TECHNICAL FIELD
[0001] The following description relates generally to an air circuit breaker having a temperature
sensor capable of sensing the temperature of an air circuit breaker by connecting
a movable contactor and a stationary contactor to thereby prevent damage to the air
circuit breaker caused by abnormal heating of a conduction unit comprising a current
conduction circuit.
BACKGROUND ART
[0002] Generally, a circuit breaker is an electric protecting apparatus installed between
an electric source and load units in order to protect the load units such as a motor
and a transformer and an electric line from an abnormal current (a large current caused
by i.e., short circuit and a ground fault) generated at an electric circuit such as
a power transmission/distribution line and private power transforming facilities.
In addition, the circuit breaker insulated by insulation at a breaker may manually
open or close an electric line under normal use state, and open or close the line
from a remote distance using an electric manipulation unit outside a metal container
and automatically break the line during over-current and short-circuit to protect
the power facilities and load units.
[0003] The air circuit breaker operates in such a manner that a stationary contactor and
a movable contactor which is movable to a closing position at which the movable contactor
contacts the stationary contactor to close the circuit and to a breaking (trip) position
at which the movable contactor is separated from the stationary contactor to open
the circuit.
[0004] The circuit breaker may be classified into an air circuit breaker, a hydraulic circuit
breaker and a spring circuit breaker according to manipulation method. The circuit
breaker may be also classified into an air circuit breaker (ACB) for distinguishing
are by blowing air, and a gas circuit breaker (GCB) for distinguishing are by blowing
gas according to extinguishing medium of arc generated in the course of separating
the movable contactor from the stationary contactor by manipulation of the breaker.
[0005] FIG. 1 is a perspective view illustrating a schematic construction of a conventional
air circuit breaker and FIG.2 is a side view illustrating a schematic inner construction
of the air circuit breaker.
[0006] Referring to FIGS. 1 and 2, the typical air circuit breakers may largely include
a conduction unit (40) constituting a conduction circuit by connecting a movable contact
point of a movable contactor (42) and a stationary contact point of a stationary contactor
(44), a base mold (10) provided with the conduction unit (40) therein, a detection
unit (20) detecting an accident current and an open/close mechanism (30) operating
the movable contactor (42) in response to a detection signal of the detection unit
(20). The air circuit breaker is mounted with a conduction unit (40) for each phase,
i.e., an R phase (13) conduction unit, an S phase (14) conduction unit and a T phase
(15) conduction unit, as shown in FIG.1.
[0007] Now, the conduction circuit of the air circuit breaker will be described with reference
to FIG.2. The stationary contactor (44) of the conduction unit (41) is connected to
an upper terminal (46) through which current is introduced into the breaker, and the
current introduced into the upper terminal (46) flows to a lower terminal (47) via
the movable contactor (42). When the conduction circuit of the air circuit breaker
is closed, the current flows to the conduction unit (40) to increase the temperature
of the air circuit breaker due to generated heat of conductors including the contact
points.
[0008] When the temperature of the air circuit breaker increases, there is a high likelihood
of the breaker being erroneously operated due to damage caused by the raised temperature.
As a result, the IEC and KS (Korean Standard) requires that a temperature rise of
an air circuit breaker be limited, and a manufacturer make a breaker to comply with
the IEC or KS requirements.
[0009] However, there is many a case where the temperature of a breaker rises due to abnormal
heating of the conduction unit (40) even if the air circuit breaker meets the requirements.
When the air circuit breaker generates a heat above the normal requirement, the breaker
itself gets damaged and wreaks havoc on the power transmission/distribution line due
to failure to break the accidental current. Therefore, it is essential that the temperature
of the conduction unit at the air circuit breaker be monitored in real time to prevent
damage caused by the abnormal heating.
[0010] One of the methods for monitoring the temperature of the conduction unit at the air
circuit breaker is to measure the temperature by intermittently photographing an upper
terminal and a lower terminal using an infrared thermal imaging camera from outside
of the air circuit breaker. However, this method suffers from a disadvantage that
it is difficult to measure an inner temperature of the air circuit breaker although
an external temperature is measurable.
