Phase loss Three Phase Voltage Monitoring Relay protection against improper phase sequence

Phase loss protectors, also known as motor phase failure protectors or power phase loss protectors, are commonly used on three-phase motor circuits. If a single circuit is missing, the motor torque will decrease and the rotor speed will drop, resulting in two other currents Increase, burn the motor winding, its principle is through different means, carries on the monitoring to the three-phase electricity, if has the disconnection situation, will automatically cut off the power source, avoids burns the winding, because the science and technology develops rapidly, the type of phase failure protection device, has passed To monitor the on-off of each voltage control, there are monitoring of each current to control.

Detect voltage to control
This type of detection voltage can also be called three-phase power supply monitor, phase sequence protector, over voltage protection device, etc.) Mainly used for AC 50/60Hz, rated voltage below 460V, industrial three-phase 220V, 380V, 440V , 460V and other voltage levels of various fault detection, the three-phase input power supply voltage is too high, voltage is too low, lack of phase, phase failure, reverse phase (phase sequence), three-phase voltage imbalance, etc. to provide protection relay products Widely used in distribution boxes, central air-conditioning units, electric control boxes, power distribution cabinets, cranes, etc., such as central air-conditioning compressor protection, power monitoring of various elevators, pumps, oil pumps against phase loss, reverse phase protection, etc. An indispensable protective product that maintains the normal working voltage of the equipment during operation.

Phase sequence protector is a kind of control relay, automatic phase sequence identification protection relay, guarantee some special electromechanical equipment

The reversed phase sequence of the power supply reversed the accident or equipment damage. Such as elevators, central air conditioning, cranes, motors, etc. If the phase sequence of the power supply is wrong after repair, it will lead to accidents. The phase sequence protector must be connected to the control circuit to ensure the phase sequence is correct. Air-conditioner compressors also use phase sequence protectors to ensure that the compressor will not be reversed after maintenance.

Sampling three-phase power supply and processing, in the case of phase sequence of the power supply phase sequence and protector terminal input, the output relay is turned on, the device main control circuit is connected. The existing two types of products are: when the phase sequence of the power supply changes, the phase sequence does not match, and the output relay cannot be turned on, thereby protecting the equipment and avoiding the occurrence of accidents; the other type uses digital micro-core technology products and can realize automatic Phase sequence recognition, and automatic phase sequence conversion, to ensure that the motor rotates in a constant phase sequence.

♦ Technical data