Three-phase rolling door machine circuit with phase loss protection

Abstract

The invention relates to a three-phase door roller circuit with phase loss protection. The circuit comprises a main circuit composed of an uplink relay, a downlink relay, a three-phase alternating current door roller motor and a three-phase power supply, a brake circuit composed of a three-phase rectifier bridge and a brake electromagnetic coil, and a control circuit, wherein the main circuit is provided with a first phase loss protection relay and a second phase loss protection relay, the input ends of the three-phase rectifier bridge in the brake circuit are connected with the tail ends of three-phase windings of the motor respectively, and the output end of the three-phase rectifier bridge is connected with the brake electromagnetic coil; the control circuit comprises an uplink control loop and a downlink control loop. By the adoption of the circuit, phase loss protection of a door roller can be effectively achieved, and the brake electromagnetic coil has a good braking effect and is easy to produce, low in failure rate and capable of saving energy.

Description

technical field [0001] The invention relates to the technical field of rolling doors, in particular to a three-phase rolling door machine circuit with phase loss protection. Background technique [0002] Electric rolling shutter doors are widely used in stores, garages and other places. The lifting of electric rolling shutter doors is driven by rolling door machines. Rolling door machines are generally composed of motors, gearboxes, braking devices, controllers, limiters, and operation buttons. Some of the existing rolling doors are driven by three-phase AC rolling door machines, and generally use air switches or contactors to switch machines. During use, one of the three-phase lines is often open due to poor contact of the power supply line, resulting in The three-phase AC motor burns out. In the prior art, it is often used to install a phase-loss protector in the power supply line to protect the three-phase motor, but most of the phase-loss protectors use electronic compon...

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Problems solved by technology

Therefore, the existing three-phase AC rolling door machine electromagnet circuit has the following problems: after a period of use of the rolling door machine, the distance between the brake pads and the brake discs increases due to wear and tear, which will cause insufficient magnetic force of the electromagnet. If the current of the brake electromagnetic coil is increased, the electromagnet will heat up when the brake system is turned on. After the iron core of the electromagnet heats up, the magnetic permeability will decrease, and then the magnetic force will decrease, which will cause the magnetic force of the cold machine and the hot machine electromagnet to be different, which is difficult to control. ;Secondly, because the brake electromagnetic coil works at a relatively high voltage, the brake electromagnetic coil has to be made with a large number of turns and a small wire diameter, resulting in difficult production and high failure rate; in addition, the current of the brake electromagnetic coil does not decrease after the brake system is turned on. waste of electricity

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