[0011] An installation of a temperature sensor for checking the temperature of the conduction
unit of the air circuit breaker may be considered a possible solution but it is not
that easy to install a temperature sensor at the upper terminal and the lower terminal
where the current flows, such that there has existed no air circuit breaker mounted
with a temperature sensor capable of sensing an abnormal heating in real time.
TECHNICAL SOLUTION
[0012] The present invention has been disclosed to solve the aforementioned disadvantages
and it is an object of the present invention to provide an air circuit breaker having
a temperature sensor capable of monitoring the temperature of the air circuit breaker
at all times, thereby preventing damage of the air circuit breaker caused by an abnormal
heating of a conduction unit constituting a conduction circuit in which a movable
contactor and a stationary contactor are connected.
[0013] The foregoing and other objects, features, aspects and advantages of the present
invention will become more apparent from the following detailed description of the
present invention when taken in conjunction with the accompanying drawings.
[0014] In one general aspect, an air circuit breaker composed of a base mold provided therein
with a conduction unit constituting a conduction circuit by connecting a movable contact
point of a movable contactor and a stationary contact point of a stationary contactor,
a detection unit detecting an accident current, and an open/close mechanism operating
the movable contactor in response to a detection signal of the detection unit, comprises:
a temperature sensor sensing a temperature by being inserted into a sensor insertion
hole formed the base mold, and a temperature display indicating a value detected by
the temperature sensor as a temperature of the conduction unit.
[0015] Implementations of this aspect may include one or more of the following features.
The temperature sensor may be electrically connected to the temperature display via
an external connector.
[0016] The air circuit breaker may further include a resilient member connected to the temperature
sensor, such that the temperature sensor is fixedly inserted into a sensor insertion
hole.
[0017] The temperature display may include an input terminal electrically connected to the
temperature sensor, a compensation unit respectively compensating the temperature
of the movable contactor of the conduction unit, the temperature of the upper terminal
connected to the stationary contactor of the conduction unit and the temperature of
the lower terminal connected to the movable contactor based on the value detected
by the temperature sensor, and a display indicating the respective compensated temperatures.
[0018] The temperature display may further include an output terminal for outputting to
an outside the value detected by the temperature sensor and the compensated temperatures.
[0019] The air circuit breaker may further include a warning device for warning to the outside
that the value detected by the temperature sensor has surpassed a predetermined reference
temperature, if the value detected by the temperature sensor surpasses a predetermined
reference temperature
[0020] The warning device may include a temperature set-up unit for setting up the reference
temperature, an over-heat detection unit determining whether the value detected by
the temperature sensor has surpassed the reference temperature set up by the temperature
set-up unit, and an over-heat notifying unit for notifying that the value detected
by the temperature senor has surpassed the reference temperature as a result of the
determination by the over-heat detection unit that the value detected by the temperature
senor has surpassed the reference temperature.
[0021] The temperature set-up unit is a DIP (Dual Inline Package) switch capable of selecting
a desired reference temperature level out of reference temperature levels classified
into various steps.
[0022] The over-heat detection unit may include an Analog-to-Digital Converter (ADC) converting
the value detected by the temperature sensor to a digital value, and the over-heat
notifying unit may include a digital display indicating the temperature converted
to the digital value by the ADC.
[0023] The over-heat detection unit may generate a control signal in response to the temperature
converted to the digital value by the ADC, and the digital display may include a plurality
of LEDs (Light Emitting Devices) to display the temperature by turning on and off
the plurality of LEDs in response to the control signal generated by the over-heat
detection unit.
[0024] The plurality of LEDs may include an LED-based 7-segment display group where respective
segments are turned on and off to display the digital numbers in response to the control
signal from the over-heat detection unit.
ADVANTAGEOUS EFFECTS
[0025] The air circuit breaker having a temperature sensor according to the present invention
may enable to monitor the temperature of the air circuit breaker at all times via
the temperature sensor and temperature display, thereby preventing damage thereto
caused by an abnormal heating of a conduction unit constituting a conduction circuit
and avoiding an accidental current caused by an erroneous operation of the air circuit
breaker.
[0026] The warning device may immediately notify to a user a failure where the temperature
detected by the temperature sensor has surpassed the reference temperature to thereby
allow the user to address the accidental situation.
