Technical Field of the Invention

The present invention relates to an earth leakage breaker, and more particularly to an electronic switching apparatus and method for preventing operational errors caused by a high frequency current and an earth leakage breaker using the same, which can prevent a power supply from being cut off due to operational errors caused by the high frequency current, by primarily connecting an N-phase switching contact due to a time difference between the N-phase switching contact and an R-phase switching contact of a power line when an earth leakage breaker starts to supply the power supply, if a leakage voltage over a set voltage is generated from electric structures such as a street lamp, a traffic signal or an electric pole or the submersion occurs.

Background Art

Usually, a leakage current or a leakage voltage is produced from electric structures such as a street lamp and a traffic signal lamp that are generally installed on a road, all kinds of industrial equipments that are used in factories and housings, and electric appliances such as a bathroom outlet, a washing machine and a refrigerator. If the leakage voltage over a set voltage is generated or a submersion occurs, the power supply must be cut off, so as to prevent an electric shock accident.

Korean Patent Publication No. 10-2004-41001 discloses an electric shock preventer for cutting off a power supply in order to prevent an electric shock accident, when the street lamp and the traffic signal are submerged,

Referring to FIG. 1, the electric shock preventer includes a main circuit breaker 12

for detecting a current state of a commercial power source (i.e., AC power supply) flowing through a gauge 10 from the outside and breaking the power supply of the commercial power source when an overcurrent or a ground current flows; a sub circuit breaker 16 connected to an output terminal of the main circuit breaker 12 with a wire and separated respectively from the wire, for supplying the AC power supply to respective general electric loads and breaking the power supply when the overcurrent or the ground current flows from respective electric loads; a controller 14 for receiving the power supply supplied through the main circuit breaker 12 to output a control signal for lighting a street lamp or a control signal for putting out the street lamp at fixed time interval; a zero sequence current transformer (ZCT) 18 for detecting the leakage current flows from respective electric loads; a relay 20 for outputting a signal of breaking the AC power supply, when the ZCT 18 detects the leakage current, and when the overcurrent is detected from a current transformer 21; a magnet switch 22 for breaking the AC power supply by the control signal from the relay 20; and an electric shock preventer 24 for receiving the AC power supply outputted from the relay 20 to generate the ground current when the submersion occurs or the leakage voltage over a set voltage is generated.

The main circuit breaker 12 and the sub circuit breaker 16 may include, for example, a Molded Case Circuit Breaker (MCCB) or an Earth Leakage Circuit Breaker (ELB/ELCB). The MCCB and ELB are applied to a power supply circuit breaker used for protecting a power load or a line of buildings such as an apartment house, an officetel, and others. The structure of the MCCB or the ELCB breaker such as single-phase 220V has 2 input terminals and 2 output terminals in case of single-phase. In an existing breaker, the MCCB has been used for protecting from the overload and the overcurrent, and the ELCB has been used for protecting from the power leakage, the overload and the overcurrent. Further, the MCCB enables a bimetallic circuit to switch the leakage current breaker off when the overload or the overcurrent is produced, and enables a hand switch to switch the

leakage current breaker on.

The ELCB (or, ELB) further includes a switching circuit for detecting a difference between an input current and an output current to perform a switching operation, when the leakage or the leakage current is produced from the load, using the ZCT 18. The electric shock preventer 24 includes a submersion sensing bar installed on a steel pole, such as a street lamp, a traffic signal or an electric pole, which is spaced by a fixed distance (e.g. 50 mm) from the ground, for sensing a submersion state, a leakage sensing bar where one sensing bar is embedded in the ground, and the other is connected to the steel pole, a leakage voltage and submersion sensing unit for sensing a submersion state from the submersion sensing bar and sensing whether the leakage voltage over a set voltage is generated, using the leakage sensing bar, and a power breaking signal generation unit for controlling so that the ground current, the overcurrent and the short current are sequentially produced, when the leakage voltage and the submersion state is sensed from the leakage voltage and submersion sensing unit. The electric shock preventer 24 is connected to an R-phase switching contact and an N-phase switching contact of the AC power supply of sensing the submersion and the leakage voltage, so that the overcurrent is prevented from being produced, the contact of the magnet switch 22, the main circuit breaker 12 and the sub circuit breaker 16 is prevented from being damaged, and a coil of a current transformer installed on an electric pole is prevented from being damaged. The electric shock preventer 24 also opens the contacts of the magnet switch 22, the main circuit breaker 12, the sub-circuit breaker 16 and so on, when a short current is generated, so that the AC power supply is cut off.

