CN2376684Y

CN2376684Y - Improved leakage current protector

Info

Publication number: CN2376684Y
Application number: CN 99225567
Authority: CN
Inventors: 钱加灿
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-01-26
Filing date: 1999-01-26
Publication date: 2000-05-03
Anticipated expiration: 2009-01-26

Abstract

The utility model relates to an improved leakage current protector. On the basis of an existing leakage current protector, the utility model is additionally provided with a thyristor and at least one sensor. One end of each sensor is connected with an electrode in a power supply circuit, and the other end which is connected in series with a resistor is connected with the trigger electrode of the thyristor. The cathode of the thyristor is connected with the negative electrode of a rectifier, the anode of the thyristor is connected with the positive electrode of the rectifier and an electrolytic capacitor is connected in parallel between the trigger electrode and the cathode of the thyristor. When an amplifier and a zero-sequence mutual inductor have malfunction, the abnormal operating conditions of an electric appliance still can be prevented, and accordingly, the safety performance can be improved.

Description

Improved residual current operated protective device

The utility model relates to the electric security protector device, specifically a kind of improved residual current operated protective device.

Residual current operated protective device is widely used, except can in time cutting off the electricity supply when electric leakage takes place, gives other safety protection function after also being modified.The scheme that Chinese patent 95214539.1 is put down in writing is exactly one of them; the feature of this scheme is that at least one transducer is installed on electrical equipment or equipment; with be connected on the current supply circuit after test loop on the zero-sequence transformer and resistance R are connected in series; except the function that prevents to leak electricity is arranged; when detected object is in abnormal operating state; the residual operating current that is provided simulation by transducer makes the earth leakage protective device action, cuts off the electricity supply.Such design; the alarm and protection effect of transducer must be cut off circuit via zero-sequence transformer trigger amplifier starting circuit breaker and realize; obviously; when integrated amplifier, the zero-sequence transformer of earth leakage protective device had fault and be also undiscovered, the abnormal operating state of detected object was as the embodiment in this patent documentation; the electric heater dry combustion method; also just can't find, therefore, still have accident potential.

The utility model is that above-mentioned residual current operated protective device is improved, and with the accident potential that the fault electrical appliance of eliminating because of earth leakage protective device self still may exist, improves fail safe.

The technical solution of the utility model is: a kind of improved residual current operated protective device; comprise by zero-sequence transformer LLH; circuit breaker ZK; amplifier; rectifier DC; the earth leakage protective device that the test loop is formed; it is characterized in that: also comprise a controllable silicon SCR and at least one transducer; one of each transducer is terminated at any utmost point in the current supply circuit; the other end of each transducer is connected respectively and is inserted the controllable silicon SCR trigger electrode after the resistance R; the controllable silicon SCR negative electrode connects the negative pole of rectifier DC; anode connects the positive pole of rectifier DC, a dielectric capacitance C in parallel between the trigger electrode of controllable silicon SCR and the negative electrode.

The sensor can be bimetal leaf, magnetic sentive switch, hydraulic pressure switch or hydraulic selector, if can be under improper operating mode (as temperature, pressure anomaly) convert normally closed transducer to and all can be used as transducer of the present utility model by often opening.

Principle of the present utility model is with by transducer; resistance; the control circuit that controllable silicon and dielectric capacitance are formed is in parallel with zero-sequence transformer; uncorrelated mutually; work alone separately; therefore can overcome the defective that original residual current operated protective device exists; the alarm and protection effect of transducer is no longer cut off circuit via zero-sequence transformer trigger amplifier starting circuit breaker and is realized; realize but cut off circuit by sensor-triggered controllable silicon starting circuit breaker; even the integrated amplifier of earth leakage protective device; when zero-sequence transformer has fault not work; the improper operating mode of electrical appliance still can be protected, and has improved the security performance of electrical appliance.

Be further described below in conjunction with embodiment of the present utility model and accompanying drawing thereof.

Fig. 1 is the utility model electrical schematic diagram.

Fig. 2 represents that the bimetal leaf transducer is installed in the structural representation on the electrothermal tube of electric heater.

Residual current operated protective device shown in the drawings is used to prevent the electric heater dry combustion method, is improved on the basis of existing earth leakage protective device.Original member comprises zero instrument transformer LLH, circuit breaker ZK, amplifier, rectifier DC, the test loop of being made up of test button T, test resistance Rt.Institute is improved to be: as shown in Figure 1, also comprise a controllable silicon SCR and at least one transducer 2, one of each transducer 2 is terminated at any utmost point in the current supply circuit, the other end of each transducer 2 is connected respectively and is inserted the controllable silicon SCR trigger electrode after the resistance R, the controllable silicon SCR negative electrode connects the negative pole of rectifier DC, anode connects the positive pole of rectifier DC, a dielectric capacitance C in parallel between the trigger electrode of controllable silicon SCR and the negative electrode.

Transducer 2 adopts bimetal leaf in the present embodiment, as shown in Figure 2, with two heat transfer sheet 5 sleeve 4 of interior dress transducer 2 is fixed on the electrothermal tube 1, and original thermostat is installed in the sleeve 3.

The requirement of electric heater safety index, under the malfunctioning situation of thermostat, anhydrous dry combustion method must not be above one minute.Even the integrated amplifier in the present embodiment, zero-sequence transformer, thermostat all have fault, as long as it is overheated dry combustion method to occur, transducer 2 also can become short circuit by open circuit, triggers controllable silicon and makes circuit breaker work, cuts off the electricity supply, and implements protection.

Claims

A kind of improved residual current operated protective device; comprise the earth leakage protective device of forming by zero instrument transformer LLH, circuit breaker ZK, amplifier, rectifier DC, test loop; it is characterized in that also comprising a controllable silicon SCR and at least one transducer; one of each transducer is terminated at any utmost point in the current supply circuit; the other end of each transducer is connected respectively and is inserted the controllable silicon SCR trigger electrode after the resistance R; the controllable silicon SCR negative electrode connects the negative pole of rectifier DC; anode connects the positive pole of rectifier DC, a dielectric capacitance C in parallel between the trigger electrode of controllable silicon SCR and the negative electrode.