Download Circuit breakers

United States Patent
[721
[.21]
[32]
I45]
[73]
Inventor
[111 3,551,625
William II. Fischer
Penn Hills, Pa.
[56]
Appl. No. 576,707
Filed
Sept. 1, 1966
Patented Dec. 29, 1970
Assignee
References Cited
UNITED STATES PATENTS
Westinghouse Electric Corporation
3.071.670
3,178,544
3,238,340
1/1963
4/l965
3/1966
1,142,201
1/1963
1,206,056
12/1965
107,686
6/1943
Yeckley et a1. ............. ..
Mayer ........................ ..
Lerch ......................... ..
200/l48(.1)
200/147
200/148(.l)
FOREIGN PATENTS
Pittsburgh, Pa.
a corporation of Pennsylvania
Germany .................... ..
Germany...
200/148(A)
..
200/147
Sweden ...................... ..
ZOO/148(3)
Primary Examiner- Robert K. Schaefer
Assistant E.raminer—Robert A. Vanderhye
Attorneys-A. T. Stratton, C. L. McI-lale and W. R. Crout
CIRCUIT BREAKERS
ABSTRACT: An improved ?uid-blast circuit interrupter is
provided having accelerating coil means electrically switched
12 Claims, 8 Drawing Figs.
[521
[511
200/148,
into the circuit during interruption so as to aid by magnetic at
200/ 1 47
traction movement of a movable piston means. A movable
..I-I01h 33/91
probe means. connected to a pair of accelerating coils, has the
are transferred thereto by a blast of ?uid generated by the
piston means. A movable orifice structure supporting the
US. Cl ...................................................... ..
Int. Cl .............................................. ..
Field of Search .......................................... .. 200/148. 1,
1506,148,148A,148.3,149,l47;335/201,l4,
15,l6,18,l9,149,186,l95;307/136;317/152,
75,11
movable probe means may be utilized, and one of the main
contacts may be apertured to facilitate arc transfer.
3,551,625
1
2
CIRCUIT BREAKERS
mounted in a separate tank if desired. The tank II’ is sup
CIRCUIT BREAKERS
rest upon a suitable'foundation 15. As shown most clearly‘in
This invention relates, generally to circuit breakers and,
more particularly, to interrupters for extinguishing arcs in cir
cuit breakers utilizing a pressurized ?uid as an interrupting
FIG. 1, the beams 14 also support a housing 16 containing a
suitable operating mechanism and a compressor. The tank I]
contains a suitable interrupting ?uid such as, for example, sul
fur hexafluoride (SF.,) gas, at a relatively low pressure. The
medium.
ported by feet I3 which rest upon beams I4, which, in turn,
'
Prior interrupters for use with a pressurized interrupting
medium such as, for example, sulfur hexa?uoride (5H,) gas,
have been of two general types, one a cross-blast interrupter
and, the other, an axial ?ow interrupter. Previous cross-blast
interrupters of the splitter type have the ability to interrupt
high currents, but can be used only at relatively low voltages
tank 12 also contains sulfur hexa?uoride (SF.,) gas at a rela
tively high pressure. The high pressure is maintained by the
compressor, which draws gas from the low pressure tank 11
after an interrupting operation and returns it to the high pres
sure tank 12.
As shown most clearly in FIG. 2, each pole unit comprises a
because of bridging insulation across the open contact mem
pair of terminal bushings 17, a relatively stationary contact
bers. Axial ?ow interrupters have the ability to withstand rela
member 18, a relatively movable contact member I9 and an
interrupter 21. The bushings 17 are mounted upon collars 22
attached to the upper portion of the tank II. The stationary
An object of this invention is to provide a circuit interrupter
contact member 18 and the interrupter 21 may be supported
having the advantages of the high interrupting capacity of a
cross-blast interrupter together with the ability of an axial ?ow 20 by one of the bushings 17. The movable contact member 19
may be pivotally attached to the inner end of the other bush
interrupter to withstand high voltage.
ing 17 as indicated by the reference numeral 20. The movable
Another object of the invention is to utilize an arc splitter in
contact members for all three pole units may be operated by
an interrupter as a probe for connecting either a shunting re
an operating shaft 23, which is connected to each one of the
sistor, or a magnetic driving coil, or both. in the circuit being
interrupted.
‘
25 movable contact members by means of an insulating linkage
24. The shaft 23 may be rotated by means of the operating
A further object of the invention is to provide a multiprobe,
tively high voltages. .
multiori?ce interrupter.
g '
-
'
'
>
Still another~object of the invention is to provide an inter
rupter having the effect of a plurality ofno‘zzles for directing
the ?ow of the interrupting medium.
A still further object of the invention is to provide for utiliz
ing the interrupter as part of a magnetic puffer structure.
