CN219957736U - Forward-reverse rotation and phase failure tester - Google Patents

Abstract

The utility model belongs to the technical field of motor phase line detection, and particularly relates to a forward and reverse rotation phase-failure tester which solves the technical problems in the background technology and comprises a phase sequence protection relay ZFZ, a first intermediate relay KA1, a second intermediate relay KA2, a third intermediate relay KA3, a first time relay KT1, a second time relay KT2, a third time relay KT3, a first red lamp HR1, a second red lamp HR2, a third red lamp HR3, a first green lamp HG1, a second green lamp HG2, a first buzzer HA1 and a second buzzer HA2. The tester greatly reduces equipment damage caused by phase failure of the control circuit, avoids error gear of the universal meter when the universal meter is used for measuring, causes internal short circuit of the universal meter when the ohm gear is used for measuring electricity, causes arc light to hurt people, fire and other electrical accidents, and reduces mechanical accidents caused by incapability of accurately converting positive and negative rotation of the control circuit and test running of the electric motor.

Description

Forward-reverse rotation and phase failure tester

Technical Field

The utility model relates to the technical field of motor phase line detection, in particular to a positive and negative rotation phase-failure tester.

Background

When the forward and reverse rotation control circuit is overhauled, the inspection of the main circuit is often neglected due to the fact that the control circuit is overhauled in a key way, once the contacts of the contactor are burnt out or the contacts are in poor contact, the main circuit can be subjected to phase failure, if the main circuit is not carefully inspected, the motor is in test running, the motor is possibly burnt out, the common method is to use a universal meter to measure whether the main circuit is normal or not at present, but when the main circuit is measured by using a hand meter, the upper contact and the lower contact of the contactor are electrified, electric shock accidents can be caused once careless, and when the universal meter is used for measuring, if the gear of the universal meter is in fault, the voltage is measured by using an ohm gear, the internal short circuit of the universal meter can be caused, arc light is caused to hurt people and fire, and potential safety hazards are very high. And if the positive and negative rotation of the control circuit can not be accurately converted, the test running of the battery can cause a larger mechanical accident.

Disclosure of Invention

The utility model provides a forward and reverse rotation phase-failure tester, which aims to overcome the technical defects that when a universal meter is used for measuring a main loop, contact accidents are easy to occur or internal short circuits of the universal meter are easy to cause safety accidents because gears are wrongly arranged.

