CN2727946Y

CN2727946Y - An electric leakage switch

Info

Publication number: CN2727946Y
Application number: CN 200420083198
Authority: CN
Inventors: 李文星
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-08-20
Filing date: 2004-08-20
Publication date: 2005-09-21
Anticipated expiration: 2014-08-20

Abstract

The utility model discloses an electric leakage switch, comprising a magnetic loop and a release. The utility model arranges the breaking positions on the A, B, and C three-phase live wires and the N-phase zero lines. The essential technical proposal is that the breaking position of the N-phase zero lines being near to the loading side is also connected with a resistor and other independent earth wires separated by other earth wires. The utility model overcomes the deficiency of the prior art, and provides the electric leakage switch having the advantages of high power supply reliability, simple structure, and low price. The electric leakage switch lacks the zone lines for power supply, the electric leakage switch can automatically trip when detecting the electric leakage current, and the electric leakage switch can not be closed when the live wires and the zone line exchange.

Description

A kind of leakage switch

[technical field]

The utility model relates to a kind of leakage switch, and the leakage switch of protection is provided to subscriber equipment when especially relating to a kind of zero line and disconnecting.

[background technology]

The power leakage switch that uses has two kinds at present:

1, a kind of is the combined integrated switch of air switch and leakage switch, this switch does not have the switch disjunction on zero line, if electric power system breaks down before the switch, bump zero line and on-load switch does not disconnect as phase line, this moment the phase line of having leaked electricity an air switch disjunction and do not have the disjunction zero line, to make zero line charged, Danger Electric shock risk will just be arranged on the zero line of power consumption equipment behind the switch;

2, another kind is pure leakage switch, has only the earth leakage protective effect, and this leakage switch zero line, phase line all have the disjunction position, and when the electric leakage action, zero line, phase line are all separated, and guarantee Electrical Safety.But in using if zero line loose contact even be equivalent to disconnect, this moment, " lacking the zero line power supply " (being that zero line is equivalent to disconnect) just can appear in using electricity system, in Fig. 1, if the three-phase load imbalance, neutral point will be offset, and the three-phase voltage deviation is big, that phase power consumption equipment of high voltage will burn in overvoltage, loss can't be estimated, and serious meeting causes appliance fire, and loss will be more serious.

The utility model has carried out useful improvement in order to overcome above shortcoming.

[utility model content]

The problem of " lacking the zero line power supply " when the utility model has overcome prior art and can not solve normal the use provides a kind of power supply reliability height, leakage switch simple in structure.

In order to solve the technical problem of above-mentioned existence, the utility model adopts following technical proposal:

A kind of leakage switch comprises magnet ring and release, and it is being provided with the disjunction position on A, B, the C three-phase firewire and on the N phase zero line, also is connected with and the separated independent ground wire DE of other ground wire by load side in N phase zero line disjunction position, is serially connected with resistance R on the independent ground wire.

Aforesaid a kind of leakage switch, the value of resistance R are the numerical value of 22 volts/leakage switch of 18 ∽ actual act electric current.

The utility model compared with prior art has following advantage: 1, power supply reliability height: when the leakage switch zero line disconnects, promptly be equivalent to lack the zero line power supply, leakage switch can detect leakage current, automatic trip; When zero line, live wire transposing, leakage switch can not close; 2, only need to increase resistance and earth connection, simple in structure, cost is also cheap.

[description of drawings]

Fig. 1 is principle analysis figure of the present utility model;

Fig. 2 is a circuit structure diagram of the present utility model;

Fig. 3 is an Experiment of Electrical Circuits winding diagram of the present utility model.

[embodiment]

Below in conjunction with accompanying drawing and embodiment the utility model is described in further detail:

In the three phase and four wire circuit system, A, B, C are three-phase firewire, and N is a zero line; In addition, E is the ground wire of the subscriber equipment earthing of casing; Leakage switch of the present utility model comprises magnet ring M and release T, and leakage switch is being provided with the disjunction position on the zero line mutually with N on A, B, the C three-phase firewire; N phase zero line disjunction position also connects and the separated independent ground wire DE of other ground wire by load side, is serially connected with resistance R on the independent ground wire DE.

The principle of leakage switch is the electric current that enters magnet ring when equating with the electric current that flows out magnet ring, and leakage switch is failure to actuate; When flowing into the electric current that flows out when unequal, produce a magnetic flux on the magnet ring, induce electric current with making on the coil of release, when induced current during greater than the operating current of release, the release would trip.

