JP2007028736A - Thermal protector, motor protector, submerged pump device, and manhole pumping device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal protector, which is to be built in a motor and which can inform an outside worker that the main circuit of the motor is cut off due to operation of itself, a motor protector, a submerged pump device, and a manhole pumping device. <P>SOLUTION: This motor protector is equipped with the above thermal protector 10 which is built in the motor and has main contacts (fixed contacts 13 and 13 and mobile contacts 15 and 15) that operate to open when the temperature reaches a specified temperature, sensing the excessive value of the current flowing to the motor or the rise of ambient temperature. It is constituted to break the main circuit which applies a current to the main coil MC of the motor when the main contact of the thermal protector openes. It is equipped with auxiliary contacts (fixed contacts 21, 21, and mobile contacts 15 and 15) which close when the main circuit of the thermal protector 10 opens, and it informs the outside worker that the main circuit of the motor is cut off by the closing of the auxiliary contacts. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a thermal protector for protecting an electric motor from overheating and burning, and an electric motor protection device incorporating the thermal protector, and in particular, a manhole type sewage relay pump device (hereinafter referred to as a “manhole pump device”) used as a sewage pumping facility. This is related to submersible pumps and other submersible pumps used for pumping up general sewage and sewage. Thermal protectors used to prevent overheating and burning of the motors that drive the pumps, and electric motors incorporating the thermal protectors The present invention relates to a protection device, a submersible pump device using the motor protection device as a protection device for a pump drive motor, and a manhole pump device using the submersible pump device.

  Conventional manhole device submersible pumps and other general wastewater submersible pumps incorporate a built-in thermal protector as shown in Patent Document 1 in an electric motor that drives the pump. FIG. 1 is a diagram showing a configuration example of a built-in thermal protector, and FIG. 2 is a circuit diagram of an electric motor incorporating the thermal protector. The thermal protector 100 includes a fixed contact 103 provided with a fixed contact 103 and a movable contact 105 that faces and separates from the fixed contact 103. The spring 107 is attached to the head of the adjustment screw 106. A main protect 110 made of a dish-shaped bimetal 102 supported by pressing and a resistor (heater) 112 provided in the vicinity of the dish-shaped bimetal 102 are provided. The resistor (heater) 112 and the dish-shaped bimetal 102 are connected in series via fixed contacts 103 and 103 and movable contacts 105 and 105 as shown in FIG. Further, the cover 108 that covers the open end of the cylindrical case 101 is fixed by a fixture 109 having good thermal conductivity.

  In FIG. 2, MC is a main coil of a single-phase induction motor, SC is an auxiliary coil, C is a starting capacitor, GS is a starting switch for a single-phase induction motor, and generally operates when the rotational speed reaches a certain number. A centrifugal force switch is used. TR and TS are connection terminals of an electric motor connected to a power source. A thermal protector 100 is connected in series between the terminal TR and the main coil MC. When an overcurrent flows due to overload or rotor restraint in the single-phase induction motor, the resistor (heater) 112 generates heat, and the dish-shaped bimetal 102 is heated by this heat generation. When the temperature reaches a predetermined temperature (for example, 160 ° C.), the dish shape is reversed, and the movable contacts 105 and 105 and the fixed contacts 103 and 103 are separated, and the current flowing through the main coil MC is interrupted. Thereby, a single phase induction motor is protected.

  The motor protection device using the thermal protector 100 is relatively inexpensive and opens the contact point in response to the temperature and operating current in the motor, so it is often used for submersible pumps for manhole pumps and other general sewage submersible pumps. There is a feature that the motor can be protected by detecting troubles such as restraint of the motor and overcurrent due to the entanglement of the foreign matter in question with good response.

  However, the motor protection device using the built-in thermal protector 100 as shown in FIG. 1 operates inside the motor and realizes a certain protection function, but there is no means for reporting the operating state to the outside, and the user There were many cases that pointed out problems related to unmanageability such as “the pump was not moving for some reason” and “the pump was stopped, but it was restored and was running again”. As is apparent from the structure of FIG. 1, the built-in thermal protector 100 detects overheating or overcurrent of the motor and opens the main circuit of the motor, but when the internal temperature decreases due to the motor stopping, the movable contact of the dish-shaped bimetal 102 105 and the fixed contact 103 are closed and return naturally. Depending on the installation conditions, the user repeatedly opened and closes the contact without noticing the operation of the thermal protector 100, and eventually the contact itself of the thermal protector 100 burned.

