The present disclosure relates generally to circuit breakers, and particularly to circuit breakers configured to be remotely operated.
Electrical panels typically house a plurality of circuit breakers that distribute power from a source to a plurality of loads while providing protection to the load circuits. The electrical panels may be single-phase, three-phase, or three-phase with switching neutral, may have a variety of voltage ratings, such as 120 Vac to 600 Vac for example, and may have a variety of current ratings, such as 125 Amps to 400 Amps for example, thereby enabling the electrical panels to serve a variety of applications. One such application is a lighting panel, which may be used to service lighting loads in a commercial building having a plurality of lighting circuits. To facilitate the efficient utilization of power in such commercial buildings, remote operated circuit breakers (ROCBs) may be employed that enable the lighting loads to be turned on and off from a location remote to the electrical panel or from within the electrical panel. During the operation of a ROCB, it is desirable to be able to rapidly open and rapidly close the main breaker contacts while the main breaker operating mechanism is in the on position. It is also desirable to be able to decouple the ROCB drive system from the main contacts when the main breaker operating mechanism is in the off or tripped position. While different types of ROCBs may employ different types of drive systems, such as solenoids and electric motors for example, not all drive systems lend themselves to perform as desired without the introduction of complex and costly subsystems. Accordingly, there is a need in the art for a ROCB that overcomes these drawbacks.
An embodiment of the invention includes a circuit breaker configured to be remotely operated. The circuit breaker includes a set of main contacts configured to connect between an electrical source and an electrical load, an operating mechanism in operable communication to open and close the main contacts, and a remotely operable drive system configured to open and close the main contacts separate from actuation of the operating mechanism. The drive system includes a motor responsive to first and second control signals, a primary drive responsive to the motor, and an opening spring responsive to the primary drive, the main contacts being responsive to the opening spring. In response to the first control signal, the primary drive moves to charge the opening spring, and in response to the second control signal and the main contacts being closed, the primary drive moves to allow the opening spring to discharge thereby resulting in the main contacts opening independent of the motor.
Another embodiment of the invention includes a multi-pole circuit breaker configured to be remotely operated. The multi-pole circuit breaker includes a master pole and a slave pole, each pole comprising a set of main contacts configured to connect between an electrical source and an electrical load, an operating mechanism in operable communication to open and close the associated main contacts, and a primary drive in operable communication to open and close the associated main contacts separate from actuation of the associated operating mechanism. A mechanism tie is disposed to operate the master and slave mechanisms together. The master pole further includes a remotely operable motor in operable communication with the master primary drive, and in operable communication with the slave primary drive via a connecting gear. The motor is responsive to first and second control signals to open and close the master and slave main contacts separate from actuation of the master or slave operating mechanisms.
Referring to the exemplary drawings wherein like elements are numbered alike in the accompanying Figures:
An embodiment of the invention provides a remote operated circuit breaker (ROCB) having a unidirectional motor and drive gear that drive a cam and cam follower. The cam follower actuates a crank assembly that serves to charge an opening spring, close the main contacts of the circuit breaker, and open the main contacts of the circuit breaker. The crank assembly interfaces with the main contacts via an intermediate crank and a mechanism crank. The unidirectional drive system of the ROCB is effective to open and close the main contacts only when the circuit breaker operating mechanism is in the on position. In the event that the operating mechanism is in the off or trip position, a decoupler serves to decouple the ROCB unidirectional drive system from the main contacts, thereby preventing the ROCB drive system from operating the main contacts in the event that the circuit breaker is off or tripped. The opening spring and the crank assembly are configured such that the opening and closing action of the main contacts via the ROCB drive system occurs in a quick-make and quick-break fashion. A status indicator flag provides a technician with visual indication of the status of the contacts. A status switch provides status logic to a controller for timely on/off control of power to the motor. A multipole ROCB may be configured by ganging together multiple single pole ROCBs, where only one of the poles, the master pole, which is usually the center pole, has the unidirectional motor. The other poles, the slave poles, are absent the unidirectional motor, being driven instead by a connecting gear that engages with the gear system of the master pole. A common trip bar provides the appropriate logic for common tripping of all poles. To ensure proper alignment and synchronization of all gears in all poles of a multipole ROCB, an alignment clip is used during assembly to position the gears in a set position. Once the multipole ROCB is assembled and operated once, the alignment clip is automatically repositioned out of the way to a non-engaging position. While embodiments described herein depict a ROCB having a specific operating mechanism and main contact structure, it will be appreciated that the disclosed invention may also be applicable to other ROCBs having different operating mechanism and main contact structures.
