CN2148421Y

CN2148421Y - Full protector for motor

Info

Publication number: CN2148421Y
Application number: CN 93233093
Authority: CN
Inventors: 李海泉
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-01-18
Filing date: 1993-01-18
Publication date: 1993-12-01
Anticipated expiration: 2003-01-18

Abstract

The utility model relates to a full protector for the motor comprising a phase failure protective circuit and an over-current and overload protective circuit. The phase failure protective circuit can trigger the thyristor to switch on through a three phase capacitor sampling circuit, a rectifying circuit, a delaying circuit and a tank circuit. A relay to control the motor is serially connected with an anode return circuit of the thyristor. The over-current and overload protective circuit can serially connect a simulation motor with the power supply phase wire of the motor, and the full protector for the motor can control a contactor of the motor through a relay to realize the protection. The full protector for the motor has the advantages of simple structure, low cost, high safety, reasonable design and multi-function.

Description

Full protector for motor

The utility model relates to a kind of emergency protective device, particularly to the protective device of motor.

Various electromechanical equipments all be unable to do without motor; and motor is because blown fuse; reasons such as contacts of contactor burns out cause phase shortage and motor termination broken string; machinery is stuck; damage of bearings; reasons such as overtension cause overcurrent overheat and to burn out motor countless; thereby the motor heat protector of external for example West Germany Siemens Company production is just adopted the protection to motor widely; it is that thermistor is embedded in the motor stator winding; be connected to protector in the control cubicle by the dedicated transport line; domestic also the development utilized current transformer; mutual induction of voltage sensing phase shortage; over-current signal; cut off motor power through amplifying circuit pusher motor type relay control contactor; above-mentioned technology has the certain protection effect to motor; but complex structure mostly; the production cost height; the former has increased the difficulty of motor technique for coiling, is often given it up after the maintenance.

The purpose of the utility model aims to provide a kind of existing phase failure protection function, have again the over-current and-load defencive function, simple in structure, production cost is low, safe and reliable, installation and maintenance motor protector easily.

Fig. 1 is the utility model circuit structure diagram.

Technical solution of the present utility model is: this motor protector is made up of open-phase protection circuit, over-current and-load holding circuit two parts; they all cut off the electricity supply to realize protecting by control motor contactor, and open-phase protection circuit is with three electric capacity (C₁、C ₂、C ₃) end, be connected to respectively and directly enter the motor three-phase power line, after the other end links together, by rectification (ZL), time-delay (C₄、R ₁), energy storage (R₂、C ₅) remove to trigger controllable silicon (KG); relay line bag (J) series connection is connected in the anode loop of controllable silicon (KG); and the normally-closed contact of relay (J) is serially connected in the line bag loop of motor contactor (CQ), and the over-current and-load holding circuit is with a simulated machine (RJ, R₃, BW) lead (RJ) be serially connected in the phase line that directly enters motor (BB '), phase line upper end (B) is also by current-limiting resistance (R₄), diode (ZD₂) after be connected to rectification (ZL) output plus terminal of above-mentioned open-phase protection circuit.

Below in conjunction with accompanying drawing the technical solution of the utility model is described in further detail:

