CN104979802A - Phase-lack circuit breaker for three-phase motor - Google Patents

Abstract

The invention discloses a three-phase motor phase loss circuit breaker, which relates to the technical field of motor control, and includes a reed switch, a hard coil, an AC contactor, a thyristor, a manual button, a power module, and a protection resistor; a reed switch They are respectively placed in the hard coil, the auxiliary contact of the AC contactor is a normally open auxiliary contact, the manual button is a normally open button, the dry reed switch is a normally open dry reed switch, and the hard coil is a primary circuit hard wire wound by hand ; The invention can quickly and effectively stop the operation of the motor when the motor is running without phase, and has high reliability, simple structure and low cost.

Description

A three-phase motor phase loss circuit breaker

technical field

The present invention relates to a three-phase motor phase loss circuit breaker, which belongs to the technical field of motor control.

Background technique

If there is a phase loss in the operation of the three-phase motor, the rotor will continue to run, but the operating current will increase a lot, causing the motor winding to burn out during overload operation. Therefore, it is necessary to implement phase loss protection measures for three-phase motors. Although various existing phase loss protection technologies are very mature, there are still blind spots in reliability, and the control circuit is relatively complicated.

Contents of the invention

In view of the above problems, the technical problem to be solved by the present invention is to provide a three-phase motor phase loss circuit breaker with no blind spots and simple structure.

A three-phase motor phase loss circuit breaker of the present invention comprises a reed switch, a hard coil, an AC contactor, a thyristor, a manual button, a power module, and a protection resistor; The auxiliary contact of the contactor is a normally open auxiliary contact, and the manual button is a normally open button.

Preferably, the reed switch is a normally open reed switch.

Preferably, the hard coil is hand-wound from a primary loop hard wire.

The beneficial effects of the invention are: the motor can be stopped quickly and effectively when the motor is running without phase, the reliability is high, the structure is simple, and the cost is low.

Description of drawings

For ease of illustration, the present invention is described in detail by the following specific implementations and accompanying drawings.

Fig. 1 is a structural schematic diagram of the present invention.

In the figure: (11, 12, 13) - normally open dry reed switch, (21, 22, 23) - hard coil, 30 - AC contactor excitation coil, (31, 32, 33) - AC contactor main contact Head, 34-AC contactor auxiliary contact, 4-SCR, 5-manual button, 6-power module, 7-protective resistor, 8-three-phase motor, (91, 92, 93)-three-phase power supply entry end.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention is described below through specific embodiments shown in the accompanying drawings. It should be understood, however, that these descriptions are exemplary only and are not intended to limit the scope of the present invention. Also, in the following description, descriptions of well-known structures and techniques are omitted to avoid unnecessarily obscuring the concept of the present invention.

As shown in Figure 1, the present embodiment adopts the following technical solutions: it comprises a reed switch (11,12,13), a hard coil (21,22,23), an AC contactor (30,31,32,33, 34), silicon controlled rectifier 4, manual button 5, power module 6, protection resistor 7; dry reed switches (11, 12, 13) are respectively placed in hard coils (21, 22, 23), and AC contactor auxiliary contacts 34 is normally open auxiliary contact, manual button 5 normally open type buttons.

Further, the reed switches (11, 12, 13) are normally open reed switches.

Further, the hard coils (21, 22, 23) are hand-wound primary circuit hard wires.

The working principle of this specific embodiment is: any phase of 91, 92, 93 three-phases has no electricity, then the corresponding reed switch is not closed, the SCR 4 control pole has no current, the system cannot enter the working state, and the motor 8 cannot start; work Any one of the three phases 91, 92, and 93 loses current due to lack of phase, the corresponding reed switch is disconnected, the control pole current of the thyristor 4 is interrupted, the AC contactor 30 loses current, and the auxiliary contact of the AC contactor (31, 32, 33, 34) are disconnected, and the motor 8 stops working. At the same time, the power supply of the power module 6 is disconnected, the control system is turned off, and the motor 8 cannot re-enter the working state unless it is manually operated; Stop working, if 93 phases lose power, the AC contactor 30 current will be interrupted, and the motor 8 will stop working.

The basic principles and main features of the present invention and the advantages of the present invention have been shown and described above. Those skilled in the industry should understand that the present invention is not limited by the above-mentioned embodiments. What are described in the above-mentioned embodiments and the description only illustrate the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will also have Variations and improvements are possible, which fall within the scope of the claimed invention. The protection scope of the present invention is defined by the appended claims and their equivalents.

Claims (3)

1. a three-phase motor open-phase circuit breaker, it is characterized in that: it comprises tongue tube (11,12,13), rigid line circle (21,22,23), A.C. contactor (30,31,32,33,34), controllable silicon (4), hand push button (5), power module (6), protective resistance (7); Tongue tube (11,12,13) is placed in rigid line circle (21,22,23) respectively, the auxiliary contact of A.C. contactor (34) for often to open auxiliary contact, hand push button (5) open type button.

2. a kind of three-phase motor open-phase circuit breaker according to claim 1, is characterized in that: described tongue tube (11,12,13) is open type tongue tube.

3. a kind of three-phase motor open-phase circuit breaker according to claim 1, is characterized in that: described rigid line circle (21,22,23) forms for the manual coiling of the hard wire in primary circuit.