CN2244260Y - Phase-interruption and overload protective device for three-phase ac motor - Google Patents
Phase-interruption and overload protective device for three-phase ac motor Download PDFInfo
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- CN2244260Y CN2244260Y CN 95233765 CN95233765U CN2244260Y CN 2244260 Y CN2244260 Y CN 2244260Y CN 95233765 CN95233765 CN 95233765 CN 95233765 U CN95233765 U CN 95233765U CN 2244260 Y CN2244260 Y CN 2244260Y
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- circuit
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- detection circuit
- overload
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Abstract
The utility model relates to a phase-interruption and overloading protective device for a three-phase AC motor. The utility model is composed of a base, a middle seat, an upper cover and an electronic circuit; the electronic circuit is composed of an electric current detection circuit, a rectification circuit, a phase interruption detection circuit, an overloading detection circuit, a relay control circuit and a power circuit, and the electric current detection circuit is composed of three inductance transformers which are respectively arranged in three hollow bodies of the base and the middle seat; an electric current transformer is provided with a primary coil which is made of main circuit flat copper wires and two groups of secondary coils. The utility model can be exchanged with a thermal relay and has reliable functions of phase interruption protection and overload protection, and the utility model can be used for the control and protection of the three-phase AC motor.
Description
The utility model relates to the protection electrical equipment of three-phase alternating-current motor, and the phase failure and the overload protection of more clearly saying so and being used for three-phase alternating-current motor are with the phase failure and the overload protective device of the three-phase alternating-current motor of avoiding damaging motor.
The protector of three-phase alternating-current motor up to now can be divided into two types basically.A kind of is simple type, and its function singleness can only be carried out open phase protection or overload protection.Another kind is a complexity, its complex circuit, and volume is bigger.Their common drawback is that protector needs external power supply, and consumed power is bigger, and failure rate is higher, can not directly exchange with the RJ type thermal relay that generally uses now.Use RJ type thermal relay widely can finish the task of overload protection now, but will adjust setting current when using, can not automatically reset, very inconvenient.The patent No. is that 922403325 the three-phase alternating-current motor phase failure and overload protective device have overcome above-mentioned shortcoming, but its reliability still remains to be improved.
The purpose of this utility model is to overcome above-mentioned shortcoming and defect, and a kind of overload and two kinds of defencive functions of the phase failure of having concurrently are provided, and uses reliably, can automatically reset, and does not need external power supply, and consumed power is less; Can exchange the three-phase alternating-current motor phase failure and overload protective device easy to use with present widely used RJ type thermal relay.The utility model is the improvement of No. 922403325 patents.
In order to achieve the above object, the utility model by housing, be installed in electronic circuit and the fastening in the housing, the loam cake that is fastened on the housing is constituted.Housing is made of middle seat and base two parts again.The base side has three binding posts, so that be connected (being the normally closed normally opened contact of relay in fact) with the main control loop of three-phase alternating-current motor.Base bottom has so as to being fixed in the porose footing on the distribution board and the cover plate of side.Electronic circuit is installed at the base middle part.Middle seat and loam cake have three cavitys that can fasten three current transformers, have three groups of binding posts that can be connected with the three-phase main circuit on the middle seat.Compare with No. 922403325 patents, structure of the present utility model is three layers, and except that loam cake, base, the centre has added seat in one deck.This structure is convenient to installation, the location of current transformer, and its electronic circuit still can be with No. 922403325 patents.
Current transformer of the present utility model can be by primary coil, be enclosed within iron core on the primary coil, be sleeved on two secondary coil skeletons on the iron core, two secondary coils that are wrapped on the secondary coil skeleton are formed.Primary coil is made of the flat type copper wire on the seat in being fastened on, and its two ends have the terminal screw that replaces the binding post that is connected with the three-phase main circuit.The punching current transformer of No. 922403325 patent uses is replaced with above-mentioned current transformer, and this is another improvements of the present utility model.Iron core is made of silicon steel sheet.As one group in two secondary coils open circuit is not connect, still use the electronic circuit of No. 922403325 patents, the utility model is then not basic to be improved, and is as primary coil (being that primary coil is a circle in fact) with the flat type copper wire on the seat in being fastened on.In addition, primary coil is simultaneously as main circuit, and its two ends have the terminal screw that is connected with main circuit.
