CN2752947Y

CN2752947Y - Electromagnetic induction relay and relay protecting device constituted with the same

Info

Publication number: CN2752947Y
Application number: CN 200420095689
Authority: CN
Inventors: 李弦
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-11-26
Filing date: 2004-11-26
Publication date: 2006-01-18
Anticipated expiration: 2014-11-26

Abstract

The utility model relates to an electromagnetic induction relay and a relay protection device thereof, which belongs to the technical field of relays and overload protection devices, and comprises an electromagnetic induction coil, a relay switch and a casing. The utility model is characterized in that the relay switch is a dry reed pipe, a high-temperature-resistant insulating sleeve which is tightly attached to an outer wall of the dry reed pipe is wound by the coil, and the three components are sealed in the casing. Contacts in the dry reed pipe can be attracted or disconnected by magnetic force which is produced when current in the coil exceeds a setting value. Various electromagnetic induction relays which have different coil amount, different coil arrangement and different coil winding directions can be widely used for manufacturing various overload protection devices for preventing over current, short circuit, electrical leakage, etc. Compared with the prior art, the utility model has the advantages of simple circuit, small size, fast response speed, low cost, good reliability and long service life.

Description

Electromagnetic induction relay reaches by its protective relaying device that constitutes

Technical field

The utility model relates to relay and protective relaying device technical field, and particularly a kind of electromagnetic induction relay reaches by its protective relaying device that constitutes.

Background technology

Electromagnetic induction relay is extensive use of in various circuit, and conventional relay is made of solenoid, electromagnet arrangement of clutch and contact assembly.Shortcoming is that volume is big, energy consumption is high, response speed is slow, manufacturing cost is high; make electrical control gear with it; as load overcurrent, short circuit, electric leakage and threephase load phase-lacking protective device, have complex circuit, response speed is slow, volume is big, production cost is high shortcoming.

The utility model content

Task to be solved in the utility model, one provides a kind of novel electromagnetic induction relay, and this relay has that volume is little, energy consumption is low, response speed is fast, advantage of low manufacturing cost; The 2nd, utilize this relay to provide the novel protective relaying device that several circuits are simple, response speed is fast, volume is small and exquisite, cost is low at load overcurrent, short circuit, electric leakage and threephase load phase shortage.

Task of the present utility model is achieved through the following technical solutions:

A kind of electromagnetic induction relay, comprise electromagnetic induction coil, relay switch and shell, it is characterized in that described relay switch is a tongue tube, on the tongue tube outer wall, be glued with a high-temperature insulation sleeve pipe, described coil is around thereon, and shell is sealed in therebetween and reserves the lead-in wire of electromagnetic induction coil and tongue tube with the three, and the magnetic force that is produced when electric current surpasses setting value in the coil can make contact adhesive or the disconnection in the tongue tube.

Further design is to be parallel with shunt at the two ends of described coil, is suitable for using in big load load, and shunt is made of the pair of electrodes plate that links to each other with described coil and at least one fen current wire being connected in therebetween.

Further design is that described coil has two, the both end sides of the same tongue tube that is placed in, and the number of turn of two coils is identical, around on the contrary, constitute a pair of coil current balanced type electromagnetic induction relay.

A kind of earth leakage protective device that constitutes by the utility model electromagnetic induction relay, it is characterized in that a mains switch is arranged in this earth leakage protective device, order is being connected in series second coil in one group of normally-closed contact, load and two coils of first coil in described two coils, a relay between the two poles of the earth of mains switch, has constituted the current supply circuit of load; Between the tie point of the tie point of the mains switch and first coil and first coil and normally-closed contact, be parallel with a series connection control branch road that constitutes by one group of normally opened contact of described tongue tube and described relay; Between the tie point of the tie point of normally opened contact and tongue tube and second coil and load, be connected to the outage self-insurance that constitutes by a described relay and a normally closed button, the control branch road resets; During electric leakage, current imbalance in first coil, second coil, make the magnetic force imbalance that is produced, the tongue tube adhesive, relay gets, its normally-closed contact disconnects, the load power-off protection, and its normally opened contact is closed and constitute the outage self-keeping circuit with first coil, normally closed button, relay and second coil; Press normally closed button, earth leakage protective device is resetted.