Moreover, the controller 14 is provided with a timer to perform the control so that the street lamp is put out in the daytime and lit up at night. The lighting hour and lights- out hour of the street lamp may be changed according to seasons. However, the controller 14 enables the street lamp to be put out from 5:30 to 20:00 and to be lit up from 20:01 to

05:29. The controller 14 outputs a street lamp control signal to the relay 20 at 20:01 everyday. If so, the current flows into a magnet coil (MC) of a magnet switch 22 by the control of the relay 20, so that switches SWl and SW2 are turned on to light the street lamp. In this time, the switches SWl and SW2 need to be turned on at the same time. However, an N-phase switch is turned on after an R-phase switch is turned on, or the R- phase switch is turned on after the N-phase switch is turned on.

FIG. 2 is a cross-sectional structure diagram of the magnet switch 22 shown in FIG. 1.

The magnet switch 22 includes a floating guide 30 for pressuring the switches SWl and SW2 when a current flows into the MC, a spring 32 that is pressured when the floating guide 30 is pressured and extended when the switch floating guide 30 is not pressured, a first switch contact driving unit 34 connected on one side of the floating guide 30 for connecting or opening a R-phase switch contact of an AC power supply, and a second switch contact driving unit 36 connected on the other side of the switch floating guide 30 for connecting or opening an N-phase switch contact of the AC power supply.

The floating guide 30 is perpendicularly floated in order to pressure the switches SWl and SW2, when the current flows into the MC. In this time, the spring 32 is pressured when the floating guide 30 is pressured and extended when the floating guide 30 is not pressured. When the floating guide 30 is pressured, the first switch contact driving unit 34 connects the R-phase switch contact of the AC power supply. When the floating guide 30 is pressured, the second switch contact driving unit 36 connects the R-phase switch contact of the AC power supply. The first and second switch contact driving units 34 and 36 include a first spring 38 and a second spring 40. When the floating guide 30 is pressured, the first and second springs 38 and 40 are pressured, and thus the first and second switch contact driving units 34 and 36 connect the R-phase and N-phase contacts of the AC power supply.

The conventional magnet switch 22 has a problem as follows. Since the first and second switch contact driving units 34 and 36 are fixed to the floating guide 30 in the same size, the R-phase and N-phase contacts of the AC power supply are not connected at the same time, but at fixed time intervals, by an elastic force or floating of a spring, when the floating guide 30 is pressured in order to light the street lamp, hi this time, if the R- phase contact is first connected, the leakage current produced by a high frequency shown in FIG. 3 flows through a coil of a street lamp ballast stabilizer, and the leakage current due to the high frequency caused by an N-phase cable is amplified. Accordingly, the earth leakage breaker equipped in the relay 20 and the magnet switch 22 becomes down, so that its operational error is produced and thus the street lamp cannot be lighted.

Disclosure of Invention

Therefore, the present invention has been made to solve the above-mentioned problems occurring in the prior art, and an object of the present invention is to provide an electronic switching apparatus for preventing operational errors caused by a high frequency and an earth leakage breaker using the same that can primarily close an N-phase contact due to a time difference between the N-phase contact and a R-phase contact of a power line, when a power supply for lighting a street lamp is applied from an electric shock preventer. Another object of the present invention is to provide an electronic switching device for preventing operational errors caused by a high frequency overcurrent and an earth leakage breaker using the same that can prevent a power supply from being cut off due to an operational error caused by the high frequency overcurrent, when the power supply is applied by a magnet switch in order to light a street lamp. Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having

ordinary skill in the art upon examination of the following or may be learned from practice of the invention.

In order to accomplish the above-mentioned objects, according to one aspect of the present invention, there is provided an earth leakage breaker, which includes a controller configured to receive a power supply applied through a circuit breaker and output a street lamp lighting control signal and a street lamp lights-out control signal at fixed time intervals; a ZCT configured to detect a leakage current flow from each electric load; a relay configured to perform the control so that an AC power supply is cut off when the ZCT detects an leakage current, and sequentially generate switching-on signals of an N-phase switching contact and an R-phase switching contact of the AC power supply with a predetermined time difference, when a street lamp lighting control signal is generated from the controller; a first magnet switch configured to connect the N-phase switching contact of the AC power supply according to the switching-on signal outputted from the relay; and a second magnet switch configured to connect the R-phase switching contact of the AC power supply, after the contact of the first magnet switch is connected.

