JP2022190500A - Relay and electromagnetic switch - Google Patents

Abstract

To provide a relay that can render a reduced capacitance of a capacitor externally recognizable, and an electromagnetic switch including the same.SOLUTION: A relay includes a capacitor, an output unit that outputs a trip signal to intercept a current flowing in wiring by being operated by the power supplied from the capacitor when a current of a rectified constant current or more flows through the wiring, a control unit for detecting a reduction in the capacitance of the capacitor, and a notification unit for notifying a user or equipment outside the relay of the capacitance reduction when the reduction in capacity is detected by the control unit. There is also provided an electromagnetic switch including the relay.SELECTED DRAWING: Figure 4

Description

The present disclosure relates to relays and electromagnetic switches.

Electronic overload relays are known that detect the load current of a motor, and when the detected load current exceeds a set value, an operating current is passed from a current detection circuit to a polarized electromagnet to open and close the contacts to perform a trip operation. (See Patent Document 1, for example).

WO2008/139533

In some relays, a capacitor is used in the power supply of the output section that outputs a trip signal for interrupting the current flowing through the wiring. However, if the capacitance of the capacitor becomes lower than the capacitance required for the operation of the output section due to aged deterioration or the like, the output of the trip signal may become impossible.

The present disclosure provides a relay capable of making the outside recognize a decrease in capacity of a capacitor, and an electromagnetic switch including the relay.

This disclosure is
a capacitor;
an output unit that outputs a trip signal for interrupting the current flowing through the wiring by operating with the power supplied from the capacitor when a current greater than or equal to the set current flows through the wiring;
a control unit that detects a decrease in capacity of the capacitor;
Provided are a relay and an electromagnetic switch comprising the relay, comprising: a notification unit that notifies the outside of the relay of the capacity reduction when the capacity reduction is detected by the control unit.

According to the technique of the present disclosure, it is possible to let the outside know that the capacitance of the capacitor has decreased.

It is a figure which illustrates an electromagnetic switch provided with the relay concerning one embodiment. 1 is an external perspective view illustrating a relay according to one embodiment; FIG. FIG. 4 is a diagram illustrating functional blocks of a relay according to one embodiment; It is a figure which shows the internal structural example of the relay which concerns on one Embodiment. 4 is a timing chart showing an example of an operation of detecting a decrease in capacity of a capacitor by measuring a decrease in potential due to discharge of the capacitor;

Embodiments will be described below.

FIG. 1 is a diagram illustrating an electromagnetic switch provided with a relay according to one embodiment. An electromagnetic switch 1 shown in FIG. 1 supplies or cuts off power to a load 2 . The electromagnetic switch 1 also protects the load 2 against overload. An electromagnetic switch 1 is connected between a load 2 and a power supply 3 . The load 2 is a device that receives power supply from the power supply 3, and is, for example, an electric motor. The power supply 3 is, for example, a three-phase power supply having U, V and W phases. The electromagnetic switch 1 includes an electromagnetic contactor 10 and a relay 20 .

The electromagnetic contactor 10 supplies or cuts off power from the power source 3 to the load 2 in response to operation of the relay 20 and the like. Magnetic contactor 10 is connected between load 2 and power supply 3 to supply power to load 2 . The magnetic contactor 10 is connected to the load 2 via the relay 20 . In addition, the magnetic contactor 10 is connected to an auxiliary contact 63 (see FIG. 3) which is a b contact (normally closed contact, normally closed contact) of the relay 20 in order to cut off power in the event of an overload. In the relay 20, when an overload is detected, the auxiliary contact 63, which is the b contact, is opened. When the auxiliary contact 63 is opened, the electromagnetic contactor 10 cuts off power to the load 2 . The electromagnetic contactor 10 can protect the load 2 by cutting off the power to the load 2 .

The relay 20 is an example of a protection relay and detects whether the power supplied to the load 2 is overloaded. The relay 20 of this embodiment is also called an electronic overload relay. The relay 20 outputs the detection result to the magnetic contactor 10 or a higher-level device (eg, programmable logic controller, etc.) through auxiliary contacts 62 and 63, which will be described later. The relay 20 is connected to the main terminal of the magnetic contactor 10 on the load 2 side. A relay 20 is provided between the electromagnetic contactor 10 and the load 2 .

