US840036A - Lightning-arrester connection. - Google Patents

Description

No. 840,036. PATENTED JAN. 1, 1907.

E. A. BALDWIN.

LIGHTNING ARRESTER CONNECTION. APPLICATION FILED we. a, 1904.

W INVENTOH 1 I I Edward fL-Baldwm,

' derground-cable work and in systems made tween conductors is particularly trouble- 'untii the insulation fails and a short circuit UNITED srArEs PATENT 'GFFIGE EDW'ARD A. BALDWIN. OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

LlGHTNING-ARRESTER CONNECTION.

. Specification of Letters Patent.

\ Patented Jan. 1, 1807.

Application filed August 8, 1904. Serial No. 219,858-

To all whom, it may concern:

Be it known that I, EDWARD A. BALDWIN, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Lightning-Arrester Connections, of which the following is a specification.

Static charges on alternating-current-transmission lines arise from two distinct causes first, from lightning discharges and inductive efi'ects due to atmospheric conditions, and, second, from resonance effects arising in the line conductors themselves. It is customany to protect against atmospheric discharges by connecting lightning-arresters between each line conductor and ground. This arrangement, however, does not fully protect the system from abnormal voltages existing between line conductors as the result of resonance. Abnormal voltages due to resonance appear .to be most common in circuits made up partly of capacities and partly of reactances and in long-distance transmissionlines. In extreme cases the abnormal v0l-, tags may be several times the normal working voltage of the system; but as the frequency is many times the normal frequency the central-station instruments will not indicate in any way this abnormal voltage. In general, no indication of its presence is given between iine conductors is formed. In unup partly of underground cables andfpartly oioverheadmvires this static discharge besome, because of the relatively small distance between the underground cables and the consequent liability of a destructive arc.

It is the object of the present invention to provide means for protecting the transmission-line from abnormal voltages arising from any source, whether from atmospheric conditions or from resonance. a

My invention will be readily understood by reference to the following description, taken in connection with the drawings forming a part of the specification. 1 shows the general arrangement of the lightning-arresters or resistance devices. Fig. 2 shows the same arran ement diagrammaticallv for convenience 0 reference.

The hinhtningmrresters shown are of the No. 669,155, March5, 1901.

general type described in .the patent to Wirt, This invention, however, is not limited to the particular form of arrester including a non-inductive resistance and spark-gaps, as shown in the above named patent, but may be any formwhich offers a suitable impedance to the flow of ouring a voltage drop in the ground connection when current flows therethrough.

The arresters shown in Fig. l consist, es-

-sentially, of an insulating base, on which are arranged two carbon resistance-rods and a plurality of metallic cylinders, between which sparks-gap are formed. The number of carbon rods and the number of spark-gaps for each unit may be increased to suit the particular voltage used for the line, and the invention is not limited to the particular number shown. Likewise the number of unitsmay be increased at will. The conductors 1', 2, and 3 represent the three linewires of the polyphase transmission-line. Between the conductors 1 and 3 is connected the resistance device composed or arresters i and 5.

The arresters 6 and 7 are connected between conductors 1 and 2, and the arresters 8 and 9 between the conductors 2 and 3. Between the arresters 4 and 5 a connection leads to a similar arrester 12, the other end of which is connected to ground. Similarly a connection from between the arr-esters 6 and,

provided a lurality of paths between each pair. of con uctors, these paths serving for the equalization of static charges between conductors. Thus between conductor 1 and ground there is a path through arresters 7 and 11 and a parallel path through arresters 4t and 12, while between conductors 1 and 2 there is one path through arresters 7 and 6 and another path through arresters 4, 12, 11, and 6, as Well as others, which are apparent from the diagram; The arrangement described provides the same number of arresters or resistance units between each conduce tor' and ground as between one conductor and another, and as part of the arresters are used both in the ground connection andgin the connection between conductors the arrangement described furnishes an efficient line conductors consisting of resistance devices connected across each phase, and means connected with each of said devices for providing a resistance-path'to ground.

2. Means for protecting line conductors of electric circuits, consisting of a resistance device connected between each two conductors of said line, said device including a spark-gap, 3 5

line comprising three conductors, of three re- 40 sistance devices arranged in delta between the three conductors, connectionsfrom the center of each side of the delta to other resistance devices, and means for connecting said last-named resistance devices to ground.

4. The combination with aipolyphase transmission-line of means for protecting the line conductors, consisting of resistance devices connected across each phase, and means connected with the center of each resistance device for providinga resistance -path to ground, said means having substantially onehalf the resistance of one of said resistance devices.

- 5. The combination with the conductors of an alternating-current-transmission line, of means for providing two permanent resistance-paths between each conductor and ground, said means providing a plurality'of resistance-paths between conductors.

In witness whereof I have hereunto set my hand this 6th day of August, 1904. r

I EDWARD A. BALDWIN. Witnesses:

BENJAMIN B. HULL, HELEN ORFoRn.

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