Description
The invention relates to a low-voltage power breaker
having an arc-quenching system, in particular for low-
voltage power breakers having very high rated current
values, in which parallel arc-quenching chamber inserts
are provided in a chamber enclosure which extends over
the entire width of the poles.
Air-break low-voltage switching devices, such as low-
voltage power breakers, require for their operation an
arc-quenching device, in the form of arcing chambers
for cooling and quenching arcs which occur when the
contact is broken, in order to quench any arcs that
occur without adversely affecting the power breaker
itself and adjacent parts of the system or other
assemblies,, since, otherwise, there would be a risk of
the hot and thus ionized arc gases causing electrical
flashovers or resulting in other damage, each arc-
quenching chamber generally comprising a large number
of arc splitter plates which are arranged between two
side walls and contribute to the cooling and quenching
of the arc.
Two fundamentally different physical forms of
conventional arc-quenching devices are known for low-
voltage power breakers. Until now, for large power
breakers, complete arcing chambers produced essentially
in a conventional manner, separately as a component,
i.e. a robust arc-, pressure- and temperature-resistant
enclosure containing arc splitter plates and having a
suitable blowing apparatus.
have been fitted to the power breaker. One arcing
chamber is generally provided per pole. This chamber
has a complete enclosure whose strength is matched to
both the mechanical and the electrical forces of the
arc which occurs in it and is to be quenched, in
particular with regard to the pressure and the
temperature of the switching gases. The arc splitter
plates are located in this chamber. The chamber may in
this case be in the form of a pot-like shaft into which
the plates are inserted, or may be in the form of a
structure composed of half-shells, for which an
apparatus is required, firstly for inserting the plates
into one half-shell, then for fitting the second half-
shell, and finally for connecting the two half-shells.
A second physical form makes use of arcing chamber
inserts, with which only the function of actual arc
quenching can be achieved in one unit. These structures
are, however, not capable of withstanding the pressure
occurring in connection with the arc. These inserts are
therefore inserted in a shaft which is provided in or
on the breaker enclosure. Until now, this physical form
has predominantly been used for small, compact power
breakers, but is increasingly also being used for
larger power breakers where the enclosures surround
these areas, i.e. the switching area and the quenching
area.
With regard to the connection to the main body of the
power breaker and the connection of its individual
parts to one another, both types have the object of
sealing the technically required gaps and joints to
prevent the ionized arc gases passing through them, and
of preventing electrical flashovers caused by gases
which may nevertheless occur.
The arc-quenching chambers can have entirely different
dimensions which are dependent on the dimensions of the
entire contact system, since the arc-quenching chamber
should after all accommodate the arc which runs from
the contact system. In this case, low-voltage power
breakers having a high rated current have, as a
function of the rated or continuous current of the
breaker and as a function of the operation, a very wide
contact system.
The arc-qusnching chamber does not necessarily have to
cover the entire width, rather it is sufficient to join
the arc by means of a horn and then to pass it into a
relatively narrow chamber which is dimensioned such
that it has the switching capacity produced by the
short-circuit switching capacity of the breaker.
If, however, the contact system is wider than the arc-
quenching chamber, this results in a system in which
guides are provided to enable the arc to be formed from
all of the arc elements which may be struck, and in
which the guides guide the arc onto arcing horns which
are proviaed and open into the chamber. This means,
however, that these additional guides are necessary,
which leads to additional complexity in terms of
materials and assembly and to additional expense in
connection with this.
It has been proven, however, that it is advantageous
and expedient if the chamber is as wide as the contact
system and that the arc, irrespective of whether it
runs on the left, the right or in the center, runs into
the arcing chamber where it can become broader.
Extremely wide arc-quenching chambers are, however,
deemed unfavorable to a certain extent with regard
to the quenching behavior in the case of short-circuit
current disconnections. The area available is therefore
advantageously filled in a modular fashion using
smaller inserts.
Such an arrangement is proposed in DE 197 15 116 C2
(WO 98/47161) . In this case, an arcing chamber system
having a chamber body is described in which a large
number of grooves are arranged on the insides of two
opposite side walls, and a number of arcing chamber
modules, which each have two opposite side parts,
between which a large number of arc splitter plates are
in each case arranged, the side parts of the arcing
chamber modules being inserted into the corresponding
grooves in the side walls.