FIG. 2 is an external perspective view illustrating a relay according to one embodiment.

The relay 20 includes a main power wiring having one end connected to a main terminal from which the main circuit current of the magnetic contactor 10 is output. In the present embodiment, the relay 20 includes a main wiring 25a having one end connected to the U-phase main terminal of the magnetic contactor 10, a main wiring 25b having one end connected to the V-phase main terminal of the magnetic contactor 10, and A main wiring 25 c having one end connected to the W-phase main terminal of the magnetic contactor 10 is provided. The relay 20 includes a main terminal 22a, a main terminal 22b, and a main terminal 22c as a plurality of main terminals that output the main circuit current to the load 2. As shown in FIG. The main terminals 22a, 22b, and 22c are, for example, screw terminals. The main terminal 22a is connected to the other end of the main wiring 25a, the main terminal 22b is connected to the other end of the main wiring 25b, and the main terminal 22c is connected to the other end of the main wiring 25c.

The relay 20 includes an auxiliary contact terminal portion 23A and an auxiliary contact terminal portion 23B. The auxiliary contact terminal portion 23A and the auxiliary contact terminal portion 23B are used to output trip signals.

The auxiliary contact terminal portion 23A includes an auxiliary terminal 23Aa and an auxiliary terminal 23Ab. The auxiliary terminal 23Aa and the auxiliary terminal 23Ab are connected to an auxiliary contact 62 (see FIG. 3) which is an a-contact (normally open contact, normally open contact), which will be described later. The circuit between the auxiliary terminal 23Aa and the auxiliary terminal 23Ab is normally open. When the later-described control unit 50 in the relay 20 detects an overload, the circuit between the auxiliary terminals 23Aa and 23Ab is closed.

The auxiliary contact terminal portion 23B includes an auxiliary terminal 23Ba and an auxiliary terminal 23Bb. The auxiliary terminal 23Ba and the auxiliary terminal 23Bb are connected to an auxiliary contact 63 (see FIG. 3) which is a b contact (normally closed contact, normally closed contact). A circuit is normally closed between the auxiliary terminal 23Ba and the auxiliary terminal 23Bb. When the later-described control unit 50 in the relay 20 detects an overload, the circuit between the auxiliary terminals 23Ba and 23Bb is opened.

The relay 20 internally includes a main wiring 25a, a main wiring 25b, and a main wiring 25c. Electric power from the power source 3 is input to the main wiring 25a, the main wiring 25b, and the main wiring 25c. The input electric power is transmitted through the main wiring 25a, the main wiring 25b, and the main wiring 25c, respectively, and is output from the main terminals 22a, 22b, and 22c, respectively.

The relay 20 according to this embodiment includes a setting dial 27 and a reset button 28, as shown in FIG. A setting dial 27 is a dial for setting a settling current. The settling current is set according to the rated current value of the load 2 . The setting dial 27 is an example of an operation unit that receives an operation for setting the settling current. The reset button 28 is a button for restoring after overload is detected.

FIG. 3 is a diagram illustrating functional blocks of a relay according to one embodiment. Note that FIG. 3 also shows elements related to the relay 20 .

The relay 20 includes a current transformer 26a, a current transformer 26b, and a current transformer 26c in the middle of each of the main wiring 25a, the main wiring 25b, and the main wiring 25c. The current transformer 26a, the current transformer 26b, and the current transformer 26c are sensors that detect currents flowing through the main wiring 25a, the main wiring 25b, and the main wiring 25c, respectively.

The relay 20 includes a detection section 30 , a power supply section 40 , an output section 60 , an adjustment section 70 , a control section 50 and a notification section 80 .

The detection unit 30 includes a rectifier circuit that rectifies currents obtained by the current transformers 26a, 26b, and 26c, and a measurement circuit that converts the currents rectified by the rectifier circuits into a plurality of analog voltage signals. is a detection circuit having A plurality of analog voltage signals output from the measurement circuit are current detection signals representing the magnitude of the main circuit currents flowing through the main wiring 25a, the main wiring 25b, and the main wiring 25c. By obtaining these current detection signals, the control unit 50 detects the magnitude of the main circuit current flowing through each of the main wiring 25a, the main wiring 25b, and the main wiring 25c.