A kind of overcurrent, short-circuit protection that is made of the utility model electromagnetic induction relay is characterized in that the side of described coil around described tongue tube; Be connected across on the power supply after one group of normally-closed contact of coil, relay and the load series connection, constituted the major loop that powers to the load; Between the series connection node of the series connection node of power supply and coil and coil and normally-closed contact, be parallel with one group of series arm that normally opened contact is formed by tongue tube, normally closed button and relay; Relay is connected in parallel between the tie point of the series connection node of tongue tube and normally closed button and load and mains switch; the overcurrent of load or short circuit current produce electromagnetic force in coil can make the tongue tube closure; relay gets electronic work, and its normally-closed contact disconnects, the load outage; meanwhile; its normally opened contact adhesive, itself and coil, button, relay are formed the self-keeping circuit, keep off-position; press button, can make load must reply the position by cable.

A kind ofly constitute the threephase load phase-lacking protective device by the utility model electromagnetic induction relay, it is characterized in that described electromagnetic induction relay has three, its three coils are respectively around the middle part of each self-corresponding tongue tube, and be connected on the phase line between threephase load and the mains switch, between threephase load and three coils, also be provided with one group of normally opened contact of A.C. contactor, constituted the major loop that three phase mains powers to the load; Between phase line A and phase line C, be provided with the phase shortage control branch road that constitutes by the tongue tube of described three electromagnetic induction relays and normally closed button, relay series connection; Between the tie point of tongue tube and phase line A and normally closed button and relay tie point, be parallel with one and often drive button; Between the tie point of tongue tube and phase line A and phase line C, also be parallel with one group of load master control branch road that normally opened contact is connected and constituted with described A.C. contactor of described relay; Under the normal condition, press and often drive button, relay, A.C. contactor adhesive, load gets electric startup, and the coil of described three electromagnetic induction relays all has electric current, its tongue tube adhesive, normally closed button is in closure state, and relay is kept adhesive, loaded work piece; When arbitrary phase line phase shortage disconnected, corresponding that tongue tube disconnected in three tongue tubes, and relay, A.C. contactor discharge, and load is in the power-off protection state and quits work.

A kind of threephase load phase shortage, overcurrent, short-circuit protection that constitutes by the utility model electromagnetic induction relay, it is characterized in that described electromagnetic induction relay has six, be divided into two groups, its coil is by on the corresponding phase line that is connected between threephase load and the mains switch of group, also be in series with one group of normally opened contact of A.C. contactor therebetween, constituted the major loop that three phase mains powers to the load; The coil of first group of three electromagnetic induction relay is used for open-phase protection, respectively around the middle part of each self-corresponding tongue tube; The coil of second group of three electromagnetic induction relay is used for overcurrent, short-circuit protection, respectively around a side of each self-corresponding tongue tube; Between phase line A and phase line C, be provided with phase shortage, overcurrent, short circuit control branch road that one group of normally-closed contact and control relay series connection by the tongue tube of described first group of three electromagnetic induction relay, normally closed button, overcurrent, short circuit control relay constitute; Being parallel with one between the tie point of one group of normally-closed contact of the tie point of first group of first tongue tube and phase line A and overcurrent, short circuit control relay and control relay resets, starts and often drive button; Overcurrent, the short circuit control branch road of after being provided with between phase line A and the phase line C, connecting with overcurrent, short circuit control relay again and being constituted by the tongue tube parallel connection of described second group of three electromagnetic induction relay; Between phase line A and phase line C, also be provided with one group of load control loop that normally opened contact is connected and constituted with A.C. contactor by control relay; During phase shortage, any one disconnection in first group of three tongue tube discharges control relay dead electricity, A.C. contactor, the load outage; When overcurrent, short circuit took place, any adhesive in second group of three tongue tube made overcurrent, short circuit control relay get electric adhesive, control relay dead electricity and A.C. contactor is discharged, and load is in the power-off protection state.

The utility model has made full use of that the dry-reed tube switch volume is little, airtight, response speed is fast, the life-span is long, high reliability features, makes the electromagnetic induction relay that is constituted and civilian, the industrial electrical control gear such as load overcurrent, short circuit, electric leakage and threephase load open-phase protection that constituted correspondingly has that circuit is simple, volume is small and exquisite, response speed is fast, production cost is low, good reliability, long advantage of life-span.

Below in conjunction with drawings and Examples the utility model is further described.