Leakage switch closes during normal the use; if zero line N loose contact disconnects; (see figure 1) is because A; B; C three-phase load imbalance; to cause producing between NN` offset voltage; offset voltage produces electric current through resistance R and independent ground wire DE; the electric current that flows into magnet ring this moment is unequal with the electric current that flows out magnet ring; be that inflow current and the difference that flows out electric current stack back are equivalent to the electric current on the independent ground wire DE; the electric current that coil induces on release is greater than the operating current of release; the release of leakage switch inside will make the leakage switch tripping operation, thus the safety of protection power consumption equipment.The leakage switch closure, if the zero line contact is good, how no matter load changes, and three-phase voltage is all normal, and neutral point voltage can not be offset, and resistance R and independent ground wire DE are to not influence of supply line.

In addition, when zero line and live wire wrong, be equivalent to resistance R and independent ground wire DE directly is connected the load side of live wire this moment, in case the leakage switch that closes will produce the operating current of leakage switch, leakage switch can not close.

The resistance to earth of independent ground wire is less than 2 Europe, and line is directly got 4mm ²More than; The necessary ground connection of independent ground wire DE is reliable, with the voltage on ground be zero, when landing, installation separates with ground wire E and lightning protection position, electrostatic grounding position, the one, guarantee that the DE line is not influenced by extraneous factor, the 2nd, prevent that independent ground wire DE from producing current potential to zero line, resistance R has electric current and makes leakage switch misoperation occur.

The resistance R value is the numerical value that equals 22 volts/leakage switch of 18 ∽ actual act electric current, and power is the cement resistor of numerical value more than or equal to 2*20 volt * actual act electric current, and the R resistance is selected as following table 1.

Table 1

Operating current on the leakage switch nameplate	The actual measurement operating current	Select the R value
Operating current on the leakage switch nameplate	The actual measurement operating current	Select the R value	0.3A	?0.17∽0.2A	100 Europe, 10 watts of cement resistors
0.03A	?0.017∽0.02A	1000 Europe, 1 watt of cement resistor	0.3A	?0.17∽0.2A	100 Europe, 10 watts of cement resistors

Electric power system operate as normal after the improvement as shown in Figure 3, to leakage switch experimentize measurement data such as table 2:

(three-phase and four-line leakage switch maiden work electric current is 0.03A, and protective resistance R selects 1000 Ω, 1W cement resistor; Threephase load is with 100W, 220 volts of bulbs, and A phase adjunction one dimmer changes whether balance of three-phase load, K ₂Be test parameters amount switch, can not install during actual the use, pass through K ₁, K ₂And the adjusting dimmer records each parameter of table 2.)

Recording data from last table can draw, when simulation lacks zero K switch ₁Close K ₂Short circuit, connecing protective device after the leakage switch zero line switch bit is present a kind of more perfect product, can extensively promote the use of.

The using method of this leakage switch is as follows:

When installing this device back leakage switch on-load additional and closing a floodgate,, close (lacking zero line when closing a floodgate) in the time of may occurring closing a floodgate behind the zero line if close a floodgate automatic tripping, can first unloading, the air switch before the first disjunction leakage switch can be unloaded or outage close.When circuit occurs leaking electricity to overhaul taking the independent grounding line earlier apart, connect after fixing a breakdown.

When leakage switch is working properly; this device looks it is unnecessary; but in fact the zero line switch bit all ubiquity the phenomenon of loose contact; when above-mentioned test if resistance R value when getting littler (getting 30 Europe, 10 watts of cement resistors) as the 0.3A leakage switch; electric leakage is opened the light the automatic trip phenomenon is just arranged, therefore necessary protective resistance and the independent ground wire that lacks zero line that install additional at leakage switch.

Table 2

Claims

1, a kind of leakage switch, comprise magnet ring and release, it is being provided with the disjunction position on A, B, the C three-phase firewire and on the N phase zero line, it is characterized in that also being connected with and the separated independent ground wire DE of other ground wire by load side in N phase zero line disjunction position, is serially connected with resistance R on the independent ground wire.

2, a kind of leakage switch according to claim 1, the value that it is characterized in that described resistance R are the numerical value of 22 volts/leakage switch of 18 ∽ actual act electric current.