The power supply unit 40 is a power supply circuit that receives the current rectified by the rectification circuit of the detection unit 30 and generates each power supply voltage in the relay 20 . The power supply unit 40 supplies the generated control power supply voltage to the control unit 50 and supplies the generated drive power supply voltage to the drive unit 61 . The power supply unit 40 may generate each power supply voltage in the relay 20 based on the power acquired from the main wirings 25a, 25b, and 25c via the detection unit 30, or may be supplied from an external power supply (not shown). Each power supply voltage within the relay 20 may be generated based on the power.

When a current greater than or equal to the set current flows through any one of the main wirings 25a, 25b, and 25c, the output section 60 is operated by the power supplied from the power supply section 40, so that the current flows through the main wirings 25a, 25b, and 25c. It is an output circuit that outputs a trip signal for interrupting the current. The output section 60 has an auxiliary contact 62 , an auxiliary contact 63 and a drive section 61 .

The auxiliary contact 62 is an a-contact (normally open contact, normally open contact). The auxiliary contact 63 is a b contact (normally closed contact, normally closed contact). Each of the auxiliary contacts 62 and 63 is driven to open or close by the driving section 61 . Specifically, when the drive unit 61 is not powered and is not driven by the drive unit 61, the auxiliary contact 62 is open and the auxiliary contact 63 is closed. On the other hand, in a state in which power is supplied to and driven by the driving portion 61, the auxiliary contact 62 is closed and the auxiliary contact 63 is open.

Auxiliary contact 62 is used, for example, to ignite the lamp by wiring between the indicator light and the power supply. Further, the auxiliary contact 63 is arranged, for example, between the operating circuit of the electromagnetic contactor 10 and the power supply. The auxiliary contact 63 is wired between the operating circuit of the electromagnetic contactor 10 and the power supply, thereby forming a circuit that the electromagnetic contactor 10 releases when the relay 20 operates.

The drive unit 61 drives the auxiliary contact 62 and the auxiliary contact 63 to open or close. The drive unit 61 includes, for example, an electromagnet. The drive unit 61 causes the electromagnet to generate electromagnetic force by, for example, supplying power from the capacitor in the power supply unit 40 to the coil of the electromagnet in the drive unit 61 based on the discharge control signal from the control unit 50 . The generated electromagnetic force drives the auxiliary contacts 62 and 63 .

The adjustment unit 70 outputs to the control unit 50 a threshold value (settling current) adjustment signal that determines a trigger for outputting a trip signal from the auxiliary contact 62 and the auxiliary contact 63 in response to a setting operation input from the setting dial 27 .

The control unit 50 is a control circuit that controls the entire relay 20, and controls power supply to the driving unit 61 and the like. The control section 50 sets the settling current according to the adjustment signal acquired from the adjustment section 70 . When a current equal to or higher than the set settling current is detected based on the detection signal from the detection unit 30, the control unit 50 permits the output of the drive current from the power supply unit 40 to the drive unit 61, and the auxiliary contact 62 and the auxiliary contact 62 The contact 63 is activated.

The power supply unit 40 has a trip capacitor charged with power obtained from the main wirings 25a, 25b, 25c via the current transformers 26a, 26b, 26c and the detection unit 30 . The power supply unit 40 discharges the charge accumulated in the trip capacitor to the drive unit 61 when the discharge control signal from the control unit 50 is input. As a result, the drive unit 61 trips the auxiliary contact 62 and the auxiliary contact 63 .

By driving the normally open contact (a contact), for example, by the trip operation, an indicator lamp (not shown) is lit to notify the user of the trip operation. Further, by driving the normally closed contact (b contact), a trip signal is output, demagnetizing the coil of the electromagnetic contactor 10 provided in the main circuit, and opening the main circuit. By opening the main circuit, overloading of the load 2 can be prevented. In this manner, the magnetic contactor 10 cuts off the current flowing through the main wirings 25a, 25b, 25c based on the trip signal.

If the relay 20 is of an external power supply type, even if the main circuit is interrupted by the electromagnetic contactor 10 after a trip, power is supplied from the power supply wiring provided separately from the main circuit. Therefore, the holding of the steady state or the tripped state, or the holding of both the steady state and the tripped state can be performed by the attractive force of the electromagnet in the driving section 61 .