Description of drawings

Fig. 1 is the structural representation of first kind of execution mode of the utility model electromagnetic induction relay;

Fig. 2 is the structural representation of second kind of execution mode of the utility model electromagnetic induction relay;

Fig. 3 is the structural representation (band shunt) of the third execution mode of the utility model electromagnetic induction relay;

Fig. 4 is the structural representation of the 4th kind of execution mode of the utility model electromagnetic induction relay;

Fig. 5 is a kind of circuit theory diagrams of the earth leakage protective device that is made of electromagnetic induction relay shown in Figure 4;

Fig. 6 is a kind of overcurrent that is made of electromagnetic induction relay shown in Figure 2, the circuit theory diagrams of short-circuit protection (coil is around an end of tongue tube);

Fig. 7 is a kind of circuit theory diagrams by Fig. 3 electromagnetic induction relay and Fig. 6 overcurrent, the improved big load overcurrent of short-circuit protection, short-circuit protection;

Fig. 8 is a kind of circuit theory diagrams of the threephase load phase-lacking protective device that is made of the utility model electromagnetic induction relay;

Fig. 9 is the circuit theory diagrams of a kind of threephase load phase shortage that is made of the utility model electromagnetic induction relay, overcurrent, short-circuit protection.

Embodiment

Embodiment:

1, a kind of electromagnetic induction relay (shown in Fig. 1 to 4) is made of electromagnetic induction coil 1, relay switch and shell 3 three parts basically.Relay switch is tongue tube 2 in the utility model, on tongue tube 2 outer walls, be glued with a high-temperature insulation sleeve pipe 4, coil 1 is on high-temperature insulation sleeve pipe 4, shell 3 is sealed in tongue tube 2, high-temperature insulation sleeve pipe 4 and coil 1 three therebetween, also fills the fire proofing 5 that completely insulate in its gap.The magnetic force that is produced when the electric current of coil 1 surpasses setting value can make contact adhesive or the disconnection in the tongue tube 2.

In the electromagnetic induction relay shown in Figure 1, coil 1 is used for open-phase protection around the middle part of tongue tube 2;

In the electromagnetic induction relay shown in Figure 2, coil 1 is used for overcurrent, short-circuit protection around a side of tongue tube 2;

In order to adapt to the needs of big load overcurrent, short circuit load protection, at the two ends of coil 1 parallel shunt 6, as shown in Figure 3.Shunt 6 is by the pair of

electrodes plate

61,62 that links to each other with coil 1 and be connected in therebetween 4 branch current wire 63) constitute, shunt 6 is sealed into one by a conjoined outer shell 3 and tongue tube 2, coil 1 etc.

In the electromagnetic induction relay of Fig. 4, two electromagnetic induction coils (7,8) are arranged, their number of turn is identical, around on the contrary, divides the both sides around tongue tube 9, constitutes twin coil current-balance type electromagnetic induction relay, is used for earth leakage protective.

2, a kind of by the earth leakage protective device that constitutes as electromagnetic induction relay among Fig. 4, as shown in Figure 5, a mains switch K1 is arranged in this earth leakage protective device, order is being connected in series first coil 7 in two coils 7,8, one group of normally-closed contact J11, the load RL1 of a relay J 1 and second coil 8 in two coils 7,8 between the two poles of the earth of mains switch K1, has constituted the current supply circuit of load RL1; Between the tie point of the tie point of the mains switch K1 and first coil 7 and first coil 7 and normally-closed contact J11, be parallel with a series connection control branch road that constitutes by one group of normally opened contact J12 of tongue tube 9 and relay J 1; Between the tie point of the tie point of normally opened contact J12 and tongue tube 9 and second coil 8 and load RL1, be connected to the outage self-insurance that constitutes by a relay J 1 and a normally closed button AN1, the control branch road resets; During electric leakage, current imbalance in first coil 7, second coil 8, make the magnetic force imbalance that is produced, tongue tube 9 adhesives, relay J 1, its normally-closed contact J11 disconnects, load RL1 power-off protection, and its normally opened contact J12 is closed and constitute the outage self-keeping circuits with first coil 7, normally closed button AN1, relay J 1 and second coil 8; Press normally closed button AN1, earth leakage protective device is resetted.