  FIG. 3 is a diagram showing a structure of an embedded thermal protector disclosed in Patent Document 2, and FIG. 4 is a circuit diagram of an electric motor provided with the embedded thermal protector. As shown in FIG. 3, the embedded thermal protector 200 includes a fixed electrode body 203 composed of a fixed-side internal lead wire 201 having a fixed-side contact 202 provided at a tip portion in a glass tube 210, and a movable-side contact 204. The movable electrode body 208 including the thermally responsive element 205, the auxiliary plate 206, and the movable side internal lead wire 207 are opposed to each other and supported by the glass beat 209. A fixed-side external lead wire 211 is connected to the fixed-side internal lead wire 201, and a movable-side external lead wire 212 is connected to the movable-side internal lead wire 207.

  In FIG. 4, MCU, MCV, and MCW are U-phase, V-phase, and W-phase stator coils of a three-phase induction motor, respectively. 200U and 200W are U-phase coil MCU and W-phase coil MCW of a three-phase induction motor, respectively. Is an embedded thermal protector embedded in Of course, the embedded thermal protector 200 may be embedded in three coils: a U-phase coil MCU, a V-phase coil MCV, and a W-phase coil MCW. TU, TV, and TW indicate power connection terminals of the three-phase induction motor.

  Since the embedded thermal protector 200 is sensitive only to the temperature of the stator coil of the motor, a heater is not incorporated unlike the protection device shown in FIG. Can't follow. The embedded thermal protector complements the operation of the protection relay built into the control panel, and the motor temperature rises even though the operating current value is low. , When the ambient temperature is too high).

In the protection device using the embedded thermal protector, the protection relay of the control panel is activated when the embedded thermal protector is operated. Therefore, the protection device does not return unless the protection relay is manually released. Further, since overheating in the electric motor is sent to the control panel as a signal, the user can be informed of the problem.
JP 7-262895 A JP-A-11-250789

    The built-in thermal protector having the configuration shown in FIG. 1 and the embedded thermal protector having the configuration shown in FIG. 3 each have advantages. Depending on the use site, in the electric motor incorporating the thermal protector having the configuration shown in FIG. There has been a request to inform the outside of the operation of the protector, that is, to notify the outside that the thermal protector has been activated. However, the built-in thermal protector having the conventional configuration cannot meet this demand.

  The present invention has been made in view of the above points, and includes a built-in thermal protector, and when the thermal protector is activated and the main circuit of the motor is shut off, the thermal can be notified to the outside. An object of the present invention is to provide a protector, an electric motor protection device provided with a reporting means, a submersible pump device, and a manhole pump device.

  In order to solve the above-mentioned problem, the invention according to claim 1 is sensitive to an excessive current value flowing in the electric motor incorporated in the electric motor or an increase in the ambient temperature, and is activated and opened when the temperature reaches a predetermined temperature. A thermal protector comprising a main contact, comprising an auxiliary contact that closes or opens when the main contact is open.

  The invention according to claim 2 is a thermal sensor comprising a main contact that is sensitive to an excessive value of current flowing through the motor incorporated in the motor or an increase in ambient temperature and that is activated and opened when the temperature reaches a predetermined temperature. An electric motor protection device comprising a protector and configured to shut off the main circuit of the electric motor when the main contact of the thermal protector is opened, and is an auxiliary device that is closed or opened when the main contact of the thermal protector is opened It has a contact point, and has a reporting means for reporting to the outside that the main circuit of the motor has been shut off by closing or opening the auxiliary contact.

  Invention of Claim 3 is a submersible pump apparatus provided with the submersible pump, the electric motor which drives this submersible pump, and a control board, The electric motor protection device of Claim 2 is used for the protection device of the above-mentioned electric motor, The notification means is configured to send a notification signal to the control panel.

  According to a fourth aspect of the present invention, in the submersible pump device according to the third aspect, a protective relay is provided in the control panel, the protective relay is activated by a notification signal from the notification means, and the thermal protector is restored naturally. Then, even if the main contact is closed, there is provided a pump restart regulating means configured so that the motor cannot be restarted while the protective relay is in operation, and can be restarted when the protective relay is reset and inactivated. It is characterized by that.

  According to a fifth aspect of the present invention, there is provided a manhole device including a manhole and a submersible pump device including a submersible pump disposed in the manhole, wherein the submersible pump device includes the submersible pump according to the third or fourth aspect. A pump device is used.

