US1825015A - Automatically operated circuit breaker - Google Patents

Description

Sept. 29, 1931. E. C. RANEY 1,s"25,o15

AUTOMATICALLY OPERATED CIRCUIT BREAKER Filed Dec. 9' 1925 2 Sheets-Sheet 2 AIIIIIIIIH llllfll! HMI;

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Patented Sept. 29, 1931 ESTEL C. BANEY, OF COLUMBUS, OHIO AUTOMATICALLY OPERATED CIRCUIT BREAKER Application led December My invention relates to an automatically` operated circuit breaker or switch mechanism of the type which opens automatically upon over load and recloses automatically at the expiration of a time interval.

In the operation of power distributing circuits accidental short circuits often occur between wires, due to various causes, such as swinging of wires during storm, falling birds coming in contact with wires, et cetera. In a great many instances, these short circuits are of a temporary nature and often thely; can be cleared by closing the circuit brea er or oil switch two or three' times successively. In'other cases these short circuits are of a permanent nature and can only be rectified by repairmen.

The purpose of this invention is to provide an efficient means of operating the circuit breaker or oil switch so that in the event of opening, due to overload or short circuit, the circuit breaker will reclose again automatically at the expiration of a short time interval for a given number of times, after which its reclosing mechanism will be rendered inoperative if the overload or short circuit still exists.

For this purpose, I thermal operated relay, having the contact members. operated by means of an. expansion member containing a volatile liquid, and a suitable resistance element for heating the liquid. This form ofIrelay is simple'in construction and positive in action. The time required to operate it can -readily be varied by regulating the amount of resistance of the heat element, or the current supplied thereto.

In the drawings, Figure 1 is a diagrammatic representation of one type of the. above-described mechanism, showing the parts in normal closed position.

Figure 2 shows the position of parts at a brief time interval after opening.

Figure 3 shows a similar arrangement except that the operating mechanism is energized from a battery or source of power other than the feeder circuit.

Figure 4 is la sectional view of one form of preferably use a 9, 1925. Serial No. 74,401.

liquid containing structure that may be used as a thermal time limit relay.

Referring to the drawings, numerals 1 indicate main Contact members connecting supply wires 2, 3, and 4 with feed wires 5, 55 6, `and 7, respectively. The contacts 1 are operated by means of coil 8 whichy is energized from supply wires 3 and 4. I

A control coil 9 effects the initial closing of the circuits for coil 8. A retarding device 10 controls the time required for contact 11 to close after being released by the opening of the breaker.

The thermal operated relay having a contact 12 serves to interrupt the circuit of the 65 operating mechanism of the circuit breaker in case of a sustained overload or short circuit. This relay comprises a container that may be formed in one part or may be formed in two parts as shown at 30 and 24. In the 70 latter form, the member 30 is not expansible While the member 24 is expansible and they both contain a highly volatile liquid, being connected by a small tube 3l which has its lower end 32 adjacent the bottom of the 75- container portion 30. The container portion 30 is placed in juxtaposition to the resistance member 23 through which current will pass Whenever the circuit breaker is open for a relatively prolonged period of time. The 30 heat of the member 23 will, in the event of a relatively prolonged opening of the circuit breaker, cause volatilization of a portion of the liquid in the container member 30 with the result that the vapor. produced will rise a5 to the upper portion 33 inv member 30 through the tube 31 into member 24 and thus extend the member 24 to open the contact member 12.

Under normal operation, coil 8 receives 90 energy from wire 3 through overload relay contact 13, wire 14, terminal 15, maintaining contact 16, terminal 17 coil 8, wire 18, contact 12, wire 19, overload contact 29 to wire 4. In the event of overload on wire 2 or 4, 95 either or both of overload contacts 13 and 20 will be momentaril opened, resulting in de-energizing coil 8, wlth the resultant opening of main contacts 1. With the contacts 1 1n open position, the circuit of coil 8 is also 100 the expiration of a short time interval, as determinedby the adjustment of 10,'the circuit of coil 9 is completed. This permits the contact 21 to close the circuit of coil 8 around contacts 15 and 17. This permits coil 8 to ybe again energized and, in closing the main contacts 1, the contact 16 is rst brought into contact with points 15 and 17 after which contact 11 is opened and the parts assume the normal position vshown in lgure 1.

At the instant of opening of main cong tacts 1, an auxiliary contact 22, Figure 2,

closes and com letes the circuit of heating element 23. A er a short time interval, the breaker will again close but, if the overload or short circuit remains, the breaker will again open instantly and the heat element will again be connected so that the cumulative effect ofthe heat generated in 23 will result in vaporizing a portion of the liquid in the container member 30, The vapor will rise to the upper portion 33 of the container 30 and displace a portion of the liquid which will be forced up through the tube 31 and will extend the member 24. The extending of the member 24 will open the contact 12 in a deinite time after the overload or short circuit occurs. Thus if the main breaker remains open for a long time interval, or there isa large aggregate of successive open periods, the main breaker will be'rendered permanently inoperative to reclose. The length of the interval or the number of times the breaker will reclose before heat element 23 raises the pressure in expansion member 24 suciently to operate the contact 12, depends upon the relative timing adjustment of retarding device 10 and heat element 23. This relation may be made any desired value. Contact.12 is preferably so arranged as to remain open permanently after opening until reset by an attendant.

From the foregoing, it will be evident that I have provided van effective means of controlling the operation of a circuit breaker or oil switch, so that momentary overload will not seriously interrupt service on a distributing system, and yet the system will be eectively protected inthe event of a sustained overload or short circuit.

Having thus described my invention, what I claim is: y

1. In a three wire circuit, a plurality of main breakers, a mainbreaker located in each of the said wires, means for automatically reclosing the said breakers, means for rendering said reclosing means inoperative and comprising a switch and a resistance element, a thermostat element located in operative relation to the resistance element, the resistance element energized when the main breakers are open to heat'the thermostat element to cause the thermostat element after a certain time to operate the switch to render the said reclosing means permanently inoperative, if the main breakers remain open for a too long time interval either continuously or an aggregate of successive open periods during the said time interval.

2. In combination with an automatically reclosing'circuit breaker of a means automatically operated to render the reclosing means permanently inoperative if the circuit breaker remains open .for a too long time interval either continuously or an aggregate of successive open periods during said time interval, said means having an element expansible by heating.

` 3. The combination with an automatically reclosing circuit breaker of a means autr matically operative to render the reclosing means permanently inoperative, if the circuit breaker remains open for a too long a time interval, either continuously or an aggregate of successive open periods during said time interval, said means having a switch, an expansible container containing a volatile liquid vaporizable by heating and means for heating the liquid, the switch being operated by the expansibleforce of said i uid. i

qd. In a circuit, a main'breaker located in the said circuit, means for automatically reclosing the said breaker, means for rendering said reclosing means inoperative comprisinga switch, a resistance element and a thermostat element, the thermostat element located in operative relation to the resistance element, the resistance element energized v substantially equal to the said time interval;

In testimony whereof T have hereunto signed my name to this specification.

ESTEL C. RANEY.

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