CN2037885U

CN2037885U - Complete motor protector

Info

Publication number: CN2037885U
Application number: CN 88218916
Authority: CN
Inventors: 王富元; 伍占禧
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-09-17
Filing date: 1988-09-17
Publication date: 1989-05-17

Abstract

The utility model provides an overheat protection device of the motor and the electric appliance, comprising a solid electronic relay (7), an electromagnetic trip (8), the thermistor (9) of the positive temperature coefficient which is connected with the electromagnetic trip in series, and the switching-type thermistor (2) of the positive temperature coefficient which is connected with the control end of the solid electronic relay through a rectification circuit which is composed of a rectifying diode (3) and a filtering capacitor (4). Because the ampacity of the electromagnetic winding (10) of the electromagnetic trip (8) is big, and the attraction voltage is low, the utility model has the advantages of small size, low cost, convenient installation. The overheat protection device of the motor and the electric appliance designed according to the advantaged has small volume, little connecting line, electricity saving, and the abilities of preventing the great fluctuation of the fluctuation electric network and preventing the interference of the strong signal.

Description

Complete motor protector

The utility model belongs to the overheat protective technology of motor and electrical equipment.

The motor of electronic type and electrical equipment overtemperature protection system in the prior art; the RZK thermistor thermostat produced of Hongming Raido Equipment Factory for example is made up of the power circuit that contains Industrial Frequency Transformer, comparison circuits for triggering, electromagnetic relay and the thermistor of experiencing the RZK positive temperature coefficient of variations in temperature usually.Make that the protective device volume is big, cost is high, line is many, power consumption is many, installation is inconvenient, anti-power network fluctuation ability owing to contain the existence of the power circuit of Industrial Frequency Transformer; and the comparison circuits for triggering of forming by simple linear or switching circuit, the interference that is subjected to spurious signal again easily causes misoperation.

The purpose of this utility model is intended to overcome the shortcoming of the overtemperature protection system of the motor of existing electronic type and electrical equipment, provides that a kind of volume is little, cost is low, line is few, the power consumptive province, easy for installation the motor that stronger anti-power network fluctuation and spurious signal disturb and the overtemperature protection system of electrical equipment is arranged.

The technical task that the utility model solved at first is illustrated by accompanying drawing 1.(7) are the pointed solid-state electronic relays of CNZL851050 in the accompanying drawing 1, (8) magnetictrip of forming by solenoid (10) and the break contact (11) that has disconnected self-locking to contain rest button (8), (9) be the semistor of electric current with solenoid (9) of time-delay restricted passage electromagnetic trip (8), (3) be rectifier diode, (4) be filter capacitor, rectifier diode (3) and filter capacitor (4) are formed rectification circuit, and (2) are the switching mode semistors.It is installed in three phase windings or controlled temperature environment of motor as temperature-sensing element.In this combination; magnetictrip (8) and thermistor (9) series connection; and then be connected on the output a of solid-state electronic relay (7); the other end of thermistor (9) is connected with the right-hand member of the break contact (11) of magnetictrip (8); the input of the rectification circuit of being made up of rectifier diode (3) and filter capacitor (4) is connected on control end C, the D of solid-state electronic relay (7), and above being connected constituted the main body (1) of overtemperature protection system.Be connected as the switching mode semistor (2) of temperature sensor on the dc output end (14), (15) of rectification circuit.In order to reduce the volume of whole device, 5 to 10 times of designing routinely of the ampacity of the solenoid (10) of magnetictrip (8) are chosen, and its pick-up voltage is chosen by 0.2 to 0.5 times of solid-state electronic relay rated operational voltage.