The grooves provided in the walls of the chamber body
reduce the strength of said chamber body, and the base
body must have, overall, a greater material strength.
This means increased use of materials and an increased
weight. A further arc-quenching arrangement is
disclosed in DE 17 46 087 Ul. A number of isolating
profiled bodies are arranged in a retaining frame,
which is formed by two flat elements and two U-shaped
elements, U-shaped profiled bodies and, in between,
double T-shaped profiled bodies in each case being
arranged in the edge regions, such that cavities are
formed between two adjacent profiled bodies. Grooves
are provided on the insides of these cavities for
accommodating arc splitter plates. This arrangement can
be regardeid as an arc-quenching chamber, but no arcing
chamber modules are used and neither is there a chamber
body since the profiled elements are only held together
by a retaining frame.
The object of the invention is thus to provide an arc-
quenching device which can be matched in a simple
manner to a predetermined switching capacity for a
power breaker and which does not have any strength-
reducing 6:lements, such as grooves in the enclosure
walls.
This object is achieved, in the case of an arc-
quenching chamber system, in particular for low-voltage
power breakers having very high rated current values,
in which parallel arc-quenching chamber inserts are
provided in a chamber enclosure which extends over the
entire width of the poles, by the fact that, in a
complete enclosure, the correspondingly large entire
arc-quenching area is divided at suitable intervals
over the main current path by one or more partitions.
Here, these partitions are advantageously part of the
enclosure.
Said partitions are expediently arranged parallel to
one another and equidistant from one another.
Compartments of equal size are then formed in the
entire arc-quenching area. The partitions can, however,
also be arranged at different distances from one
another such that compartments of differing size are
formed.
These different arrangements can be provided, as a
function of a different distribution of the contact
levers, with or without a primary arcing contact and
arcing horn, on the contact support, since the
distribution of base points for the arc elements
forming should also expediently be configured as a
function of the distribution of these contact levers.
An appropriate arc splitter cartridge is inserted in
each of these compartments which are formed by said
partitions.
These arc splitter cartridges comprise a number of arc
splitter plates, which are arranged between two
isolating walls arranged parallel to one another, and
form autonomous components which can be inserted or
withdrawn individually.
In order to support and accommodate the arc splitter
cartridges, the partitions have support elements and
holders for the isolating walls of the arc splitter
cartridges. In order to retain the arc splitter
cartridges in the entire arc-quenching area, one arcing
chamber cover is provided per switching pole. These
arcing chajTiber covers and arc splitter cartridges are
independent of one another and can be inserted and
removed individually.
Arc guide norns are provided on the fixed terminal bar
of the low-voltage power breaker to match the
distribution of the contact levers with or without a
primary arcing contact and arcing horns and the
distribution of the base points for the arc elements by
the arrangement of the arc splitter cartridges. In this
case, one arc guide horn is advantageously arranged on
the fixed terminal bar for each quenching device
element.
The invention will be explained in more detail below
for elucidation purposes with reference to a preferred
exemplary embodiment which does not limit the scope of
the patent.
The single figure shows, in section, an illustration of
A
a three-pole low-voltage power breaker.
The low-voltage power breaker 1 shown in section in the
figure shows the breaker feet 2, 3, the side walls 4, 5
and the three switching poles 6, 7, 8. Here, in the
present example, the switching poles 6, 7, 8 are
illustrated as possible different exemplary
embodiments.
The left-hand switching pole 6 in the figure shows a
conventional arc splitter arrangement 10, which extends
over the entire width of the entire arc-quenching area
9, having arc guide horns 11 located underneath which
are distributed uniformly over the width of the
switching pole 6, as well as the moveable contact
levers 12 on the moveable contact support 13. The upper
closure of the entire arc-quenching area 9 is formed by
a arcing chamber cover 43 which at the same time
performs the function of retaining the arc splitter
arrangement 10. A design of this kind for the quenching
system is customary for conventional contact lever
arrangements in which contact levers without a primary
arcing contact are arranged on the outside and contact
levers with a primary arcing contact are arranged in
the center.
