CN2457776Y - Phase lost controller for three phase AC motor - Google Patents

Abstract

The utility model relates to an open phase controller for a three-phase AC motor, which is composed of a relay, a contactor, a rectifying diode, a resistor, a signal indicator and a button. The utility model is arranged in an insulation box and connected to a three-phase voltage (current) signal and a motor starter operating line to become an independent open phase monitoring unit. The utility model can also be arranged in a power distribution box to join in the integrated high-low voltage protection of the motor. The utility model is characterized in that the rectified output discontinuity wave is monitored after one of the three phases is open by using the cut-off function of controllable silicon to the non-continuous direct current waves; simultaneously, the utility model cuts off the motor operating lines.

Description

Three-phase alternating-current motor phase shortage controller

The utility model relates to the electric motor protecting field, particularly a kind of three-phase alternating-current motor phase shortage controller.

At present; known low-tension motor open-phase protection; usually with thermal relay or the relaying protection of electric current and voltage comparison expression; the former is bigger because of multiple external cause (season and circumstance of temperature difference, corrosive gas, the wet dust of water, motor start mode and load characteristic etc.) error; the latter is because of the internal structure complexity; the price height; not easy-maintaining, not popularization and application; Gu the three-phase alternating-current motor that a large amount of so far 10KW is following; still by the fuse protection; so after an earlier disconnected phase fuse often took place, motor was continuing accident of burning in service.

The purpose of this utility model is to provide a kind of not only can accurately discern the motor three-phase power phase shortage, thereby cuts off motor power, and prevents the three-phase alternating-current motor phase shortage controller that motor starts when the power supply phase shortage.

The purpose of this utility model is achieved in that a kind of three-phase alternating-current motor phase shortage controller, is made up of relay, contactor, rectifier diode, resistance, signal lamp and button; It is characterized in that: the end of three rectifier diode 2CZ in the control circuit meets three phase mains A, B, C respectively, the end of the common sending and receiving optical diode of other end FG, and the other end of light-emitting diode FG is succeeded electric apparatus coil K _S, relay coil K _SAnother termination current-limiting resistance R, the controllable silicon 3CT that two of another terminations of R are connected in parallel, the other end ground connection of 3CT; Button ON is sent out in the control utmost point contact of controllable silicon 3CT _SStart-up circuit is connected to the arbitrary phase in A, B, the C three phase mains respectively, and connecting ground connection behind moving disconnected button OFF, making button ON, ac contactor coil K and another fuse successively by fuse F, three normally opened contacts of K insert respectively between the fuse F and motor M of A, B, C three phase mains; Be connected in parallel to two normally opened contact K, K that are connected in series at the two ends of making button ON _SThe end of three rectifier diode 2CZ the in-described control circuit meets three phase mains A, B, C by fuse F respectively, and the other end is connected to relay coil K altogether by light-emitting diode FG respectively _SAn end, relay coil K _SAnother termination current-limiting resistance R, the controllable silicon 3CT that two of another terminations of R are connected in parallel, the other end of 3CT meets three phase mains A, B, C respectively by three rectifier diode 2CZ respectively again; The control utmost point of the controllable silicon 3CT trigger button ON that is connected in parallel _SReach button with making button ON interlock; Start-up circuit is connected to any two-phase in A, B, the C three phase mains respectively, and connecting moving disconnected button OFF, making button ON, ac contactor coil K and another fuse successively by fuse F, three normally opened contacts of K insert respectively between the fuse F and motor M of A, B, C three phase mains; Be connected in parallel to two normally opened contact K, K that are connected in series at the two ends of making button ON _S

Owing to above-mentioned structure is arranged, makes to the utlity model has following advantage:

(1), because controllable silicon, consolidates utility model phase shortage controller to the identification of phase shortage rectified wave with dam and act on simultaneously dams to phase shortage identification with to control relay and be that contactless is simultaneously carried out.

(2), technology of the present utility model shown that controllable silicon has and the gate logic function at automation field, promptly three-phase voltage rectified wave (or current wave) has only entirely mutually group once to put to close and triggers the back and continue circulation, in case controllable silicon anode input U _AU _BU _C(or I _AI _BI _C) in have one to be " 0 ", the output of controllable silicon negative electrode is " 0 ", controllable silicon has replaced one group of AND circuit element.

(3), be applied in above high-voltage motor high-tension circuit voltage (electric current) the instrument transformer electrical secondary system of 380V and do the phase shortage monitoring.

Below in conjunction with drawings and Examples the utility model is further described.

Fig. 1, for the utility model is used for the halfwave rectifier winding diagram of 380V three-phase four-wire system distribution line monitoring power supply four lines, three phase mains lacks a phase time, rectified waveform has Fig. 6 to become Fig. 7.

Fig. 2, for the utility model is used for 380V three phase full wave rectification phase shortage monitoring winding diagram, lack a phase time rectified waveform and become Fig. 9 by Fig. 8.

