Background technology
As a rule, the residential block household electricity adopts 220V single phase poaer supply, i.e. a phase firewire in the 380V three-phase four-wire system distribution system and the voltage between the zero line.Please refer to Fig. 1, Fig. 1 is the structural representation of existing 220V single phase poaer supply electric power system, as shown in Figure 1, this 220V single phase poaer supply electric power system comprises first transformer 1 and electrical equipment 7, described first transformer 1 is drawn three-phase firewire, be respectively the first phase firewire A, the second phase firewire B and third phase live wire C, the described first phase firewire A, the second phase firewire B and the third phase live wire C joint in described first transformer 1 is a neutral point 2, wherein, be equipped with the switch 3 and second fuse 4 on every phase firewire in the described three-phase firewire, and draw a secondary neutral line 5 from described neutral point 2, the other end of the described secondary neutral line 5 is connected on the ground connection busbar 6, described ground connection busbar 6 ground connection; Described electrical equipment 7 is connected between the described first phase firewire A and the described secondary neutral line 5.Certainly, described electrical equipment 7 can also be connected between the described second phase firewire B or the third phase live wire C and the described secondary neutral line 5.The described switch 3 and second fuse 4 can in time disconnect when described single phase poaer supply electric power system big electric current occurs because of current fluctuation, thereby protect described electrical equipment 7 not burnt.
Yet, the secondary neutral line 5 in the above-mentioned existing 220V single phase poaer supply electric power system may disconnect with described ground connection busbar 6, thereby cause residential electricity consumption voltage to be elevated to 380V by original 220V, as shown in Figure 2, Fig. 2 is the situation that the secondary neutral line in the existing 220V single phase poaer supply electric power system and ground connection busbar disconnect, because the described secondary neutral line 5 disconnects with described ground connection busbar 6, causes the voltage on the electrical equipment 7 to be elevated to 380V by original 220V, thereby causes electrical equipment 7 to be burnt.
Therefore, be necessary to provide a kind of anti-overvoltage protective device, avoid the secondary neutral line and the disconnection of ground connection busbar in the single phase poaer supply electric power system and cause electrical equipment to burn.
The utility model content
The purpose of this utility model is to provide a kind of low pressure single phase poaer supply anti-overvoltage protective device; to solve single phase poaer supply electric power system of the prior art the anti-overvoltage protective device is not set, thereby causes the secondary neutral line and ground connection busbar to disconnect and the problem that causes electrical equipment to burn.
For addressing the above problem, the utility model proposes a kind of low pressure single phase poaer supply anti-overvoltage protective device, be used for preventing the secondary neutral line and the disconnection of ground connection busbar of single phase poaer supply electric power system and causing electrical equipment to burn, wherein, described single phase poaer supply electric power system comprises first transformer, first phase firewire of drawing from described first transformer, second phase firewire, the third phase live wire and the secondary neutral line, described first phase firewire, second phase firewire and the third phase live wire joint in described first transformer is a neutral point, described electrical equipment is connected on described first phase firewire, between the arbitrary phase firewire in second phase firewire and the third phase live wire and the described secondary neutral line, this low pressure single phase poaer supply anti-overvoltage protective device comprises: contactor, control transformer and binding post, described contactor comprises contact mechanism and solenoid, and described contact mechanism is arranged on described first phase firewire, on second phase firewire and the third phase live wire; Described control transformer comprises primary coil and secondary coil, and an end of described primary coil links to each other with described first phase firewire, and the other end links to each other with described second phase firewire; Link to each other with described ground connection busbar by described binding post after one end of described secondary coil links to each other with described solenoid, the other end links to each other with described neutral point by described binding post.
Optionally, also comprise first fuse, described first fuse is arranged between the end and described first phase firewire of described primary coil, between the other end of described primary coil and described second phase firewire and between the end and described solenoid of described secondary coil.
Optionally, described control transformer is that 380V changes the 220V transformer.
Optionally, described contactor is an A.C. contactor.