  According to the first aspect of the present invention, since the thermal protector is provided with the auxiliary contact that is closed or opened when the main contact is opened, the outside is notified through the auxiliary contact that the main contact is opened. It becomes possible.

  According to the invention described in claim 2, since the reporting means reports that the main circuit of the motor has been shut down by closing or opening the auxiliary contact of the thermal protector, it is known that the main circuit of the motor has been shut off. Therefore, it is possible to take appropriate measures, and by repeatedly opening and closing the main contact of the thermal protector, it is possible to prevent an accident such as the main contact being burned out and the electric motor being burned out.

  According to the invention described in claim 3, since the motor protection device according to claim 2 is used as the motor protection device for driving the submersible pump, the motor due to overload of the submersible pump and entanglement of foreign matter into the submersible pump. If the main circuit is shut down by the thermal protector responding to the overcurrent caused by the rotor's restraint, it is possible to quickly know the main circuit has been shut down, and the appropriate cause such as removing the cause of these overloads or entanglement of the pump. It is possible to take appropriate measures.

  According to the fourth aspect of the present invention, the protective relay provided in the control panel is operated by a notification signal from the notification means, and the motor is restarted while the protective relay is in operation even when the thermal protector is naturally restored and its main contact is closed. Since the pump restart restricting means configured to be able to restart when the protective relay is reset and becomes inoperable due to the inability to start is provided, the main contact of the thermal protector is repeatedly opened and closed without the user's knowledge. Accidents such as burning of the electric motor with burned main contacts are eliminated.

  According to the fifth aspect of the present invention, the submersible pump device according to the third or fourth aspect is used for the submersible pump device of the manhole pump device. It is possible to quickly know that the main circuit has been shut off due to the thermal protector responding to the overcurrent due to the restraint of the motor rotor, and it is possible to take appropriate measures against them. In addition, the main contact of the thermal protector is repeatedly opened and closed so that the main contact is not seized and an accident such as damage to the electric motor can be prevented.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 5 is a diagram showing a configuration of a thermal protector used in the motor protection device according to the present invention, and FIG. 6 is a circuit diagram of an electric motor incorporating the thermal protector. As shown in FIG. 5, the thermal protector 10 includes a fixed contact plate 14 provided with a fixed contact 13, and a movable contact 15 facing and separating from the fixed contact 13. A main protector 30 made of a dish-shaped bimetal 12 pressed against and supported by a spring 17 and a resistor (heater) 22 provided in the vicinity of the dish-shaped bimetal 12 are provided.

  A terminal support member 20 is fitted into the bottom opening of the cylindrical case 11, and a fixed contact plate 19 having a fixed contact 21 is planted on the terminal support member 20. The opening of the terminal support member 20 is closed with a cover 18. The fixed contact 21 is arranged to face the fixed contact 13 at a predetermined distance, and as shown in FIG. 6, the movable contacts 15 and 15 of the dish-shaped bimetal 12 are normally connected to the fixed contacts 13 and 13 as shown by solid lines. When the dish-shaped bimetal 12 is heated and reversed as shown by the dotted line, the movable contacts 15 and 15 come into contact with the fixed contacts 21 and 21.

  6, MC is a main coil of a single-phase induction motor, SC is an auxiliary coil, C is a starting capacitor, GS is a start-up switch for a single-phase induction motor, and generally has a fixed number of rotations. Centrifugal force switches are used that operate when TR and TS are connection terminals of an electric motor connected to a power source. A thermal protector 10 is connected in series between the terminal TR and the main coil MC. The fixed contacts 21 and 21 are connected to the terminals P1 and P2.

  If an overcurrent flows due to an overload or rotor restraint of the motor, the overcurrent also flows to the resistor (heater) 22, so that the resistor (heater) 22 generates heat higher than the normal load current, and this heat generation The dish-shaped bimetal 12 is heated. When the temperature reaches a predetermined temperature (for example, 160 ° C.), the dish shape is reversed, the movable contacts 15 and 15 and the fixed contacts 13 and 13 are separated, the current flowing through the main coil MC is cut off, and the single-phase induction motor is turned on. Protect.

