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1. Why is the motor now more easily burned than in the past? Due to the continuous development of the insulation technology, the design of the motor requires not only increased output, but also requires a reduction in the volume, so that the heat capacity of the new type of motor becomes smaller and smaller, and the overload capacity becomes weaker and weaker; The motor often runs in many ways such as frequent starting, braking, reversing, changing load and so on, which puts forward higher requirements for the motor protection device. In addition, the application of the motor is often more widely used in harsh environments, such as humid, high temperature, dust, corrosion and other occasions. Coupled with the non-standard motor repair, equipment management oversight. All of these have caused the current motor to be more easily damaged than in the past. 2. Why is the traditional protection device less effective? The traditional motor protection devices are mainly fuses and thermal relays. The fuse is the oldest and simplest protection device. In fact, fuses are mainly used for short-circuit fault protection, protection of power lines, reducing the scope of the fault. It is believed that the fuse can protect the motor from short-circuit or overload. It is unscientific to select the fuse according to the rated current, instead of selecting the fuse according to the starting current of the motor. I do not know, this is more likely to cause the motor to damage the motor due to phase failure. Thermal relays are the most widely used motor overload protection devices. However, the thermal relay has a single function, low sensitivity, large error, and poor stability. It has been recognized by the majority of electrical workers and all these defects cause the motor protection to be unreliable. This is exactly the case; despite the fact that many devices have thermal relays installed, the phenomenon of motor damage that affects normal production still prevails. 3. Protector selection principle? The purpose of selecting the motor protection device can not only make the motor fully exert the overload capacity, but also avoid the damage, and it can also improve the reliability of the electric drive system and the continuity of production. At the same time when choosing protection devices, several contradictory factors must be considered, namely reliability, economy, simple structure, convenient operation and maintenance. In the case of meeting the protection requirements, the simplest protection device is first considered, and only when the simple protection device cannot meet the requirements, or when higher requirements are placed on the protection characteristics, consideration is given to the application of a complex protection device. 4, the ideal motor protector? The ideal motor protector is not the most functional, nor is it the most advanced, but should be the most practical. So what is practical? The utility should meet the reliability, economy, convenience and other factors, and have a high performance-cost ratio. So what is reliable? The reliability must first meet the reliability of the function. For example, the overcurrent and phase-off functions must be able to reliably perform overcurrent and phase failure in various applications, processes, and methods. Second, its own reliability (since the protector is to protect others, in particular, should have high reliability) must have a variety of harsh environments, adaptive stability, durability. Economical: Adopt advanced design, reasonable structure, specialization, large-scale production, reduce product cost, bring high economic benefits to users. Convenience: Must be at least as similar to the thermal relay in terms of installation, use, adjustment, wiring, etc., as far as possible more convenient and convenient. It is precisely for this reason that the experts have predicted that in order to simplify the electronic motor protection device, a design without a power transformer (passivation) should be designed and used, and a semiconductor (such as a thyristor) should be used instead of a contacted electromagnetic actuator. element. In this way, it is possible to manufacture a protective device consisting of a minimum number of components. We know that: Active will inevitably bring about unreliability, one normal work requires working power, and the other will definitely lose its working power when it is out of phase. This is a contradiction that cannot be overcome at all. In addition, it needs long-term power-on, which is easily affected by the fluctuation of the power grid voltage and the impact of large current. The failure rate of the system itself will be greatly increased. At the same time, the volume and cost will be increased, and the power supply voltage level needs to be considered, resulting in inconvenience in use. Therefore, the motor protection industry takes active and passive as milestones in technological progress. As a user, passive products should also be considered first. 5, dragon UL series protector features? UL series protectors have symmetry faults (such as overload, locked rotor, overvoltage, undervoltage, etc.) and asymmetrical faults (such as phase failure, current imbalance, phase-to-phase short circuit, and turn-to-turn short circuit), and AC protection. The use of contactors can provide fast and reliable protection for any type of three-phase motor. This protector adopts current detection technology, no external power supply, and the output interface adopts the design scheme of intelligent zero-crossing shut-off AC solid state relay. The whole series adopts the core-through type and fully-enclosed structure. The protector is not only simple in structure, reliable in operation, convenient to use and low in price, but also has no power consumption, no spark, no maintenance, long service life, and small size. It is the only electronic motor protector that can really replace the thermal relay in China. It is especially suitable for occasions where the working environment is harsh and the quality of the power grid is poor, which has an immediate effect. 6 Why is the "Dragon" protector the domestic preferred brand? As Julong's concept of “customer first†permeates every employee and implements every link of scientific research, manufacturing and service, the products launched have truly achieved high quality and low cost, making our services reflect sincere and faithful. . High quality: It has three leading technologies in the world: passive, wear-through, and intelligent. The six outstanding advantages of the company's peers: perfect protection functions, ideal protection features, intuitive indication functions, simple wiring, precise settings, and easy installation. Cheap: Professional, large-scale production, so that dragon protection device has an unparalleled performance-cost ratio. The advanced design, reasonable structure, superb craftsmanship, and meticulous work attitude ensure the high reliability of the product and dare to promise to the society: free trial, unconditional return and lifetime warranty system.
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