US3521127A - Remotely operated circuit breaker - Google Patents

Description

July 21, 1970 1.R. sHAND 3,521,127

REMQTEI OPERATED CIRCUIT BREAKER Filed oct. 13, 1967 2 sheets-sheet INVENTOR .Jo/m R. Sha/1d nited States Patent O 3,521,127 REMOTELY OPERATED CIRCUIT BREAKER John Richard Shand, Easton, Md., assignor to Airpax Electronics, Incorporated, Cambridge, Md., a corporation of Maryland Filed Oct. 13, 1967, Ser. No. 675,177 Int. Cl. H02h 1/00 U.S. Cl. 317-54 2 Claims ABSTRACT OF THE DISCLOSURE A circuit breaker including a remote switch operating a silicon-controlled rectifier coupled in series with a circuit breaker reset coil and a switch mechanically coupled to the circuit breaker so as to be open when the circuit breaker is closed and to be closed when the circuit breaker is open. During operation, with the circuit breaker open, manual or automatic depression of the remote switch lires the SCR which energizes the reset solenoid to close the breaker. When the breaker is closed, a mechanically coupled switch is opened to remove the solenoid current and turn off the SCR. The remote switch must be actuated each time the circuit breaker is to be reset or initially turned on.

BACKGROUND AND DETAILED DESCRIPTION OF THE EMBODIMENTS This invention relates to electrical circuit breakers and, more particularly, any electro-mechanical circuit breaker which includes on-off and reset circuits that can be operated from a remote position by means of an on-otf switch.

An object of this invention is to provide a toggle-type electromagnetic circuit breaker combined in a hermetically sealed package with a rotary type solenoid to provide a circuit breaker arrangement which can be electrically turned on or off, or be reset by a remote switch.

A further object of this invention is to provide a remotely operated circuit breaker which requires application of actuating power for only an instant (less than' .030 sec). Once set on or oiif power is not required to maintain condition.

Briefly described, features of the invention include a remote switch operating a silicon-controlled rectifier in series with a breaker reset coil and a switch mechanically coupled to the circuit breaker so as to be open when thecircuit breaker is closed and to be closed when the circuit breaker is open. During operation, with the circuit breaker open, operation of the remote switch fires the SCR which energizes the reset solenoid to close the breaker. When the breaker is closed, a mechanically coupled switch is opened to remove the solenoid current and turn the SCR off. With a subsequent overload opening of the circuit breaker. the remote switch must again be operated to energize the SCR.

Another object of this invention is to provide a remote reset circuit breaker which will protect multiple loads up to amps, 240- volts A.C. or D.C. and still withstand high vibration and shock conditions while providing long life capability.

Further objects of this invention include providing design in which (l) the circuit breaker cannot be turned on or reset into an overload condition; (2) full reset power is not conducted by external reset control switch thereby minimizing electrical losses when the circuit breaker is a long distance from the reset control switch; and (3) protection is built in against circuit breaker failure when reset is attempted into overload condition.

These and other objects of this invention are set forth in the following detailed description of the invention in conjunction with the appended drawings in which:

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FIG. 1 is a side elevation of the remote reset circuit breaker with the case particularly cut away so the internal parts are exposed.

FIG. 2 is a plan view of the remote reset circuit breaker with the case partially cut away so the internal parts are exposed.

FIG. 3 is a horizontal sectional view of FIG. 2 taken on line 3 3.

FIG. 4 is a schematic diagram of the remote controlled circuit breaker showing both the electrical and mechanical circuits.

It is preferable that the remote control circuit breaker be contained in a hermetically sealed case 1 which is mounted to panel 2 by means of mounting screws 3 which attach to inserts 4 having larger diameter ends on the inside of the case than on the outside. Electrical connections may be conventionally made through pins 5. A 3- pole magnetic circuit breaker, generally indicated as 6, is arranged within the case together with rotary solenoid 7 generally as shown. A separate case 8 is held to the circuit breaker case by screws 9. Circuit breaker 6 can be of any suitable design, for example, of the type described in U.S. Pat. No. 3,251,232 or U.S. patent application Ser. No. 618,001 tiled Feb. 23, 1967 and having a common assignee. One suitable example of rotary solenoid 7 is disclosed in U.S. Pat. No. 2,496,880.