As shown in Figure 1, this motor protector is made up of open-phase protection circuit, overcurrent and overheating protection circuit two parts, and open-phase protection circuit is by electric capacity the three phase mains that motor directly enters to be carried out voltage sampling, and by its neutral point output, capacitor C ₁, C ₂, C ₃One end connects the three-phase power line that directly enters motor respectively, and the other end connects together, and is connected to the input of rectifier (ZL), and the output two ends of rectifier (ZL) are parallel with capacitor C ₄, resistance R ₁, R ₂With C ₅The series circuit of series circuit, controllable silicon (KG) and relay (J), resistance R ₂With capacitor C ₅The connection mid point be connected to the trigger electrode of controllable silicon (KG), R by voltage-stabiliser tube WY ₂, C ₅The connection mid point also by diode ZD ₁Be connected to the power positive end of rectifier output, when the three phase mains balance operate as normal of motor, capacitor C ₁, C ₂, C ₃Connection neutrality be output as 0, as lacking one mutually or two-phase power supply, capacitor C ₁, C ₂, C ₃Tie point produce voltage immediately, this voltage after rectifier (ZL) rectification, output certain value voltage, through the time-delay (C ₄, R ₁), energy storage (R ₂, C ₅) after; and the conducting of removing triggering and conducting controllable silicon (KG), controllable silicon (KG) by voltage stabilizing didoe (WY); make the relay line bag (J) that is connected on controllable silicon (KG) anode obtain operating current; relay (J) adhesive; cut off A.C. contactor (CQ) the line bag power supply of motor work, contactor (CQ) discharges, and cuts off the motor three phase mains; obtain protection, the over-current and-load protective circuit then is with a simulated machine (RJ, R ₃, BW) lead (RJ) be connected on and directly enter in the electronic power supply phase line (BB '), simulated machine is by lead (RJ), conductor resistance R ₃And the thermoswitch (BW) that is installed in lead (RJ) limit forms, and periphery can be carried out certain encapsulation, conductor resistance (R ₃) being connected to motor power phase line B end behind the semifixed resistor (TR) of also can connecting, the B end is also by current-limiting resistance, diode (ZD ₂) be connected to the output plus terminal of rectifier (ZL), thermoswitch (BW) end and resistance R ₃, the zero line loop connects the other end and R ₄, ZD ₂Tie point connect, during electric motor normal working, its power line electric current is by the flow through lead (R of simulated machine of B point ₅) to B ', enter motor again, its voltage drop almost can be ignored, the heating normal as operating current, that lead (RJ) can be not too many, as motor because overload, machinery blocks, when reasons such as damage of bearings cause electric current to increase, the simulated machine lead (RJ) of flowing through between the BB ' just can generate heat rapidly, and its result can make thermoswitch BW flick, and B point current potential is through current-limiting resistance R ₄, diode ZD ₂Add to rectifier (ZL) output plus terminal, through time-delay, after the energy storage; trigger the controllable silicon conducting, A.C. contactor (CQ) line bag power supply is cut off in relay (J) adhesive; contactor (CQ) discharges, and cuts off the working power of whole motor, realizes the protection to motor; simulated machine can use separately; thermoswitch BW directly is serially connected in the motor contactor line bag loop, as uses two simulated machines, be serially connected in respectively in two phase lines of motor; then protection is stronger, complete.Be actual electric elements of this protector and connecting relation thereof in the frame of broken lines in the accompanying drawing 1; the fuse on top (RDK), push switch (TA, QA), contactor (CQ) manually boot, stop control loop for motor commonly used; but when the startup of motor stops by the automatic control of other electrical equipment realizations of control cubicle (shown in dotted line), then can connect an electric capacity (C at the input of rectifier (ZL) ₆), the normally opened contact (J of relay (J) ₂) series arm, be connected to the mains terminals (shown in dotted line) that motor start-up stops control loop thereafter again, can prevent like this A.C. contactor (CQ) suction, put frequent movement, to guarantee the normal use of this protector.

The existing phase failure protection function of the utility model has the over-current and-load defencive function again, and is simple in structure, production cost is low, safe and reliable, installation and maintenance convenient, and are reasonable in design, are skillfully constructed, multiple functional, can extensively promote the use of.

Claims

1, a kind of motor protector is characterized in that being made up of open-phase protection circuit, over-current and-load protective circuit two parts, and open-phase protection circuit is with three electric capacity (C ₁, C ₂, C ₃) end is connected to respectively and directly enters the motor three-phase power line, after the other end links together, by rectification (ZL), time-delay (C ₄, R ₁), energy storage (R ₂, C ₅) remove to trigger controllable silicon (KG); relay line bag (J) is connected in the anode loop of controllable silicon (KG); and the normally-closed contact of relay (J) is serially connected in the line bag loop of motor contactor (CQ), and the over-current and-load protective circuit is with a simulated machine (RJ, R ₃, BW) lead (RJ) be serially connected in the phase line that directly enters motor (BB '), phase line upper end (B) is also by current-limiting resistance (R ₄), diode (ZD ₂) after be connected to rectification (ZL) output plus terminal of above-mentioned open-phase protection circuit.

2,, it is characterized in that simulated machine (RJ, the R of over-current and-load protective circuit according to the motor protector of claim 1 ₃, BW) by lead (RJ), conductor resistance (R ₃) and the thermoswitch (BW) that is installed in lead (RJ) limit form, periphery is carried out certain encapsulation.

3,, it is characterized in that the conductor resistance (R of over-current and-load protective circuit according to the motor protector of claim 1 ₃) be connected to motor power phase line upper end, thermoswitch (BW) end and resistance (R behind the semifixed resistor (JR) of also can connecting ₃), the zero line loop connects the other end and R ₄, ZD ₂Tie point connect.

4,, it is characterized in that when the startup of motor stops by the automatic control of other electrical equipment realizations of control cubicle, then can connecting an electric capacity (C at the input of rectifier (ZL) according to the motor protector of claim 1 ₆), the normally opened contact (J of relay (J) ₂) series arm, be connected to the power end that motor start-up stops control loop thereafter again.