Un-lengthened 18mm-width multifunctional residual current circuit breaker

Abstract

An un-lengthened 18mm-width multifunctional residual current circuit breaker comprises a fixed contact and a movable contact, wherein a cavity is formed at the lower layers of both the fixed contact and the movable contact; a leakage trip device is arranged in the cavity; and a coil iron core of the leakage trip device is directly in transmission connection with a lock catch through a transmission part. The invention has the benefits that the un-lengthened 18mm-width circuit breaker can achieve leakage protection even when a zero line is broken and has the 6000V breaking capacity; the electromagnetic compatibility meets the national standard and leakage tripping can be reliably realized when the voltage is below 50V; and a current coil and a voltage coil neither adopt an inserting and sleeving structure nor share a framework core and a spring, instead, are independent mechanisms respectively placed in different positions, so that heating burning and electromagnetic mutual inductance, caused by dual-coil inserting and sleeving, are avoided, and the problem of insufficient leakage tripping force is solved.

Description

technical field [0001] The invention relates to a circuit breaker, in particular to a circuit breaker capable of leakage protection no matter whether the zero line is connected or not. Background technique [0002] The leakage circuit breaker with a width of 18mm belongs to the range of small circuit breakers, with a rated voltage of 230V / 400V and a rated current below 63A. The width is the commonly used 18mm size, and there is no space for extension to increase the length. In the past, the 18mm leakage circuit breaker without extended size did not have The ground leakage protection function, and the leakage and short circuit protection function of the circuit breaker is achieved by inserting the voltage coil sleeve into the current coil to save the space of the circuit breaker. Chinese patents ZL95246348.2 and ZL200420081810.6 are all such structures. The problem that this brings is: [0003] 1. When the double-coil sleeve is plugged in and energized, it will generate an i...

AI Technical Summary

Problems solved by technology

[0003] 1. When the double-coil sleeve is plugged in and energized, it will generate an induced current through mutual induction, and the generated voltage will be superimposed on the external voltage, which will cause the circuit breaker to fail to meet the relevant standards for electromagnetic compatibility and burn out the circuit breaker;

[0004] 2. The distance between the double-coil sleeves is too close to each other, which is not conducive to heat dissipation when the coil is energized, resulting in reduced product life or direct burnout of the circuit breaker;

[0005] 3. The double-coil sleeve insertion will bring conflicts. The specific situation of the conflict is that the two coils share the iron core and the iron core spring, and the current passing through the current coil is relatively large. In order to meet the requirements of the instantaneous tripping standard, it is necessary to match the corresponding larger The iron core spring, and the current through the voltage coil is small, and the electromagnetic force generated during the leakage is insufficient. Sometimes it is difficult to make the shared iron core spring move, and it cannot play the role of leakage protection, and the leakage trigger current for a long time cannot make the switch At the same time, the voltage coil will always be energized and the heat generated by the work will directly burn out the coil. In addition, if the circuit breaker reduces the turn ratio of the current coil to reduce the electromagnetic force of the current coil to achieve the purpose of reliable operation of the double coil, from the surface It seems to be ok on the surface, but the actual problem is that the resistance of the current coil decreases at the same time, which is not conducive to the current limiting of the product. The tripping force cannot be large enough to quickly disconnect the circuit breaker, and a large number of arcs generated in an instant cannot be instantaneously released. If it goes out and burns out the circuit breaker, it cannot meet the requirements of the relevant national standards for the breaking index of small circuit breakers;

[0006] 4. The jumper of similar products has a round hole, the U-shaped bolt cannot be displaced in the hole, and the torque will not change when the switch is closed. The pressure at the joint between the jumper and the lock is very high, and the increased friction requires leakage tripping. The device has a greater tripping force, which cannot be achieved by the existing double-coil socket structure;

[0008] 6. Due to the unreasonable design of these products, the space cannot be used effectively, so the magnetic ring with the protection of the plastic shell that meets the national standard requirements cannot be accommodated. The magnetic ring is easily damaged without the plastic shell protection, and the lead wire of the magnetic ring will be easily damaged. Falling off, although the magnetic ring body is wrapped with insulating tape, the effect is not ideal, and the contact between the magnetic ring and the surrounding parts during assembly increases the risk of burning out the circuit breaker

[0009] In addition to the above common faults, these products also have the defect that the disconnection time of the product model is 6000A or lower during the current breaking test is slow, the arc light generated is too large, and the arc extinguishing mechanism cannot quickly extinguish the arc, which directly burns the circuit breaker.

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