It is desirable that the predetermined time difference of the relay is 0.1 or 0.2 second.

According to another aspect of the present invention, there is provided an earth leakage breaker, which includes a ZCT configured to receive an AC power supply applied from a circuit breaker and detect a leakage current flow from an electric load; a relay configured to perform the control so that the AC power supply is cut off, when the ZCT detects the leakage current, and generate a power switching-on signal when a power supply control signal is generated from the outside; a timer configured to delay and output the power switching-on signal outputted from the relay for a set time; a first magnet switch configured to connect an N-phase switching contact of the AC power supply according to the switching-on signal outputted from the relay; and a second magnet switch

configured to connect an R-phase switching contact, after the contact of the first magnet switch closes according to the power switching-on signal that is delayed by the set time from the timer.

The set time of the timer is 0.1 or 0.2 second. According to still another aspect of the present invention, there is provided an earth leakage breaker, which includes a circuit breaker configured to detect a current state of an AC power supply (i.e., commercial power) that is applied from outside and cut off the AC power supply, when an overcurrent or a ground current flows; a ZCT configured to detect a leakage current flow from an electric load; a relay configured to perform the control so that the AC power supply is cut off when the ZCT detects the leakage current, and generate a switching-on signal of an R-phase switching contact and an N-phase switching contact of the AC power supply, when a control signal for applying a power supply to the electric load is generated from the outside; and a magnetic switch configured to connect the N-phase switching contact and the R-phase switching contact of the AC power supply, respectively, according to the switching-on signal outputted from the relay; wherein the magnetic switch includes a magnet coil (MC) configured to output a signal for driving a switch according to the power switching-on signal outputted from the relay; and first and second switches configured to connect the N-phase switching contact and the R-phase switching contact of the AC power supply, by being switched on by the driving signal of the MC; and wherein the first and second switches include a floating guide configured to pressure a switch contact to be connected; a spring that is pressured when the floating guide is pressured and extended when the floating guide is not pressured; a first switch contact driving unit, connected to one side of the floating guide, configured to connect or open the N-phase switch contact of the AC power supply; and a second switch contact driving unit, connected to the other side of the floating guide and formed in length shorter

than the first switch contact driving unit, configured to connect or open the R-phase switch contact of the AC power supply.

According to still another aspect of the present invention, there is provided an electronic switching apparatus for preventing operational errors caused by a high frequency of an earth leakage breaker, which includes a magnet coil (MC) configured to output a signal for driving a switch according to a power switching-on signal inputted from the outside; and a first and second switches configured to connect an N-phase switching contact and an R-phase switching contact of an AC power supply, respectively, by being switched on by the driving signal of the MC; wherein the first and second switches include a floating guide configured to pressure switch contacts to be connected; a spring that is pressured when the floating guide is pressured and extended when the floating guide is not pressured; a first switch contact driving unit, connected to one side of the floating guide, configured to connect or open the N-phase switching contact of the AC power supply; and a second switch contact driving unit, connected to the other side of the floating guide and formed in length shorter than the first switch contact driving unit, configured to connect or open the R-phase switch contact of the AC power supply.

The first switch connects the N-phase switching contact of the AC power supply by being driven according to the switch driving signal of the MC, and the second switch connects the R-phase switching contact of the AC power supply, after the contact of the first switch closes.

According to still another aspect of the present invention, there is provided an electronic switching apparatus for preventing operational errors caused by a high frequency of an earth leakage breaker, which includes a timer configured to delay a power switching-on signal inputted from outside for a set time; a first magnet switch configured to connect an N-phase switching contact of an AC power supply according to the power

switching-on signal inputted from the outside; and a second magnet switch configured to connect an R-phase switching contact of the AC power supply according to the power switching-on signal delayed from the timer.

It is desirable that the second magnet switch connects the R-phase switching contact of the AC power supply, after the contact of the first magnet switch closes.

According to still another aspect of the present invention, there is provided an electronic switching method for preventing operational errors caused by a high frequency, which includes connecting primarily an N-phase switching contact; and connecting an R- phase switching contact, after the N-phase switching contact is connected.

