation of the soft starter is judged. Under the action of the third branch, the normal operation of the motor is ensured without affecting the production requirements. Description of the Drawings

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following-described drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0013] Figure 1 It is a schematic diagram of the main circuit of the utility model;

[0014] Figure 2 It is a schematic diagram of the control circuit of the utility model;

[0015] In the figure: main circuit 1, control circuit 2, first branch 2.1, second branch 2.2, third branch 2.3, circuit breaker QF, first intermediate relay KA1, second intermediate relay KA2, third intermediate relay KA3, fourth intermediate relay KA4, fifth intermediate relay KA5, first indicator light HL1, second indicator light HL2, third indicator light HL3, fourth indicator light HL4, fifth indicator light HL5, sixth indicator light HL6, main control contactor KM, fault dry contact J of the soft starter, stop button SB1, three-phase power supply, thermal relay FR, motor M, soft starter 3. Detailed Embodiments

[0016] The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without making creative efforts shall fall within the protection scope of the present utility model.

[0017] As Figure 1-2 shown, a control circuit for judging the faults of a soft starter circuit board includes a main circuit 1 and a control circuit 2;

[0018] The control circuit 2 includes a first branch 2.1, a second branch 2.2, and a third branch 2.3;

[0019] The first branch 2.1 includes a normally open contact of a circuit breaker QF, a normally open contact of a first intermediate relay KA1, and a first indicator light HL1, which are sequentially connected in series. The first indicator light HL1 is paralleled with a normally open contact of a second intermediate relay KA2 and a second indicator light HL2, which are sequentially connected in series. The second indicator light HL2 is paralleled with a normally open contact of a third intermediate relay KA3 and a third indicator light HL3, which are sequentially connected in series. The third indicator light HL3 is paralleled with a normally closed contact of a fourth intermediate relay KA4 and a fourth indicator light HL4, which are sequentially connected in series. The third indicator light HL3 is also paralleled with a normally open contact of a fourth intermediate relay KA4, a normally closed contact of a main control contactor KM, and a coil of a fifth intermediate relay KA5. A fifth indicator light HL5 is paralleled between the normally closed contact of the main control contactor KM and the coil of the fifth intermediate relay KA5;

[0020] The second branch 2.2 includes a fault dry contact J of a soft starter 3 and a coil of a fourth intermediate relay KA4, which are sequentially connected in series. The coil of the fourth intermediate relay KA4 is paralleled with a sixth indicator light HL6;

[0021] The third branch 2.3 includes a normally closed contact of a thermal relay FR, a stop button SB1, a normally open contact of a fifth intermediate relay KA5, and a coil of a main control contactor KM. The normally open contact of the fifth intermediate relay KA5 is paralleled with a normally open contact of the main control contactor KM.

[0022] Furthermore, the main circuit 1 includes a three-phase power supply, a normally open contact of a circuit breaker QF, a normally open contact of a relay KM in the main circuit 1, a thermal relay FR, and a motor M, which are sequentially connected in series. A first intermediate relay KA1 is connected between the A phase of the three-phase power supply and the neutral line, a second intermediate relay KA2 is connected between the B phase of the three-phase power supply and the neutral line, and a third intermediate relay KA3 is connected between the C phase of the three-phase power supply and the neutral line.

[0023] With the cooperation of the first branch 2.1, the second branch 2.2 and the third branch 2.3, the fault direction can be quickly found, improving the maintenance efficiency and ensuring the smooth progress of production. The function of the first branch 2.1 is to detect the three-phase power supply and accurately judge the phase loss of the three-phase power supply. At the same time, under the action of the second branch 2.2, the abnormal situation of the soft starter 3 is judged. Under the action of the third branch 2.3, the normal operation of the motor M is ensured without affecting the production requirements.