Further, when the relay 20 is self-powered and the main circuit is cut off by the electromagnetic contactor 10 after tripping, power is no longer supplied from the main wirings 25a, 25b, 25c. Therefore, only a small amount of electric power stored in the capacitor or the like in the power supply section 40 can be used to maintain the steady state or the tripped state. Therefore, the relay 20 may be configured to maintain the holding state using the attraction force of a permanent magnet, a mechanical mechanism, or the like, or may be configured to manually or automatically return from the tripped state to the steady state. good.

The control unit 50 according to this embodiment has a function of detecting a decrease in capacity of the trip capacitor in the power supply unit 40 . The notification unit 80 is a notification circuit that notifies the outside of the relay 20 of the decrease in the capacity of the tripping capacitor when the control unit 50 detects the decrease in the capacity of the tripping capacitor.

By notifying the outside of the relay 20 of the decrease in capacity of the tripping capacitor, a user or device outside the relay 20 can recognize the deterioration of the tripping capacitor inside the relay 20 . As a result, the user can be urged to repair or replace the relay 20, so that, for example, it is possible to prevent the capacity of the capacitor from decreasing below the capacity required for the operation of the output section 60 due to deterioration over time. .

Next, an internal configuration example of the relay 20 will be described in more detail.

FIG. 4 is a diagram showing an internal configuration example of a relay according to one embodiment. FIG. 4 shows a configuration example of the power supply unit 40, the output unit 60, and the control unit 50. As shown in FIG.

The power supply unit 40 is a power supply circuit that charges a capacitor 45 based on power input from the main wirings 25a, 25b, 25c via the current transformers 26a, 26b, 26c and the detection unit 30 . The power supply unit 40 has a constant voltage circuit 41 , a step-down circuit 42 , a diode 43 , a capacitor 45 , a potential monitoring circuit 44 and a discharge control switch 46 .

The constant voltage circuit 41 is a power supply circuit that generates a constant voltage based on the power of the main wirings 25a, 25b, and 25c obtained via the detection section 30. FIG. The step-down circuit 42 steps down the constant voltage generated by the constant voltage circuit 41 to generate a control power supply voltage (for example, 3.3 volts) lower than the constant voltage. The microcomputer 51 of the control unit 50 operates with the control power supply voltage.

The constant voltage circuit 41 charges the capacitor 45 via the diode 43 with the generated constant voltage. A capacitor 45 is a trip capacitor used as a power source for driving the output section 60 . Specific examples of the capacitor 45 include capacitive elements such as aluminum electrolytic capacitors and electric double layer capacitors.

The potential monitoring circuit 44 monitors the potential Vc of the capacitor 45 (also called capacitor voltage). The potential monitoring circuit 44 monitors the potential Vc by dividing the capacitor voltage by the voltage dividing circuit, and supplies the monitoring result to the microcomputer 51 of the control unit 50 . The voltage dividing circuit divides the capacitor voltage by resistors 44a and 44b, for example.

The discharge control switch 46 operates according to a discharge control signal supplied from the microcomputer 51 of the controller 50 . The discharge control switch 46 is, for example, a switching element such as a field effect transistor.

The output unit 60 has an electromagnetic relay 64 that outputs a trip signal when excited by the power supplied from the capacitor 45 . Electromagnetic relay 64 has auxiliary contact 62 , auxiliary contact 63 , electromagnet 65 and plunger 66 . Electromagnet 65 and plunger 66 are an example of drive unit 61 described above. Auxiliary contact 62 and auxiliary contact 63 interlock with the linear movement of plunger 66 .

The controller 50 has a charge control switch 52 . The charge control switch 52 operates according to a charge control signal supplied from the microcomputer 51 of the control section 50 . The charge control switch 52 is, for example, a switching element such as a field effect transistor.

The control unit 50 has a microcomputer 51 . The microcomputer 51 has a function of detecting a current equal to or higher than the set current, a function of detecting deterioration of the capacitor 45, and the like. The microcomputer 51 has a processor such as a CPU (Central Processing Unit), a memory, and the like. Each function of the control unit 50 is realized by the processor operating according to the program stored in the memory. Each function of the control unit 50 may be implemented by an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit).