BRIEF DESCRIPTION OF THE DRAWINGS

The above objects, other features and advantages of the present invention will become more apparent by describing the preferred embodiments thereof with reference to the accompanying drawings, in which: FIG. 1 is a configuration diagram of a conventional ground breaker;

FIG. 2 is a cross-sectional diagram of a magnet switch shown in FIG. 1 ;

FIG. 3 is a waveform diagram of a high frequency leakage current that is generated by firstly switching-on an N-phase switching contact earlier than an R-phase switching contact of an AC on power; FIG. 4 is a circuit diagram illustrating the configuration of an earth leakage breaker according to an exemplary embodiment of the present invention;

FIG. 5 is a circuit diagram illustrating the configuration of an earth leakage breaker according to another exemplary embodiment of the present invention;

FIG. 6 is a circuit diagram illustrating the configuration of an earth leakage breaker according to still another exemplary embodiment of the present invention;

FIG. 7 is a structure diagram of a first and second switches shown in FIG. 6; and

FIG. 8 is a contact structure diagram of the first and second switches according to still another exemplary embodiment shown in FIG. 6.

Best Mode for Carrying Out the Invention Hereafter, a power switching apparatus for preventing operational errors caused by a high frequency will be explained in detail with reference to the accompanying drawings.

FIG. 4 is a circuit diagram illustrating the configuration of an earth leakage breaker according to an exemplary embodiment of the present invention. The earth leakage breaker includes a circuit breaker 50 configured to detect a current state of a commercial power supply applied from outside and cut off the commercial power when an overcurrent or a ground current flows; a controller 54 configured to receive the power supply applied through the circuit breaker 50 and output a street lamp lighting control signal or a street lamp lights-out control signal at fixed time intervals; a ZCT 52 configured to detect a leakage current flows from each electric loads; a relay 56 configured to perform the control so that the AC power supply is cut off when the ZCT 52 detects the leakage current and sequentially generate switching-on signals of an R-phase switching contact and an N-phase switching contact of the AC power supply with a predetermined time difference (e.g. 0.1-0.2 second), when the street lamp lighting control signal is generated from the street lamp lighting controller 54; a first magnet switch 58 configured to connect the N-phase switching contact of the AC power supply according to the switching-on signal outputted from the relay 56; and a second magnet switch 60 configured to connect the R-phase switching contact of the AC power supply, after the contact of the first magnet switch 58 closes, according to the switching-on signal outputted from the relay 56.

The circuit breaker 50 detects a current state of the commercial power applied

from outside and cuts off the commercial power, when an overcurrent or a leakage current flows. If the circuit breaker 50 is not a bimetallic type, but an embedded shunt coil type, the circuit breaker 50 cuts off the power supply according to a switching-off signal generated from the relay 56. The street lamp lighting controller 54 receives the power supply applied through the circuit breaker 50 and outputs a street lamp lighting control signal and a street lamp lights-out control signal at fixed time intervals. The ZCT 52 receives the AC power supply applied through the circuit breaker 50 and detects the leakage current flow from an electric load. In this time, the relay 56 cuts off the AC power supply when the ZCT 52 detects the leakage current and performs the control so that the AC power supply is cut off, when a ground current and a short current are detected by means of a current transformer. Moreover, the relay 56 controls the first and second magnet switches 58 and 60 to cut off the power supply.

Moreover, when the circuit breaker 50, the relay 56 and the first and second magnet switches 58 and 60 is turned on and thus the power supply is applied. The lighting hour and lights-out hour of the street lamp may be changed according to seasons. However, the controller 54 produces a street lamp lighting control signal and a street lamp lights-out signal so as to enable the street lamp to be put out from 5:30 to 20:00 and to be lit up from 20:01 to 05:29. In this time, the relay 56 generates a first switching-on signal when the street lamp lighting control signal is generated, to turn the first magnet switch 58 on, and generates a second switching-on signal, when a predetermined set time (e.g. 0.1-0.2 second) is elapsed, to turn the second magnet switch 60 on. Since the first magnet switch 58 connects an N-phase switching of the AC power supply, when the power supply is applied, and the second magnet switch 60 connects an R-phase switching contact of the AC power supply in 0.1-0.2 second, so that operational errors caused by a high frequency current explained in FIG. 3 can be prevented.