Optionally, the described secondary neutral line is connected between described neutral point and the described ground connection busbar.
Optionally, be provided with the switch and second fuse on described first phase firewire, second phase firewire and the third phase live wire.
Compared with prior art, the low pressure single phase poaer supply anti-overvoltage protective device that the utility model provides comprises contactor, control transformer and binding post, described contactor comprises contact mechanism and solenoid, and described contact mechanism is arranged on described first phase firewire, second phase firewire and the third phase live wire; Described control transformer comprises primary coil and secondary coil, and an end of described primary coil links to each other with described first phase firewire, and the other end links to each other with described second phase firewire; Link to each other with described ground connection busbar by described binding post after one end of described secondary coil links to each other with described solenoid, the other end links to each other with described neutral point by described binding post; Because described control transformer and described solenoid and the described secondary neutral line form the closed-loop path, when the described secondary neutral line disconnects, described contact mechanism also disconnects, thereby has prevented that electrical equipment from burning because of overvoltage, has improved the fail safe of single phase poaer supply electric power system.
Simultaneously; the low pressure single phase poaer supply anti-overvoltage protective device that the utility model provides also comprises first fuse; when described single phase poaer supply electric power system big electric current occurs because of current fluctuation; described first fuse disconnects; thereby described contact mechanism disconnects, and has prevented that electrical equipment from burning because of transient current is excessive.
Embodiment
Below in conjunction with the drawings and specific embodiments the low pressure single phase poaer supply anti-overvoltage protective device that the utility model proposes is described in further detail.According to the following describes and claims, advantage of the present utility model and feature will be clearer.It should be noted that accompanying drawing all adopts very the form of simplifying and all uses non-ratio accurately, only be used for conveniently, the purpose of aid illustration the utility model embodiment lucidly.
Core concept of the present utility model is, a kind of low pressure single phase poaer supply anti-overvoltage protective device is provided, be used for preventing the secondary neutral line and the disconnection of ground connection busbar of single phase poaer supply electric power system and causing electrical equipment to burn, this low pressure single phase poaer supply anti-overvoltage protective device comprises contactor, control transformer and binding post, described contactor comprises contact mechanism and solenoid, and described contact mechanism is arranged on described first phase firewire, second phase firewire and the third phase live wire; Described control transformer comprises primary coil and secondary coil, and an end of described primary coil links to each other with described first phase firewire, and the other end links to each other with described second phase firewire; Link to each other with described ground connection busbar by described binding post after one end of described secondary coil links to each other with described solenoid, the other end links to each other with described neutral point by described binding post; Because described control transformer and described solenoid and the described secondary neutral line form the closed-loop path, when the described secondary neutral line disconnects, described contact mechanism also disconnects, thereby has prevented that electrical equipment from burning because of overvoltage, has improved the fail safe of single phase poaer supply electric power system.
Please refer to Fig. 3, the structural representation of the low pressure single phase poaer supply anti-overvoltage protective device that Fig. 3 provides for the utility model embodiment, as shown in Figure 3, described single phase poaer supply electric power system comprises first transformer 1, the first phase firewire A that draws from described first transformer 1, the second phase firewire B, the third phase live wire C and the secondary neutral line 5, the described first phase firewire A, the second phase firewire B and the third phase live wire C joint in described first transformer 1 is a neutral point 2, described electrical equipment 7 is connected between the described first phase firewire A and the described secondary neutral line 5, the low pressure single phase poaer supply anti-overvoltage protective device 100 that the utility model embodiment provides comprises contactor, control transformer 140 and binding post 120, described contactor comprises contact mechanism 110 and solenoid 111, and described contact mechanism 110 is arranged on the described first phase firewire A, on the second phase firewire B and the third phase live wire C; Described control transformer 140 comprises primary coil and secondary coil, and an end of described primary coil links to each other with the described first phase firewire A, and the other end links to each other with the described second phase firewire B; Link to each other with described ground connection busbar 6 by described binding post 120 after one end of described secondary coil links to each other with described solenoid 111, the other end links to each other with described neutral point 2 by described binding post 120.