But the utility model also can adopt reliable more multiple electronic circuit.Because three current transformers of the utility model have two groups of secondary coils, can join with electronic circuit respectively.Such as, electronic circuit can be by the three-phase alternating current current detection circuit that links to each other with one group of secondary coil of three current transformers, link to each other with current detection circuit and to carry out the rectification circuit of rectification, filtering, amplitude limiting processing, open-phase detection circuit that links to each other with rectification circuit and overload detection circuit, bang-bang circuit that links to each other with overload detection circuit with open-phase detection circuit and then link to each other with the main control loop of three-phase alternating-current motor and the DC-stabilized circuit that links to each other with another group secondary coil of three current transformers constitute.Compare with No. 922403325 patents, the basic structure of electronic circuit is identical with basic principle.But because of current transformer has two groups of secondary coils, its second group special joins with power circuit, and power supply is stable, reliably.This current transformer is made primary coil by a circle flat type copper wire, in the cavity of seat and loam cake, is convenient to assembling in just can installing, being fastened on.
All the corresponding size with RJ type thermal relay is identical for overall dimension of the present utility model, the size that is fixed in the fixing hole of the porose footing on the distribution board, position, the hole size of screw that is used to install binding post and the physical dimension of screw self, thereby has guaranteed the exchange of it and RJ type thermal relay.
The three-phase alternating current current detection circuit is formed with one group of primary coil of three current transformers.Its number of primary turns is 1 circle.Change the secondary number of turn, can adapt to the detection of the different electric currents of different capabilities motor.
Open-phase detection circuit is made up of two four-input terminal NAND gate circuit and the delay circuit that is made of a resistance, diode and electric capacity that is connected between the two.When the phase failure occurring, it is 0V that the output of rectification circuit has a phase voltage, first NAND gate circuit output high level " 1 ".This high level after the delay circuit time-delay that resistance, diode and electric capacity are formed, is imported second NAND gate circuit again, makes it be output as low level " 0 ".The control relay circuit that this low level input NE555 time-base circuit and relay constitute; make NE555 the 3rd pin output be " 0 ", relay gets electronic work, and its normally closed interlock that is connected in the main control loop disconnects; three-phase alternating-current motor is disconnected, realized open phase protection.The delay circuit that resistance, diode and electric capacity are formed is the misoperation during for fear of electric motor starting.
Rectification circuit is made up of three diode three phase rectifiers and three groups of resistance, electric capacity, voltage stabilizing didoe parallel circuitss.Resistance, electric capacity and voltage stabilizing didoe parallel circuits play slicing, filtering and amplitude limit effect.Three-phase output inserts first NAND gate circuit of open-phase detection circuit simultaneously.
Bang-bang circuit is made of a NE555 time-base circuit and a relay that is connected its output.A normally-closed contact of relay is connected in the main control loop of three-phase alternating-current motor.This point front is addressed.
Overload detection circuit is made up of three diodes that link to each other with rectification circuit, resistance capacitance divider, encoder, resistance capacitance starting delayer and MA741 voltage comparator.Its output signal and then links to each other with two inputs of the NE555 time-base circuit of bang-bang circuit again after the time-delay of diode and capacitance-resistance overload delayer.Overload detection circuit is taken out overload signal voltage through dividing potential drop, through delay circuit voltage signal is imported the 6th pin of NE555 again.When this voltage signal surpasses
V
Cc(V
Cc=6V) time, the 3rd pin of NE555 is output as " 0 ", and the actuating of relay has realized overload protection.Regulate the R of encoder
9～R
18, can adjust overload current.Delay circuit is the misoperation that causes for the impulse current that prevents electric motor starting and when overload.
Electric current by another group secondary coil induction is imported 7808 voltage stabilizing circuit voltage stabilizings again after full-wave rectification, just exportable+8V DC voltage-stabilizing electricity, supplies with above-mentioned each circuit and uses.At 7808 outputs and connect a capacitor, play the energy storage effect.
Task of the present utility model comes to this and finishes.
The utility model provides a kind of overload and two kinds of defencive functions of the phase failure of having concurrently, uses reliably, can automatically reset; can exchange with present widely used RJ type thermal relay; easy to use, do not need external power supply, the low three-phase alternating-current motor phase failure and the overload protective device of self power consumption.After the use, motor has reduced 40～70% because of the damage that the phase failure or overload cause.It can be widely used in three-phase alternating-current motor control, the protection loop in.