The utility model discloses a forward-reverse rotation and phase-failure tester, which comprises a phase sequence protection relay ZFZ, a first intermediate relay KA1, a second intermediate relay KA2, a third intermediate relay KA3, a first time relay KT1, a second time relay KT2, a third time relay KT3, a first red light HR1, a second red light HR2, a third red light HR3, a first green light HG1, a second green light HG2 and a first buzzer HA1, wherein the phase sequence protection relay ZFZ is respectively connected with a three-phase power supply through three wiring terminals of the phase sequence protection relay ZFZ, and a first fuse F1, a second fuse F2 and a third fuse F3 are respectively connected in series between the three wiring terminals of the phase sequence protection relay ZFZ and the three-phase power supply; the coils of the first intermediate relay KA1, the second intermediate relay KA2 and the third intermediate relay KA3 are connected through a star connection method, the three remaining ends are respectively connected to a three-phase power supply of the phase sequence protection relay ZFZ, the coils of the first time relay KT1, the second time relay KT2 and the third time relay KT3 are connected end to end through a triangle connection method, one end of a delay disconnection contact KT1-1 of the first time relay KT1 is connected to a C-phase power supply in parallel, the other end of the delay disconnection contact KT2-1 of the second time relay KT2 is connected to a position between the second time relay KT2 and the third time relay KT3 in parallel, one end of a delay disconnection contact KT3-1 of the third time relay KT3 is connected to a position between the B-phase power supply in parallel, and the other end of the delay disconnection contact KT2 is connected to a position between the first time relay KT1 and the second time relay KT 2; the delay closing contact KT1-2 of the first time relay KT1 is connected to an A-phase power supply in series, the delay closing contact KT1-3 of the first time relay KT1 is connected to a B-phase power supply in series, the delay closing contact KT3-2 of the third time relay KT3 is connected to a C-phase power supply in series, the front end of the delay closing contact KT2-2 of the second time relay KT2 is connected to the front end and the rear end of the delay closing contact KT1-3 of the first time relay KT1 in parallel, the front end of the delay closing contact KT2-3 of the second time relay KT2 is connected to the front end and the rear end of the delay closing contact KT3-2 of the third time relay KT3 in parallel, and the front end of the delay closing contact KT3-3 of the third time relay KT3 is connected to the rear end of the delay closing contact KT1-3 of the first time relay KT1 in parallel, and the front end and the rear end of the delay closing contact KT2 of the delay closing contact KT1-2 of the second time relay KT3 is connected to the front end and the rear end of the delay closing contact KT2 of the first time relay KT1-3 in parallel; the normally open contact KA1-1 of the first intermediate relay KA1 is connected in series with the first red light HR1 to form an A-phase indication loop, one end of the A-phase indication loop is connected in parallel with the rear end of the delay closing contact KT1-2 of the first time relay KT1, and the other end of the A-phase indication loop is connected in parallel with the rear end of the delay closing contact KT3-3 of the third time relay KT 3; the normally open contact KA2-1 of the second intermediate relay KA2 is connected with the second red light HR2 in series to form a B-phase indication loop, and the B-phase indication loop is connected to two ends of the A-phase indication loop in parallel; the normally open contact KA3-1 of the third intermediate relay KA3 is connected with the third red light HR3 in series to form a C-phase indication loop, and the C-phase indication loop is connected to two ends of the B-phase indication loop in parallel; the normally closed contact KA1-2 of the first intermediate relay KA1, the normally closed contact KA2-2 of the second intermediate relay KA2 and the normally closed contact KA3-2 of the third intermediate relay KA3 are connected in parallel and then connected with the first buzzer HA1 and the second buzzer HA2 in series to form a phase-failure alarm loop, and the phase-failure alarm loop is connected to two ends of the C-phase indication loop in parallel; the normally open contact KA1-3 of the first intermediate relay KA1, the normally open contact KA2-3 of the second intermediate relay KA2, the normally open contact ZFZ-1 of the phase sequence protection relay ZFZ and the first green light HG1 are connected in series to form a forward rotation indication loop, and two ends of the forward rotation indication loop are connected in parallel to two ends of the open-phase alarm loop; the normally closed contact ZFZ-2 of the phase sequence protection relay ZFZ and the second green light HG2 are connected in series to form a reverse indication loop, and the reverse indication loop is connected in parallel to two ends of a series circuit of the normally open contact ZFZ-1 of the phase sequence protection relay ZFZ and the first green light HG 1.

The coils of the first intermediate relay KA1, the second intermediate relay KA2 and the third intermediate relay KA3 are connected according to the star connection method, namely, the head ends or the tail ends of the coils of the first intermediate relay KA1, the second intermediate relay KA2 and the third intermediate relay KA3 are connected, so that the reliability of the actions of the first intermediate relay KA1, the second intermediate relay KA2 and the third intermediate relay KA3 can be ensured.

Preferably, the delay time of the first time relay KT1 is adjusted to 0.1s, the delay time of the second time relay KT2 is adjusted to 1.5s, and the delay time of the third time relay KT3 is adjusted to 3s. The coils of the first time relay KT1, the second time relay KT2 and the third time relay KT3 are connected end to end by adopting a triangle connection method, and delay time of the three time relays is inconsistent, so that the first time relay KT1, the second time relay KT2 and the third time relay KT3 are not attracted at the same time, and short circuit accidents are avoided.

Compared with the prior art, the technical scheme provided by the utility model has the following advantages: compared with the current situation, the method greatly reduces equipment damage caused by phase failure of the control circuit, avoids error gear of the universal meter when the universal meter is used for measuring, causes internal short circuit of the universal meter when the ohm gear is used for measuring electricity, causes arc light to hurt people, fire and other electrical accidents, and reduces mechanical accidents caused by incapability of accurately converting positive and negative rotation of the control circuit and test running of the electric motor; the tester is simple in structure, practical and efficient, can be widely applied to the forward and reverse rotation control circuit in the electric control of a ground production unit and the test operation of a production mine after the 80N and 120N switches are overhauled on the ground, can accurately judge whether the forward and reverse rotation control circuit or the 80N and 120N switch main circuits after overhauling are out of phase according to the audible and visual alarm display of the tester, and can accurately judge whether the forward and reverse rotation of the control circuit can be accurately converted.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the utility model and together with the description, serve to explain the principles of the utility model.

