JPH086358Y2 - Circuit protector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field to which the Invention belongs] The present invention relates to a motor control circuit protection device having an earth leakage protection function, an overload protection function, and an open phase protection function.

Recent electric circuit breakers for controlling electric motors are required to have an earth leakage protection function, an overload protection function, and an open phase protection function, and to be housed in a distribution board in a small occupied area.

FIG. 2 shows a conventional device for a motor control protector having this type of leakage protection function, overload protection function, and open-phase protection function. In FIG. 2, 1 is an electromagnetic switch including an electromagnetic contactor 2 and a thermal relay 4, 3 is a leakage protection relay,
The combination is known in which the electromagnetic switch 1 and the zero-phase current transformer penetration type earth leakage protection relay 3 are mounted on the distribution board, for example, on the user side, and necessary wiring is carried out.

However, in the electric motor control protector of the combination as shown in FIG. 2, the main circuit load side conductor 8 is passed through the zero phase current transformer through hole 3d of the leakage protection relay 3 on the user side, and then the electromagnetic switch 1 Since it is necessary to connect to the load side terminal, the electromagnetic switch 1
There is a problem that the conductor cannot be connected unless the A-size interval between the leakage protection relay 2 and the leakage protection relay 2 is secured to a considerably large value. Therefore, there is a drawback that the B dimension, that is, the entire length dimension of the constituent devices is inevitably large, and when a plurality of combination protectors are used, the distribution board for accommodating them is large.

[Purpose of device]

The purpose of this invention is to mount a magnetic contactor, an electronic leakage protection relay, and a thermal relay on a mounting plate, and a circuit protection having a leakage protection function, an overload protection function, and an open-phase protection function that are simple in configuration and easy to assemble. To provide a device.

[Key points of device]

On the mounting plate, an electromagnetic contactor connected to a main circuit to which a load is connected so as to open and close the main circuit, and an electronic leakage protection relay that detects a leakage of the main circuit and gives an interruption command to the electromagnetic contactor. A circuit protection device that integrally incorporates a thermal relay that detects that the current of the main circuit is excessive or that the main circuit is out of phase and that gives a disconnection command to the electromagnetic contactor, An electronic leakage protection relay is arranged between the electromagnetic contactor and the thermal relay, and a primary conductor is passed through the through-type zero-phase current transformer with the built-in electronic leakage protection relay. The load side main circuit terminal of the electromagnetic contactor and the power source side main circuit terminal of the thermal relay are connected, a power source is supplied to the power source side main circuit terminal of the electromagnetic contactor, and a load side main circuit terminal of the thermal relay is loaded. To By doing so, the wiring work between the above-mentioned devices can be performed at the same time as the device assembly, so that the wiring work is easy and the space between the devices can be narrowed. A circuit protection device for controlling a motor can be obtained.

[Example of device]

FIG. 1 is a perspective view of an essential part showing an embodiment of a motor control circuit protection device according to the present invention. In the figure, the same parts as those of the conventional device shown in FIG.
Reference numeral 2 denotes an electromagnetic contactor that can withstand high-frequency switching under the control of an electric motor. The electromagnetic contactor 2 has a main circuit terminal, in the case of the drawing, a load-side main circuit terminal 2a. Reference numeral 3 indicates an electronic leakage protection relay having a built-in through-type zero-phase current transformer 5 having a primary conductor 9 penetrating therethrough and having an earth leakage protection function, on the upper surface of which a well-known reset button 3a, test button 3b and A leakage operation indicator light 3c is provided. Reference numeral 4 denotes a thermal relay having an overload protection function and an open phase protection function. The thermal relay 4 has a power supply side main circuit terminal 4a and a load side main circuit terminal 4b. Reference numeral 10 denotes a mounting plate to which the electromagnetic contactor 2, the earth leakage protection relay 3 and the thermal relay 4 are mounted by mounting screws 11.