  When the dish-shaped bimetal 12 is reversed and the movable contacts 15 and 15 are separated from the fixed contacts 13 and 13, the movable contacts 15 and 15 come into contact with the fixed contacts 21 and 21. Here, when the movable contacts 15 and 15 and the fixed contacts 13 and 13 are the main contacts, and the movable contacts 15 and 15 and the fixed contacts 21 and 21 are the auxiliary contacts, the main contact acts to interrupt the main circuit of the motor, The auxiliary contact can be provided with a function of notifying the outside (for example, the control panel) that the main contact is disconnected and the main circuit is cut off.

  When the thermal protector 10 having the configuration shown in FIG. 5 is incorporated in an electric motor that drives the pump of the submersible pump device, and the motor circuit is configured as shown in FIG. 6, the submersible pump device is a sewage pumping facility, a manhole pump device, and the like. When used in a submersible pump device used for pumping up sewage and sewage, if the electric motor is overloaded or the pump is contaminated with foreign matter and overcurrent flows due to rotor restraint, etc., the dish-shaped bimetal 12 will generate heat and the temperature will increase. When the temperature reaches a predetermined temperature (for example, 160 ° C.), the dish shape is reversed and the movable contacts 15 and 15 and the fixed contacts 13 and 13 are separated, the current flowing through the main coil MC is cut off, and the main circuit of the motor is cut off. . The fact that the main circuit has been interrupted is notified to the outside, for example, the control panel, through contact between the movable contacts 15 and 15 as auxiliary contacts and the fixed contacts 21 and 21. Thereby, it can be known externally that the main circuit is shut off. As a result, it is possible to take measures such as investigating the cause of the interruption of the main circuit and removing the cause.

  In addition, although illustration is omitted, a protective relay is provided in the control panel of the submersible pump device, and there is a report that the main circuit is cut off via the movable contacts 15 and 15 and the fixed contacts 21 and 21 as the auxiliary contacts. In addition, the protection relay is activated by the notification signal, and once the protection relay is activated, a holding circuit is provided to hold the operation state until the reset is reset, and further, power is supplied to the terminals TR and TS of the motor by the operation of the protection relay. Pump restart restriction means configured to open the electromagnetic switch MSW to be supplied is provided. As a result, the electromagnetic switch MSW is opened until the protective relay is reset. After the main circuit is shut off by the heating inversion of the dish-shaped bimetal 12, the dish-shaped bimetal 12 is naturally cooled. By returning, overcurrent flows again to the electric motor, and by repeating this, accidents such as burning of the electric motor due to seizing of the main contact of the dish-shaped bimetal 12 can be prevented.

  FIG. 7 is a longitudinal sectional view showing the structure of the submersible pump. As shown in the figure, the submersible pump has a configuration including a pump unit 40, an electric motor unit 60, and a mechanical seal unit 50 disposed between the pump unit 40 and the electric motor unit 60. The pump unit 40 includes a pump casing 41 in which a suction port 42 and a discharge port 43 are formed, and an impeller 44 that is fixed to the tip of a pump main shaft 46 and rotatably disposed in the pump casing 41. . The water sucked from the suction port 42 due to the negative pressure generated by the rotation of the impeller 44 is boosted by the centrifugal force of the impeller 44, and the discharge port 45 connected to the discharge port 43 through the discharge port 43. Is exhaled from.

  The electric motor unit 60 includes a motor casing 61, a stator 62 fitted in the motor casing 61, and a rotor 63 fixed to the motor main shaft 64 and rotatably arranged at the center of the stator 62. It is the structure to do. The mechanical seal portion 50 includes a seal casing 51, and the pump main shaft 46 passes through the seal casing 51. The mechanical seal 52 is disposed with the pump main shaft 46 in contact with the outer periphery. The pump main shaft 46 and the motor main shaft 64 are connected at an end, and are rotatably supported by a bearing 53 and a bearing 65. The pump casing 41, the seal casing 51, and the motor casing 61 are integrally connected. The inside of the seal casing 51 is classified into a secret state by a mechanical seal 52 on the pump side and the motor side.

  The end of the motor casing 61 opposite to the pump is closed by a cover 66, and the thermal protector 10 having the configuration shown in FIG. Reference numeral 67 denotes a signal cable, the core end of which is connected to terminals P1 and P2 (see FIG. 6) connected to the fixed contacts 21 and 21 of the thermal protector 10, and the other end is a control panel (not shown). )It is connected to the. Through the signal cable 67, a notification signal is sent to the control panel informing that the main contact of the thermal protector 10 is opened and the main circuit is shut off. Reference numeral 68 denotes a power supply cable, and the tip of the thermal protector 10 is connected to terminals TR and TS to supply power to the electric motor unit 60. When drive power is supplied to the stator 62 of the electric motor unit 60 and the rotor 63 rotates, the rotational force is transmitted from the motor main shaft 64 to the pump main shaft 46, and the impeller 44 rotates.

