CN204809857U - Low voltage network zero line broken string protection device - Google Patents
Low voltage network zero line broken string protection device Download PDFInfo
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- CN204809857U CN204809857U CN201520142664.1U CN201520142664U CN204809857U CN 204809857 U CN204809857 U CN 204809857U CN 201520142664 U CN201520142664 U CN 201520142664U CN 204809857 U CN204809857 U CN 204809857U
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- 230000009286 beneficial effect Effects 0.000 abstract 1
- 230000007935 neutral effect Effects 0.000 description 10
- 230000001681 protective effect Effects 0.000 description 9
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000012423 maintenance Methods 0.000 description 2
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 230000034994 death Effects 0.000 description 1
- 231100000517 death Toxicity 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000004520 electroporation Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
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Abstract
The utility model discloses a low voltage network zero line broken string protection device comprises switch, voltage relay, ac contactor and signal transmitter, and voltage relay's inlet wire L1, inlet wire L2 and inlet wire L3 pass through the switch and link to each other with low voltage network's A, B, C three -phase live wire respectively, and inlet wire N links to each other with the zero line, and first, the 2nd normally open contact links to each other with B looks live wire and ac contactor's coil respectively, ac contactor's the main contacts one side of normally opening links to each other with the distribution network zero line, and the opposite side links to each other with the grounding body, signal transmitter's the 2nd normally open contact of one end and voltage relay links to each other, and the other end links to each other with the grounding body. The utility model has the beneficial effects of: zero line when broken string forms a functional earthing at broken string point rear side temporarily, and it is in a basic balance to make the three phase voltage reach, because of the voltage swing in consumer rated range, so stopped the consumer accident of burning out, can not influence the normal work of consumer yet, more can not influence the normal operating that the distribution network was distinguished to whole platform.
Description
Technical field
The utility model relates to a kind of protective device, is specifically related to a kind of low-voltage network zero line break protection device, belongs to electroporation field.
Background technology
In the low voltage three-phase four-wire system system of common zero line, if zero line (neutral line) is because of accident disconnection, when three-phase load unbalance, each phase voltage will be caused to distort, make the electric voltage exception of each phase load, namely the zero line by disconnecting makes every two-phase load in series form loop and bears line voltage, and in fact, load is unbalanced mostly, threephase load impedance is different, electric current in two phase loads in loop is identical, but load power is different, so the impedance of two phase loads is not identical yet, because U=I*Z, therefore load is large compared with a little phase load impedance, voltage is also high, more than 260V can be reached, the phase load impedance that load is large is little, load voltage reduces, at below 160V, phase voltage rising can cause this phase partial electric equipment burnout, and this part power consumption equipment equipment out of service after, this phase load is lighter, phase voltage is higher, formation vicious circle like this, until this phase load is all burnt or out of service.A finally remaining phase load is obstructed and have a power failure because load in front two-phase burns out rear circuit.
Because low-voltage network neutral line break can cause a large amount of user power utilization equipment burnouts, so electric company needs the maintenance fund paying great number.
In addition, on rear side of zero line break point during electrical appliance enclosure electric leakage, be equivalent to be with phase voltage, once these electrical appliance enclosure of human contact, electric shock injures and deaths will be caused.
Utility model content
For solving the deficiencies in the prior art; the purpose of this utility model is to provide a kind of low-voltage network zero line break protection device; this protective device can make odd-job ground connection on rear side of neutral line break reach the balance of voltage, thus ensures that power consumption equipment normally works while not burnt.
In order to realize above-mentioned target, the utility model adopts following technical scheme:
A kind of low-voltage network zero line break protection device, is characterized in that, be made up of switch, voltage relay, A.C. contactor and signal projector,
The inlet wire L of aforesaid voltage relay
1, inlet wire L
2with inlet wire L
3be connected with A, B, C three-phase firewire of low-voltage network respectively by aforementioned switches, inlet wire N is connected with the zero line of low-voltage network, and the first normally opened contact is connected with B phase firewire, and the second normally opened contact is connected with the coil of A.C. contactor;
The main contacts side of often opening of aforementioned A.C. contactor is connected with power distribution network zero line, and opposite side is connected with earth electrode;
One end of aforementioned signal reflector is connected with the second normally opened contact of voltage relay, and the other end is connected with earth electrode.
Aforesaid low-voltage network zero line break protection device, is characterized in that, aforementioned signal reflector is buzzer.
Aforesaid low-voltage network zero line break protection device, is characterized in that, aforementioned signal reflector is wireless signal transmitter.
Usefulness of the present utility model is:
(1) imbalance of three-phase voltage and cross this feature of under voltage when utilizing neutral line break; voltage relay, A.C. contactor and signal projector is adopted to form protective device; when neutral line break; an interim formation working earthing (interim zero line) on rear side of break point; three-phase voltage is made to reach in a basic balance; because voltage swing is in power consumption equipment rated range; therefore stopped power consumption equipment burnout failure; also can not affect the normal work of power consumption equipment, more can not affect the normal operation of whole district's power distribution network.
(2) invest little, economic benefit to give prominence to.
(3) easy and simple to handle, only in the terminal of 0.4 kilovolt, the effect that protective device of the present utility model can reach protection one Ge Tai district need be installed.
(4) protective device of the present utility model not only can repeatedly use, and can also use as user side protective device.