When the microcomputer 51 of the control unit 50 detects that the current detected by the current transformers 26a, 26b, 26c and the detection unit 30 is equal to or higher than the set current, a trip signal is output from the auxiliary contacts 62 and 63. control so that Specifically, the controller 50 turns on the discharge control switch 46 to excite the electromagnet 65 with the power supplied from the capacitor 45 . When the electromagnet 65 is excited, the plunger 66 moves, so that the auxiliary contact 62, which is an a-contact (normally open contact, normally open contact), is closed and a b-contact (normally closed contact, normally closed contact). The auxiliary contact 63 is opened. A state in which the current value of the main circuit current is greater than the settling current may be referred to as an overload state.

In this embodiment, the state in which the auxiliary contact 63 is open is defined as the state in which the trip signal is output. By outputting the trip state, the above-described electromagnetic contactor 10 cuts off current flow in the main wirings 25a, 25b, and 25c.

The microcomputer 51 of the control unit 50 detects the capacity of the capacitor 45 by monitoring the potential Vc of the capacitor 45 with the potential monitoring circuit 44 in order to avoid the problem that the output of the trip signal becomes impossible due to the decrease in the capacity of the capacitor 45. do. The microcomputer 51 detects a decrease in capacity of the capacitor 45 by, for example, measuring a decrease in potential due to discharge of the capacitor 45 . According to such a measuring method, a decrease in capacity of the capacitor 45 can be detected relatively easily.

FIG. 5 is a timing chart showing an example of the operation of detecting a decrease in capacity of a capacitor by measuring a decrease in potential due to discharge of the capacitor. t represents time. The microcomputer 51 stops the output of the constant voltage circuit 41 by turning on the charge control switch 52 . As a result, the charging of the capacitor 45 is stopped, so that the influence of the charging of the capacitor 45 from the constant voltage circuit 41 on the measurement accuracy of the potential Vc of the capacitor 45 can be suppressed. The microcomputer 51 discharges the capacitor 45 while stopping the charging of the capacitor 45 by the constant voltage circuit 41 .

As an example of a method for detecting a decrease in the capacity of the capacitor 45, the microcomputer 51 detects that the measured value of the potential Vc of the capacitor 45 becomes equal to or lower than a predetermined discharge start potential V0, and the capacitor 45 is kept for a preset fixed discharge time ΔT. Discharge. The microcomputer 51 measures the potential V1 of the capacitor 45 at the discharge end time T1 when the discharge time ΔT has elapsed from the discharge start time T0 of the capacitor 45 . As the deterioration of the capacitor 45 progresses (as the capacity decreases), the capacitor potential at the discharge end time T1 decreases. Using this characteristic, the microcomputer 51 determines that the capacity of the capacitor 45 is decreased when the measured potential V1 is lower than a predetermined threshold potential.

As another example of a method for detecting a decrease in capacity of the capacitor 45, the microcomputer 51 detects the elapsed time from the discharge start time T0 of the capacitor 45 when the measured value of the potential Vc of the capacitor 45 becomes equal to or lower than the predetermined discharge start potential V0. is started by a timer. The microcomputer 51 measures the discharge time ΔT from when the measured value of the potential Vc of the capacitor 45 becomes equal to or lower than the predetermined discharge start potential V0 to when it drops to the preset discharge end potential V1 (V1=V0 -ΔV). There is a characteristic that the discharge time ΔT shortens as the deterioration of the capacitor 45 progresses (as the capacity decreases). Using this characteristic, the microcomputer 51 determines that the capacity of the capacitor 45 has decreased when the measured discharge time ΔT is shorter than a predetermined threshold time.

It should be noted that the method of detecting a decrease in the capacity of the capacitor 45 is not limited to these, and other methods may be used.

The microcomputer 51 turns on the discharge control switch 46 as shown in FIG. 5 to start discharging from the capacitor 45 to the coil of the electromagnet 65 of the output section 60 . The microcomputer 51 may detect a decrease in capacity of the capacitor 45 by measuring a decrease in potential of the capacitor 45 due to discharge from the capacitor 45 to the output section 60 . This makes it possible to simplify the configuration for detecting a decrease in the capacity of the capacitor 45 compared to a configuration (not shown) in which a dedicated discharge circuit for discharging the charge of the capacitor 45 is installed in parallel with the capacitor 45 in order to detect the capacity of the capacitor 45. can be As a result, the size of the relay 20 can be reduced.