Fig. 3, to be the utility model insert caprice full-wave rectification phase shortage monitoring winding diagram from major loop protective current transformer, secondary side, and lacking a phase time rectified wave has Fig. 8 to become Fig. 9.This figure is phase shortage monitoring and adorns the integrated protection winding diagram that the overcurrent short-circuit protection combines, when current transformer first and second electric current just often, after the controllable silicon conducting; rectifier bridge is in the short circuit state, lack one mutually after, controllable silicon by; electric current passes through from resistance R, at control relay K _SThe coil two ends produce operation voltage, disconnect normally closed auxiliary contact K _S, the electric current of disconnection relay coil K is opened motor switch.

Fig. 4 forms Y/Y with the small transformers of three 220V/5V/1W ₀Connection, insert 380V voltage, Circuit Fault on Secondary Transformer phase voltage 5V direct voltage after halfwave rectifier is 5 * K=5 * 1.7=5.85V (K is a three-phase semiwave direct current connection factor in a formula) monitoring part with 1 controllable silicon and 6V miniature relay, be the minimum phase shortage controller of member, lack a phase time rectified waveform and become Fig. 7 by Fig. 6.

Among the figure, the Q-isolating switch; The F-fuse; The 2CZ-rectifier diode; The 3CT-controllable silicon; K-ac contactor coil and electric make and break contact and auxiliary switch; K _S-control relay coil and contact thereof; The ON-making button; The R-current-limiting resistance; FG signal lamp (light-emitting diode); The M-motor; T _A-current transformer; T _Y-small transformers; ON _S-trigger button; The moving disconnected button of OFF-; A, B, C-three-phase voltage; The N-neutral line (or ground wire) K _AF-overcurrent short-circuit protection and action connection point thereof.

Referring to Fig. 5 (a) and (b) are 380V threephase motor example structure figure according to Fig. 1 circuit structure specific design.Among the figure: the 1-connecting terminal block; The 2-insulation booth, the 4-controllable silicon; 5-trigger button ON _S6-control relay JZC-23F; 7-signal lamp FG (light-emitting diode); The 8-rectifier diode; 9-terminal board terminal screw.At the bottom of the 10-insulation booth; The 11-lid that insulate.Using method (1), test method(s): N, A, B, the C terminal of connecting terminal block are inserted the neutral line and U respectively _A, U _B, U _CThree-phase voltage clicks ON _SButton triggers the silicon controlled control utmost point, and signal lamp FG is luminous, and the expression three-phase mains voltage is normal, and rectification circuit is through the controllable silicon conducting, and control relay JZC coil gets electronic work, and after removing a power supply lead wire, signal lamp extinguishes, and the relay coil dead electricity is restored.(2), assembling method: the utility model is contained in by the A.C. contactor in the distribution board, and connecting terminal block N, A, B, C terminal be the neutral line and U respectively _A, U _B, U _CThree-phase voltage, 1,2 two-terminal and contactor normally opened contact K are connected in series, and (3,4 two-terminal such as needs can go between to the moving trigger button that closes) clicks ON _SButton, signal lamp is luminous, and expression drops into phase shortage and has monitored.

Claims (2)

1, a kind of three-phase alternating-current motor phase shortage controller is made up of relay, contactor, rectifier diode, resistance, signal lamp and button; It is characterized in that: the end of three rectifier diode 2CZ in the control circuit meets three phase mains A, B, C respectively, the end of the common sending and receiving optical diode of other end FG, and the other end of light-emitting diode FG is succeeded electric apparatus coil K _S, relay coil K _SAnother termination current-limiting resistance R, the controllable silicon 3CT that two of another terminations of R are connected in parallel, the other end ground connection of 3CT; Button ON is sent out in the control utmost point contact of controllable silicon 3CT _SStart-up circuit is connected to the arbitrary phase in A, B, the C three phase mains respectively, and connecting ground connection behind moving disconnected button OFF, making button ON, ac contactor coil K and another fuse successively by fuse F, three normally opened contacts of K insert respectively between the fuse F and motor M of A, B, C three phase mains; Be connected in parallel to two normally opened contact K, K that are connected in series at the two ends of making button ON _S

2, a kind of three-phase alternating-current motor phase shortage controller according to claim 1, it is characterized in that: the end of three rectifier diode 2CZ in the described control circuit meets three phase mains A, B, C by fuse F respectively, and the other end is connected to relay coil K altogether by light-emitting diode FG respectively _SAn end, relay coil K _SAnother termination current-limiting resistance R, the controllable silicon 3CT that two of another terminations of R are connected in parallel, the other end of 3CT meets three phase mains A, B, C respectively by three rectifier diode 2CZ respectively again; The control utmost point of the controllable silicon 3CT trigger button ON that is connected in parallel _SReach button with making button ON interlock; Start-up circuit is connected to any two-phase in A, B, the C three phase mains respectively, and connecting moving disconnected button OFF, making button ON, ac contactor coil K and another fuse successively by fuse F, three normally opened contacts of K insert respectively between the fuse F and motor M of A, B, C three phase mains; Be connected in parallel to two normally opened contact K, K that are connected in series at the two ends of making button ON _S

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