FIG. 5 is a circuit diagram illustrating the configuration of an earth leakage

breaker according to another exemplary embodiment of the present invention.

The earth leakage breaker includes a circuit breaker 100 configured to detect a current state of a commercial power applied from outside and cut off the commercial power, when an overcurrent or a short circuit current flows; a ZCT 102 configured to receive an AC power supply supplied from the circuit breaker 100 and detects leakage current flows from an electric load; a relay 104 configured to perform the control so that the AC power supply is cut off, when the ZCT 102 detects the leakage current, and generate a power switching-on signal when a power supply control signal is generated from outside; a timer 106 configured to delay and output the power switching-on signal outputted from the relay 104 for a set time (e.g. 0.1-0.2 second); a first magnet switch 108 configured to connect a switching contact of an N-phase switching contact of the AC power supply according to the switching-on signal outputted from the relay 104; and a second magnet switch 110 configured to connect an R-phase switching contact of the AC power supply, after the contact of the first magnet switch 108 closes, according to the power switching-on signal that is delayed by the set time from the timer 106.

The operation of another exemplary embodiment of the present invention will now be explained in detail with reference to FIG. 5.

The circuit breaker 100 detects a current state of a commercial power applied from outside and cuts off the commercial power when an overcurrent or a short circuit current flows. The ZCT 102 receives the AC power supply applied through the circuit breaker 100 and detects leakage current flows from an electric load. In this time, the relay 104 performs the control so that the AC power supply is cut off, when the ZCT 102 detects the leakage current. The relay 104 also performs the control so that the AC power supply is cut off, when the ZCT 102 detects the leakage current. Further, the relay 104 controls the first and second magnet switches 108 and 110, so that the power supply is cut off.

Moreover, when the circuit breaker 100 is turned on and the power is supplied, the

relay 104 generates a power switching-on signal if a power supply control signal is applied from the outside and outputs the switching-on signal to the first magnet switch 108 and the timer 106. In this time, the first magnet switch 108 connects an N-phase switching contact of the AC power supply. Further, the timer 106 receives the power supply control signal outputted from the relay 104, generates a power supply switching-on signal after delaying during a predetermined set time (e.g. 0.1-0.2 second), and approves the generated power supply switching-on signal to the second magnet switch 110, so that the second magnet switch 110 is turned on. When the power is supplied to a load, the first magnet switch 108 connects the N-phase contact of the AC power supply and the second magnet switch 110 connects the R-phase contact of the AC power supply, for example, after 0.1-0.2 second, so that an operational error caused by the same high frequency current as that of FIG. 3 can be prevented.

FIG. 6 is a circuit diagram illustrating the configuration of an earth leakage breaker according to another exemplary embodiment of the present invention. The earth leakage breaker includes a circuit breaker 200 configured to detect a current state of a commercial power applied from the outside and cut off the commercial power when an overcurrent or a leakage current flows; a controller 206 configured to receive a power supply supplied through the circuit breaker 200 and outputs a street lamp lighting control signal and a street lamp lights-out control signal at fixed time intervals; a ZCT 202 configured to detect leakage current flows from each electric load; a relay 204 configured to perform the control so that the AC power supply is cut off when the ZCT 202 detects the leakage current, and generate switching-on signals of an R-phase switching contact and an N-phase switching contact of the AC power supply when a street lamp lighting control signal is generated from the controller 206, and a magnet switch 208 configured to connect the N-phase switching contact and the R-phase switching contact of the AC power supply caused by the switching-on signal outputted from the relay 204.

The magnet switch 208 includes a magnet coil (MC) configured to output a signal for driving a switch according to the power switching-on signal outputted from the relay

204; and a first and second switches 210 and 212 configured to connect the N-phase and

R-phase switching contacts of the AC power supply by being switched on according to the driving signal of the MC.

The first switch 210 connects the switching contact of N-phase of the AC power supply by being driven according to the switch driving signal of the MC. The second switch 212 connects the R-phase switching contact of the AC power supply, after the contact of the first switch 210 closes. FIG. 7 is a structure diagram of the first and second switches shown in FIG. 6.

