US1061671A - Lightning-arrester. - Google Patents

Description

J. 1).: HILLIARD, JR. & 0Q E. PARSONS. LIGHTNING ARRESTER.

APPLICATION FILED 11111.29, 1906.

1,061,671. Patented May13,1913.

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resistance must be inserted between the lines,

which will eventually transformer which are words it-isya .high

rather than'i'tp ground which causes the- UNITED STATES PATENT OFFICE.

JOHN D. HILLIARD, JR., AND CHARLES E. PARSONS, OF GLENS FALLS, NEW YORK.

LIGHTNING-'ARRESTER.

Specification of Letters Patent.

Patented May 13,1913.

Application filed January 29, 1906. Serial No. 298,439.

To all whom it may concern:

Be it known thatwe, JOHN D. Hnmnum, Jr., and Crninnns E. Masons, citizens of the United States, residing at Glens Falls, in the county of Warren and State of New York, have invented certain new and useful Improvements in LightningArresters, of which the following is a specification, reference being had therein to the accompanying drawing. 7

Our lnvention relates to safety systems and especially to lightning arresters therefor.

The object of the invention is the pro vision of means which will adequately take care of all discharges on the line.

In order to secure adequate lightning protection an arrester scheme must meet the following conditions: First, it mustfurnish a discharge path between wires of the same circuit which will equalize the pressure *henever a dangerous difference of potential exists; second, it must perform the same function between the wires and the ground; third, whenever an arc is established across gaps between lines or between lines and ground, the arc must be automatically ruptured as soon as the line resumes its normal conditionyfourth, in order that'no discharge may cause a short circuit, suita and this resistance must have such a heat capacity that it can withstand repeated discharges without being destroyed; fifth, the resistance circuit must be as nearly noninductive as possible. The voltage required to break down the gaps to ground must be greater than between lines, or in other words, the break down voltage between lines must be as nearly equal to the opeating voltage as possible and allow a proper factor of safety so as to insure against a break down under normal operating conditions. This necessarily means'agreater break-down voltage to earth, for if one wire of a circuit becomes grounded the condenser action be: tween line and ground produces an excessive voltage across the gap or gaps and tends to establish result in the destruction of the same. Experience has shown that in nearly every side turns of the coils at the outside of the destroyed, or in other voitage, between lines ble an are at the arrester instance it the outbreak-down, alt-hough'in largo transformers the transformer electrostatic capacity may be 5.?) great that the charging current to the transformer as a condenser may cause the break-down.

Our invention is designed to meet the foregoing conditions and to obviate all the difficulties mentioned.

It comprises a resistance which can withstand repeated high voltage'and large energy discharges,- with a gap which of itself regulates and limits the duration of arc discharges.

Further objects of the invention will appear upon reading the specification in connection with the accompanying drawing which forms a part of the application and in which- Y Figure l'is a diagram showing in detail the position of the gaps and resistances with relation to the lines and the ground. Fig. 2 is a diagram of the circuit; used. Referring to the drawings 1, 2, 3 and 4 represent four lines, three only of which are shown in the circuit diagram and between which and a common connection 5 to ground are interposed the arresters 6 and the resistances 7. In parallel with each resistance 7 is a special arrester shunt circuit 8, having the gap .9 which is adjusted to'a high break down point so that an excessive stroke meeting too great opposition in the resistance will jump the gap and o to ground on a short circuit. Theballs orming theterminals of the gaps are preferably"mounted upon the several tile cases of the resistances 7. Interposed between the ground and the common connection 5 is a single horn arrester 11. The arresters 6 and 11 as used by us are similar to the common horn type in that two horns 12 and 13 are employed, diverging from their lower extremities to their outer ends. \Yith our invention, however, the horn 13, is provided with a rearward extension 14, which is dovetailed on its bottom and 'slidably mounted in a groove formed 111 an iron cap 15, cemented to an insulator 16, which is provided with a crown to receive the cap and the usual petticoat 17. The extension 14 is provided-with a threaded end on which the thumbscrew 18, is mounted. By this uneans the. horn 13 may be adjusted toward, and away from the horn 12, thus making the point of break-down low or high. The resistanc'es 7 are composed eachof anouter shell. 19 of porcelain or other suitable material, which for high voltages may be constructed of a plurality of unit lengths, each pair of units being connected. together by a collar or petticoat 20 cemented to the lengths in the following manner; The collar or petticoat is slipped over the lower end of the upper length of the shell while the same is held upside down and cement is inserted between the collar and the shell, which cement rests againstva, flange 21 formed on the shell or against a temporary stop held around the shell in the same position. The lower length of the shell is then placed within the flange 22 and a itchy substance inserted so as to rest on top of the cement and to having a cup-shaped portion 38 adap cover the joint bet-ween the upper and lower ialves of the shell. Cement is then placed upon the pitchy substance between the lower length and the flange 22. The ends of the lengths of the shell are corrugated as shown so that a surface is provided to which the cement will hold with great tenacity. The lower portion of the shell is corrugated and the bottom 23, of metal, similarly corrugated so that it may be cemented'to the shell in a like manner to the-petticoat, with the pitchy substance at the joint between the shell and the bottom.

