CN2175983Y - Protecting starter of single-wire motor - Google Patents

Abstract

The utility model relates to a protecting starter of a single-wire motor, belonging to a protecting and starting device of a three-phase asynchronous motor. The protecting starter of a single-wire motor is composed of a mutual inductor B, diodes D1-D5, resistors R1-R3, transistors BG1 and BG2, capacitors C1 and C2, a potentiometer Rw, a three-terminal integrate manostat 7812 and a relay J, wherein, the mutual inductor B and the diodes D1-D5 are arranged on a single-wire motor. The diodes D1-D4 are connected into a bridge rectifier; the input terminal of the bridge rectifier is connected with the secondary stage of a mutual inductor; the capacitor C1 is arranged at the output terminal of the bridge rectifier. When serially connected, the R1 and the Rw are connected with the output terminal of the bridge rectifier in parallel; the input terminal of the three-terminal integrate manostat 7812 is connected with the output terminal of the rectifier. The utility model has the advantages of simple structure, complete function, stable performance, low cost and long service life.

Description

Protecting starter of single-wire motor

The utility model single line motor protection starter belongs to threephase asynchronous protection starting device.

Motor protector divides thermal element protection and Electronic Protection two big classes in the prior art; version is inequality; two lines in three power lines of need detection motor or three-way; obtain control signal; owing to there is plural signal to control jointly; influential mutually between each signal, complex structure, the accuracy of operating current value, repeatability, opposing environmental factor jamming performance are poor.

The purpose of the utility model single line motor protection starter; be to overcome above-mentioned shortcoming and design a kind of single line motor protection starter; it need detect in three motor power lines one; obtain control signal; realize the various functions of motor protector; simple in structure, accurate safety, strong anti-interference performance.

The utility model single line motor protection starter takes following scheme to realize, is made of single line protector and A.C. contactor and shell, and starting button and stop button are set on the shell, and the single line protector is by instrument transformer B and diode D ₁-D ₅With resistance R ₁-R ₃, triode BG ₁With BG ₂, capacitor C ₁, C ₂And potentiometer R _W, three terminal integrated voltage stabilizer 7812 and relay J constitute.Single line protector electronic component device is on printed circuit board (PCB), and circuit board and instrument transformer B constitute the single line protector, and the single line protector is series at the line in three power lines of motor, and ac contactor coil connects on other two lines.During the motor operation, instrument transformer B is elementary to have electric current to flow through, the corresponding alternating voltage of secondary induction, and this voltage is through D ₁-D ₄Rectification and C ₁Filtering obtains direct voltage V _C1, pressurizer 7812 is with V _C1After the voltage stabilizing, output 12V stable DC voltage, the power supply of supply relay J, resistance R ₁And R _WSeries loop is with V _C1Send BG after the sampling ₁Base stage.Sampling voltage is less than 0.6V during fault-free, BG ₁Be in cut-off state, R ₂With D ₅To C ₂Charging, and pass through R ₃To BG ₂Supply with base current, BG ₂Saturation conduction, relay J adhesive, J _KControl A.C. contactor CJ adhesive, the normal operation of motor energising.During the elementary no current of instrument transformer B, secondary no alternating voltage output, the protector circuit does not have electricity, and relay J discharges.When instrument transformer B primary current is excessive, V _C1Raise R ₁With R _WBG is sent in sampling ₁Base voltage surpasses 0.6V, BG ₁Saturation conduction, D ₅Anodal shorted to earth, C ₂Pass through R ₃To BG ₂The base stage discharge, BG ₂Continue conducting.3-5 C in second ₂Discharge off, BG ₂Lose base current and end, relay J discharges.The supercurrent operating value is regulated by RW, C ₂With R ₃Constitute delay circuit.At motor starting, power-supply fluctuation, moment avoids shutting down phenomenon when transshipping.Work as electromotor overload, overtension is low excessively, during the electrical machinery fault, three power line electric currents exceed permissible value, it is excessive to be series in the b line protector electric current, and control contactor CJ disconnects motor power, when the motor side a or the c phase failure or mains side a or c short of electricity cause single-phase operation, the b line current exceeds permissible value, and the excessive control contactor CJ of protector electric current disconnects motor power; When the motor side b phase phase failure or the short of electricity of power supply b phase, b line no current, the protector short of electricity, internal relay discharges, J _KControl contactor CJ disconnects motor power; During the motor side short circuit, contactor coil decompression automatic disconnection motor power, protection motor.

The effect of the utility model single line motor protection starter is simple in structure, detects in three motor power lines, obtains control signal, and mono signal detects, and operating current is accurate, and repeatability is good, and cost is low, and is multiple functional, stable and reliable for performance.

The utility model single line motor protection starter will be further described in conjunction with the accompanying drawings.

Fig. 1 is an outer casing construction drawing of the present utility model.

Fig. 2 is a structural representation of the present utility model.

Fig. 3 is a circuit diagram of the present utility model.