[0024] The specific operation process of this embodiment:

[0025] 1. When the main circuit 1 is operating normally

[0026] Close the circuit breaker QF in the control circuit 2;

[0027] In the first branch 2.1, when the A phase of the three-phase power supply is normal, the coil of the first intermediate relay KA1 is energized, and the first indicator light HL1 lights up at this time; when the B phase of the three-phase power supply is normal, the coil of the second intermediate relay KA2 is energized, and the second indicator light HL2 lights up at this time; when the C phase of the three-phase power supply is normal, the coil of the third intermediate relay KA3 is energized, and the third indicator light HL3 lights up at this time, indicating that the input voltage of the motor M is normal.

[0028] In the second branch 2.2, when the soft starter 3 is operating normally and there is no reported input phase loss, the fault dry contact J of the soft starter 3 is disconnected, the coil of the fourth intermediate relay KA4 is not energized, and the normally closed point of the fourth intermediate relay KA4 is in the closed state, and the fourth indicator light HL4 lights up, indicating that the circuit board of the soft starter 3 is intact.

[0029] 2. When the soft starter 3 is in an abnormal situation

[0030] The soft starter 3 reports input phase loss. At this time, the motor M stops running, the fault dry contact J of the soft starter 3 closes, the coil of the fourth intermediate relay KA4 is energized, and at the same time the sixth indicator light HL6 lights up, indicating the fault action indication of the soft starter 3.

[0031] In the first branch 2.1, at this time, the normally open point of the fourth intermediate relay KA4 is in the closed state, the fifth indicator light HL5 lights up, indicating that the circuit board is damaged. At the same time, the coil of the fifth intermediate relay KA5 is energized.

[0032] In the third branch 2.3, the normally open point of the fifth intermediate relay KA5 closes, the coil of the main control contactor KM is energized, and at the same time the normally open contact of the main control contactor KM closes, making the main control contactor KM self-locked, and the motor M runs normally.

[0033] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A control circuit for determining a soft starter circuit board fault, characterized in that: It includes a main circuit and a control circuit; The control loop includes a first branch, a second branch, and a third branch; The first branch includes a normally open contact of a circuit breaker QF, a normally open contact of a first intermediate relay KA1, and a first indicator light HL1, which are sequentially connected in series; the first indicator light HL1 is connected in parallel with a normally open contact of a second intermediate relay KA2 and a second indicator light HL2, which are sequentially connected in series; the second indicator light HL2 is connected in parallel with a normally open contact of a third intermediate relay KA3 and a third indicator light HL3, which are sequentially connected in series; the third indicator light HL3 is connected in parallel with a normally closed contact of a fourth intermediate relay KA4 and a fourth indicator light HL4, which are sequentially connected in series; the third indicator light HL3 is also connected in parallel with a normally open contact of a fourth intermediate relay KA4, a normally closed contact of a main control contactor KM, and a coil of a fifth intermediate relay KA5, which are sequentially connected in series; a fifth indicator light HL5 is connected in parallel between the normally closed contact of the main control contactor KM and the coil of the fifth intermediate relay KA5; The second branch includes a fault dry contact J of a soft starter and a coil of a fourth intermediate relay KA4 which are sequentially connected in series, and a sixth indicator light HL6 is connected in parallel to the coil of the fourth intermediate relay KA4; The third branch includes the normally closed contact of the thermal relay FR, the stop button SB1, the normally open contact of the fifth intermediate relay KA5, and the coil of the main control contactor KM which are arranged in series in sequence. The normally open contact of the fifth intermediate relay KA5 is connected in parallel with the normally open contact of the main control contactor KM.

2. The control circuit for determining a soft starter circuit board fault according to claim 1, characterized in that: The main circuit includes a three-phase power supply, a normally open contact of a circuit breaker QF, a normally open contact of a main circuit relay KM, a thermal relay FR, and a motor M which are arranged in series in sequence. A first intermediate relay KA1 is connected between phase A of the three-phase power supply and a neutral line, a second intermediate relay KA2 is connected between phase B of the three-phase power supply and a neutral line, and a third intermediate relay KA3 is connected between phase C of the three-phase power supply and a neutral line.

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