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings that are required to be used in the description of the embodiments or the prior art will be briefly described below, and it will be obvious to those skilled in the art that other drawings can be obtained from these drawings without inventive effort.

Fig. 1 is a schematic circuit diagram of a positive and negative rotation phase failure tester according to the present utility model.

Detailed Description

In order that the above objects, features and advantages of the utility model will be more clearly understood, a further description of the utility model will be made. It should be noted that, without conflict, the embodiments of the present utility model and features in the embodiments may be combined with each other.

In the description, it should be noted that the terms "first," "second," and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. It should be noted that, unless explicitly stated or limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the terms described above will be understood by those of ordinary skill in the art as the case may be.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present utility model, but the present utility model may be practiced otherwise than as described herein; it will be apparent that the embodiments in the specification are only some, but not all, embodiments of the utility model.

Specific embodiments of the present utility model will be described in detail below with reference to the accompanying drawings.

In one embodiment, as shown in fig. 1, a forward-reverse rotation and phase-failure tester comprises a phase sequence protection relay ZFZ, a first intermediate relay KA1, a second intermediate relay KA2, a third intermediate relay KA3, a first time relay KT1, a second time relay KT2, a third time relay KT3, a first red light HR1, a second red light HR2, a third red light HR3, a first green light HG1, a second green light HG2 and a first buzzer HA1, wherein the phase sequence protection relay ZFZ is respectively connected with a three-phase power supply through three wiring terminals of the phase sequence protection relay ZFZ, and a first fuse F1, a second fuse F2 and a third fuse F3 are respectively connected in series between the three wiring terminals of the phase sequence protection relay ZFZ and the three-phase power supply; the coils of the first intermediate relay KA1, the second intermediate relay KA2 and the third intermediate relay KA3 are connected through a star connection method, the three remaining ends are respectively connected to a three-phase power supply of the phase sequence protection relay ZFZ, the coils of the first time relay KT1, the second time relay KT2 and the third time relay KT3 are connected end to end through a triangle connection method, one end of a delay disconnection contact KT1-1 of the first time relay KT1 is connected to a C-phase power supply in parallel, the other end of the delay disconnection contact KT2-1 of the second time relay KT2 is connected to a position between the second time relay KT2 and the third time relay KT3 in parallel, one end of a delay disconnection contact KT3-1 of the third time relay KT3 is connected to a position between the B-phase power supply in parallel, and the other end of the delay disconnection contact KT2 is connected to a position between the first time relay KT1 and the second time relay KT 2; the delay closing contact KT1-2 of the first time relay KT1 is connected to an A-phase power supply in series, the delay closing contact KT1-3 of the first time relay KT1 is connected to a B-phase power supply in series, the delay closing contact KT3-2 of the third time relay KT3 is connected to a C-phase power supply in series, the front end of the delay closing contact KT2-2 of the second time relay KT2 is connected to the front end and the rear end of the delay closing contact KT1-3 of the first time relay KT1 in parallel, the front end of the delay closing contact KT2-3 of the second time relay KT2 is connected to the front end and the rear end of the delay closing contact KT3-2 of the third time relay KT3 in parallel, and the front end of the delay closing contact KT3-3 of the third time relay KT3 is connected to the rear end of the delay closing contact KT1-3 of the first time relay KT1 in parallel, and the front end and the rear end of the delay closing contact KT2 of the delay closing contact KT1-2 of the second time relay KT3 is connected to the front end and the rear end of the delay closing contact KT2 of the first time relay KT1-3 in parallel; the normally open contact KA1-1 of the first intermediate relay KA1 is connected in series with the first red light HR1 to form an A-phase indication loop, one end of the A-phase indication loop is connected in parallel with the rear end of the delay closing contact KT1-2 of the first time relay KT1, and the other end of the A-phase indication loop is connected in parallel with the rear end of the delay closing contact KT3-3 of the third time relay KT 3; the normally open contact KA2-1 of the second intermediate relay KA2 is connected with the second red light HR2 in series to form a B-phase indication loop, and the B-phase indication loop is connected to two ends of the A-phase indication loop in parallel; the normally open contact KA3-1 of the third intermediate relay KA3 is connected with the third red light HR3 in series to form a C-phase indication loop, and the C-phase indication loop is connected to two ends of the B-phase indication loop in parallel; the normally closed contact KA1-2 of the first intermediate relay KA1, the normally closed contact KA2-2 of the second intermediate relay KA2 and the normally closed contact KA3-2 of the third intermediate relay KA3 are connected in parallel and then connected with the first buzzer HA1 and the second buzzer HA2 in series to form a phase-failure alarm loop, and the phase-failure alarm loop is connected to two ends of the C-phase indication loop in parallel; the normally open contact KA1-3 of the first intermediate relay KA1, the normally open contact KA2-3 of the second intermediate relay KA2, the normally open contact ZFZ-1 of the phase sequence protection relay ZFZ and the first green light HG1 are connected in series to form a forward rotation indication loop, and two ends of the forward rotation indication loop are connected in parallel to two ends of the open-phase alarm loop; the normally closed contact ZFZ-2 of the phase sequence protection relay ZFZ and the second green light HG2 are connected in series to form a reverse indication loop, and the reverse indication loop is connected in parallel to two ends of a series circuit of the normally open contact ZFZ-1 of the phase sequence protection relay ZFZ and the first green light HG 1.