1-shell 2-A.C. contactor CJ 3-single line protector K ₁-starting button K ₂-stop button

With reference to Fig. 1,2,3, the utility model protecting starter of single-wire motor, it is by starter shell (1) starting button K to be set₁With stop button K₂, the single line protector is by transformer B and diode D₁－D ₅With resistance R₁－R ₃, triode BG₁With BG₂, capacitor C₁With C₂, potentiometer R_WThree terminal integrated voltage stabilizer 7812 consists of with relay J; single line protector (3) electronic component device is on printed circuit board (PCB); the circuit board transformer consists of the single line protector; single line protector (3) is series in three power line one lines of motor, and A.C. contactor (2) coil connects on other two lines. Motor operation, transformer B is elementary to have electric current to flow through, secondary feel corresponding alternating voltage, voltage is through D₁To D₄Rectification and C₁Filtering obtains DC voltage V_C1, voltage-stablizer 7812 is with V_C1After the voltage stabilizing, output 12V stable DC voltage, the power supply of supply relay J, resistance R₁And R_WSeries loop is with V_C1Send BG after the sampling₁Base stage. During fault-free, sampling voltage is less than 0.6V, BG₁Be in cut-off state, R₂With D₅To C₂R is passed through in charging₃To BG₂Supply with base current, BG₂Saturation conduction, relay J adhesive, J_KControl A.C. contactor CJ adhesive, the normal operation of motor energising. During the elementary no current of transformer B, secondary no alternating voltage output, single line protector (3) circuit does not have electricity, and relay J discharges. Transformer B primary current is excessive, V_C1Raise R₁With R_WBG is sent in sampling₁Base voltage surpasses 0.6V, BG₁Saturation conduction, D₅Anodal shorted to earth, C₂Pass through R₃To BG₂The base stage discharge, BG₂Continue conducting. 3-5 C in second₂Discharge off, BG₂Lose the base current cut-off, relay J discharges. The supercurrent working value is by R_WRegulate C₂With R₃Consist of delay circuit, at motor starting, power-supply fluctuation, moment avoids shutting down phenomenon when transshipping. Three power lead currents exceed permissible value, and it is excessive to be series in the b line protector electric current, and control contact ac device CJ disconnects motor power. When the disconnected phase of motor side a or c or mains side a or c short of electricity caused single-phase operation, the b line current exceeded permissible value, and the excessive control A.C. contactor of protector electric current CJ disconnects motor power; when motor side b breaks phase or the short of electricity of power supply b phase mutually, b line no current, protector short of electricity; internal relay discharges, J_KControl A.C. contactor CJ disconnects motor power, during the motor side short circuit, and ac contactor coil decompression automatic disconnection motor power, protection motor.

The embodiment of the utility model single line motor protection starter, it is by on the starter shell (1) starting button K being set ₁With stop button K ₂, single line protector (2) is by instrument transformer B and diode D ₁-D ₅With resistance R ₁-R ₃, triode BG ₁With BG ₂, capacitor C ₁With C ₂, potentiometer R _W, three terminal integrated voltage stabilizer 7812 constitutes with relay J.Diode D ₁-D ₄Connect into bridge rectifier, it is secondary that input connects instrument transformer, capacitor C ₁Be connected output, R ₁And R _WAfter the series connection and at rectifier output end, sampled signal is by R _WSlide head send BG ₁Base stage, three terminal integrated voltage stabilizer 7812 inputs connect rectifier output end, and output provides power supply to relay J, BG ₁Grounded emitter, collector electrode string R ₂Connect pressurizer 7812 outputs, D ₅The anodal BG that connects ₁Collector electrode, negative pole series connection R ₃Connect BG ₂Base stage, C ₂Two ends are ground connection and D respectively ₅Negative pole, BG ₂Grounded emitter, collector electrode string relay coil connects pressurizer 7812 outputs.Instrument transformer B is elementary to be series in three arbitrary lines of power line of motor, and ac contactor coil connects on other two lines.Button K ₁And K ₂Connect the ac contactor coil loop, be installed on shell (1) front panel.A, b, three power lines of c connect the A.C. contactor upper end, and motor line a directly is connected the A.C. contactor lower end with c, lead to motor after b string instrument transformer B is elementary.Electronic component in the protector is connected on the printed circuit board.Operating current numerical value is by R _WRegulate, time of delay is by C ₂And R ₃Numerical value is determined.

Claims (3)

1, a kind of single line motor protection starter it be by A.C. contactor (2) and single line protector (3) and starting button K ₁And stop button K ₂Constitute, it is characterized in that single line protector (3) is by instrument transformer B and diode D ₁-D ₅With resistance R ₁-R ₃, triode BG ₁With BG ₂, capacitor C ₁With C ₂, potentiometer R _W, three terminal integrated voltage stabilizer 7812 constitutes with relay J.

2, according to the described single line motor protection of claim 1 starter, it is characterized in that diode D ₁-D ₄Connect into bridge rectifier, it is secondary that input connects instrument transformer, capacitor C ₁Be installed on output, R ₁And R _WAfter the series connection and at rectifier output end, three terminal integrated voltage stabilizer 7812 inputs connect rectifier output end, BG ₁Grounded emitter, collector electrode string R ₂Connect pressurizer 7812 outputs, D ₅The anodal BG that connects ₁Collector electrode, negative pole series connection R ₃Connect BG ₂Base stage, C ₂Two ends are ground connection and D respectively ₅Negative pole, BG ₂Grounded emitter, collector electrode string relay coil connects pressurizer 7812 outputs.

3,, it is characterized in that instrument transformer B is elementary to be series in three power line one lines of motor that ac contactor coil connects on other two lines according to the described single line motor protection of claim 1 starter.

Images