Mutual inductor protection circuit

Abstract

The utility model discloses a mutual inductor protection circuit, which relates to the technical field of motor protection circuits and comprises a soft starter, a starting alternating current contactor and a bypass operation alternating current contactor. The soft starter is connected with an external power supply and is connected in series with the starting AC contactor which is connected with the motor. The bypass operation AC contactor is connected with a power supply and is connected in parallel with the soft starter and the starting AC contactor and then is connected with the motor. The soft starter comprises a mutual inductor, a JD-5 protector and an ampere meter. The mutual inductor is connected with the JD-5 protector and the ampere meter in series. The number of the mutual inductors and the number of the ampere meters are both three, and each mutual inductor is connected with a JD-5 protector and then connected with one ampere meter in series to form a three-path parallel circuit. According to the utility model, a plurality of devices can be started, and the next device can be started after the first device enters a working state; according to the control mode, the cost can be saved, the control sensitivity is improved, and the equipment is better protected.

Description

Technical Field

[0001] The utility model relates to the technical field of motor protection circuits, in particular to a motor protection circuit using a mutual inductor. Background Art

[0002] With the rapid development of my country's economy, motors have been widely used in various fields, and a number of products have emerged specifically designed for motor protection, such as thermal relays. However, due to the mismatch between the thermal relay's operating curve and the motor's actual protection curve, these relays lose their protective effectiveness. Furthermore, thermal relays suffer from drawbacks such as difficult installation, poor repeatability, inability to reuse after high-current overloads or short-circuits, large adjustment errors, susceptibility to malfunction or failure due to ambient temperature and contamination from dust and impurities, high power consumption, high consumables, and poor performance.

[0003] In recent years, with the development of electronic technology, especially chip technology, some electronic motor protection circuits have emerged. They have made great progress in protection characteristics and sensitivity compared with traditional thermal relays. However, such motor protection circuits are expensive and not conducive to promotion.

[0004] Therefore, a mutual inductor protection circuit has become an issue that needs to be solved urgently. Utility Model Content

[0005] The technical problem to be solved by the utility model is to provide a mutual inductor protection circuit which can start multiple devices and has high sensitivity.

[0006] In order to solve the above technical problems, the technical solution provided by the present utility model is as follows: a mutual inductor protection circuit, comprising a soft starter, a starting AC contactor, and a bypass running AC contactor;

[0007] The soft starter is connected to an external power supply and is connected in series with a starting AC contactor, and the starting AC contactor is connected to a motor;

[0008] The bypass AC contactor is connected to a power source and is connected in parallel with the soft starter and the starting AC contactor, and then connected to the motor.

[0009] Furthermore, the soft starter includes a mutual inductor, a JD-5 protector, and an ammeter, and the mutual inductor, the JD-5 protector, and the ammeter are connected in series.

[0010] Furthermore, there are three mutual inductors and three ammeters, and each mutual inductor is connected to a JD-5 protector and then connected in series with an ammeter to form a three-way parallel circuit.

[0011] The advantages of the present invention over the prior art are that the present invention can start multiple devices, and the next device can be started after the first device enters the working state; this control method can save costs, improve control sensitivity, and better protect equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 The utility model is a circuit principle diagram of a mutual inductor protection circuit.

[0013] Figure 2 This is the circuit diagram of the soft starter.

[0014] As shown in the figure: 1. Soft starter, 2. Starting AC contactor, 3. Bypass running AC contactor, 4. Transformer, 5. JD-5 protector, 6. Ammeter. DETAILED DESCRIPTION

[0015] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "inside", "outside", "vertical", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply 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 present invention.

[0016] In this utility model, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integral connection; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0017] The following is a detailed description of a mutual inductor protection circuit of the present invention in conjunction with the accompanying drawings.

[0018] Combined with attachment Figure 1-2 The specific implementation process of the mutual inductor protection circuit of the utility model is as follows:

[0019] A mutual inductor 4 protection circuit includes a soft starter 1, a starting AC contactor 2, and a bypass AC contactor 3; the soft starter 1 is connected to an external power supply and connected in series with the starting AC contactor 2, and the starting AC contactor 2 is connected to a motor; the bypass AC contactor 3 is connected to a power supply and connected in parallel with the soft starter 1 and the starting AC contactor 2, and then connected to the motor.

[0020] Preferably, the soft starter 1 includes a mutual inductor 4, a JD-5 protector 5, and an ammeter 6, and the mutual inductor 4, the JD-5 protector 5, and the ammeter 6 are connected in series.

[0021] Preferably, three mutual inductors 4 and three ammeters 6 are provided, and each mutual inductor 4 is connected to a JD-5 protector 5 and then connected in series with an ammeter 6 to form a three-way parallel circuit.

[0022] This motor protection circuit is particularly suitable for motors with a power output of 280 kW or more. A single soft starter (1) can start multiple devices at the same location. When soft starter 1 begins, KM1 engages, and the motor enters the starting state. Once the start is complete, KM2 engages, entering the operating state, and KM1 releases. Once the first device enters the operating state, soft starter 1 can start the second device, and so on, for the third. This control method saves costs, improves control sensitivity, and provides better equipment protection.

[0023] The above description of the present invention and its embodiments is non-limiting. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. In short, if a person skilled in the art is inspired by the above, and does not deviate from the purpose of the present invention, without inventive design, a structure and embodiment similar to the technical solution should fall within the scope of protection of the present invention.

Claims

1. A transformer protection circuit, characterized in that: Including soft starter, starting AC contactor, bypass operation AC contactor; The soft starter is connected to an external power supply and is connected in series with a starting AC contactor, and the starting AC contactor is connected to a motor; The bypass operation AC contactor is connected to the power supply and connected in parallel with the soft starter and the starting AC contactor, and then connected to the motor.

2. A mutual inductor protection circuit according to claim 1, characterized in that: The soft starter comprises a mutual inductor, a JD-5 protector and an ammeter, wherein the mutual inductor is connected in series with the JD-5 protector and the ammeter.

3. A mutual inductor protection circuit according to claim 2, characterized in that: The mutual inductors and ammeters are provided in three, and each mutual inductor is connected to a JD-5 protector and then connected in series with an ammeter to form a three-way parallel circuit.

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