[0027] The user may be allowed to set up the reference temperature based on the current
temperature in response to the load and to accurately check the state of the air circuit
breaker at all times.
[0028] As a result, the air circuit breaker may protect power systems from overload caused
by over-current exceeding a critical value, protect the user from the hazard of fire
caused by over-heating inside the air circuit breaker, and prolong the life of the
air circuit breaker by using the breaker on a stable basis.
DESCRIPTION OF DRAWINGS
[0029]
FIG. 1 is a perspective view illustrating a schematic configuration of a conventional
air circuit breaker.
FIG.2 is a side view illustrating a schematic inner configuration of the air circuit
breaker of FIG.1.
FIG. 3 is a perspective view illustrating a schematic configuration of an air circuit
breaker having a temperature sensor according to an exemplary implementation.
FIG.4 is a schematic configuration of a temperature sensor according to an exemplary
implementation.
FIG.5 is a perspective view illustrating a state of the temperature sensor being coupled
to a resilient member according to an exemplary implementation.
FIG.6 is a perspective view illustrating a front base mold formed with a sensor insertion
hole for mounting a temperature sensor to the air circuit breaker according to an
exemplary implementation.
FIG. 7 is a perspective view illustrating a rear base mold coupled to the front base
mold in FIG.5.
FIG.8 is a side view schematically illustrating an air circuit breaker having a temperature
sensor according to an exemplary implementation.
FIG.9 is a plan view illustrating a temperature display according to an exemplary
implementation.
FIG. 10 is a schematic block diagram illustrating configuration of a warning device
according to an exemplary implementation.
FIG.11 is a plan view illustrating a temperature setting unit according to an exemplary
implementation.
BEST MODE
[0030] The object, the construction for achieving the object, and an operational effect
of the air circuit breaker according to the present invention will be clearly understood
through the following description on the implementations of the present invention
made with reference to the accompanying drawings.
[0031] FIG. 3 is a perspective view illustrating a schematic configuration of an air circuit
breaker having a temperature sensor according to an exemplary implementation, FIG.4
is a schematic configuration of a temperature sensor according to an exemplary implementation,
FIG.5 is a perspective view illustrating a state of the temperature sensor being coupled
to a resilient member according to an exemplary implementation, FIG.6 is a perspective
view illustrating a front base mold formed with a sensor insertion hole for mounting
a temperature sensor to the air circuit breaker according to an exemplary implementation,
FIG. 7 is a perspective view illustrating a rear base mold coupled to the front base
mold in FIG.5, FIG.8 is a side view schematically illustrating an air circuit breaker
having a temperature sensor according to an exemplary implementation, FIG.9 is a plan
view illustrating a temperature display according to an exemplary implementation,
FIG. 10 is a schematic block diagram illustrating configuration of a warning device
according to an exemplary implementation and FIG.11 is a plan view illustrating a
temperature setting unit according to an exemplary implementation.
[0032] First, the configuration of an air circuit breaker having a temperature sensor will
be described.
A base mold (110) may include a front base mold (112) and a rear base mold (117) and
be provided therein with a conduction unit (140).
[0033] FIG. 6 refers to the front base mold (112) and FIG. 7 refers to the rear base mold
(117). The base mold (110) is so formed as to have an inner space at places where
each phase (R, S, T phase) is situated. The base mold (110) may be made of insulation
material such as plastic and the like.
[0034] Each phase (R phase, S phase, T phase) of 3-phase alternating current breaker is
provided with the conduction unit (140) as shown in FIG.3.
[0035] The conduction unit (140) may include a movable contactor (142) having a movable
contact point and a stationary contactor (144) having a stationary contact point as
shown in FIG.8. The stationary contactor (144) may be connected to an upper terminal
(146) into which current is introduced, and the movable contactor (142) may be connected
to a lower terminal (147) to constitute a conduction circuit.
[0036] A detection unit (120) may be provided at a front surface of the base mold (110)
to detect an accidental current such as over-current or short-circuited current.
[0037] An open/close mechanism (130) is provided at a front surface of the base mold (110)
to operate the movable contactor (142) of the conduction unit in response to a detection
signal from the detection unit (120).