Further; this low pressure single phase poaer supply anti-overvoltage protective device 100 also comprises first fuse 130, and described first fuse 130 is arranged between the end and the described first phase firewire A of described primary coil, between the other end of described primary coil and the described second phase firewire B and between the end and described solenoid 111 of described secondary coil.Described first fuse 130 disconnects when the electric current of single phase poaer supply electric power system is too high, thereby described contact mechanism 110 is disconnected, and has avoided electrical equipment 7 to burn because of the current fluctuation of single phase poaer supply electric power system causes.
Further, described control transformer 140 changes the 220V transformer for 380V.
Further, described contactor is an A.C. contactor.
Further, the described secondary neutral line 5 is connected between described neutral point 2 and the described ground connection busbar 6.
Further, be provided with the switch 3 and second fuse 4 on the described first phase firewire A, the second phase firewire B and the third phase live wire C.
The operation principle of the low pressure single phase poaer supply anti-overvoltage protective device 100 that this use new embodiment provides is:
When described single phase poaer supply electric power system operate as normal, the closed-loop path operate as normal that described control transformer 140 and described solenoid 111 and the described secondary neutral line 5 form, described contact mechanism 110 closures, the voltage at described electrical equipment 7 two ends is 220V, described electrical equipment operate as normal;
When described single phase poaer supply electric power system big electric current occurred because of current fluctuation, described first fuse 130 disconnected, thereby described contact mechanism 110 disconnects, and makes that the voltage at described electrical equipment 7 two ends is 0V, has prevented that electrical equipment 7 from burning because of transient current is excessive;
When the secondary neutral line in the described single phase poaer supply electric power system 5 disconnects, described control transformer 140 disconnects with the closed-loop path that the described solenoid 111 and the described secondary neutral line 5 form, thereby described contact mechanism 110 also disconnects, make that the voltage at described electrical equipment 7 two ends is 0V, prevented that electrical equipment 7 from burning because of overvoltage, improved the fail safe of single phase poaer supply electric power system.
In above-mentioned specific embodiment, described electrical equipment 7 is connected between the described first phase firewire A and the described secondary neutral line 5, yet should be realized that described electrical equipment 7 can also be connected between the described second phase firewire B or the described third phase live wire C and the described secondary neutral line 5.
In above-mentioned specific embodiment, one end of described primary coil links to each other with the described first phase firewire A, its other end links to each other with the described second phase firewire B, yet should be realized that the two ends of described primary coil can also link to each other with wantonly two phase firewires among the described first phase firewire A, the second phase firewire B and the third phase live wire C.
In sum, the utility model provides a kind of low pressure single phase poaer supply anti-overvoltage protective device, be used for preventing the secondary neutral line and the disconnection of ground connection busbar of single phase poaer supply electric power system and causing electrical equipment to burn, this low pressure single phase poaer supply anti-overvoltage protective device comprises contactor, control transformer and binding post, described contactor comprises contact mechanism and solenoid, and described contact mechanism is arranged on described first phase firewire, second phase firewire and the third phase live wire; Described control transformer comprises primary coil and secondary coil, and an end of described primary coil links to each other with described first phase firewire, and the other end links to each other with described second phase firewire; After linking to each other with described solenoid, one end of described secondary coil links to each other with described ground connection busbar by described binding post, the other end links to each other with described neutral point by described binding post, because described control transformer and described solenoid and the described secondary neutral line form the closed-loop path, when the described secondary neutral line disconnects, described contact mechanism also disconnects, thereby prevented that electrical equipment from burning because of overvoltage, improved the fail safe of single phase poaer supply electric power system.
Obviously, those skilled in the art can carry out various changes and modification to utility model and not break away from spirit and scope of the present utility model.Like this, if of the present utility model these are revised and modification belongs within the scope of the utility model claim and equivalent technologies thereof, then the utility model also is intended to comprise these changes and modification interior.