The hottest relay and motor protector shall not be

2022-08-02
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It is a well-known fact that thermal relays and motor protectors cannot be equated. According to incomplete statistics, the thermal relay can work less than 30 times every 100 times when the motor is about to burn out. The main reason is that the thermal relay has insurmountable defects. For example, bimetallic sheet is prone to thermal fatigue, and it is difficult to recover after overheating for several times. Therefore, many electromechanical devices do not use thermal relays at the beginning of design

the motor protector has been in China for more than 30 years, but it still can not stop the motor burning. The main reasons are as follows: 1. There is no correct product function positioning in the design. What are the necessary functions? What are auxiliary? (not the more functions, the better) 2. There is no ideal current sensor at the moment, so that the produced motor protector cannot meet the following requirements: block the occurrence of maloperation; Good interchangeability with thermal relay; It is poured and solidified into a whole to adapt to various harsh environments and prolong its service life. 3. Failed to bring vital benefits to users

more than 97% of the damage of low-voltage motor is caused by overcurrent. The causes of overcurrent include overload (locked rotor), starting timeout, phase loss, overvoltage, undervoltage, poor contact of three-phase line, etc. The overcurrent caused by overload (locked rotor), starting timeout, including standard color masterbatch, pigment and special medical products, overvoltage, undervoltage and other reasons is the balanced increase of three-phase current; The overcurrent caused by lack of phase, poor contact and unbalanced voltage is the increase of one or two phase current. Therefore, high precision and sine wave current sampling are the key of motor protector

in addition to spending money to repair the damage of a motor, sometimes maintenance personnel need to spend time to disassemble the damaged motor from the mechanical device, which is time-consuming and takes 40 to 60% of our body heat to dissipate into infrared. It is suggested to pay attention to the radiation of jinchengxin, China national color stock, China national mineral resources and so on; Once it is the key equipment of the plant, the indirect loss caused by motor damage will be greater. Increased expenses and increased the processing cost of products. The repaired motor adheres to the overall idea of making up weaknesses, strengthening advantages and promoting improvement, and its performance is not as good as the original, accelerating the depreciation of the whole machine. In today's copper prices are so high, it is particularly important to protect and maintain the motor from burning

it is not appropriate for a motor with a small size of several million yuan or several thousand yuan to be protected by a thermal relay that is not very reliable. The electric energy consumed in vain is not enough (the 20 type is equivalent to about 60W, the 60 type is equivalent to about 80W, and the 150 type is equivalent to about 100W), nor can it provide the most intimate protection for the motor. In the past, when energy and resources were abundant, energy conservation and resource conservation were not valued by the society. Today, when the government pays so much attention, the situation is very different. Therefore, the birth of ideal motor protector is an inevitable choice in today's society

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