Residual current protecting device

Abstract

The invention provides a residual current protecting device. The residual current protecting device comprises a first current transformer, a second current transformer, a switching unit, a first residual current detecting module and a second residual current detecting module, wherein the second residual current detecting module comprises a first detecting unit and a second detecting unit; the switching unit is used for switching the residual current protecting device between a first state and a second state, so that, in the first state, the coil of the first current transformer and the coil of the second current transformer can be connected in series and both ends of the formed series-connected coil set can be connected with the two input electrodes of the first residual current detecting module, and in the second state, both ends of the coil of the first current transformer can be connected with the first detecting unit and both ends of the coil of the second current transformer can be connected with the second detecting unit. The residual current protecting device can enhance the sensitivity under the premise of no increase in size.

Description

technical field [0001] The invention relates to a residual current protection device. Background technique [0002] Residual current protection devices are widely used in power distribution systems to protect personal safety. At present, residual current protection products mainly include AC type, A type and B type. Among them, the AC type is used for the detection of AC residual current, and is mainly used in general AC circuits. Type A is used for the detection of AC and DC pulsating residual current, and is usually used in circuits with more electronic equipment, such as: microcomputers, cash registers, electronic scales and other electrical equipment. Type B is used for the detection of AC and DC pulsation and DC smooth residual current. It is usually used in smooth DC or smooth DC circuits with slight aftermath when a fault occurs, such as: frequency converter, CT-equipment, X-ray equipment , Uninterruptible power supply equipment. Among them, the B-type residual cu...

AI Technical Summary

Problems solved by technology

However, in some application scenarios, such as wet environments or medical scenarios, even a residual current of less than 30mA may cause certain harm, so the market expects a more sensitive B-type residual current protection to provide better safety protection

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