  Also in the submersible pump with the above structure, the circuit configuration of the electric motor is as shown in FIG. 6, and the rotor of the electric motor unit 60 is restrained by foreign matters entangled with the pump overload or impeller 44. Overcurrent flows through the stator 62 where 63 is restrained. This overcurrent flows through the dish-shaped bimetal 12 and heats up. When the temperature reaches a predetermined temperature (for example, 160 ° C.), the dish shape is reversed, the movable contacts 15 and 15 and the fixed contacts 13 and 13 are separated, and the current flowing through the main coil MC is interrupted. This interruption is notified to the outside and the control panel via the movable contacts 15 and 15 which are auxiliary contacts and the fixed contacts 21 and 21. Thereby, it can be known from the control panel that the main circuit is shut off. As a result, it is possible to take measures such as investigating the cause of the interruption of the main circuit and removing the cause.

  Also, as described above, the control panel is provided with a protective relay and a holding circuit that holds the operating state until reset, and the protective relay is activated by this notification signal that the main circuit has been shut off from the thermal protector 10. The electromagnetic switch MSW that supplies electric power to the electric motor is opened. As a result, the electromagnetic switch MSW is opened until the protective relay is reset. After the main circuit is shut off by the heating inversion of the dish-shaped bimetal 12, the dish-shaped bimetal 12 is naturally cooled. By returning, an overcurrent flows again to the electric motor, and by repeating this, it is possible to prevent an accident such as the main contact of the dish-shaped bimetal 12 being burned out.

  The submersible pump having the configuration shown in FIG. 7 is installed in a manhole (not shown), the thermal protector 10 having the configuration shown in FIG. 5 is incorporated in the motor unit 60, and the motor circuit is configured as shown in FIG. The manhole pump device is configured so that the control circuit is notified by closing the auxiliary contacts (fixed contacts 21, 21 and movable contacts 15, 15) that the main circuit is interrupted due to the opening of 13, 13 and the movable contacts 15, 15). By doing so, the same effect as the above can be obtained. Further, by providing a protective relay on the control panel of the manhole pump device and providing the pump restart restricting means configured as described above, it is possible to prevent accidents such as burnout of the motor due to seizure of the main contact of the dish-shaped bimetal 12. .

  In the embodiment described above, the thermal protector operates when the temperature reaches a predetermined temperature and opens when the main contact (consisting of the fixed contacts 13 and 13 and the movable contacts 15 and 15) is normally open. Although the auxiliary contact (consisting of the fixed contacts 21 and 21 and the movable contacts 15 and 15) is closed when the main contact is opened, the auxiliary contact is always in the same manner as the main contact. May be configured to open when the main contact is opened when closed.

  In this case, for example, as shown in FIG. 9, a plate-shaped bimetal 12 serving as a main contact and a strip-shaped conductor plate 24 serving as an auxiliary contact are provided, and the conductor plate 24 is deformed in conjunction with the plate-shaped bimetal 12. It is attached to the dish-shaped bimetal 12 with an insulating material 23 interposed. Movable contacts 15, 15 are attached to the dish-shaped bimetal 12, and movable contacts 25, 25 are also provided at both ends of the conductor plate 24. Fixed contacts 13 and 13 are provided to face the movable contacts 15 and 15, and fixed contacts 26 and 26 are provided to face the movable contacts 25 and 25 (see FIG. 8). 9B is a cross-sectional view taken along line AA in FIG. 9A, FIG. 9A is a plan view, and FIG. 9C is a cross-sectional view taken along line BB in FIG.

  In the dish-shaped bimetal 12 and the conductor plate 24 configured as described above, the movable contacts 15 and 15 of the dish-shaped bimetal 12 are normally closed in contact with the fixed contacts 13 and 13, and the movable contacts 25 and 25 of the conductor plate 24 are closed. Is also in contact with the fixed contacts 26, 26 and closed. When the dish-shaped bimetal 12 is heated from this state and reaches a predetermined temperature, the plate-shaped bimetal 12 is reversed as indicated by the dotted line in FIG. 9B, and the movable contacts 15 and 15 are separated from the fixed contacts 13 and 13. In conjunction with the reversal of the dish-shaped bimetal 12, the conductor plate 24 is also deformed so that the movable contacts 25, 25 are separated from the fixed contacts 26, 26.