3, a kind of by the overcurrent, the short-circuit protection that constitute as Fig. 2 or electromagnetic induction relay shown in Figure 3, as shown in Figure 6, coil 10 is around a side of tongue tube 11; One group of normally-closed contact J21 of coil 10, relay J 2 and load RL2 series connection back (by K switch 2) are connected across on the power supply 12, have constituted the major loop to load RL2 power supply; Between the series connection node of the series connection node of power supply 12 and coil 10 and coil 10 and normally-closed contact J21, be parallel with one group of series arm that normally opened contact J22 forms by tongue tube 11, normally closed button AN2 and relay J 2; Relay J 2 is connected in parallel between the tie point of the series connection node of tongue tube 11 and normally closed button AN2 and load RL2 and mains switch K2; overcurrent or short circuit current produce electromagnetic force in coil 10 can make tongue tube 11 closures; relay J 2 gets electronic work, and its normally-closed contact J21 disconnects, load RL2 outage; meanwhile; its normally opened contact J22 adhesive, itself and coil 10, button AN2, relay J 2 are formed the self-keeping circuit, keep off-position; press button AN2, can make load RL2 must reply the position by cable.

For the ease of state indication, the series arm malfunction indicator light LM that can connect.

In order to satisfy the needs of big load load, as shown in Figure 7, can on the position of load RL2, one contactor QC1 be arranged reconfiguration in this example, load RL2 then is connected across between the tie point of the tie point of normally-closed contact J21 of coil 10 and relay J 2 and relay J 2 and power supply through one group of normally opened contact QC11, QC12 of this contactor QC1, adopts the electromagnetic induction relay of band shunt shunt 6 to be connected in parallel on the two ends of coil 10.

4, a kind of threephase load phase-lacking protective device that constitutes by electromagnetic induction relay as shown in Figure 1, as shown in Figure 8, electromagnetic induction relay has three, its three coils 13,14,15 are respectively around the middle part of each self-corresponding tongue tube 131,141,151, and be connected on the phase line between threephase load RL3 and the mains switch K3, between threephase load RL3 and three coils 13,14,15, also be provided with one group of normally opened contact QC21, QC22, the QC23 of A.C. contactor QC2, constituted the major loop of three phase mains to load RL3 power supply; Between phase line A and phase line C, be provided with the phase shortage control branch road that constitutes by the tongue tube 131,141,151 of three electromagnetic induction relays and normally closed button AN3, relay J 3 series connection; Between the tie point of tongue tube 131 and phase line A and normally closed button AN3 and relay J 3 tie points, be parallel with one and often open button AN4; Between the tie point of tongue tube 131 and phase line A and phase line C, also be parallel with one group of load master control branch road that normally opened contact J31 connects and constituted with A.C. contactor QC2 of relay J 3; Under the normal condition, press and often open button AN4, relay J 3, A.C. contactor QC2 adhesive, load gets electric startup, the coil 13,14,15 of three electromagnetic induction relays all has electric current, its tongue tube 131,141,151 adhesives, and normally closed button AN31 is in closure state, relay J F3 keeps adhesive, load RL3 work; When arbitrary phase line phase shortage disconnected, corresponding that tongue tube disconnected in three tongue tubes 131,141,151, and relay J 3, A.C. contactor QC2 discharge, and load RL3 is in the power-off protection state and quits work.

A kind of by the threephase load phase shortage, overcurrent, the short-circuit protection that constitute as Fig. 1 and Fig. 2 or electromagnetic induction relay shown in Figure 3, as shown in Figure 9, electromagnetic induction relay has six, be divided into two groups, its

coil

16,17,18,19,20,21 is by on the corresponding phase line that is connected between threephase load RL4 and the mains switch K4 of group, also be in series with one group of normally opened contact QC31,32,33 of A.C. contactor QC3 therebetween, constituted the major loop of three phase mains to load RL4 power supply; The

coil

16,17,18 of first group of three electromagnetic induction relay is used for open-phase protection, respectively around the middle part of each self-corresponding tongue tube 161,171,181; The

coil

19,20,21 of second group of three electromagnetic induction relay is used for overcurrent, short-circuit protection, respectively around a side of each self-corresponding tongue tube 191,201,211; Between phase line A and phase line C, be provided with phase shortage, overcurrent, short circuit control branch road that one group of normally-closed contact J41 and control relay J5 series connection by the tongue tube 161,171,181 of first group of three electromagnetic induction relay, normally closed button K5, overcurrent, short circuit control relay J4 constitute; Being parallel with one between the tie point of the one group of normally-closed contact J41 of the tie point of first group of first tongue tube 161 and phase line A and overcurrent, short circuit control relay J4 and control relay J5 resets, starts and often open button AN6; Overcurrent, the short circuit control branch road of after being provided with between phase line A and the phase line C, connecting with overcurrent, short circuit control relay J4 again and being constituted by tongue tube 191,201,211 parallel connections of second group of three electromagnetic induction relay; Between phase line A and phase line C, also be provided with one group of load RL4 control loop that normally opened contact J51 connects and constituted with A.C. contactor QC3 by control relay J5; During phase shortage, any one disconnection in first group of three tongue tube 161,171,181 discharges control relay J5 dead electricity, A.C. contactor QC3, load (RL4) outage; When overcurrent, short circuit took place, any adhesive in second group of three tongue tube 191,201,211 made overcurrent, short circuit control relay J4 get electric adhesive, control relay J5 dead electricity and A.C. contactor QC3 is discharged, and load RL4 is in the power-off protection state.

