Abstract: This article will introduce the under voltage protection of motor, especially in PR260 motor undervoltage protection relay.
Table of Contents
What is Under Voltage Protection?
Under voltage protection is a mechanism or feature designed to safeguard electrical and electronic equipment from damage or malfunction caused by voltage levels that are lower than the specified or acceptable range. It is a crucial component of many electrical systems and devices, as they can be sensitive to variations in voltage. Under-voltage can occur due to various factors, including fluctuations in the power grid, electrical faults, or overloading of circuits.
Key aspects of under-voltage protection include:
Voltage Threshold: Under-voltage protection systems are typically designed with a predefined voltage threshold. When the voltage falls below this threshold, the protection mechanism is activated.
Tripping or Shutdown: When the voltage drops below the threshold, the protection system can initiate various actions, such as tripping a circuit breaker, shutting down a device, or activating an alarm. The specific response depends on the design of the protection system and the nature of the equipment being protected.
Prevention of Damage: Under-voltage protection is critical in preventing damage to sensitive equipment. When voltage levels are too low, electrical devices may not operate correctly, which can lead to overheating, reduced efficiency, and even permanent damage.
Load Shedding: In some cases, under-voltage protection systems may initiate load shedding, a process in which non-essential loads are disconnected to maintain power to critical equipment or to prevent a complete system shutdown.
Adjustable Settings: Some under-voltage protection systems allow for adjustable settings, enabling users to set the voltage threshold and response parameters to suit their specific requirements.
Under voltage protection of motor is a critical feature that safeguards electric motors from operating under voltage conditions that could be harmful to their performance and longevity. Electric motors, particularly induction motors, rely on a stable and specified voltage level for proper operation. When the voltage supplied to a motor falls below a certain threshold, it can lead to a range of issues, including decreased efficiency, increased heating, and potential damage. Under voltage protection is employed to mitigate these risks
Key aspects of under-voltage protection for a motor typically include:
Voltage Monitoring: The protection system monitors the real-time status of the power supply voltage.
Threshold Setting: The system establishes a voltage threshold, often the rated voltage of the motor. When the power supply voltage drops to or below this threshold, the under-voltage protection system is activated.
Alarms and Protective Measures: When the power supply voltage drops below the threshold, the under-voltage protection system can take various actions, such as triggering alarms, reducing the motor’s operating speed, stopping the motor, or disconnecting the motor from the power source. These measures help prevent the motor from continuing to run under low-voltage conditions, reducing the risk.
Restart and Recovery: Once the power supply voltage returns to normal levels, the under-voltage protection system typically allows for motor restart or deactivation of the protection state, enabling the motor to resume operation.
What is under voltage protection of motor in the PR260?
PR260 series motor protection relay of Blue Jay company is an all-in-one solution designed to continuously monitor 3-phase power lines for abnormal conditions. it is suitable for the protection and monitoring of low-voltage motors with a rated voltage of less than 690V and a rated current of up to 820A.
The series of products monitor the field signals in real-time and detect the faults caused by abnormal starting, overload, overcurrent, overheating, stalled rotor, phase loss and imbalance, under voltage, overvoltage, under power, underload, grounding, or leakage of the motor.
The following is the under-voltage protection setting logic of PR260:
Any of the three-phase voltage < Threshold set value