[0038] A temperature sensor (150) may include a sensor unit (152) for measuring temperatures,
an electric lead line (154) extended from the sensor unit (152), and a connector (156)
connected to the lead line (154) for access to a temperature display (160), as illustrated
in FIG.4. Although the temperature sensor (150) may be directly connected to the temperature
display (160), a connector (160) of the temperature sensor (150) is preferably connected
to a connection terminal (172) of an external connector (170) as the air circuit breaker
is typically mounted with the external connector (170) as shown in FIG.8. In other
words, the external connector (170) is connected to an input terminal (162) of the
temperature display (160) to allow the temperature sensor (150) and the temperature
display (160) to be electrically connected.
[0039] The temperature sensor (150) may be disposed inside the air circuit breaker for measuring
temperature of the conduction unit (140). As it is difficult to directly measure the
temperature of the conduction unit (140), a temperature nearby may be measured for
consideration as the temperature of the conduction unit (140). To this end, an experimental
data may be obtained on relationship between the temperature of the conduction unit
(140) and a temperature where the temperature sensor (150) is installed. As a result,
the temperature where the temperature sensor (150) is located may be considered the
temperature of the conduction unit (140) based on the experimental data.
[0040] The temperature sensor (150) in the three phase (R, S, T) air circuit breaker may
be installed at a base mold between R phase and S phase, and at a base mold between
S phase and T phase. This is because, as described above, an accurate temperature
cannot be measured due to circulating air at the inner space if the temperature sensor
(150) is disposed at the inner space as each base mold (110) has the inner space per
phase. Therefore, as depicted in FIG.6, two sensor insertion holes (115) insertable
by the temperature sensor (150) may be formed at the first rib partition (113) of
a front base mold formed between R phase and S phase, and at a second rib partition
(114) of the front base mold formed between S phase and T phase, and the temperature
sensor (150) may be inserted into the two holes. The sensor insertion hole (115) may
be formed deep enough to enable the measurement of temperature inside the breaker.
The sensor insertion hole (115) may be formed at an inlet side thereof with a guide
groove (116) to prevent the electrical lines of the temperature sensor (150) from
being interfered with other elements of the breaker.
[0041] Preferably, the temperature sensor (150) may be formed in such a manner that a sensor
unit (152) is inserted into a rubbery resilient member (158) to be partially exposed
from the resilient member (158) as shown in FIG.5. The temperature sensor (150) coupled
with the resilient member (158) may be fixedly inserted into the sensor insertion
hole (115) as illustrated in FIGS.3 and 8.
[0042] The temperature display (160) electrically connected to the temperature sensor (150)
is a device for displaying measurement values by compensating the values by the temperature
of the conduction unit (140), whereby a user can monitor the temperature inside the
air circuit breaker in real time.
[0043] Referring to FIG.9, the temperature display (160) may include an input terminal (162)
electrically connected to the temperature sensor (150), a compensator (not shown)
compensating the value measured by the temperature sensor (150) by the temperature
of the conduction unit, and a display unit (164) displaying the compensated temperature
of the conduction unit.
[0044] The compensator (not shown) may work in such a way as to consider the value measured
by the temperature sensor (150) as the temperature of the conduction unit using the
experimental data. At this time, preferably, the values measured by the temperature
sensor (150) are respectively considered as the temperature of the movable contactor
(142) at the conduction unit, the temperature of the upper terminal (146) and the
temperature of the lower terminal and displayed on the display unit (164).
[0045] Preferably, the temperature display (160) may further include an output terminal
for outputting the measured temperatures to the outside, whereby the inner temperature
of air circuit breaker can be monitored in real time from the site where the breaker
is located and from a remote distance as well.
MODE FOR INVENTION
[0046] Meanwhile, referring to FIG.10, the air circuit breaker having a temperature sensor
may further include a warning device (200) warning that the value detected by the
temperature sensor (150) has surpassed a predetermined reference temperature if the
value detected by the temperature sensor (150) is greater than the predetermined reference
temperature. The warning device (200) may comprise any structure, preferably in plural
structure, for notifying the impending danger to users in real time, and notifying
wirelessly to a user in a distant place.