Claims

1, a kind of electromagnetic induction relay, comprise electromagnetic induction coil (1), relay switch and shell (3), it is characterized in that: described relay switch is tongue tube (2), be glued with a high-temperature insulation sleeve pipe (4) at tongue tube (2) outer wall, described electromagnetic induction coil (1) is on high-temperature insulation sleeve pipe (4), shell (3) is sealed in the three therebetween and reserves the lead-in wire of electromagnetic induction coil (1) and tongue tube (2), and the magnetic force that the electric current of coil (1) is produced when surpassing setting value can make contact adhesive or the disconnection in the tongue tube (2).

2, electromagnetic induction relay according to claim 1 is characterized in that: the two ends of described electromagnetic induction coil (1) are parallel with shunt (6).

3, electromagnetic induction relay according to claim 2 is characterized in that: described shunt (6) by the pair of electrodes plate (61,62) that links to each other with described electromagnetic induction coil (1) and be connected in therebetween at least one minute current wire (63) constitute.

4, electromagnetic induction relay according to claim 1, it is characterized in that described electromagnetic induction coil (7,8) has two, split both end sides in same tongue tube (2), and their coil turn is identical, around on the contrary, constitute twin coil current-balance type electromagnetic induction relay.

5, a kind of earth leakage protective device that is made of the described electromagnetic induction relay of claim 4 is characterized in that: be provided with a mains switch (K1) in this earth leakage protective device,

Order is being connected in series second coil (8) in one group of normally-closed contact (J11), load (RL1) and two coils (7,8) of first coil (7) in described two coils (7,8), a relay (J1) between the two poles of the earth of mains switch, has constituted the current supply circuit of load (RL1);

Between the tie point of the tie point of mains switch (K1) and first coil (7) and first coil (7) and normally-closed contact (J11), be parallel with a series connection control branch road that constitutes by one group of normally opened contact (J12) of described tongue tube (9) and described relay (J1);

Between the tie point of the tie point of normally opened contact (J12) and tongue tube (9) and second coil (8) and load (RL1), be connected to the outage self-insurance that constitutes by a described relay (J1) and a normally closed button (AN1), the control branch road resets;

During electric leakage, current imbalance in first coil (7), second coil (8), make the magnetic force imbalance that is produced, tongue tube (9) adhesive, relay (J1), its normally-closed contact (J11) disconnects, load (RL1) power-off protection, and its normally opened contact (J12) is closed and constitute the outage self-keeping circuit with first coil (7), normally closed button (AN1), relay (J1) and second coil (8); Press normally closed button (AN1), earth leakage protective device is resetted.

6, a kind of overcurrent, short-circuit protection that constitutes by claim 1,2 or 3 described electromagnetic induction relays, it is characterized in that: described coil (10) is around a side of described tongue tube (11);

Be connected across on the power supply (12) after one group of normally-closed contact (J21) of coil (10), relay (J2) and load (RL2) series connection, constituted major loop to load (RL2) power supply;

Between the series connection node of the series connection node of power supply and coil (10) and coil (10) and normally-closed contact (J21), be parallel with the series arm of forming by one group of normally opened contact (J22) of tongue tube (11), normally closed button (AN2) and relay (J2);

Relay (J2) is connected in parallel between the tie point of the series connection node of tongue tube (11) and normally closed button (AN2) and load (RL2) and power supply;

The overcurrent of load (RL2) or short circuit current produce electromagnetic force and make tongue tube (11) closure in coil (10); relay (J2) gets electronic work; its normally-closed contact (J21) disconnects; load (RL2) outage, meanwhile, its normally opened contact (J22) adhesive; itself and coil (10), button (AN2), relay (J2) are formed the self-keeping circuit; keep off-position, press button (AN2), can make load (RL2) must reply the position by cable.

7, overcurrent according to claim 6, short-circuit protection is characterized in that: also be in series with a malfunction indicator light (LM) in the series arm of being made up of one group of normally opened contact (J22) of tongue tube (11), normally closed button (AN2) and relay (J2).