The coils of the first intermediate relay KA1, the second intermediate relay KA2 and the third intermediate relay KA3 are connected according to the star connection method, namely, the head ends or the tail ends of the coils of the first intermediate relay KA1, the second intermediate relay KA2 and the third intermediate relay KA3 are connected, so that the reliability of the actions of the first intermediate relay KA1, the second intermediate relay KA2 and the third intermediate relay KA3 can be ensured. Where "front side" refers to the end into which current flows and "rear side" refers to the end from which current flows.

Based on the above embodiments, in a preferred embodiment, the delay time of the first time relay KT1 is adjusted to 0.1s, the delay time of the second time relay KT2 is adjusted to 1.5s, the delay time of the third time relay KT3 is adjusted to 3s, the coils of the first time relay KT1, the second time relay KT2 and the third time relay KT3 are connected end to end by adopting a triangle connection method, and the delay times of the three time relays are inconsistent, which is to ensure that the first time relay KT1, the second time relay KT2 and the third time relay KT3 are not simultaneously attracted, so as to avoid the occurrence of a short circuit accident.

In a specific embodiment, the forward and reverse rotation phase-failure tester is installed in an electric cabinet with the dimensions of 150mm multiplied by 200mm multiplied by 300mm, wherein a phase sequence protection relay ZFZ, a first intermediate relay KA1, a second intermediate relay KA2, a third intermediate relay KA3, a first time relay KT1, a second time relay KT2 and a third time relay KT3 are installed in the electric cabinet; the first red light HR1, the second red light HR2, the third red light HR3, the first green light HG1, the second green light HG2, the first buzzer HA1 and the second buzzer HA2 are embedded in the front surface of the electric cabinet. The specification of the electric element model of the forward and reverse rotation phase failure tester is shown in table 1.

The working principle of the forward and reverse rotation phase failure tester of the utility model is as follows: when the power supply is used, the A, B, C three terminals are connected to the load side of the forward and reverse rotation control circuit or the load side of the 80N switch and the 120N switch, and the forward and reverse rotation control circuit or the 80N switch and the 120N switch are closed, and specifically, the following cases exist.

When the positive and negative rotation control circuit or the 80N and 120N switch main circuit is not in phase shortage, the KA1, KA2 and KA3 coils are electrified and attracted, the KT1 coil is electrified and attracted, the delay-off contact KT1-1 of the KT1 is delayed for 0.1 second to be opened, meanwhile, the KT2 and KT3 coil circuits are cut off, the KT2 and KT3 coils lose power, the ABC phase indication circuit, the phase shortage alarm circuit and the positive and negative rotation indication circuit are provided by conducting the power supply through the delay-off contact KT1-2 and the delay-off contact KT1-3 of the KT1 for 0.1 second, the KA2-1 and the KA3-1 are conducted, the first red lamp HR1, the second red lamp HR2 and the third red lamp HR3 on the A, B, C three-phase indication circuit are on, meanwhile, the KA1-2 and KA2-2 are cut off, the buzzer is not in power supply, and no phase shortage is indicated. When the phase sequence of the three-phase power supply is normal, KA1-3, KA2-3 and ZFZ-1 are conducted, ZFZ-2 is disconnected, a first green light HG1 in the forward rotation indication loop is on, and a second green light HG2 in the reverse rotation indication loop is not on. If the power source A, B is changed, after being electrified, KA1-3, KA2-3 and ZFZ-2 are conducted, ZFZ-1 is disconnected, the first green light HG1 in the forward rotation indication loop is not on, and the second green light HG2 in the reverse rotation indication loop is on.