  Using the dish-shaped bimetal 12 and the conductor plate 24 having the above-described configuration, an electric motor circuit is configured as shown in FIG. When an overcurrent flows due to overload or rotor restraint of the motor, the resistor (heater) 22 generates heat above the rated load current due to this overcurrent, and the dish-shaped bimetal 12 is heated. When the temperature reaches a predetermined temperature (for example, 160 ° C.), the dish shape is reversed, and the movable contacts 15 and 15 and the fixed contacts 13 and 13 are separated. At the same time, the conductor plate 24 is deformed in conjunction with the dish shape bimetal 12. The movable contacts 25 and 25 are also separated from the fixed contacts 26 and 26. As a result, the current flowing through the main coil MC is interrupted, and the movable contacts 25, 25 and the fixed contacts 26, 26 are disconnected to notify the outside that the motor circuit is interrupted.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea described in the claims and the specification and drawings. Is possible. For example, in the above embodiment, the electric motor that drives the pump has been described as a single-phase induction motor. However, it is a matter of course that a three-phase induction motor may be used.

It is a figure which shows the structure of the conventional built-in thermal protector. It is a figure which shows the circuit structure of the electric motor incorporating the conventional built-in thermal protector. It is a figure which shows the structure of the conventional embedded thermal protector. It is a figure which shows the circuit structure of the electric motor which embedded the conventional embedded type thermal protector. It is a figure which shows the structure of the built-in type thermal protector which concerns on this invention. It is a figure which shows the circuit structure of the electric motor incorporating the built-in type thermal protector which concerns on this invention. It is a longitudinal cross-sectional view which shows the structure of the submersible pump which concerns on this invention. It is a figure which shows the circuit structure of the electric motor incorporating the built-in type thermal protector which concerns on this invention. It is a figure which shows the structural example of the plate-shaped bimetal of the built-in-type thermal protector which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Thermal protector 11 Cylindrical case 12 Countersunk bimetal 13 Fixed contact 14 Fixed contact plate 15 Movable contact 16 Adjustment screw 17 Spring 18 Cover 19 Fixed contact plate 20 Terminal support member 21 Fixed contact 22 Resistor (heater)
23 Insulating Material 24 Conductor Plate 25 Movable Contact 26 Fixed Contact 30 Main Protector 40 Pump Unit 41 Pump Casing 42 Suction Port 43 Discharge Port 44 Impeller 45 Discharge Port Pipe 46 Pump Main Shaft 50 Mechanical Seal Portion 51 Seal Casing 52 Mechanical Seal 53 Bearing 60 Motor unit 61 Motor casing 62 Stator 63 Rotor 64 Motor spindle 65 Bearing 66 Cover 67 Signal cable 68 Power supply cable

Claims (5)

A thermal protector comprising a main contact that is activated and opened when the temperature reaches a predetermined temperature in response to an excessive current value flowing through the motor incorporated in the motor or an increase in ambient temperature,
A thermal protector comprising an auxiliary contact that is closed or opened when the main contact is opened. A thermal protector is provided that has a main contact that responds to an excessive current value flowing through the motor and an increase in the ambient temperature and is opened when the temperature reaches a predetermined temperature. An electric motor protection device configured to cut off the main circuit of the electric motor when the contact is opened,
Provided with an auxiliary contact that closes or opens when the main contact of the thermal protector is opened, and has a reporting means for reporting to the outside that the main circuit of the motor has been shut off by closing or opening of the auxiliary contact. An electric motor protection device. In a submersible pump, a submersible pump device provided with a control panel, an electric motor that drives the submersible pump,
3. The submersible pump device according to claim 2, wherein the motor protection device according to claim 2 is used as the motor protection device, and the notification means is configured to send a notification signal to the control panel. The submersible pump device according to claim 3,
Provide a protective relay in the control panel,
The protective relay is activated by a notification signal from the reporting means, and even if the thermal protector is spontaneously restored and its main contact is closed, the motor cannot be restarted while the protective relay is in operation, and the protective relay is reset. A submersible pump device provided with a pump restart restricting means configured to be restartable when it becomes inoperative. In a manhole device comprising a manhole and a submersible pump device comprising a submersible pump disposed in the manhole,
A manhole pump device using the submersible pump device according to claim 3 or 4 as the submersible pump device.

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