8, according to claim 6 or 7 described overcurrents, short-circuit protection; it is characterized in that: reconfiguration one contactor (QC1) on the position of described load (RL2); described load (RL2) is connected across through one group of normally opened contact (QC11, QC12) of this contactor (QC1) between the tie point of the tie point of normally-closed contact (J21) of described coil (10) and described relay (J2) and described relay (J2) and power supply, and a shunt (6) is connected in parallel on the two ends of coil (10).

9, a kind of by claim 1, the threephase load phase-lacking protective device that 2 or 3 described electromagnetic induction relays constitute, it is characterized in that: described electromagnetic induction relay has three, its three coils (13,14,15) respectively around each self-corresponding tongue tube (131,141,151) middle part, and be connected on the phase line between threephase load (RL3) and the mains switch (K3), at threephase load (RL3) and three coils (13,14,15) also be provided with one group of normally opened contact (QC21 of A.C. contactor (QC2) between, QC22, QC23), constituted the major loop of three phase mains to load (RL3) power supply; Between phase line A and phase line C, be provided with the phase shortage control branch road that constitutes by the tongue tube (131,141,151) of described three electromagnetic induction relays and normally closed button (AN3), relay (J3) series connection; Between the tie point of tongue tube (131) and phase line A and normally closed button (AN3) and relay (J3) tie point, be parallel with one and often drive button (AN4); The load master control branch road that the one group of normally opened contact (J31) that also is parallel with described relay (J3) between the tie point of tongue tube (131) and phase line A and phase line C and described A.C. contactor (QC2) are connected and constituted; Under the normal condition, press and often drive button (AN4), relay (J3), A.C. contactor (QC2) adhesive, load gets electric startup, the coil of described three electromagnetic induction relays (13,14,15) all has electric current, its tongue tube (131,141,151) adhesive, and normally closed button (AN31) is in closure state, relay (JF3) is kept adhesive, load (RL3) work; When arbitrary phase line phase shortage disconnected, corresponding that tongue tube disconnected in three tongue tubes (131,141,151), and relay (J3), A.C. contactor (QC2) discharge, and load (RL3) is in the power-off protection state and quits work.

10, a kind of threephase load phase shortage, overcurrent, short-circuit protection that constitutes by claim 1,2 or 3 described electromagnetic induction relays, it is characterized in that described electromagnetic induction relay has six, be divided into two groups, its coil (16,17,18,19,20,21) is connected on the phase line between threephase load (RL4) and the mains switch (K4) by the group correspondence, also be in series with one group of normally opened contact (QC31,32,33) of A.C. contactor (QC3) therebetween, constituted the major loop of three phase mains to load (RL4) power supply; The coil of first group of three electromagnetic induction relay (16,17,18) is used for open-phase protection, respectively around the middle part of each self-corresponding tongue tube (161,171,181); The coil of second group of three electromagnetic induction relay (19,20,21) is used for overcurrent, short-circuit protection, respectively around a side of each self-corresponding tongue tube (191,201,211); Between phase line A and phase line C, be provided with tongue tube (161,171,181), normally closed button (K5), overcurrent, one group of normally-closed contact (J41) of short circuit control relay (J4) and phase shortage, overcurrent, the short circuit control branch road that control relay (J5) series connection constitutes by described first group of three electromagnetic induction relay; Being parallel with one between the tie point of one group of normally-closed contact (J41) of the tie point of first group first tongue tube (161) and phase line A and overcurrent, short circuit control relay (J4) and control relay (J5) resets, starts and often drive button (AN6); Overcurrent, the short circuit control branch road of after being provided with between phase line A and the phase line C, connecting with overcurrent, short circuit control relay (J4) again and being constituted by tongue tube (191,201, the 211) parallel connection of described second group of three electromagnetic induction relay; Between phase line A and phase line C, also be provided with load (RL4) control loop of connecting and being constituted with A.C. contactor (QC3) by one group of normally opened contact (J51) of control relay (J5); During phase shortage, any one disconnection in first group of three tongue tube (161,171,181) discharges control relay (J5) dead electricity, A.C. contactor (QC3), load (RL4) outage; When overcurrent, short circuit generation; any adhesive in second group of three tongue tube (191,201,211); make overcurrent, short circuit control relay (J4) electric adhesive, control relay (J5) dead electricity and A.C. contactor (QC3) is discharged, load (RL4) is in the power-off protection state.