The receptacle isflfilled to a point marked X with acidulated water or saline solution 24, the strength of Which regulates the resistance. This solution is covered with oil 25 to prevent evaporation. Floating on the top of the liquid is a hollow' terminal member .25 open at the bottom so that its walls may be exposed to the same pressure within and without under all conditions to prevent col lapsing. Projecting perpendicularly from this float is a vrtical conducting rod 26 passing above the shell and servingboth as a telltale to. indicate the liquid level in the casing and also as one terminal. Clamping nuts 27 are threaded on the end of-the rod, to which the line wire can be attached. A suitable top 28 is placed upon the shell to exclude rain, du st, etc., and the bottom 23 i provided with an outlet port 29 by which the contents of the shell may be drained.

In the'working embodiment of the invention the horn arresters and the resistances are mounted in the following manner on cross-arms 30 secured to the pole 31: The insulators of the horn arrester are secured upon wooden pins 32 set a proper distance apart. The insulator holding the horn 12' is provided with the receivin member 33 of a knife switch 34 supporte on an insulator 35 similar 'to the insulators 16, and adapted to form the terminal of the line wire. An insulator 36 secured to one of the cross-arms 30 is provided with an iron ap 37 ed to receive a stud 39 integral with the bottom 23 on the shell 10. This pivots the shell 10 so discharge means connected that it can be rotated if desired or necessary. Surrounding the shell at the top is a band of metal connected'to an insulator 40, mounted on a cross-arm 30 and adaptedto permit rotation of the shell and at the same time hold it in a vertical position.

' When the line is affected by heavy charges so that its potential is raised to a dangerous point, an arc springs from one horn to the other, reducing the potential difference, and gradually rises along the diverging horns,

vthus eventually breaking itself. If it is the pressure to ground which israised the cui-= rent jumps the gap at the arrester 11. When a discharge arcs from one side of the arrester to the other, metallic gases are formed affording a low resistance path for the current. This are is continued sometimes long after the abnormal condition of the line has ceased to exist and is of course very detrimental to the arrester. To avoid this we interpose 'the resistances 7 which are suflicient to points of the arrester be too close to each other and the resistances 7 inadequatgiart of the acidulated water or saline solution ma be drained through the port 29 and fresli water added by removing the top 28 and the points may be adjusted by revolving the prevent current at normal potential from leaking to ground. Should the thumb-screw 18. This increases the air gap and also increases the resistance. poslt'e conditions occur, added and the points of the arrester moved toward each other which will decrease the resistance by decreasing the length of the air gap.

Having thus described our invention What we claim and desire to secure by Letters Patout 19 7 1. The combination with a three conductor electrical circuit, of three bridge circuits connecting the three main conductors to a common point, an arrester and a switch in each bridge circuit, an adjustable resistance shunted by a gap in eachbridge, and 'a connection from the said common point through an arrester to ground, whereby any one of the phases or conductors can be disconnected without disconnecting the others and a balance is maintained under normal conditions.

2. A protective system for multiphase circuits comprising the following instrumentalities: a bridge circuit from each conductor to a point common to all of them,a switch, and ahigh potential discharge means in each bridge between its conductor and a common point, and separate high potential between said common point and the ground. 3. A protective cuits comprising "the following. instrumen- "When op more acid may be '7 system for multiphase cirtalities t line eonductors carried on insulators,

Isa

.cha-rge means and a resistance carried vsald associated insulators,

conductor, a switch,

disconnected I from ground, a balance being maintaine under normal conditions;

4:. The combination with a three-conductor electrical circuit, of three bridge circuits connecting the three main conductors to a common point, an adjustable resistance shunted by a gap in eczch bridge, and a' connection through. an adjustable gap from the common point to ground, substantially as described.

5. A protective system for multi-phase circuits comprising the following instrumentalities: a bridge circuit from each conductor to a point common-to all of them,

high potential discharge means and a retalities:

sistance in each bridge between its conductor and the' common point, and separate high potential discharge means connected between saicl common point and the ground, substantially as described.

6. Aprotective system for multi-phase on cuits comprising the following instrumentalities: a bridge between each of the line conductors and a common point, an adjustable high potential discharge means and an adjustable resistance in each bridge, and separate adjustable high potential discharge means connected between said common point and the ground, substantially as described.

7. Aprotective system for multi-phase circuits comprising the following instrumena bridge from each of the line conductors to each bridge adaptedto resist the passage mentalities: a line conductor carried a common point, means in of current at normal line voltages, but to break down and permit-the passage of current at an excessive voltage, and high po tential discharge means connected between V the common point and ground, substantially as described.

8. A protective system for transmission circuits comprising the following instrumentalitiesr a line conductor carried on insulators, separate insulators associated therewith, a switch and an adjustable high potential discharge means carried onsaid as sociatedinsulators, a bridge wire from the line conductor through said switch and discharge means in series to ground, the said switch arranged tobe accessible, visible, and

movable from a distance, whereby an operator before and after adjusting the high potential discharge means may disconnect an thereafter connect the line conductor to the high potential discharge means with certainty and without risk.

9. A protective system for transmission circuits comprising the following instruon insulators, a triple set of separate insulators associated therewith, a switch blade and an adjustable high potential discharge ,means mounted across said insulators, the middle insulator carrying connected coiiperating terminals of .both the switch and the discharge means, an electrical' connection from the line conductor to one'terminal of the switch and in series throu h the switch and discharge means erator when adjusting the discharge means may disconnect the same with absolute certainty and safety. In testimony whereof we aflix our signatures in presence of two witnesses,

JOHN D. HILLIARD, Ja CHARLES E. PARSONS. Witnesses:

C. LSNOW, WM. B, SMITH, Jr."

to ground, whereby, an op-

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