Patent Application
20120138442
1. Field
The disclosed concept pertains generally to electrical switching apparatus and, more particularly, to circuit breakers including a plurality of separable contacts.
2. Background Information
U.S. Pat. No. 6,614,334 discloses a series arrangement of two circuit breaker mechanisms. The interruption performance of the circuit breaker is determined by the “current limitation of series arcs,” which provides two arcs in series, thereby having twice the resistance of a single arc.
It is known to connect multiple poles of circuit breakers in series to provide a high voltage for a low voltage switching and interruption device (e.g., without limitation, 750 VDC; 1000 VDC; 1500 VAC).
Circuit breakers are typically available in one-, two-, three- and four-pole construction, although larger counts of poles are possible.
For a 1000 VDC application, typically multiple circuit breakers are tied together. Most known existing six-pole or eight-pole air circuit breakers are designed such that the poles are electrically connected internally in breaker structures in a predetermined manner. This limits the flexibility of wiring the six-pole or eight-pole circuit breakers in switchgear and switchboards.
There is room for improvement in electrical switching apparatus, such as circuit breakers including a plurality of separable contacts.
These needs and others are met by embodiments of the disclosed concept, in which an electrical switching apparatus comprises: at least one pole; a plurality of first terminals; a plurality of second terminals; a plurality of pairs of separable contacts; and a plurality of field-configurable jumpers, each of the plurality of field-configurable jumpers electrically connecting two of the pairs of separable contacts in series, each of the plurality of field-configurable jumpers being electrically connected to: (a) two of the first terminals, (b) two of the first terminals or two of the second terminals; or (c) one of the first terminals and one of the second terminals.
N may be an integer count of the at least one pole; the N of the plurality of first terminals may be input terminals; the N of the plurality of second terminals may be output terminals; two of the pairs of separable contacts may be electrically connected in series for each of the at least one pole; and each of the N of the plurality of field-configurable jumpers may be electrically connected between one of the plurality of first terminals that may be not one of the input terminals and one of the plurality of second terminals that may be not one of the output terminals.
The at least one pole may be the integer count N of a plurality of poles structured to power an AC load having the integer count N of a plurality of phases.
Each of the plurality of field-configurable jumpers may be electrically connected to the one of the first terminals and the one of the second terminals.
N may be an integer count of the at least one pole; the N of the plurality of second terminals may be input terminals; the N of the plurality of second terminals may be output terminals; two of the pairs of separable contacts may be electrically connected in series for each of the at least one pole; and each of the N of the plurality of field-configurable jumpers may be electrically connected between two of the plurality of first terminals.
Each of the plurality of field-configurable jumpers may be electrically connected to the two of the first terminals.
Two of the plurality of first terminals may be input terminals; two of the plurality of second terminals may be output terminals; N may be an integer count of the plurality of field-configurable jumpers; two of the pairs of separable contacts may be electrically connected to the output terminals; half of the N field-configurable jumpers may electrically connect half of the pairs of separable contacts in series between one of the input terminals and one of the output terminals; the other half of the N field-configurable jumpers may electrically connect the other half of the pairs of separable contacts in series between the other one of the input terminals and the other one of the output terminals; and the output terminals may be structured for electrical connection to a load.
One of the plurality of first terminals may be an input terminal; another one of the plurality of first terminals may be an output terminal; N may be an integer count of the plurality of field-configurable jumpers; one of the pairs of separable contacts may be electrically connected to the input terminal; another one of the pairs of separable contacts may be electrically connected to the output terminal; the N of the plurality of field-configurable jumpers may electrically connect the pairs of separable contacts in series between the input terminal and the output terminal; and the input terminal and the output terminal may be structured to receive the series combination of a load and a power source.
Each of the plurality of field-configurable jumpers may be electrically connected to the two of the first terminals or two of the second terminals.
A full understanding of the disclosed concept can be gained from the following description of the preferred embodiments when read in conjunction with the accompanying drawings in which:
As employed herein, the term “number” shall mean one or an integer greater than one (i.e., a plurality).
As employed herein, the term “fastener” shall mean screws, bolts and the combinations of bolts and nuts (e.g., without limitation, lock nuts) and bolts, washers and nuts.
As employed herein, the term “electrical conductor” shall mean a wire (e.g., solid; stranded; insulated; non-insulated), a copper conductor, an aluminum conductor, a suitable metal conductor, or other suitable material or object that permits an electric current to flow easily.
As employed herein, the term “low voltage” shall mean a voltage less than or equal to about 1000 VAC or about 750 VDC.
As employed herein, the term “high voltage for a low voltage device” shall mean greater than a “low voltage” and up to approximately 1500 volts, although this may be slightly higher depending upon the application but no more than 2000 volts.
As employed herein, the statement that two or more parts are “connected” or “coupled” together shall mean that the parts are joined together either directly or joined through one or more intermediate parts. Further, as employed herein, the statement that two or more parts are “attached” shall mean that the parts are joined together directly.
The disclosed concept is described in association with six-pole circuit breakers (i.e., having six pairs of separable contacts), although the disclosed concept is applicable to a wide range of electrical switching apparatus having eight poles (i.e., having eight pairs of separable contacts) or any other suitable plurality of poles.
An example six-pole air circuit breaker as disclosed herein can include terminals accessible for every pole for both high voltage (for a low voltage device) AC and DC applications. With accessibility to terminals of each pole, the six-pole circuit breaker can be wired or otherwise configured in different ways. For example, with six poles electrically connected in series, it can be used for applications with systems voltages over 600 VDC. With two poles tied in series, for instance, it can be used for three-phase applications over 600 VAC.
In a “potentially grounded load”, the system ground could be either at the power end or at the load (at the site).
The disclosed concept can be employed, for example and without limitation, for “green” systems (e.g., wind and solar segments).
Referring to
It will be appreciated that the example circuit breakers 100,200,300,400 can be the same or similar devices except for the specific example configurations of the various field-configurable jumpers 110,210,310,410.
For example, with reference to
The three example poles 102 are structured to power an AC load (not shown) having three example phases. It will be appreciated, however, that any suitable number of phases can be employed for either AC or DC loads.
For example, with reference to
The three example poles 202 are structured to power an AC load (not shown) having three example phases. It will be appreciated, however, that any suitable number of phases can be employed for either AC or DC loads.
For example, with reference to
The example load 312 is a DC load, and the example pole 302 is structured to power the DC load. For example, the circuit breaker 300, as configured in
For example, with reference to
The example load 412 is a DC load, and the pole 402 is structured to power the DC load. For example, the circuit breaker 400, as configured in
As shown in
As shown in
While specific embodiments of the disclosed concept have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the disclosed concept which is to be given the full breadth of the claims appended and any and all equivalents thereof.
