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Principle of current instantaneous trip protection

        Current instantaneous trip protection is defined as the protection of rapid removal of fault circuit in the shortest time, current instantaneous trip protection is a current protection without a time limit or with light time limit, its core function is to reduce and shorten the time duration of fault, prevent the accident further expanded. Then let’s understand the principle of current instantaneous trip protection, constitution, and regulated type in detail.

 
i.Constitution of current instantaneous trip protection
       The current instantaneous trip protection consists of an outlet component, a starting component, and a signal component. It is generally based on the changes of short circuit current in certain location as criterion, to obtain the selective action. When the power system occur short circuit fault, the current will increase, when the current exceeds the set value of our range, protective components will quickly break the faulty circuit, so as to ensure the device does not being damaged, it has the advantage of strong selectivity and fast sensitivity, accurate and convenient setting and debugging.
 
ii.Classification of current instantaneous trip protection
Current instantaneous trip protection
       The difference between current instantaneous trip protection and over current protection lies in that its action current value is not to escape the maximum load current, but must be greater than the maximum short circuit current when outside of protective scope occur short circuit. When a short circuit occurs outside the protected circuit, it does not act. The principle of current instantaneous trip protection and the principle of definite time over-current protection are basic the same.
 
Time delay current instantaneous trip protection
       The biggest advantage of current instantaneous trip protection is rapid action, but can only protect head end of the circuit. Although the time delay over-current can protect the full length of the circuit, but the action time limit is too long. Therefore, its scope of protection will certainly extend to the head end of the next circuit. So, when a short circuit occurs at the head end of the next current, the protection will start. In order to ensure the selectivity requirements, we must make sure the time limit range of the action time limit is greater than the current instantaneous trip protection, and its action current also need to be greater than that of the current instantaneous trip protection in next circuit. The current instantaneous trip protection with a slight time limit can be used as the main protection of the protected circuit.
 
Definite time over-current protection.
       Because the current instantaneous trip protection can only protect the part of the circuit, it cannot be used as the main protection of the circuit, and can only be used as an auxiliary protection for breaking the head end fault of circuit; The current instantaneous trip protection with a slight time limit can protect the overall length of the circuit, so it can be used as the main protection of the protected circuit, but cannot be used as the back-up protection of next circuit; the time delay over-current can also be used as the back-up protection for circuit(when the action time limit is short, it can be used as main protection, but not install the current instantaneous trip protection with a slight time limit any more), but can be used as back-up protection of next circuit, however the time limit of breaking the fault is a little bit longer. 
 
       This is the detailed introduction of our company for current instantaneous trip protection, 94X  protection relay, 95X protection relay, and 97X  protection relay, of our company all have perfect current instantaneous trip protection function, especially 94X microprocessor protection device. Compared with the traditional relay protection, it uses microprocessor control principle, and reliability, sensitivity, stability are far more reliable than the relay protection and the price is cheap, service life is long, is the the best choice of current protection. Welcome to consult.
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