The handle links 16 of circuit breaker 6 are connected by a common pin 15, better seen in FIGS. 2 and 3 where the circuit breaker is illustrated in the off or open condition. The rotor of solenoid 7 is spring biased so that depending pin 14 attached thereto is in the general position illustrated in FIG. 3 when the solenoid 7 is not actuated. When solenoid 7 is actuated against the mechanical bias, as further described below, pin 14 moves to the position shown in phantom carrying pin 15 along with it. Switch mechanism 10, held to case 8 by screws 11 and 13 and flange 12, includes an actuating bar 17 depending into the path of travel for bar 15. As better seen in FIG. 1, bar 15 contacts bar 17 near the end of travel to ensure links 16 have passed beyond the dead point and will remain in the on or closed position when bar 15 contacts bar 17. As can be seen, bar 17 is in the normally closed position and opens the contacts of switch mechanism 10 when moved by bar 15.

Referring now to FIG. 4, a D.C. voltage is normally applied to terminals A and B at all times to provide reset power. In order to turn the breaker on (or reset the breaker after it has responded to an overload condition) external switch 18, which is normally biased to contact a negative side of the source, is actuated. The positive voltage pulse required to cause the silicon-controlled rectifier 22 to conduct is applied from voltage divider resistors 19 and 20 through capacitor 21. With switch 10 normally closed, rotary solenoid 7 is then actuated. As described above, solenoid 7 responds by moving pin 14 in the arc shown in FIG. 3 thereby moving pin 15 and handle links 16 from an off position to an on position. When links 16 have moved far enough to ensure being latched in the on condition, switch 10 is opened by pin 15 moving against bar 17 so as to deenergize solenoid 7 and turn oif SCR 22. The parallel arrangement of diode 23 and capacitor 24 is provided to dissipate the voltage transient generated by solenoid 7 when the series circuit including switch 10 is open.

When solenoid 7 is deenergized, pin 14 returns to its normal position under the mechanical biasing action as described. If switch 18 remains depressed, this will have no effect on the circuit since capacitor 21 is by this time fully charged and furthermore, switch 10 is held open by bar 15. When switch 18 is released, capacitor 21 discharges to the negative side of the power source.

In order to turn the breaker ofi from a remote location, external switch 25 is provided to operate a cut-off solenoid 26. Actuation of switch 2S applies voltage through coil 26 which in turn operates the tripping mechanism within the circuit breaker as described in the aforementioned U.S. Pat. No. 3,251,232. When turned off, bar 15 and links 16 move to the positions shown in FIG. 3 and the breaker is ready for turn on or reset as previously described.

With the breaker in the on condition, if an overload condition or fault develops in the protected circuit, the breaker trips to the open position as described in the aforementioned U.S. patent and patent application. The breaker will open under these circumstances whether or not switch 18 is being depressed.

It will be appreciated that other and further modicaf tions can be made to the herein-disclosed example of the present invention without departing from the spirit and scope thereof.

What is claimed is:

1. A remotely operated circuit breaker comprising handle link means movable between open and closed positions to open and close respectively the associate circuit, solenoid means to move the handle link means from the open to the closed position upon actuation thereof, a normally closed deactivating switch mechanism connected in electrical series with the coil element of said solenoid means and being physically positioned to be opened by the handle link means when the latter is moving toward and near the closed position, a reset circuit including a power supply and reset circuit means operated by a reset switch located remote from the circuit breaker for applying power through said deactivating switch to actuate the solenoid means when the reset switch is depressed, said solenoid means being deactivated when said deactivating switch is opened and said reset circuit means including means to prevent, after the reset switch is depressed, the

reset circuit means from again applying power to the solenoid means until the reset switch is again released and depressed, said solenoid means including a rotary solenoid having a rotor mechanically biased to a deenergized position, a first pin extending from said rotor, said handle link means including a second pin arranged generally perpendicular to the first pin and crossing the arcuate path of movement thereof such that the first pin moves the second pin and remainder of the handle link means toward the latters closed position when the solenoid means is energized.

2. The circuit breaker of claim 1 wherein said deactivating switch includes an actuate bar crossing the travel path of said second pin near the closed position end thereof, said second pin contacting and moving the bar to open said deactivate switch when the second pin moves to the closed position, said rotor in response to the mechanical bias returning to its deenergized position upon the opening of said deactivating switch.

References Cited UNITED STATES PATENTS 2,921,238 1/1960 Wollerton 317-54 XR 2,991,396 7/1961 Schurr.

2,994,805 8/1961 Nash 335-10 XR 3,109,903 11/1963 Lychyk 335-125 3,175,063 3/1965 Rhodes 335-125 3,183,416 5/1965 Circle 317-54 XR 3,213,322 10/1965 Bruderly 335-175 XR 3,214,642 10/1965 Baude 317-54 3,246,100 4/1966 Russell 335-190 XR 3,397,350 8/1968 Garzon 317-54 XR d WILLIAM M. SHOOP, JR., Primary Examiner U.S. C1. X.R. 317-58; 335-125

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