[0047] As shown in FIG.9, the warning device (200) mounted along with the temperature display
(160) may warn to the outside that the value detected by the temperature sensor (150)
has surpassed a predetermined reference temperature if the value detected by the temperature
sensor (150) is greater than the predetermined reference temperature, may visually
warn the user by way of an LED lamp (167), and may audibly warn via a speaker. The
warning device (200) may include a temperature set-up unit (210), an over-heat detection
unit (220) and an over-heat notifying unit (230), as illustrated in FIG.10.
[0048] The temperature set-up unit (210) may be manipulated by a user and set up a reference
temperature that is compared with the values detected by the temperature sensor (150).
In other words, the temperature set-up unit (210) may select (turn on) number 1 from
a DIP (Dual Inline Package) switch where reference temperature level is classified
from number 1 to number 4 per step , and set up the reference temperature by turning
off the other numbers, as illustrated in FIG.11. To be more specific, the temperature
set-up unit may select a desired reference temperature level out of reference temperature
levels classified into various steps using the DIP switch.
[0049] The over-heat detection unit (220) may determine whether the value detected by the
temperature sensor (150) has surpassed the reference temperature set up by the temperature
set-up unit (210). The over-heat detection unit (220) may further include an ADC (Analog-to-Digital
Converter. 225) that converts an analog temperature value detected by the temperature
sensor (150) to a digital value. Successively, the over-heat detection unit (220)
may determine whether the temperature digitally converted by the ADC (225) has surpassed
the reference temperature set up by the temperature set-up unit (210).
[0050] The over-heat detection unit (220) may generate a control signal in response to the
temperature digitally converted by the ADC (225). The control signal may function
as a signal for controlling a digital display (described later. 235), where the digital
display (235) displays the temperature in response to the control signal.
[0051] As a result of the determination by the over-heat detection unit (220), if the value
detected by the temperature sensor (150) has surpassed the set-up reference temperature,
the over-heat notifying unit (230) may notify the fact to the outside. The over-heat
notifying unit (230) may include a warning sound generator (not shown) generating
a warning sound, or a light on-off unit (not shown) turning on or off a light to notify
to the user that the air circuit breaker has been over-heated by the temperature inside
the breaker having surpassed the set-up reference temperature.
[0052] The over-heat notifying unit (230) may further include a digital display (235), and
the digital display (235) may display the digitally-converted temperature by the ADC
(225) of the over-heat detection unit (220) to allow the user to be informed of the
temperature inside the air circuit breaker.
[0053] The digital display (235) may display the temperature using a single color LED, a
tri-color LED or an LED-based 7-segment display group.
[0054] Now, the digital display (235) mounted with the single color LED, the tri-color LED
or the LED-based 7-segment display group will be described in detail.
[0055] The digital display (235) may be mounted with a plurality of single color LEDs (red,
green, blue included) and turn on or off a plurality of predetermined LEDs out of
the plurality of single color LEDs in response to the control signal generated by
the over-heat detection unit (220), or turn on or off the predetermined color LEDs
(red, green or blue) for display of the temperature. The digital display (235) may
be disposed with a tri-color LED and turn on or off a predetermined color LED out
of the tri-color LED in response to the control signal generated by the over-heat
detection unit (220) for display of the temperature. The turning on or off of the
predetermined color using the single color LED or the tri-color LED in the above description
is applicable to a case where colors are pre-defined by classifying the temperatures
per step.
[0056] The digital display (235) may be disposed with at least one or more LED-based 7-segment
displays, and turn on or off a relevant segment of the LED-based 7-segment displays
according to the control signal generated by the over-heat detection unit (220) for
displaying the temperatures in digital numbers.
[0057] To be more specific, the digital display (235) may serve to notify the user the accurate
state inside the air circuit breaker, even if the warning sound generator or light
on-off unit of the over-heat notifying unit (230) fails to function properly. The
digital display (235) may notify the user a current temperature inside the air circuit
breaker to allow the user to set up a reference temperature based on a temperature
commensurate to a current load volume, if the user sets up the reference temperature
inside the air circuit breaker via the temperature set-up unit (210).
