CN205070854U

CN205070854U - Motor start control circuit

Info

Publication number: CN205070854U
Application number: CN201520846315.8U
Authority: CN
Inventors: 王赞强; 王力争; 田建锋
Original assignee: Lingbao Jinyuan Mining Co Ltd
Current assignee: Lingbao Jinyuan Mining Co Ltd
Priority date: 2015-10-29
Filing date: 2015-10-29
Publication date: 2016-03-02
Anticipated expiration: 2025-10-29

Abstract

The utility model discloses a motor start control circuit, a normally open contact of first contactor connects between alternating current power supply and motor, the 2nd normally open contact of first contactor connects in parallel at starting switch's both ends, auxiliary relay's a normally open contact and the coil of second contactor are established ties the branch road formed and are connected in parallel at the both ends of the coil of first contactor, auxiliary relay's the 2nd normally open contact and auxiliary relay's coil are established ties the branch road formed and are connected in parallel at the both ends of the coil of first contactor, time relay's normally open contact connects in parallel at the 2nd normally open contact's of auxiliary relay both ends, a normally closed contact of second contactor and time relay's coil are established ties the branch road formed and are connected in parallel at the both ends of the coil of first contactor, frequency sensitive rheostat is connected with the motor, and the normally open contact of second contactor is parallelly connected with frequency sensitive rheostat. The utility model discloses frequency sensitive rheostat is gone into to the cluster in the motor start -up course, and it is steady to make the motor start, avoids burning out the motor.

Description

Motor start-up control circuit

Technical field

The utility model relates to motor control technologies field, particularly relates to a kind of motor start-up control circuit.

Background technology

A large amount of motor used in modern industry is produced, generally the former commonly uses auto-coupling voltage-reduction starting, it starts control switching device majority and adopts common time relay, overload protection adopts thermal relay, this starting protection has following problem: the reliability of the time relay is lower, the precision in control time is not high, and motor is opening in process, and control loop acts on without detection starting state; To the faulty operation of operating personnel without eliminating measure.Due to the existence of these problems, the normal fault occurring startup convert failed, the accident that autotransformer or relevant electric component such as frequency quick resistance and motor etc. are burnt out, causes direct economic loss, even makes industrial production interrupt.

Utility model content

The utility model provides a kind of electric motor starting control circuit, can detect electric motor starting state, effectively avoid autotransformer or frequently the relevant electrical equipment such as quick resistance and motor burn out accident.

The technical solution adopted in the utility model is: a kind of motor start-up control circuit, comprise shutdown switch, starting switch, the first contactor, the second contactor, auxiliary relay, the time relay, frequency sensitive trheostat, current transformer and thermal relay, one end of the normally-closed contact of thermal relay connects DC power anode, and the other end of the normally-closed contact of thermal relay is connected with DC power cathode with the coil of the first contactor by shutdown switch, starting switch successively; First normally opened contact of the first contactor is connected between AC power and motor; Second normally opened contact of the first contactor is connected in parallel on the two ends of starting switch; The branch circuit parallel connection that first normally opened contact of auxiliary relay and the coils connected in series of the second contactor form is at the two ends of the coil of the first contactor; The branch circuit parallel connection that second normally opened contact of auxiliary relay and the coils connected in series of auxiliary relay form is at the two ends of the coil of the first contactor; The normally opened contact of the time relay is connected in parallel on the two ends of auxiliary relay second normally opened contact; The branch circuit parallel connection that first normally-closed contact of the second contactor and the coils connected in series of the time relay form is at the two ends of the coil of the first contactor; Frequency sensitive trheostat is connected with motor, and the normally opened contact of the second contactor is in parallel with frequency sensitive trheostat, and the normally opened contact of the second contactor is that triangle connects envelope star structure; Current transformer is connected with the heater element of thermal relay, and the second normally-closed contact of second section contactor is connected in parallel on the two ends of the heater element of thermal relay.

Described AC power is 220V, and described DC power supply is 24V.

The utility model seals in frequency sensitive trheostat in motor start-up procedure, makes electric motor starting steady, avoids burning out motor.The utility model is also provided with current transformer and thermal relay, can detect the electric current in motor line, and when motor overload heating is serious, the normally-closed contact of thermal relay disconnects, the power supply of cutting-off controlling circuit, thus cuts off main circuit, protects motor.The normally opened contact of second contactor of connecting with frequency sensitive trheostat in the utility model adopts triangle to be connected and seals star structure, play shunting action, and the temperature often opened of the second contactor is declined, and extends the useful life of contactor, thus improves the running rate of equipment.

Accompanying drawing explanation

Fig. 1 is schematic block circuit diagram of the present utility model.