In an exemplary embodiment, operating mechanism 110 operates in a manner described in commonly assigned U.S. Pat. No. 4,679,016, which is incorporated herein by reference in its entirety.
As a general note, and for descriptive purposes, the several figures described herein depict ROCB 100 and various components of ROCB 100 in either a left side view or a right side view. As used herein, a left side view refers to a view from the left pole side of the circuit breaker with the main contacts 105 toward the left side of the figure, and a right side view refers to a view from the right pole side of the circuit breaker with the main contacts 105 toward the right side of the figure. As such,
Referring now to
Follower surface 166 of cam follower 165 is biased against cam 160, such that as motor 125 drives worm drive 140, worm gear 150 rotates cam gear 155 clockwise (reference to
In response to the motor 125 receiving an open signal, and in reference now to
In view of the foregoing description, it will be appreciated that in response to a first control signal (a charge signal) at motor 125, the primary drive 130 (including cam 160 and follower 165) moves to charge the opening spring 135, and in response to a second control signal (an open signal) and with the main contacts 105 being initially closed, the primary drive 130 (also including first and second cranks 175, 180) moves in the same direction to cause the follower 165 to traverse a drop-off shelf 161 that allows the stored energy in the opening spring 135 to rapidly discharge, thereby resulting in the main contacts 105 being rapidly driven open independent of the speed of the motor 125.
Also in response to the first control signal, and with the main contacts 105 starting from a held open condition, the drive system 115 serves to close the main contacts 105, which will now be discussed with primary reference to
In response to motor 125 receiving a first signal (also herein referred to as a charge-and-close signal), and with reference now to
In view of the foregoing description, it will be appreciated that in response to the first control signal (a charge-and-close signal), with the main contacts 105 being held open and the operating mechanism 110 being in the on position, the motor 125 causes the drive crank system 170 (including first crank 175 and second crank 180) to move in a direction to charge the opening spring 135 while the blocking prop 190 serves to temporarily block movement of the second crank 180, and in response to the opening spring 135 being fully charged, the motor 125 causes the blocking prop 190 to rapidly release its temporary block of the second crank 180, thereby allowing the stored energy in the contact spring 208 to cause the main contacts 105 to rapidly close under the biasing influence of the contact spring 208 and independent of the speed of the motor 125.
Referring now to
Decoupler 225 has an engagement arm 236 at the first end 235 that interfaces with a pick-up tab 193 of blocking prop 190, an engagement surface 237 at the first end 235 that interfaces with drive plate 195 of first crank 175 of drive crank system 170, and an engagement tab 241 at the second end 240 that interfaces with a lobe 217 of mechanism crank 215 (best seen by referring to
In response to operating mechanism 110 being in the on position, and with reference now to
In response to the operating mechanism 110 being in the off position, and with reference now to
In view of the foregoing description, it will be appreciated that in response to the operating mechanism 110 being in the on position, the decoupler 225 allows the drive plate 195 to engage the first crank 175 with the second crank 180, which allows engagement of the drive system 115 with the contact arm assembly 220. It will also be appreciated that in response to the operating mechanism 110 being in the off position, the decoupler 225 disallows the drive plate 195 to engage the first crank 175 with the second crank 180, which disallows engagement of the drive system 115 with the contact arm assembly 220, and that in response to the operating mechanism 110 being in the off position and the motor 125 being responsive to the first or the second control signal, the contact arm assembly 220 is non-responsive to the drive system 115. It will be further appreciated that in response to the operating mechanism 110 being in the on position, the decoupler 225 allows the blocking prop 190 to temporarily block the action of the second crank 180 of the drive crank system 170 in response to the drive crank system 170 moving in a direction so as to cause the main contacts 105 to close, and in response to the operating mechanism 110 being in the off position, the decoupler 225 disallows the blocking prop 190 to temporarily block the action of the drive crank system 170 in response to the drive crank system 170 moving in a direction so as to cause the main contacts 105 to close.
The aforementioned discussion has been made with reference to a first control signal (a charge-and-close signal) and a second control signal (an open signal). However, the ROCB drive system 115 also operates by employing motor-off signals, which are controlled using a status switch. In addition to the use of a status switch, a status indicator is employed for providing a user with a visual indication as to the status of the main contacts 105, which will both now be discussed in more detail.
Referring now to
At a bottom end of status indicator 245 is an actuator tab 248 that is disposed to interface with a flag arm 255 of intermediate crank 200, also depicted in
When ROCB drive system 115 is engaged, as described above, intermediate crank 200 rotates counter-clockwise (reference to
When ROCB drive system 115 is disengaged, as described above, intermediate crank 200 is decoupled from drive system 115, but is still positionable by roller 206 of contact arm 205 (see
In view of the foregoing description, it will be appreciated that the status indicator 245 is in operable communication with the intermediate crank 200 and is configured to indicate a closed main contact condition in response to the operating mechanism 110 being in the on position and the main contacts 105 being closed, and to indicate an open main contact condition in response to the operating mechanism 110 being in the on position and the main contacts 105 being held open.