INDUSTRIAL APPLICABILITY
[0058] The warning device (200) thus configured and mounted on the air circuit breaker can
break the power supply to load systems when an over-current exceeding a critical value
is generated inside the air circuit breaker, and monitor the temperature inside the
breaker at all times to protect the user against the dangerous fire, thereby allowing
the user to use the breaker stably for a long time.
[0059] As the present concept may be implemented in several forms without departing from
the spirit or essential characteristics thereof, it should also be understood that
the above-described implementations are not limited by any of the details of the foregoing
description, unless otherwise specified, but rather should be construed broadly within
its spirit and scope as defined in the appended claims, and therefore all changes
and modifications that fall within the metes and bounds of the claims, or equivalence
of such metes and bounds are therefore intended to be embraced by the appended claims.
1. An air circuit breaker composed of a base mold (110) provided therein with a conduction
unit (140) constituting a conduction circuit by connecting a movable contact point
of a movable contactor (142) and a stationary contact point of a stationary contactor
(144), a detection (120) unit detecting an accident current, and an open/close mechanism
(130) operating the movable contactor (142) in response to a detection signal of the
detection unit (120), the breaker characterized by: a temperature sensor (150) sensing a temperature by being inserted into a sensor
insertion hole (115) formed the base mold (110), and a temperature display (160) indicating
a value detected by the temperature sensor (150) as a temperature of the conduction
unit (140).
2. The breaker as claimed in claim 1, characterized in that the temperature sensor (150) is electrically connected to the temperature display
(160) via an external connector (170).
3. The breaker as claimed in claim 1, further characterized by a resilient member (158) connected to the temperature sensor (150), such that the
temperature sensor (150) is fixedly inserted into a sensor insertion hole (115).
4. The breaker as claimed in claim 1, characterized in that the temperature display (160) includes an input terminal electrically connected to
the temperature sensor (150), a compensation unit respectively compensating the temperature
of the movable contactor (142) of the conduction unit (140), the temperature of the
upper terminal connected to the stationary contactor (144) of the conduction unit
(140) and the temperature of the lower terminal connected to the movable contactor
(142) based on the value detected by the temperature sensor (150); and a display unit
(164) indicating the respective compensated temperatures.
5. The breaker as claimed in claim 4, characterized in that the temperature display (160) further includes an output terminal for outputting
to an outside the value detected by the temperature sensor (150) and the compensated
temperatures.
6. The breaker as claimed in claim 1, further characterized in that a warning device (200) for warning to the outside that the value detected by the
temperature sensor (150) has surpassed a predetermined reference temperature, if the
value detected by the temperature sensor (150) surpasses a predetermined reference
temperature
7. The breaker as claimed in claim 6, characterized in that the warning device (200) includes a temperature set-up unit (210) for setting up
the reference temperature, an over-heat detection unit (220) determining whether the
value detected by the temperature sensor (150) has surpassed the reference temperature
set up by the temperature set-up unit (210); and an over-heat notifying unit (230)
for notifying that the value detected by the temperature senor (150) has surpassed
the reference temperature as a result of the determination by the over-heat detection
unit (230) that the value detected by the temperature senor (150) has surpassed the
reference temperature.
8. The breaker as claimed in claim 7, characterized in that the temperature set-up unit (210) is a DIP (Dual Inline Package) switch capable of
selecting a desired reference temperature level out of reference temperature levels
classified into various steps.
9. The breaker as claimed in claim 7, characterized in that the over-heat detection unit (220) includes an Analog-to-Digital Converter (ADC.
225) converting the value detected by the temperature sensor (150) to a digital value,
and the over-heat notifying unit (230) comprises a digital display (235) indicating
the temperature converted to the digital value by the ADC (225).
10. The breaker as claimed in claim 9, characterized in that the over-heat detection unit (220) generates a control signal in response to the
temperature converted to the digital value by the ADC (225), and the digital display
(235) includes a plurality of LEDs (Light Emitting Devices) to display the temperature
by turning on and off the plurality of LEDs in response to the control signal generated
by the over-heat detection unit (220).
11. The breaker as claimed in claim 10, characterized in that the plurality of LEDs includes an LED-based 7-segment display group where respective
segments are turned on and off to display the digital numbers in response to the control
signal from the over-heat detection unit (220).