Further specify outside the connection and the course of work of the present utility model below by accompanying drawing 1.The secondary operation loop of motor or electrical equipment by the starting button (5), stop button (6), ac contactor coil (17) is formed; they are connected in the two-phase (13) and (20) of power frequency supply by the break contact (11) of magnetictrip (8), and power end one end of overtemperature protection system main body (1) is connected on the zero-power line N by the auxiliary normally open contact (18) of A.C. contactor.By above outside the connection as can be seen, it is outside to connect tradition to have an electronic type overtemperature protection system line that contains power frequency supply power of transformer circuit few.Circuit carries out work by following process:

Press starting by (5), contactor coil (17) gets electric, auxiliary normally open contact (18) closure, and overtemperature protection system main body (1) gets electric and in running order.If motor or electrical equipment are in normal operating conditions, switching mode semistor (2) is in low state, solid-state electronic relay (7) is turn-offed, electromagnetic trip (8) break contact (11) remains closed, and motor or electrical equipment are kept operate as normal.If because electrical network phase shortage; motor overload; electric machine temperature rise is transfinited motor windings short interruption etc. or the electric controlled ambient temperature transfinites; switching mode positive temperature coefficient temperature-sensitive electricity (2) resistance dramaticallys increase; solid-state electronic relay (7) is open-minded; the break contact (11) of magnetictrip (8) blocks and self-locking immediately; A.C. contactor discharges; its normally open contact (18) disconnects; the utility model quits work, thereby realizes the overtemperature protection to motor or electrical equipment.Fault is pressed the rest button of magnetictrip (8) after getting rid of, and overtemperature protection system of the present invention is in again treats operating state.

Under the fault of special circumstances; can not thread off by normal protection process if adhesion has taken place relay contact; because temperature rise is directed at resistance and strengthens by continuous current to be connected on semistor (9) on the magnetictrip (8); thereby limited electric current, protected its unlikely burning and reach the purpose that reduces volume and improve moving disconnected characteristic by magnetictrip (8).

In the inefficacy of solid-state electronic relay (7) its mainly to distribute be the AC contact-less switch break-through; when its break-through; the break contact (11) of magnetictrip (8) is moving disconnected; the A.C. contactor fail to start, thus prevent that motor or electrical equipment from moving under unshielded situation.

It is little to have a volume according to the electronic type electric motor of such scheme manufacturing or electrical equipment overtemperature protection system, and cost is low, line is few, power consumptive province, easy for installation and higher anti-power network fluctuation and the interference performance of spurious signal.

First embodiment of the present utility model is given by accompanying drawing 2, and it is the overheated holding device of a general motor or electrical equipment.This figure provides in 1 to 15 ratio.

Accompanying drawing 3 has provided second kind of embodiment of the present utility model, it is integrated with connecting terminal of motor, wherein (18) are the binding posts of three windings of three-phase induction motor, and (19) are six joints of these windings.If switching mode semistor of the present utility model (2) is embedded in the motor windings in advance, this motor then has from overheat protective function, thereby makes the overtemperature protection system of motor that simplification is installed.Certainly line should make corresponding changes; for example the link (12) with overheat protector main body (1) directly is connected on the zero line N, and the right-hand member of semistor (9) directly is connected on the wiring pile crown of arbitrary phase inlet wire of three-phase alternating current of motor connector lug (19).

Claims

1; a kind of motor; the overtemperature protection system of electrical equipment is characterized in that by solid-state electronic relay (7); be connected the magnetictrip (8) of the output a of solid-state electronic relay (7); the positive temperature coefficient heat-sensitive of the current limliting of connecting electricity (9) with magnetictrip; be connected on solid-state electronic relay control end C; the rectification circuit of forming by rectifier diode (3) and filter capacitor (4) of D and be connected rectification circuit output end (14); (15) switching mode positive temperature coefficient temperature-sensitive electricity (2) is formed.

2, motor according to claim 1, electrical equipment overtemperature protection system is characterized in that 5 to 10 times that the ampacity of the solenoid (10) of magnetictrip (8) designs are routinely chosen, and its pick-up voltage is chosen by 0.2 to 0.5 times of the rated operational voltage of solid-state electronic relay (7).