In FIG. 4 , when the microcomputer 51 is set to a predetermined test mode, the capacitor 45 may be discharged, and the decrease in the capacity of the capacitor 45 may be detected by measuring the potential decrease due to the discharge of the capacitor 45 . As a result, the operation mode of the relay 20 can be classified into a test mode in which a decrease in the capacity of the capacitor 45 is detected and a steady mode in which a trip signal is output when a current exceeding the set current is detected during normal operation of the relay 20. By dividing the operation modes in this manner, it is possible to prevent the discharge operation for detecting the decrease in the capacity of the capacitor 45 and the output operation of the trip signal from overlapping in the steady mode. The test mode is an operation mode set when detecting a decrease in capacity of the capacitor 45 . The test mode is also called inspection mode or inspection mode.

For example, when the microcomputer 51 is set to a predetermined test mode, the capacitor 45 discharges to the coil of the electromagnet 65 of the output section 60 so as to output a trip signal, and the potential drop due to the discharge of the capacitor 45 is measured. By doing so, a decrease in capacity may be detected. This prevents the trip signal output in the test mode from being misunderstood as the trip signal output when a current greater than or equal to the set current is detected. In addition, it is possible to prevent the operation of outputting a trip signal for detecting a decrease in the capacity of the capacitor 45 from being unintentionally performed during normal operation of the relay 20 .

The test mode may be set, for example, by operating the setting dial 27 (see FIG. 2) to the test mode setting position. As a result, the setting dial 27 can be used both for setting the settling current and for setting the test mode, so that the size of the relay 20 can be reduced. For example, the position at which the setting dial 27 stops when the setting dial 27 is rotated clockwise or counterclockwise is the set position of the test mode. The microcomputer 51 of the control unit 50 sets the operation mode of the relay 20 to the test mode when the adjustment unit 70 detects that the setting dial 27 has been operated to the test mode setting position.

Note that the setting operation to the test mode may be accepted via an operation unit different from the setting dial 27 .

In addition, the microcomputer 51 discharges from the capacitor 45 to the coil of the electromagnet 65 of the output unit 60 so as not to output the trip signal, and measures the potential drop due to the discharge of the capacitor 45, thereby detecting the capacity drop of the capacitor 45. may In other words, the microcomputer 51 may detect a decrease in the capacity of the capacitor 45 by measuring a decrease in the potential of the capacitor 45 when the capacitor 45 is discharged to such an extent that the trip signal is not output. This makes it possible to detect a decrease in the capacity of the capacitor 45 without outputting a trip signal.

For example, the microcomputer 51 may cause the capacitor 45 to discharge to the output section 60 so that the trip signal is not output when the setting dial 27 is at the setting position of the settling current (steady mode). The microcomputer 51 detects the capacity drop of the capacitor 45 by measuring the potential drop due to the discharge of the capacitor 45 at this time. As a result, it is possible to prevent the trip signal from being output in the steady mode even though the current equal to or greater than the set current is not detected. The microcomputer 51 may have a timer function that periodically discharges the capacitor 45 to the output section 60 so that the trip signal is not output when the setting dial 27 is at the set position of the settling current (steady mode). As a result, in the steady mode, it is possible to periodically detect the decrease in the capacity of the capacitor 45 without interrupting the current flowing through the main wirings 25a, 25b, and 25c.

Note that the method of discharging the capacitor 45 so as not to output the trip signal for detecting a decrease in the capacity of the capacitor 45 is not limited to the steady mode, and may be implemented in the test mode.

The notification unit 80 may notify the outside of the relay of the decrease in the capacity of the capacitor 45 by light emission from a light emitting diode, indication by a display, sound by a speaker, communication signal by a communication circuit, or any combination thereof. Accordingly, when the microcomputer 51 detects a decrease in the capacity of the capacitor 45, a user or equipment outside the relay can easily recognize the decrease in the capacity of the capacitor 45. FIG.