Embodiment

As shown in Figure 1, the utility model comprises shutdown switch SB1, starting switch SB2, the first contactor, the second contactor, auxiliary relay, the time relay, frequency sensitive trheostat RF, current transformer TA and thermal relay, one end of the normally-closed contact FR1 of thermal relay connects DC power anode, and the other end of the normally-closed contact FR1 of thermal relay is connected with DC power cathode with the coil KM1 of the first contactor by shutdown switch SB1, starting switch SB2 successively; First normally opened contact KM11 of the first contactor is connected between AC power and motor; Second normally opened contact KM12 of the first contactor is connected in parallel on the two ends of starting switch SB2; The branch circuit parallel connection that first normally opened contact KA1 of auxiliary relay and the coil KM2 of the second contactor is composed in series is at the two ends of the coil KM1 of the first contactor; The branch circuit parallel connection that second normally opened contact KA2 of auxiliary relay and the coil KA of auxiliary relay is composed in series is at the two ends of the coil KM1 of the first contactor; The normally opened contact KT1 of the time relay is connected in parallel on the two ends of the second normally opened contact KA2 of auxiliary relay; The branch circuit parallel connection that first normally-closed contact KM21 of the second contactor and the coil KT of the time relay is composed in series is at the two ends of the coil KM1 of the first contactor; Frequency sensitive trheostat RF is connected with motor, and the normally opened contact KM22 of the second contactor is in parallel with frequency sensitive trheostat RF, and the normally opened contact KM22 of the second contactor is that triangle connects envelope star structure; Current transformer TA connects with the heater element FR of thermal relay, and the second normally-closed contact KM23 of the second contactor is connected in parallel on the two ends of the heater element FR of thermal relay.

Described AC power is 220V, and described DC power supply is 24V.

Operation principle of the present utility model is as follows: during startup, press start button, the coil KM1 of the first contactor obtains electric adhesive, and the second normally opened contact KM12 of the first contactor closes self-locking, first normally opened contact KM11 of the first contactor closes, and motor rotor circuit seals in frequency sensitive trheostat RF and starts.Meanwhile, the coil KT of the time relay obtains electric trigger, after reaching delay time, the normally opened contact KT1 of the time relay closes, the coil KA of auxiliary relay obtains electric adhesive, first normally opened contact KA1 of auxiliary relay closes, the coil KM2 of the second contactor obtains electric, first normally-closed contact KM21 of the second contactor disconnects, and has cut off the power supply of the coil KT of the time relay, the coil KT power-off release of the time relay, simultaneously, the normally opened contact KM22 of the second contactor closes, and got up by frequency sensitive trheostat short circuit, start-up course terminates.Current Mutual Inductance receiver detects the electric current in electric motor loop, and when motor low cruise, the heater element FR of thermal relay is not put into operation by the second normally-closed contact KM23 short circuit of the second contactor.After motor total head is run, the second normally-closed contact KM23 of the second contactor disconnects, and thermal relay obtains electric putting into operation; when motor overload heating is serious, the normally-closed contact FR1 of thermal relay disconnects, and the power supply of control circuit is cut off; thus main circuit is also cut off, motor is protected.

Claims

1. a motor start-up control circuit, it is characterized in that: comprise shutdown switch, starting switch, the first contactor, the second contactor, auxiliary relay, the time relay, frequency sensitive trheostat, current transformer and thermal relay, one end of the normally-closed contact of thermal relay connects DC power anode, and the other end of the normally-closed contact of thermal relay is connected with DC power cathode with the coil of the first contactor by shutdown switch, starting switch successively; First normally opened contact of the first contactor is connected between AC power and motor; Second normally opened contact of the first contactor is connected in parallel on the two ends of starting switch; The branch circuit parallel connection that first normally opened contact of auxiliary relay and the coils connected in series of the second contactor form is at the two ends of the coil of the first contactor; The branch circuit parallel connection that second normally opened contact of auxiliary relay and the coils connected in series of auxiliary relay form is at the two ends of the coil of the first contactor; The normally opened contact of the time relay is connected in parallel on the two ends of auxiliary relay second normally opened contact; The branch circuit parallel connection that first normally-closed contact of the second contactor and the coils connected in series of the time relay form is at the two ends of the coil of the first contactor; Frequency sensitive trheostat is connected with motor, and the normally opened contact of the second contactor is in parallel with frequency sensitive trheostat, and the normally opened contact of the second contactor is that triangle connects envelope star structure; Current transformer is connected with the heater element of thermal relay, and the second normally-closed contact of second section contactor is connected in parallel on the two ends of the heater element of thermal relay.

2. motor start-up control circuit according to claim 1, is characterized in that: described AC power is 220V, and described DC power supply is 24V.