Another object of the invention is to provide for inserting a
mechanism which may be of a type well known in the circuit
breaker art.
I
The interrupter 21 comprises a body member 25 which is
constructed to provide an interrupting chamber 26 on the in
side of the body member with an arc splitter 27 disposed
within the chamber 26. The body member 25 and the arc
splitter 27 are preferably composed of an insulating material
such as, for example, polytetra?uoroethylene, which is sold
plurality of magnetic coils into the circuit being interrupted.
Other objects of the invention will be explained fully 35 under the trade name “Teflon."
hereinafter or will be apparent to those skilled in the art.
In accordance with one embodiment of the invention, a cir
cuit breaker is provided with an interrupter of the ?uid~blast
type. The interrupter is so constructed that the ?ow of inter
The interrupting chamber 26 has an inlet opening 28, a
cross-blast exhaust opening 29 and an axial ?ow exhaust open
ing 31. The inlet opening 28 is connected to the high pressure
tank 12 through a blast tube 32 and a blast valve 33. The valve
rupting’fluid is directed across the arc drawn between contact
members of the breaker and also axially along at least one of
the contact members. The are is driven toward an arc splitter
33 is opened, in conjunction with the opening of the breaker
shunting resistor, or a magnetic driving coil, or both, in the cir
cross-blast openings 29. As shown by the arrows in FIG. 3,
part of the ?uid also ?ows through the axial flow exhaust
opening 31 along the movable contact member I9. In this
contact members to admit pressurized ?uid, such as (SF.,) gas,
into the interrupting chamber 26 to extinguish the arc 30
drawn between the contact members when they are separated.
in the interrupting chamber and into a cross-blast opening for
As shown most clearly in FIG. 3. the interrupter is so con
the chamber. The cross-blast and axial ?ow of the fluid
45 structed that the ?ow of the interrupting ?uid is directed
cooperate to extinguish the arc. A conductor or are horn on
across the are 30 to drive it towards the arc splitter 27 into the
the arc splitter engaged by the arc is utilized to connect a
cuit being interrupted.
.
For a better understanding of the nature and objects of the
invention, reference may be had to the following detailed
manner the cross-blast action and the axial flow action
cooperate to extinguish the arc. Such a scheme combines the
description, taken in conjunction with the accompanying
drawings, in which:
advantages of the high interrupting capacity of a cross-blast
of'the breaker being in the closed position;
circuit relation with a portion of the arc by means of an arc
interrupter together with the high voltage withstandability of
FIG. I is a view, in side elevation, of a three-phase circuit
breaker embodying principal features ofthe invention; ’
55 an axial flow interrupter.
In order to still further increase the interrupting capacity of
FIG. 2 is a view, in section taken along the line II—II of FIG.
the interrupter, a shunting resistor 35 is connected in parallel
1, showing one pole unit of the breaker, the contact members
horn or conducting means 36 on the inner end of the arc
FIG. 3 is a view, similar to FIG. 2; the contact members
being in the open position; .
60 splitter 27. The conducting means 36 is connected to one ter
minal of the resistor 35 by a conductor 37. The other terminal
FIG. 4 is a view, in section, ofa modified type ofinterrupter
of the resistor is connected to the stationary contact member
constructed in accordance with the invention. the contact
18. As shown, the resistor 35 may be mounted on the contact
members being closed;
member 18 or it may be supported in any other suitable
FIG. 5 is a view of the interrupter of FIG. 4, the contact "
65 manner. Thus, the resistor 35 is connected in the circuit being
members being partly open;
interrupted. When the arc 30 engages the conducting means
FIG. 6 is a view, in section, ofa combined puffer and inter
36 a portion of the arc current ?ows through the resistor 35.
rupter embodying features of the invention;
The modi?ed interrupter 21' shown in FIGS. 4 and 5 is
FIG. 7 is a view, in section ofa modi?ed interrupter of the
generally similar to the interrupter shown in FIGS. 1, 2 and 3.
type shown in FIG. 6; and
FIG. 8 is a view, in section. of another modified interrupter. 70 The movable contact member I9’ is ofthe reciprocating type.
Also, an axial ?ow exhaust opening 39 is provided around the
Referring to the drawings and particularly to FIGS. 1, 2 and
?xed Contact member I8’. Thus, as shown by the arrows in
3. the circuit breaker shown therein is of the dual pressure
FIG. 5, ?uid ?ows through the exhaust openings 31’ and 39
type having a low pressure tank II and a high pressure tank I2
along both contact members 19' and I8’. Since the contact
mounted on top of the tank I I. As shown, three pole units are
mounted inside the one tank II. Each pole unit may be 75 members are separated from the solid insulating material of
3
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the interrupter by the high dielectric interrupting medium
when in the open position, the voltage withstandability of the
interrupter is increased.
4
The modi?ed-type interrupter shown in FIG. 7 is similar to
the one shown in FIG. 6 with the exception that an additional
arc splitter 72 is provided in the interrupter. A conducting
As shown in FIG. 5, the ?uid ?ow is directed into the inter
member or arc horn 73 is provided on the inner end of the
rupting chamber 26’ to drive the are 38 toward the arc splitter 5 splitter 72. The conducting member 73 may be connected to a
27’ and into the cross~blast exhaust openings 29'. The ?uid
shunting resistor R by means of a conductor 74. Thus, the
?ow is also directed through the exhaust openings 31' and 39
shunting resistor and the magnetic driving coils, previously
to assist in extinguishing the arc. The resistor 35' is connected
described, may be connected in the circuit being interrupted.
in the circuit being interrupted by conducting means 36' and
It becomes more difficult to insert magnetic coils into a cir
cuit as the number of turns (i.e. inductance) increases. It also
conductor 37' in the manner hereinbefore described.
In the modi?cation of the invention‘ shown in FIG. 6, a
puffer mechanism and an interrupter are combined into one
unit. The puffer comprises a relatively movable cylinder 41
and a relatively stationary piston 42 disposed inside the
cylinder 41. A nozzle 43 is formed integrally with a cylinder
head 44. The nozzle 43 is constructed to form an interrupting
chamber 45 inside the nozzle having an axial ?ow tapered ex
becomes more difficult as the amount of current being inter
rupted increases. The present structure can be used with large
inductance coils and large currents. It has this ability since es~
sentially a separate interrupter is used to insert the coils into
the circuit. Also, a relatively long are can be drawn and fresh
un-ionized gas is utilized to extinguish the arc.
FIG. 8 shows an interrupter in which an annular vent 75 is
provided in the interrupter nozzle 76. This has the effect of a
haust opening 46 and a cross-blast opening 47 through the
sidewall of the nozzle 43. A throat opening 48 through the 20 nozzle within a nozzle. Two nozzles are shown in FIG. 8. Addi
tional nozzles could be provided by providing additional annu
cylinder head 44 connects the interrupting chamber 45 with
lar vents, similar to the vent 75. A circular arcing ring 77 is
the area 49 inside the puffer cylinder 41. The cylinder 41 and
provided at the entrance to the annular vent 75 on an arc
the nozzle 43 are composed of a suitable insulating material,
splitter 78. The ring 77 is connected to one terminal ofa radial
such as, for example, polytetra?uoroethylene. The piston 42 is
also composed of a suitable insulating material.
25 magnetic field coil 79 by a conductor 81. The coil 79 is
disposed in a body member 82 in which the contact fingers 51
A plurality of contact ?ngers 51 are pivotally mounted in
the throat opening 48 which extends through the cylinder
head 44. The ?ngers 51 are biased inwardly by a garter spring
52. When the breaker is closed, the contact fingers 51 engage
a relatively stationary contact member 53 which extends
through the nozzle opening 48. The continuous current car
ried by the breaker flows through the contact member 53, the
contact ?ngers 51, and conducting strip.54r and continuous
current collector 55 to a terminal member 56. The current
are mounted. Since this is a conducting member, the other ter~
minal ofthe coil 79 may be connected to the body member as
at 83. Thus, the coil 79 is energized by arc current to produce
a magnetic field which spins the are around the circular arc
ring 77. This reduces the erosion on the contact members and
the insulating nozzle 76. The spinning also enhances interrup
tion.
When the contact member 53' is separated from the contact
collector 55 is biased outwardly by a spring 57. The terminal 35 fingers 51 and the interrupting ?uid ?ows through the throat
opening 48', the are 61 is driven toward the arcing ring 77 and
member 56 may be connected to one terminal of the circuit
breaker L1. Likewise, the contact member 53 may be con
nected to the other terminal L2 of the breaker, thereby
completing a circuit through-one pole unit of the breaker.
When the breaker is opened, the cylinder head 44 is moved
towards the piston 42, thereby compressing the interrupting
into the annular vent 75. Fluid also flows through the nozzle
opening 46 along the contact member 53’. As previously ex
plained, the annular vent 75 functions as an additional nozzle
40 which cooperates with the nozzle opening 46 in extinguishing
the arc. The spinning action produced by the radial magnetic
field coil 79 also assists in'extinguishing the arc. The circuit in
?uid within the cylinder and forcing it through the throat
terrupter of FIG. 8 is described and claimed in my divisional
opening 48 into the interrupting chamber 45. The cylinder 41
patent application referred to above.
may be actuated by pull rods 58 which are attached to pins 59 45
The above-described interrupters may be utilized in a
on the outside of the cylinder wall and are driven by a suitable
number of different ways from low-power, low-voltage to
operating mechanism (not shown).
. When the contact fingers 51 are separated from the contact
high-power, high-voltage circuit breakers. If desired, several
interrupters may be utilized in series for higher voltage appli~
members 53, an are 61 is drawn within the interrupting
Furthermore, other interrupting media such as air, oil,
chamber 45. The flow of ?uid through the throat opening 48 50 cations.
or CO2 may be utilized in place SF“ if desired, As previously
drives the are 61 toward an arc splitter 62 disposed within the
explained, the present structures combine the advantages of
I chamber 45. As shown, the arc is driven into the cross-blast
exhaust opening 47. Part of the ?uid also ?ows through the
nozzle opening 46 along the contact member 53. Thus,_the
cross-blast'action and the axial flow action cooperate to extin
guish the arc.
cross-blast interrupters and axial ?ow interrupters.
Certain features of the instant application‘ are set forth and
claimed in applications ?ied Jan. 26, l965, Ser. No. 428,077
now Pat. No. 3,379,848 by Robert G. Colclaser, Jr. and Frank
L. Reese, and filed Sept. 18, I964, Ser. No. 397,512, now Pat.
No. 3,291,949 by Charles F. Cromer, and assigned to the as
As explained in the copending application Ser. No.
576,739, filed Sept. 1, 1966, now Pat. No. 3,524,959 by R. E.
signee of the instant application.
Frink and assigned to the Westinghouse Electric Corporation,
Since numerous changes may be made in the above
60
the force produced by two spaced magnetic coils, which are
described construction and different embodiments of the in
energized by the current being interrupted may be utilized to
vention may be made without departing from the spirit and
assist in operating the puffer mechanism to drive the interrupt
scope thereof, it is intended that all subject matter contained
ing ?uid into the interrupting chamber. Accordingly, one coil
in the foregoing description or shown in the accompanying
63 is provided in the cylinder head 44 and another coil 64 is 65 drawings shall be interpreted as illustrative and not in a limit
provided in the piston 42. One terminal of the coil 63 is con
ing sense.
nected to a conducting member 65 on the inner end of the arc
lclaim:
splitter 62 by a conductor 66. The other terminal ofthe coil 63
1. A ?uid-blast circuit interrupter including separable main
-
is connected to one terminal ofthe coil 64 through a conduct
contact means for establishing a main current are, piston
ing strip '67, a current collector 68 and a conducting member
means for generating ?uid under pressure and forcing the
69. The other terminal of the coil 64 is connected to the ter
same against the main current arc, electromagnetic means in
minal member 56 by a conducting member 71. Thus, when the
cluding a pair of accelerating coils for assisting the piston
are 61 engages the conducting means 65 on the are splitter 62,
the magnetic driving coils 63 and 64 are connected to be ener
means in rapidly generating fluid under pressure, movable
probe means insulated from the separable main contact means
gized by arc current.
75 electrically connected to said two accelerating coils, and
3,551,625
5
6
means utilizing said generated pressure from the movement of
the piston means for effecting arc transfer from the separable
cludes an ori?ce structure for more positively directing ?uid
flow against the established main current arc.
7. The combination ofclaim 1, wherein one of the separable
main contacts is a nozzle-shaped movable contact.
main contact means to the movable probe means to thereby
insert said two accelerating coils serially into the electrical cir
8. The combination ofclaim 4, wherein the movable operat
ing cylinder carries a nozzle-shaped movable contact
cuit, whereby piston operation is mechanically assisted.
2. The combination according to claim 1, wherein at least
therewith.
9. The combination of claim 8, wherein the other contact is
a relatively stationary plug-type contact penetrating the mova
ble nozzle-shaped contact in the closed-circuit position of the
one of the separable main contact means is a hollow contact
and has the ?uid ?ow passing therethrough.
3. The combination according to claim ' I. wherein the
movable probe means is centrally located with respect to the
interrupter.
stationary contact means.
10. The combination of claim 6. wherein the movable probe
4. The combination of claim 1, wherein the piston means
comprises a movable operating cylinder movable over a rela
means is in the ori?ce structure.
11. The combination of claim 6‘ wherein the orifice struc
tively stationary piston.
ture is movable and provides both lateral and axial venting of
the ?uid under pressure.
12. The combination of claim 1. wherein the fluid is sulfur
5. The combination of claim 4, wherein one of the ac~
celerating coils moves with the movable operating cylinder
and the other accelerating coil is supported by the relatively
stationary piston.
hexa?uoride (SFG) gas.
.
6. The combination of claim 1, wherein the piston means in
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