When the positive and negative rotation control circuit or the 80N and 120N switch main circuit lacks A phase, the KA1 coil is cut off, the KA2 and KA3 coils are electrified and are in attraction, the KT1 and KT3 are not in attraction, the KT2 is in attraction, the KT2 delay disconnection contact KT2-1 is in delay for 1.5 seconds and is disconnected, meanwhile, the KT1 and KT3 coil circuits are cut off, the KT1 and KT3 are in power failure, the ABC phase indication circuit, the phase failure alarm circuit and the positive and negative rotation indication circuit are provided through the delay conduction contact KT2-2 and the delay conduction contact KT2-3 of the KT2-3 for 1.5 seconds, at this time, the KA1-1 is disconnected, the KA2-1 and KA3-1 are in conduction, the first red lamp HR1 on the A, B, C three-phase indication circuit is not on, the second red lamp HR2 and the third red lamp HR3 are on, meanwhile, the KA1-2 and KA3-2 are disconnected, and the buzzer is electrified, and an alarm is displayed, namely the phase failure is displayed. In the case of phase failure, the first green light HF1 and the second green light HG2 in the forward and reverse rotation indication loop are not lighted.

Similarly, when the positive and negative rotation control circuit or the 80N and 120N switch main circuit lacks B phase, the KA2 coil is cut off, the KA1 and KA3 coils are electrified and attracted, the KT1 and KT2 are not attracted, the KT3 is attracted, the KT3 delay disconnection contact KT3-1 is disconnected for 3 seconds, meanwhile, the KT1 and KT2 coil circuits are cut off, the KT1 and KT2 are powered down, the ABC phase indication circuit, the phase failure alarm circuit and the positive and negative rotation indication circuit are provided through the delay conduction contacts KT3-2 and KT3-3 for 3 seconds of the KT3, at this time, the KA2-1 is disconnected, the KA1-1 and KA3-1 are conducted, the first red lamp HR1 on the A, B, C three-phase indication circuit is lighted, the second red lamp HR2 is not lighted, the third red lamp HR3 is lighted, meanwhile, the KA2-2 and KA3-2 are disconnected, and the buzzer is powered up, so that the alarm is displayed, namely the phase failure is displayed. In the case of phase failure, the first green light HF1 and the second green light HG2 in the forward and reverse rotation indication loop are not lighted.

Similarly, when the positive and negative rotation control circuit or the 80N and 120N switch main circuit lacks C phase, the KA3 coil is cut off, the KA1 and KA2 coils are electrified and attracted, the KT3 and KT2 are not attracted, the KT1 is attracted, the KT1 delay-off contact KT1-1 is delayed for 0.1 second to be disconnected, meanwhile, the KT3 and KT2 coil circuits are cut off, the KT3 and KT2 are deenergized, the ABC phase indication circuit, the phase failure alarm circuit and the positive and negative rotation indication circuit are provided through the delay-on contact KT1-2 and the delay-on contact KT1-3 of the KT1 for 0.1 second, at this time, the KA3-1 is disconnected, the KA1-1 and KA2-1 are connected, the first red lamp HR1 and the second red lamp HR2 on the A, B, C three-phase indication circuit are on, the third red lamp HR3 is not on, the KA1-2 and the buzzer is powered off, and an alarm is sent, namely, the phase failure display is displayed, and the third red lamp HR3 is not displayed. In the case of phase failure, the first green light HF1 and the second green light HG2 in the forward and reverse rotation indication loop are not lighted.

The foregoing is only a specific embodiment of the utility model to enable those skilled in the art to understand or practice the utility model. Although described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the embodiments, and they should be construed as covering the scope of the appended claims.