For the central switching pole 7, the entire arc-
quenching area 14 is divided by two partitions 15, 16
such that two narrower compartments 17, 19 are formed
on the lateral edge regions of the entire arc-quenching
area 14, and, in the central region, a wider
compartment 18. The partitions 15, 16 are part of the
enclosure and have support elements 20 and holders 21
for the isolating walls 22, 23, 24, 25, 26, 27 of the
arc splitter cartridges 28, 29, 30. The upper closure
of the entire arc-quenching area 14 is formed by a
arcing chamber cover 44 which at the same time performs
the function of retaining the arc splitter cartridges
28, 29, 30.
For the right-hand switching pole 8, the entire arc-
quenching area 31 is divided by a partition 32 into two
compartments 33, 34 which are both of equal size. The
partition 32 is part of the enclosure in this case too
and has support elements 35 and holders 36 for the
isolating walls 37, 38, 39, 40 of the arc splitter
cartridges 41, 42. The upper closure of the entire arc-
quenching area 31 is formed by a arcing chamber cover
45 which at the same time performs the function of
retaining the arc splitter cartridges 41, 42.
The major advantage of the solution according to the
invention is the fact that the arc splitter cartridges
are held in the arcing chamber. The mechanical
difference is that, instead of the grooves in the
chamber enclosure into which the arc splitter stacks
are pushed, partitions are provided for holding the arc
splitter slacks in the arcing chamber.
WE CLAIM
1. Low-voltage circuit breaker (1) having an arc-quenching system for low-
voltage circuit breakers having very high rated current values, having
parallel arc-quenching chamber inserts (28, 29, 30; 41, 42) arranged in a
chamber enclosure which extends over the entire width of the poles and
surrounds an entire arc-quenching area, one or more partitions (15, 16;
32) which divide the entire arc-quenching area (14; 31) of the chamber
enclosure into compartments (17, 18, 19; 33, 34), being provided for the
purpose of holding the arc-quenching chamber inserts, these partitions
(15,16; 32) are formed as part of the chamber enclosure.
2. Low-voltage circuit breaker as claimed in Claim 1, wherein the partitions
(15, 16; 32) are arranged parallel to one another.
3. Low-voltage circuit breaker as claimed in one of the preceding claims,
wherein the compartments are of different sizes.
4. Low-voltage circuit breaker as claimed in one of the preceding claims,
wherein an appropriate arc splitter cartridge (28, 29, 30; 41, 42) is
inserted in each of these compartments (17, 18, 19; 33, 34) which are
formed by said partitions (15, 16; 32).
5. Low-voltage circuit breaker as claimed in Claim 4, wherein each arc
splitter cartridge (28, 29, 30; 41, 42) comprises a number of arc splitter
plates which are arranged between two isolating walls (22, 23, 24, 25, 26,
27) which are arranged parallel to one another, and wherein said arc
splitter cartridge forms an autonomous component which can be inserted
or withdrawn individually.
6. Low-voltage circuit breaker as claimed in one of the preceding claims,
wherein, in order to support and accommodate the arc splitter cartridges
(28, 29, 30; 41, 42), the partitions (15, 16; 32) have a support elements
and holders for the isolating walls (22, 23, 24, 25, 26, 27) of the arc
splitter cartridges (28, 29, 30; 41, 42).
7. Low-voltage circuit breaker as claimed in Claim 4, wherein, in order to
retain the arc splitter cartridges (28, 29, 30; 41, 42) in the entire arc-
quenching area (9; 14; 31), one arcing chamber cover (43, 44, 45) is
provided per switching pole (6, 7, 8).
8. Low-voltage circuit breaker as claimed in one of the preceding claims,
wherein arc guide horns (11) are provided on the fixed terminal bar of the
low-voltage circuit breaker.
9. The low-voltage circuit breaker as claimed in Claim 8, wherein one arc
guide horn (11) Is arranged on the fixed terminal bar for each quenching
device element.

Low-voltage circuit breaker (1) having an arc-quenching system for low-voltage
circuit breakers having very high rated current values, having parallel arc-
quenching chamber inserts (28, 29, 30; 41, 42) arranged in a chamber enclosure
which extends over the entire width of the poles and surrounds an entire arc-
quenching area, one or more partitions (15, 16; 32) which divide the entire arc-
quenching area (14; 31) of the chamber enclosure into compartments (17, 18,
19; 33, 34), being provided for the purpose of holding the arc-quenching
chamber inserts, characterized in that these partitions (15, 16; 32) are formed as
part of the chamber enclosure.