Below in conjunction with embodiment and accompanying drawing thereof the utility model is done further explanation.
Figure l is the structural representation of the utility model embodiment.
Fig. 2 is the electronic circuit schematic diagram of embodiment.
Shown in Figure 1, the utility model embodiment is made of base 1, electronic circuit 2, loam cake 3 and middle seat 4.In the cavity of loam cake 3 and middle seat 43 current transformers 5 are installed.Binding post 6 is installed on the base 1, and the bottom has porose 7 footing 8.Current transformer 5 is made up of 1 circle primary coil 9, iron core 10, two secondary coil skeletons 11, two secondary coils 12 and 13.Primary coil 9 is made of the flat type copper wire on the seat 4 in being fastened on, 1 circle, and two ends have terminal screw 14.
Shown in Figure 2, the electronic circuit 2 of present embodiment is made of the current detection circuit of forming with three current transformers 5 15, rectification circuit 16, open-phase detection circuit 17, overload detection circuit 18, bang-bang circuit 19 and power circuit 20.Open-phase detection circuit 17 by two four-input terminal NAND gate circuit 21 and 22 and the delay circuit that constitutes by resistance, diode, electric capacity constitute.Bang-bang circuit 19 is made of a NE555 time-base circuit 23 and relay 24, and a normally-closed contact 25 of relay 24 is connected in the main control loop 27 of three-phase alternating-current motor 26.Overload detection circuit 18 is made of diode, voltage divider 28, encoder 29, starting delayer 30, voltage comparator 31, overload delayer 32.
Present embodiment is used for the phase failure and the overload protection of three-phase alternating-current motor, can exchange with RJ type thermal relay, and easy to use, reliable, the motor spoilage has descended 40%.
Claims (3)
1, a kind of three-phase alternating-current motor phase failure and overload protective device; it by housing, be installed in electronic circuit and the fastening in the housing, the loam cake that is fastened on the housing is constituted; it is characterized in that said housing is made of middle seat and base two parts; have three binding posts on the base; the bottom has so as to being fixed in porose footing and the cover plate on the distribution board; middle seat and loam cake have three cavitys that can fasten three current transformers, have three groups of binding posts that can be connected with the three-phase main circuit on the middle seat.
2, according to the described three-phase alternating-current motor phase failure of claim 1 and overload protective device; it is characterized in that said current transformer by primary coil, be enclosed within iron core on the primary coil, be sleeved on two secondary coil skeletons on the iron core, two secondary coils that are wrapped on the secondary coil skeleton are formed; primary coil is made of the flat type copper wire on the seat in being fastened on, and its two ends have the terminal screw that replaces the binding post that is connected with the three-phase main circuit.
3; according to the described three-phase alternating-current motor phase failure of claim 2 and overload protective device; it is characterized in that said electronic circuit is by the three-phase alternating current current detection circuit that links to each other with one group of secondary coil of three current transformers; link to each other with current detection circuit and to carry out rectification; filtering; the rectification circuit of amplitude limiting processing; open-phase detection circuit that links to each other with rectification circuit and overload detection circuit, bang-bang circuit that links to each other with overload detection circuit with open-phase detection circuit and then link to each other with the main control loop of three-phase alternating-current motor and the DC-stabilized circuit that links to each other with another group secondary coil of three current transformers constitute.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 95233765 CN2244260Y (en) | 1995-05-04 | 1995-05-04 | Phase-interruption and overload protective device for three-phase ac motor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 95233765 CN2244260Y (en) | 1995-05-04 | 1995-05-04 | Phase-interruption and overload protective device for three-phase ac motor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2244260Y true CN2244260Y (en) | 1997-01-01 |
Family
ID=33877843
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 95233765 Expired - Fee Related CN2244260Y (en) | 1995-05-04 | 1995-05-04 | Phase-interruption and overload protective device for three-phase ac motor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN2244260Y (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104218823A (en) * | 2014-08-14 | 2014-12-17 | 河南开启电力实业有限公司 | Current mutual inductance type three-phase rectifier power supply device |
-
1995
- 1995-05-04 CN CN 95233765 patent/CN2244260Y/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104218823A (en) * | 2014-08-14 | 2014-12-17 | 河南开启电力实业有限公司 | Current mutual inductance type three-phase rectifier power supply device |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |