Research on a Novel Voltage Sampling Motor Protector

Research on a Novel Voltage Sampling Motor Protector

Qian Jinchuan Zhu Shoumin (Zhejiang Taihua Electric Co., Ltd. 325604)

introduction

In the use of three-phase AC motors, more and more are used for three-phase irreversible transmission equipment (such as pumps, fans, air compressors, elevator motors, etc.). In order to protect the motor in time phase, phase sequence, over voltage and under voltage, the corresponding protector should have the above protection function to ensure the normal operation of the motor and equipment. In the voltage sampling type protector, the working voltage of the motor is usually monitored by a protector to judge its voltage state (such as overvoltage, undervoltage, phase sequence, phase error, and the above fault indication is presented on the protector panel), such as In case of failure, the protector controls the control electric appliance (such as the AC contactor) in the three-phase power supply circuit, and breaks the main circuit power supply, thereby effectively protecting the motor and the transmission equipment.

Compared with the current sampling type, the voltage sampling type protector has the biggest feature: it is independent of the power level of the protected electrical equipment, and is only protected according to the quality of the power supply of the power grid, so that the protected electrical appliance can avoid damage caused by poor power quality. Especially in the three-phase irreversible equipment or the feeder line, after the phase sequence is to be determined, the protector can identify the original phase sequence when the repair or change of the power supply line is in phase contact with the original phase sequence, thereby And the corresponding equipment for protection.

First, the main technical parameters of the protector

1.1 working voltage: AC three-phase 300V ~ 460V 50Hz;

1.2 Overvoltage protection: 380V ~ 460V adjustable, delay of about 0.5S ~ 5S adjustable;

1.3 undervoltage protection: 300V ~ 380V adjustable, delay about 1S ~ 10S adjustable;

1.4 phase failure and phase sequence protection: action time ≤ 0.2S;

1.5 protection contact capacity: AC220V 5A (resistive);

1.6 power consumption: <3VA;

1.7 Protector undervoltage and overvoltage action characteristics (Figure 1, Figure 2)

In FIG. 1 and FIG. 2, the characteristic line 1 is a single-phase over-voltage characteristic line; the characteristic line 2 is a two-phase over-voltage characteristic line; and the characteristic line 3 is a three-phase over-voltage characteristic line.

Simple LED Street Light

Simple LED Street Light,LED Street Light Fixtures ,LED Street Light ,Street Light

LED Street Light Co., Ltd. , http://www.nbsolarlights.com