REMOTE CONTROL CIRCUIT BREAKER SYSTEM

• US 3,706,916 A
• Filed: 01/19/1972
• Issued: 12/19/1972
• Est. Priority Date: 01/19/1972
• Status: Expired due to Term

• Current Assignee: Clyde F. Robbins, John A. Quaal, Lawrence J. Ryczek, Walter L. Rutchik, Werner B. Halbeck
• Original Assignee: Clyde F. Robbins, John A. Quaal, Lawrence J. Ryczek, Walter L. Rutchik, Werner B. Halbeck
• Inventors: Robbins, Clyde F., Halbeck, Werner B., Quaal, John A., Rutchik, Walter L., Ryczek, Lawrence J.
• Primary Examiner(s): Miller, J. D.
• Assistant Examiner(s): Fendelman, Harvey
• Application Number:
  US05/218,955
• Time in Patent Office: 335 Days
• Field of Search: 317/13R,58,60,54,27,33SC,37,132 307/141.8,115,99 335/13
• US Class Current: 361/102
• CPC Class Codes: H01H 75/12 having combined electrothermal and electromagnetic release
• CPC Class Codes: H02H 7/005 for remote controlled apparatus; for lines connecting such apparatus

Abstract

A remote control circuit breaker system in which an electronic logic unit is built into a main electromagnetically operated circuit breaker to act as the controlling interface between the latter and a remotely located pilot control-circuit breaker unit. In addition to directing main circuit breaker operation to provide closing and opening of the same in correspondence with the operation of the pilot unit, the logic unit responds on overload trip open of the main circuit breaker to subject the pilot unit to a controlled value of simulated overload current as will cause the latter to trip open and afford indication of the occurrence of overload tripping in the main circuit breaker. The logic unit also affords coordination of a plurality of such circuit breakers in a multiphase A.C. system so that all will be responsive to the operation of a single remote pilot unit, and will also trip open following overload response of any thereof. Further the logic unit automatically functions in the event of a fault occurring in the pilot unit or the line connecting it with the main breaker to limit the value of fault to a non-destructive value, and prevents repeated circuit breaker cycling in the event the pilot breaker fails to open. The main circuit breaker uses double-break contacts and permanent magnet latching to improve its arc rupture withstandability and eliminate the necessity of continuous energization of its electromagnetic operating coils. The overload trip mechanism in the main circuit breaker uses a low friction latch, and together with ambient temperature compensation in the bimetal latch release enhances the trip point precision.

Claims

1. In remote control circuit breaker system, in combination:

1. a main electro-responsive circuit breaker comprising;

a. main power contacts, b. overload trip contacts, c. means including thermally responsive latch means normally holding said overload trip contacts in open position and responsive to overload current in the circuit in which said main power contacts are connected to unlatch and cause said overload trip contacts to close and said main power contacts to open, d. an armature pivotally movable between two positions to close an open said main power contacts, and e. a pair of electromagnetic means spaced apart on opposite sides of the armature pivot point and energizible alternatEly to move said armature from one to the other of said two positions and vice versa. 2. a pilot control-circuit breaker unit which is manually operable between open and close positions, and which is responsive to current flow therethrough above a given value to trip to open position, and 3. electronic means in circuit with said pilot control-circuit breaker, said electromagnetic means and said overload trip contacts, said electronic means in response to opening and closing of said pilot control circuit breaker energizing the appropriate electromagnetic means to move said armature to one or the other of its positions to afford closed and open positions of said main contacts in correspondence with the operating condition of said pilot control circuit breaker, said electronic means being responsive to closing of said overload trip contacts of a magnitude above said given value to cause opening of the latter.

2. a pilot control-circuit breaker unit which is manually operable between open and close positions, and which is responsive to current flow therethrough above a given value to trip to open position, and

3. The combination according to claim 1 wherein said electronic means has an input power connection with the main power input terminal in the main circuit breaker, and has another input terminal for connection to an optional power source, and wherein said electronic means including means for alternately accepting input power from main input or its optional D.C. input terminals according to which provides power at the higher potential.

4. The combination according to claim 1 wherein said electronic means has silicon controlled rectifiers individual to each of said electromagnetic means, wherein each of said electromagnetic means has associated cutthroat contacts that are connected between the same and its associated silicon controlled rectifier, wherein one or the other of said silicon controlled rectifiers is rendered conducting as a result of manual change of the operating condition of said pilot control-circuit breaker to energize its associated electromagnetic means and cause change in the position of said armature, and wherein the cutthroat contacts associated with a just energized electromagnetic means are opened as a result of said change in the armature position to deenergize its associated silicon controlled rectifier and electromagnetic means.

5. The combination according to claim 4 wherein said electronic means includes means operable in response to closing of the overload trip contacts to prevent energization of the silicon controlled rectifier whose energization results in movement of the armature to contact position open, until the pilot control circuit breaker has tripped open.

6. The combination according to claim 1 wherein said electronic means includes thermistor means which, following closure of the overload trip contacts and occurrence of an electrical fault in either said pilot control circuit breaker or in its connection with said electronic means will increase markedly in its ohmic resistance to limit current flow and thus prevent runaway heat built-up.

7. The combination according to claim 4 wherein said electronic means includes means clamping the control electrode of one silicon controlled rectifier to ground when the other silicon controlled rectifier is energized in correspondence with operation of said pilot control-circuIt breaker.

8. The combination according to claim 1 wherein said electromagnetic means each comprise a core and a pair of separate coils concentrically wound about said core, wherein a common permanent magnet member is in the magnetic circuit between said electromagnetic means, and wherein said electronic means in response to manual closing and opening of said pilot control circuit breaker simultaneously energizes the inner coil of one or the other of said electromagnetic means and the outer coil of the remaining electromagnetic means to buck out the magnetic latching of the armature by the core of said remaining electro-magnetic means and said common permanent magnet member and pivot said armature to its other position wherein it is magnetically latched by the action of the last mentioned magnet member and the core of the first mentioned electromagnetic member.