The first and second switches 210 and 212 include a floating guide 62 configured to pressure the first and second switches 210 and 212 when a current flows into the MC, a spring 64 that is pressured when the floating guide 62 is pressured and extended when the floating guide 62 is not pressured, a first switch contact driving unit 66 connected to one side of the floating guide 62 for connecting or opening the N-phase switch contact of the AC power supply, and a second switch contact driving unit 68, installed in parallel to the first switch contact driving unit 66 and formed in length shorter than the first switch contact driving unit 66, for connecting or opening the R-phase switch contact of the AC power supply. The first and second switch contact driving units 66 and 68 include a first spring

70 and a second spring 72. In the first and second switch contact driving units 66 and 68, the first and second springs 70 and 72 are pressured when the floating guide 62 is pressured, so that the R-phase and N-phase switching contacts of the AC power supply are respectively connected. In this time, the first switch 210 is first turned on and then the second switch 212 is turned on, when the floating guide 62 is pressured by forming the first switch contact driving unit 66 larger than the second switch contact driving unit 68 in

size.

The operation of another exemplary embodiment of the present invention will now be explained in detail with reference to FIGS. 6 and 7.

The circuit breaker 200 detects a current state of a commercial power applied from the outside and cuts off the commercial power when an overcurrent or a ground current flows. The controller 206 receives the power supply applied through the circuit breaker 200 and outputs a street lamp lighting control signal and a street lamp lights-out control signal at fixed time intervals. The ZCT 202 receives the AC power supply applied through the circuit breaker 200 and detects leakage current flows from an electric load. In this time, the relay 204 performs the control so that the AC power supply is cut off when the ZCT 202 detects the leakage current. The relay 204 also controls the first and second magnet switches 208, so that the power supply is cut off.

Moreover, when the circuit breaker 200 and the relay 204 are turned on and the power supply is applied, the lighting hour and lights-out hour of the street lamp may be changed according to seasons. However, the controller 14 generates a street lamp lighting control signal and a street lamp lights-up control signal, so as to enable the street lamp to be put out from 5:30 to 20:00 and to be lit up from 20:01 to 05:29. In this time, the relay 204 generates a power switching-on signal when the street lamp lighting control signal is generated so as to output the produced signal to the MC. The floating guide 62 is pressured by a current flow of the MC. If the floating guide 62 is respectively pressured, the first switch 210 is first turned on and then the second switch 212 is turned on, after 0.1-0.2 second, because length of the first switch contact driving unit 66 is longer than that of the second switch contact driving unit 68.

Accordingly, in order to light the street lamp, when the magnet switch 208 is turned on to apply the power supply, the first switch 210 connects the N-phase switching contact of the AC power supply and the second switch 212 connects the R-phase contact

of the AC power supply, in 0.1-0.2 second, thereby preventing the operational error caused by the high frequency current explained in FIG. 3.

In FIG. 7, length of the first switch contact driving unit 66 is different from that of the second switch contact driving unit 68. Accordingly, the time difference between the N- phase switching contact and the R-phase switching contact of the AC power supply occurs.

However, in FIG. 2, the length of the first switch contact driving unit 34 is the same as that of the second switch contact driving unit 36. Also, as shown in FIG. 8, the N- phase switching contact is always maintained to a short state, and only second switch 212 is turned on according to the power switching-on signal from the relay 204. As a result thereof, when the power supply is applied by turning the magnet switch on in order to light the street lamp, the N-phase switching contact of the AC power supply connected to the first switch 210 is always connected, and when the second switch 212 is connected to the N-phase switching contact of the AC power supply, the R-phase switching contact of the AC power supply is connected, thereby preventing the operational errors caused by the high frequency current as explained in FIG. 3.

Industrial Applicability

As described above, according to the present invention, if the power supply is supplied to a load such as a street lamp at the predetermined set time to light the street lamp, the leakage current caused by the high frequency can be prevented from being generated, and the cutoff of the power supply can be prevented by turning the circuit breaker and the magnet switch off.

Further, when the power is supplied to the load such as the street lamp, the N- phase switching contact of the AC power supply is first connected in comparison with the R-phase switching contact, thereby preventing the circuit breaker and the magnet switch from being turned off by producing the ground current due to the high frequency. In

addition, an administrator can manage the street lamp without moving toward an installation location of the circuit breaker, because the circuit breaker is automatically operated.

The forgoing embodiments are merely exemplary and are not to be construed as limiting the present invention. The present teachings can be readily applied to other types of apparatuses. The description of the present invention is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art.