CN101752830A

CN101752830A - Open-phase protection contactor

Info

Publication number: CN101752830A
Application number: CN200810183685A
Authority: CN
Inventors: 李薇薇
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-12-06
Filing date: 2008-12-06
Publication date: 2010-06-23

Abstract

The invention discloses a current type open-phase protection contactor which has the advantages of simple structure, small volume and low cost and can cause a circuit detector to be combined with an alternating current contactor into a whole and ensure that when any places from a three-phase power supply to an electric device generate open circuit and open phase, the burnout of the three-phase electric device can be completely avoided. The circuit detector is used for detecting the current balance of a monitored circuit, thereby ensuring the safety and the reliability; the circuit detect is in a to-move state (namely three-phase current balance) in case of no failure of the monitored circuit, and a resultant magnetic field is generated in the circuit detector at the moment in case of no current caused by phase breakage, so that the circuit detector starts to work. A power supply of the alternating current contactor is powered off, a power supply of the three-phase electric device is cut off, and the circuit detector has the advantages of no power consumption, no noise, wide application scope, convenient use and long service life.

Description

Open-phase protection contactor

1. technical field

The present invention relates to three-phase ac contactor----open-phase protection contactor, it is applicable to the occasion that needs open-phase protection three-phase power consumption equipment (as motor) and any needs to prevent the three-phase electricity phase-deficient operation.

2. background technology

In industrial and agricultural production, three-phase ac contactor is a large amount of general electronic corporations that use.Three-phase power consumption equipment (as threephase motor) is three characteristics of the middle term electricity phase shortage often, causes motor to burn.At present, many kinds of open phase protectors are arranged, as: the super stream protector that A.C. contactor and thermal relay are formed; The protection that A.C. contactor and electronic type open phase protector are formed etc.The super stream protector that A.C. contactor and thermal relay are formed is insensitive because of it, long action time does not have protective effect substantially.The protector that A.C. contactor and electronic type open phase protector are formed; only three-phase electricity power supply phase shortage is played a protective role (both voltage-type open phase protectors), and A.C. contactor is not all had protective effect to the phase shortage that opens circuit, power consumption equipment internal break phase shortage in the circuit between the power consumption equipment.Therefore, they are incomplete open-phase protection.

3. summary of the invention

Purpose of the present invention just provides a kind of simple in structure, and volume is little, and cost is low.Circuit detector and A.C. contactor are combined as a whole, when opening circuit phase shortage Anywhere in can guaranteeing from the three phase mains to the power consumption equipment, and the equal current mode open-phase protection contactors that can avoid the three-phase power consumption equipment to burn fully.

Basic principle of the present invention is as follows: during three-phase power consumption equipment operate as normal, (as threephase motor) is kind relatively threephase load of symmetry, this moment three-phase balance, the resultant magnetic field in the circuit detector is zero.And, produce the resultant magnetic field in the circuit detector this moment when having one when disconnecting no current mutually, and circuit detector is started working, and disconnects the ac contactor coil power supply, and A.C. contactor discharges, and cuts off three-phase power consumption equipment power supply, reaches the open-phase protection effect.(in fact because three phase mains itself just exists asymmetricly, add the incomplete symmetry that the three-phase power consumption equipment is made, so the resultant magnetic field in the circuit detector still exists, but very I is not remembered to ignore.)

It comprises the performer (as Fig. 1, Fig. 2) of power consumption equipment starting control the present invention, and be characterized in: it is provided with circuit detector, and the normally-closed contact of circuit detector is connected in series with A.C. contactor.Circuit detector and A.C. contactor are combined into one.

It can also be characterized in the present invention as shown in Figure 3: circuit detector is by the transformer of three phase lines as primary coil, and transformer secondary output connects a miniature relay, and the normally-closed contact of relay is connected in series with A.C. contactor.

The present invention it can also be as shown in Figure 4, transformer secondary output order, bidirectional triode thyristor trigger electrode, other the two poles of the earth of controllable silicon also are connected in A.C. contactor.

The present invention's its advantage compared with the prior art is: circuit detector detects the current balance type of monitored circuit, safe and reliable, during monitored circuit fault-free, (both three-phase balances) circuit detector is in " treating state ", not power consumption itself, noiselessness, cost is low, and is simple in structure, applied widely, easy to use, the life-span is long.

4. description of drawings

Fig. 1 is both circuit diagrams of structural representation of the present invention.

Numbering: (1) start button (2) shutdown button (3) A.C. contactor normally opened contact

(4) ac contactor coil (5) circuit detector (6) circuit detector normally-closed contact

Fig. 2 is a circuit detector internal structure schematic diagram.

Fig. 3 is transformer type circuit detector internal structure and connects the miniature relay schematic diagram.

Fig. 4 is a transformer type circuit detector internal structure and single, double to controllable silicon and contactor connection diagram

5. specific embodiment

Shown in Figure 1, normal as circuit, three-phase balance, the interior resultant magnetic field of circuit detector (5) is zero, circuit detector is in " treating state ", the power consumption equipment operate as normal; When having one to occur mutually opening circuit phase shortage in the three-phase circuit; three-phase current unbalance; produce a resultant magnetic field in the circuit detector (5) immediately; circuit detector (5) adhesive; circuit detector normally-closed contact (6) disconnects, and cuts off ac contactor coil (4) power supply, and A.C. contactor normally opened contact (3) discharges; cut off three phase mains, reach the open-phase protection effect.

Claims

1. the invention belongs to a kind of inspection streaming open-phase protection contactor, by A.C. contactor (ac contactor coil 4, A.C. contactor normally opened contact 3), circuit detector 5, circuit detector normally-closed contact 6 is formed.It is characterized in that: circuit detector and A.C. contactor are combined as a whole, and the normally-closed contact of circuit detector is connected in series with the coil of A.C. contactor.

2. as the described open-phase protection contactor of right (1), it is characterized in that: circuit detector is surrounded on an auxiliary relay of forming on the magnetic core by three phase lines.

3. as the described open-phase protection contactor of right (1), it is characterized in that: circuit detector can also be by the transformer of three phase lines as primary coil, and transformer secondary output connects a miniature relay or single, double to controllable silicon, comes control contactor.