Accompanying drawing explanation
Fig. 1 is the winding diagram in kind of protective device of the present utility model;
Fig. 2 is that line map is decomposed in protective device of the present utility model access distribution.
The implication of Reference numeral in figure: 1-switch, 2-voltage relay, 3-A.C. contactor, 4-signal projector.
Embodiment
Below in conjunction with the drawings and specific embodiments, concrete introduction is done to the utility model.
With reference to Fig. 1, low-voltage network zero line break protection device of the present utility model is made up of switch 1, voltage relay 2, A.C. contactor 3 and signal projector 4, introduces the mode of connection between them below.
Voltage relay 2 is common voltage relay, and function has: measure A phase firewire and zero voltage between lines, measure B phase firewire and zero voltage between lines, measure C phase firewire and zero voltage between lines, the concrete mode of connection is: the inlet wire L of voltage relay 2
1, inlet wire L
2with inlet wire L
3be connected with A, B, C three-phase firewire of low-voltage network respectively by switch 1, inlet wire N is then connected with the zero line of low-voltage network, and the first normally opened contact is connected with B phase firewire, and the second normally opened contact is connected with the coil of A.C. contactor 3.When A phase firewire and these three voltages of zero voltage between lines, B phase firewire and zero voltage between lines, C phase firewire and zero voltage between lines wherein any magnitude of voltage raise suddenly (higher than 260V), when any magnitude of voltage reduces suddenly (lower than 160V) simultaneously, the second normally opened contact and the first normally opened contact close.
The main contacts side of often opening of A.C. contactor 3 is connected with power distribution network zero line, and opposite side is then connected with earth electrode.
One end of signal projector 4 is connected with the second normally opened contact of voltage relay 2, and the other end is connected with earth electrode.
Protective device of the present utility model is arranged on power distribution network 400 volts of line ends, and the decomposition line map of access distribution as shown in Figure 2.
With reference to Fig. 2, when low-voltage network normally runs, voltage relay 2 measures low-voltage network three-phase voltage in real time.Because the second normally opened contact of voltage relay 2, the first normally opened contact disconnect, the coil no current of A.C. contactor 3 flows through, so the main contacts of often opening of A.C. contactor 3 is also disconnect, signal projector 4 also no current flows through.
When the low-voltage network neutral line (zero line) disconnects because of accident, the A phase firewire that voltage relay 2 is measured and zero voltage between lines, B phase firewire and zero voltage between lines, C phase firewire and these three voltages of zero voltage between lines have a phase to raise suddenly (higher than 260V), there is a phase to reduce suddenly (lower than 160V) simultaneously, now trigger the second normally opened contact, first normally opened contact closes, electric current flows through the coil of A.C. contactor 3, adhesive A.C. contactor 3 often open main contacts, low-voltage network zero line (on rear side of neutral line break point) often leaves main contacts through A.C. contactor and closes ground connection, thus maintain the balance of voltage, protect power consumption equipment not burnt.Meanwhile, electric current also flows through signal projector 4, sends neutral line break signal.
Signal projector 4 can be buzzer, is applicable to on-site supervision, sends ring sound after energising, reminds operation maintenance personnel power distribution network neutral line break.
Signal projector 4 can also be wireless signal transmitter, is applicable to remote monitoring, sends wireless signal, after receiving terminal receives this wireless signal, just know power distribution network neutral line break after energising.
It should be noted that, above-described embodiment does not limit the utility model in any form, the technical scheme that the mode that all employings are equal to replacement or equivalent transformation obtains, and all drops in protection range of the present utility model.
Claims (3)
1. low-voltage network zero line break protection device, is characterized in that, is made up of switch (1), voltage relay (2), A.C. contactor (3) and signal projector (4),
The inlet wire L of described voltage relay (2)
1, inlet wire L
2with inlet wire L
3be connected with A, B, C three-phase firewire of low-voltage network respectively by described switch (1), inlet wire N is connected with the zero line of low-voltage network, first normally opened contact is connected with B phase firewire, and the second normally opened contact is connected with the coil of A.C. contactor (3);
The main contacts side of often opening of described A.C. contactor (3) is connected with power distribution network zero line, and opposite side is connected with earth electrode;
One end of described signal projector (4) is connected with the second normally opened contact of voltage relay (2), and the other end is connected with earth electrode.
2. low-voltage network zero line break protection device according to claim 1, is characterized in that, described signal projector (4) is buzzer.
3. low-voltage network zero line break protection device according to claim 1, is characterized in that, described signal projector (4) is wireless signal transmitter.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520142664.1U CN204809857U (en) | 2015-03-13 | 2015-03-13 | Low voltage network zero line broken string protection device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520142664.1U CN204809857U (en) | 2015-03-13 | 2015-03-13 | Low voltage network zero line broken string protection device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN204809857U true CN204809857U (en) | 2015-11-25 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201520142664.1U Expired - Fee Related CN204809857U (en) | 2015-03-13 | 2015-03-13 | Low voltage network zero line broken string protection device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN204809857U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104734128A (en) * | 2015-03-13 | 2015-06-24 | 国家电网公司 | Low-voltage distribution network null wire break protector |
-
2015
- 2015-03-13 CN CN201520142664.1U patent/CN204809857U/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104734128A (en) * | 2015-03-13 | 2015-06-24 | 国家电网公司 | Low-voltage distribution network null wire break protector |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20151125 |