As shown in FIG. 1, an electromagnetic contactor 2, an electronic leakage protection relay 3, and a thermal relay 4 are arranged in this order on a mounting plate 10 from the power source side (left side in the figure). The electronic leakage protection relay 3 having such a structure has a built-in through-type zero-phase current transformer 5, and the main circuit conductor, that is, the primary conductor 9 of the zero-phase current transformer, is connected to the through-type zero-phase current transformer 5. After passing through the through-hole 3d, attach both ends of the primary conductor to the electromagnetic contactor 2
Main circuit terminal 2a and the main circuit terminal 4a of thermal relay 4
The internal main circuit conductive portion of the circuit protection device is formed by connecting to the. The electronic leakage protection relay 3
Has a thin structure in order to downsize the circuit protection device and minimize the dimension B in FIG. 2, and the width dimension is within the width dimension of the existing electromagnetic contactor and thermal relay. In addition, since the electronic leakage protection relay 3 is provided with the reset button 3a, the test button 3b, and the leakage operation indicator light 3c on the upper surface in terms of its function,
The height dimension H is set slightly higher than the electromagnetic contactor 2 and the thermal relay 4 in consideration of operability and confirmation. By providing internal wiring for the control circuit further necessary for the circuit protection device having the configuration of FIG. 1, that is, internal wiring for transmitting the outputs of the leakage protection relay 3 and the thermal relay 4 to the electromagnetic contactor, leakage protection and overload protection are provided. The earth leakage breaker for motor control equipped with the three-phase function of open-phase protection is completed. When this circuit protection device is used by being stored in a distribution board or the like, the necessary control circuit wiring and main circuit wiring are carried out after it is mounted on the distribution board or the like through the mounting holes 10a etc. provided in the mounting plate 10. In this case, especially, in the main circuit wiring, since only three conductors are connected to the power source side and the load side terminal portions in accordance with the load rating, the wiring work is simple and easy.

[Effect of device]

According to the present invention, an electromagnetic contactor that withstands high-frequency switching of electric motor control from the power source side on a mounting plate, an electronic leakage protection relay in which a through-type zero-phase current transformer with a primary conductor penetrated has a leakage protection function, and A thermal relay having an overload protection function and an open phase protection function is arranged in order, and both ends of the primary conductor that penetrates the zero-phase current transformer are connected to the electromagnetic contactor and the main circuit terminals of the thermal relay. By
(EN) It is possible to provide a motor control circuit protection device having a three-component function of earth leakage protection, overload protection, and open-phase protection, which has a simple structure, is easy to assemble, and is particularly easy to wire, and is small and easy for the user to use.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part of a circuit protection device for controlling a motor showing an embodiment of the present invention, and FIG. 2 is a perspective view of a main part of a conventional device. 2: Electromagnetic contactor, 3: Leakage protection relay, 4: Thermal relay,
5: Zero-phase current transformer, 9: Primary conductor, 10: Mounting plate, 2a, 4a, 4b: Main circuit terminals.

Continuation of front page (72) Inventor Hiroki Machii 1186-16 Hoshinomiya, Ikata, Iwase-cho, Nishi-Ibaraki-gun, Ibaraki Ushin Electric Co., Ltd. (56) Reference JP-A-57-11928 (JP, A) 56-97844 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. An electromagnetic contactor connected to a main circuit to which a load is connected on a mounting plate so as to open and close the main circuit, and an electronic which detects a leakage of the main circuit and gives a cutoff command to the electromagnetic contactor. Circuit that integrally incorporates a system type earth leakage protection relay and a thermal relay that gives an interruption command to the electromagnetic contactor by detecting that the current of the main circuit is excessive or the phase of the main circuit is open In the protection device, the electronic leakage protection relay is arranged between the electromagnetic contactor and the thermal relay, the primary conductor is passed through the through-type zero-phase current transformer with the built-in electronic leakage protection relay, and this penetration The main circuit terminal on the load side of the electromagnetic contactor and the main circuit terminal on the power supply side of the thermal relay are connected by the primary conductor, and the power supply is connected to the main circuit terminal on the power supply side of the electromagnetic contactor and the load side of the thermal relay. Main circuit Circuit protection devices, characterized by connecting the load to the child.