The notification unit 80 may have an output relay that operates when the microcomputer 51 of the control unit 50 detects a capacity drop, and may notify the outside of the relay of the capacity drop of the capacitor 45 by the operation of this output relay. This output relay, for example, adopts the same configuration as the output section 60 (more specifically, the electromagnetic relay 64) in FIG. may be output.

Although the embodiments have been described above, the present invention is not limited to the above embodiments. Various modifications and improvements such as combination or replacement with part or all of other embodiments are possible.

For example, the auxiliary contact is not limited to being driven by an electromagnet, which is an example of the driving section. For example, a semiconductor switch may be used as the auxiliary contact. In that case, instead of the electromagnet, a drive circuit (an example of a drive section) for driving each semiconductor switch may be provided.

1 Electromagnetic Switch 2 Load 3 Power Supply 10 Electromagnetic Contactor 20 Relay 23A Auxiliary Contact Terminal Part 23Aa, 23Ab Auxiliary Terminal 23B Auxiliary Contact Terminal Part 23Ba, 23Bb Auxiliary Terminal 25a, 25b, 25c Main Wiring 26a, 26b, 26c Current Transformer 27 Setting dial 28 Reset button 30 Detector 40 Power supply 44 Potential monitoring circuit 45 Capacitor 50 Control unit 60 Output unit 61 Drive unit 62, 63 Auxiliary contact 64 Electromagnetic relay 65 Electromagnet 66 Plunger 70 Adjustment unit 80 Notification unit

Claims (15)

a capacitor;
an output unit that outputs a trip signal for interrupting the current flowing through the wiring by operating with the power supplied from the capacitor when a current greater than or equal to the set current flows through the wiring;
a control unit that detects a decrease in capacity of the capacitor;
a notification unit that notifies the outside of the relay of the capacity reduction when the capacity reduction is detected by the control unit. 2. The relay according to claim 1, wherein said control unit detects said capacity drop by measuring a potential drop due to discharge of said capacitor. 3. The relay according to claim 2, wherein said control unit detects said capacity drop by measuring a potential drop of said capacitor due to discharge from said capacitor to said output unit. 4. The relay according to claim 2 or 3, wherein said control unit, when set to a test mode, discharges said capacitor, and detects said capacity drop by measuring a potential drop due to the discharge of said capacitor. When the test mode is set, the control unit causes the capacitor to discharge to the output unit so as to output the trip signal, and measures the potential drop due to the discharge of the capacitor to detect the capacity drop. 5. The relay of claim 4, which senses. An operation unit that receives a setting operation of the settling current,
The relay according to claim 4 or 5, wherein the test mode is set by operating the operation unit to the test mode setting position. 7. The relay according to claim 6, wherein said operation unit is a dial for setting said settling current. 5. The controller according to claim 3, wherein the controller discharges the capacitor to the output part so that the trip signal is not output, and detects the capacity decrease by measuring a potential decrease due to the discharge of the capacitor. relay. An operation unit that receives a setting operation of the settling current,
The control unit causes the capacitor to discharge to the output unit so as not to output the trip signal while the operation unit is at the setting position of the settling current, and measures the potential drop due to the discharge of the capacitor. 9. The relay according to claim 8, which senses the capacity drop. The control unit periodically discharges the capacitor to the output unit so as not to output the trip signal while the operation unit is in the setting position of the settling current, and measures the potential drop due to the discharge of the capacitor. 10. The relay according to claim 9, wherein said capacity drop is detected by doing so. A power supply circuit that charges the capacitor based on the power input from the wiring,
11. The relay according to any one of claims 2 to 10, wherein said controller discharges said capacitor while stopping charging of said capacitor by said power supply circuit. The relay according to any one of claims 1 to 11, wherein the output section includes an electromagnetic relay that outputs the trip signal when excited by power supplied from the capacitor. The relay according to any one of claims 1 to 12, wherein the notification unit notifies the outside of the relay of the decrease in capacity by emitting light. 14. The notification unit according to any one of claims 1 to 13, wherein the notification unit has an output relay that operates when the capacity drop is detected by the control unit, and the operation of the output relay notifies the outside of the relay of the capacity drop. A relay as described in An electromagnetic switch, comprising: the relay according to any one of claims 1 to 14; and an electromagnetic contactor that cuts off current flowing through the wiring based on the trip signal.

Images