Claims (2)

1. The forward-reverse rotation phase-failure tester is characterized by comprising a phase sequence protection relay ZFZ, a first intermediate relay KA1, a second intermediate relay KA2, a third intermediate relay KA3, a first time relay KT1, a second time relay KT2, a third time relay KT3, a first red light HR1, a second red light HR2, a third red light HR3, a first green light HG1, a second green light HG2, a first buzzer HA1 and a second buzzer HA2, wherein the phase sequence protection relay ZFZ is respectively connected with a three-phase power supply through three wiring terminals of the phase sequence protection relay ZFZ, and a first fuse F1, a second fuse F2 and a third fuse F3 are respectively connected in series between the three wiring terminals of the phase sequence protection relay ZFZ and the three-phase power supply; the coils of the first intermediate relay KA1, the second intermediate relay KA2 and the third intermediate relay KA3 are connected through a star connection method, the three remaining ends are respectively connected to a three-phase power supply of the phase sequence protection relay ZFZ, the coils of the first time relay KT1, the second time relay KT2 and the third time relay KT3 are connected end to end through a triangle connection method, one end of a delay disconnection contact KT1-1 of the first time relay KT1 is connected to a C-phase power supply in parallel, the other end of the delay disconnection contact KT2-1 of the second time relay KT2 is connected to a position between the second time relay KT2 and the third time relay KT3 in parallel, one end of a delay disconnection contact KT3-1 of the third time relay KT3 is connected to a position between the B-phase power supply in parallel, and the other end of the delay disconnection contact KT2 is connected to a position between the first time relay KT1 and the second time relay KT 2; the delay closing contact KT1-2 of the first time relay KT1 is connected to an A-phase power supply in series, the delay closing contact KT1-3 of the first time relay KT1 is connected to a B-phase power supply in series, the delay closing contact KT3-2 of the third time relay KT3 is connected to a C-phase power supply in series, the front end of the delay closing contact KT2-2 of the second time relay KT2 is connected to the front end and the rear end of the delay closing contact KT1-3 of the first time relay KT1 in parallel, the front end of the delay closing contact KT2-3 of the second time relay KT2 is connected to the front end and the rear end of the delay closing contact KT3-2 of the third time relay KT3 in parallel, and the front end of the delay closing contact KT3-3 of the third time relay KT3 is connected to the rear end of the delay closing contact KT1-3 of the first time relay KT1 in parallel, and the front end and the rear end of the delay closing contact KT2 of the delay closing contact KT1-2 of the second time relay KT3 is connected to the front end and the rear end of the delay closing contact KT2 of the first time relay KT1-3 in parallel; the normally open contact KA1-1 of the first intermediate relay KA1 is connected in series with the first red light HR1 to form an A-phase indication loop, one end of the A-phase indication loop is connected in parallel with the rear end of the delay closing contact KT1-2 of the first time relay KT1, and the other end of the A-phase indication loop is connected in parallel with the rear end of the delay closing contact KT3-3 of the third time relay KT 3; the normally open contact KA2-1 of the second intermediate relay KA2 is connected with the second red light HR2 in series to form a B-phase indication loop, and the B-phase indication loop is connected to two ends of the A-phase indication loop in parallel; the normally open contact KA3-1 of the third intermediate relay KA3 is connected with the third red light HR3 in series to form a C-phase indication loop, and the C-phase indication loop is connected to two ends of the B-phase indication loop in parallel; the normally closed contact KA1-2 of the first intermediate relay KA1, the normally closed contact KA2-2 of the second intermediate relay KA2 and the normally closed contact KA3-2 of the third intermediate relay KA3 are connected in parallel and then connected with the first buzzer HA1 and the second buzzer HA2 in series to form a phase-failure alarm loop, and the phase-failure alarm loop is connected to two ends of the C-phase indication loop in parallel; the normally open contact KA1-3 of the first intermediate relay KA1, the normally open contact KA2-3 of the second intermediate relay KA2, the normally open contact ZFZ-1 of the phase sequence protection relay ZFZ and the first green light HG1 are connected in series to form a forward rotation indication loop, and two ends of the forward rotation indication loop are connected in parallel to two ends of the open-phase alarm loop; the normally closed contact ZFZ-2 of the phase sequence protection relay ZFZ and the second green light HG2 are connected in series to form a reverse indication loop, and the reverse indication loop is connected in parallel to two ends of a series circuit of the normally open contact ZFZ-1 of the phase sequence protection relay ZFZ and the first green light HG 1.

2. The positive and negative rotation phase loss tester according to claim 1, wherein the delay time of the first time relay KT1 is adjusted to 0.1s, the delay time of the second time relay KT2 is adjusted to 1.5s, and the delay time of the third time relay KT3 is adjusted to 3s.