The above described interaction between intermediate crank 200 and status indicator 245 via flag arm 255, also applies to the interaction between intermediate crank 200 and a status switch 260 (depicted in
For example, with ROCB drive system 115 engaged and a charge-and-close signal present at motor 125, drive system 115 operates in the manner described above to charge opening spring 135 and close the main contacts 105. In response to the blocking prop 190 releasing its temporary hold of second crank 180, intermediate crank 200 is now free to move under the influence of roller 206. With the movement of intermediate crank 200, not only are main contacts 105 committed to close, but also flag arm 255 and switch arm 265 are committed to drive status indicator 245 and status switch 260, respectively. It is this timely change of state of status switch 260 that provides logic to the controller to send a motor-off signal to motor 125, thereby stopping the motor 125 from continuing to run through another cycle.
Similarly, with ROCB drive system 115 engaged and an open signal present at motor 125, drive system 115 operates in the manner described above to discharge the stored energy in opening spring 135 to open the main contacts 105. In response to the intermediate crank 200 rapidly moving to drive the main contacts 105 open via roller 206, so the flag arm 255 and the switch arm 265 also rapidly move to disengage with the status indicator 245 and status switch 260, respectively. It is this timely change of state of status switch 260 that provides logic to the controller to send a motor-off signal to motor 125, thereby stopping the motor 125 from continuing to run through another cycle.
In view of the foregoing description, it will be appreciated that the status switch 260 is in operable communication with the intermediate crank 200 and is configured to indicate a closed main contact state in response to the operating mechanism 110 being in the on position and the main contacts 105 being closed, and is also configured to indicate an open main contact state in response to the operating mechanism 110 being in the on position and the main contacts 105 being held open via the ROCB drive system 115.
It will also be appreciated that in response to the operating mechanism 110 being in the on position and the main contacts 105 being driven open via the ROCB drive system 115 and the intermediate crank 200, the intermediate crank 200 is configured to reposition the status switch 260, thereby causing the status switch 260 to change state in response to operation of the motor 125 and to a change of state at the main contacts 105.
As previously discussed and with reference now to
To facilitate synchronized tripping of all poles of a multi-pole ROCB 100 and with reference now to
With reference first to
With reference now to
In view of the foregoing description, it will be appreciated that the common trip bar 320 is in operable communication with each operating mechanism 110 of each pole of a multi-pole ROCB 100 such that a trip action at one operating mechanism 110 results in a trip action at each operating mechanism 110 of the multi-pole ROCB 100.
In a multi-pole ROCB 100 where only a single motor 125 is employed to drive more than one set of gears in primary drives 130, such as that depicted in
During the assembly of a master pole 300 and before the motor 125 is installed in housing 101, the cam gear 155 is rotated until the follower 165 is positioned against the drop-off shelf 161 of the cam 160, which is herein referred to as the set position. Once the cam gear 155 is in the set position, the motor 125, with worm drive 140 attached, is installed, thereby locking the master pole 300 in the set position.
During the assembly of the slave pole 305, which is absent a motor 125, the cam gear 155 is likewise rotated to the set position, and then the locking member 375 is installed in a first position that engages with and locks the cam gear 155 in place. This first locked position is depicted in
As disclosed, some embodiments of the invention may include some of the following advantages: a unidirectional drive system for remotely operating a circuit breaker; an opening spring for a ROCB configured to open the main contacts independent of the speed of the driving motor and gears that charge the spring; a multi-pole ROCB having a single drive motor; a self-disengaging locking member for proper alignment of the gears of a multi-pole ROCB; a blocking prop for a ROCB configured close the main contacts independent of the speed of the driving motor; a unidirectional drive system for a ROCB capable of producing a quick-make and quick-break action at the main contacts; a decoupler for engaging and disengaging the ROCB drive system depending on the position of the breaker operating mechanism; a common trip bar for synchronized common tripping; a status indicator for providing visual indication as to the status of the main contacts regardless of whether the main contacts are actuated locally or remotely; a status switch for providing logical control for powering the motor on and off; and, a status switch for providing remote indication as to the status of the breaker main contacts.
While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best or only mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.
This application claims the benefit of U.S. Provisional Application Ser. No. 60/557,226, filed Mar. 29, 2004, which is incorporated herein by reference in its entirety.
Number | Date | Country | |
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60557226 | Mar 2004 | US |