CN2191488Y - Phase interruption protector for motor - Google Patents

Abstract

The utility model discloses a phase failure protector for a motor. The utility model is characterized in that a connection point (4) and the connection point N of a zero line are connected with the input terminal of a bridge rectifier; voltage sampling circuits are respectively connected between the connection point (4) and the connection points (1), (2) and (3); power supply indicating circuits which are formed by serially connecting Rs, Ds, LEDs are respectively connected between a connection point N and the connection point (1), (2) and (3). After the filtering of a C4 and the voltage regulation of a D8, the output terminal of the bridge rectifier is connected with a time delay switching circuit which is composed of an adjustable resistor W, a C5, a C8 and a transistor J; the coil of a relay J is connected with an output circuit J. The utility model is suitable for protecting a three-phase AC motor from a phase failure or a phase fault or unbalance, etc.

Description

Phase interruption protector for motor

The utility model relates to open-phase protection device for electromotor.

At present existing phase failure protector of electric motor mostly is the zero-sequence current type, has the defective that versatility is poor, defencive function is few, is difficult to satisfy actual needs.

The purpose of this utility model is, designs a kind of phase failure protector of electric motor, is signal source with the residual voltage, has highly versatile, big small machine is suitable for, the characteristics of low in energy consumption and long service life.

The technical solution of the utility model is, it has in order to the contact that joins with the three phase mains phase line respectively with in order to connect the contact of zero-power line, its design feature is, another contact and zero line contact are connected to the bridge rectifier input that is constituted by a diode, and are connected to the R by parallel connection between described each phase line contact and described another contact respectively ₁With C ₁, R ₂With C ₂, R ₃With C ₃The three-phase voltage sampling testing circuit of forming is connected to the R by series connection respectively between each phase line contact and zero line contact ₄, D ₁, LED ₁R with series connection ₅, D ₂, LED ₂And the R of series connection ₆, D ₃, LED ₃The three phase mains indicating circuit of forming, described bridge rectifier output is through filter capacitor C ₄With voltage stabilizing didoe D ₃Be connected to by adjustable resistance W, capacitor C ₅, resistance R ₃, the delay switch circuit formed of transistor T, the coil of relay J is connected in the output loop of described transistor T, this relay has in order to be serially connected in a normally-closed contact and the normally opened contact in the electromotor control circuit.

Make below in conjunction with drawings and Examples and to further specify.

Description of drawings, accompanying drawing are practical structures of the present utility model.

By accompanying drawing as can be known, this practicality is emerging to be had in order to the contact (1) (2) (3) that joins with the three phase mains phase line respectively with in order to meet the contact N of zero-power line, and its design feature is that another contact (4) and contact N are connected to by diode D ₄To D ₇The bridge rectifier input of forming is connected to respectively by parallel resistor R between described contact (1) (2) (3) and the contact (4) ₁With capacitor C ₁, resistance R ₂With capacitor C ₂, resistance R ₃With capacitor C ₃The three-phase voltage sampling testing circuit of forming is connected to the resistance R by series connection respectively between contact (1) (2) (3) and contact N ₄, diode D ₁, LED ₁R with series connection ₅, D ₂, LED ₂And the R of series connection ₆, D ₃, LED ₃The three phase mains indicating circuit of forming, the output of described bridge rectifier is through filter capacitor C ₄With voltage stabilizing didoe D ₄Be connected to by adjustable resistance W, capacitor C ₅, resistance R ₈, the delay switch circuit formed of transistor T, the coil of relay J is connected in the output loop of described transistor T, described relay J has in order to be serially connected in normally-closed contact (5-7) and the normally opened contact (6-7) in the electromotor control circuit.

Operation principle of the present utility model is, by R ₁To R ₃, C ₁To C ₃Form the sampling testing circuit, contact (1) (2) (3) connects three phase mains, and contact N connects zero-power line, and the residual voltage under the normal condition between contact (4) and N is very little, and when faults such as the generation phase failure, three-phase imbalance, residual voltage raises, through D ₄To D ₇Rectification, C ₄Filtering, D ₈Voltage stabilizing is to W, C ₅, R ₈, the delay switch circuit formed of T provides power supply.When residual voltage during greater than the setting value of design, the T conducting of delay time, the relay J action is series at the relevant contact action of electromotor control circuit, and the contactor coil dead electricity discharges, and cut-out electric capacity is protected motor.

As known from the above; the utility model is a kind of phase failure protector of electric motor; with the residual voltage is signal source; while is as the working power of control circuit; can have the integrated protection function to motor opening circuit, cutting off the electricity supply automatically during fault such as three-phase imbalance, phase fault, phase line ground connection.Its highly versatile, wide, low in energy consumption, the long service life of defencive function, and simple in structure, cost is low, dependable performance.The utility model is to be advisable in the housing that is made in an integral body.Be suitable for 380 volts, 660 volts three-phase angular flux motor.

Claims (1)

1, a kind of phase failure protector of electric motor comprises in order to contact (1) (2) (3) that joins with the three phase mains phase line respectively and the contact N that connects zero-power line, it is characterized in that another contact (4) and contact N are connected to by diode D ₄To D ₇Be connected to respectively by R in parallel between the bridge rectifier input of forming, contact (1) (2) (3) and contact (4) ₁With C ₁, R ₂With C ₂, R ₃With C ₃The three-phase voltage sampling testing circuit of forming is connected to the R by series connection respectively between contact (1) (2) (3) and the contact N ₄, D ₁, LED ₁R with series connection ₅, D ₂, LED ₂And the R of series connection ₆, D ₃, LED ₃The three phase mains indicating circuit of forming, described bridge rectifier output is through filter capacitor C ₄With voltage stabilizing didoe D ₈Be connected to by adjustable resistance W, capacitor C ₅, resistance R ₈, the delay switch circuit formed of transistor J, the coil of relay J is connected in the output loop of described transistor J, this relay has in order to be serially connected in normally-closed contact (5-7) and the normally opened contact (6-7) in the electromotor control circuit.