GE 489-P1-LO-A20-T-H generator protection relay

GE 489-P1-LO-A20-T-H generator protection relay

Overall overview
It is an intelligent relay specially designed for generator protection and control. It integrates a variety of protection functions, measurement functions and communication functions to fully monitor and protect the generator, ensuring the safe and stable operation of the generator under various operating conditions.

Current correlation parameter
Phase current input: Suitable for 1A phase CT secondary power supply. It can accurately measure the phase current of the generator and provide accurate current signals for various protection functions and measurement calculations.
Analog output: with 4-20mA analog output signal. Through this output, the relay can convert the internal measured electrical parameters, such as current, voltage, power, etc. into standard analog signals, which are convenient for connection and data transmission with other external devices, such as the signal can be transmitted to the data acquisition system or other monitoring devices to achieve remote monitoring and recording of the generator operating parameters.

Input-output characteristic
Digital input: It is generally equipped with seven assignable digital inputs, which use optical isolation technology to effectively prevent external electrical interference and ensure the accuracy and stability of the input signal. The digital input can be used to receive external switching signals, such as circuit breaker position signals, tool brake position signals, protective device action signals, etc., so that the relay can monitor various states of the generator in real time.
Output relays: Provide multiple output relays, usually of type Form-C, with good electrical isolation and load driving capability. These output relays can be used to control external devices such as trip coils, alarm devices, indicator lights, etc. Through the output relay, the relay can carry out corresponding control and protection actions on the generator according to the internal protection logic and measurement results, such as sending out a trip signal when the fault occurs, so that the circuit breaker cuts off the connection between the generator and the power grid, or start the alarm device to remind the operation and maintenance personnel.
Voltage transformer input: there are four voltage transformer inputs, three of which are used to connect the generator end voltage transformer and one is used for the neutral line voltage transformer. With these voltage transformer inputs, the relay can accurately measure the generator’s terminal voltage and neutral line voltage, providing an accurate voltage signal for voltage protection functions, power calculations, and other voltage-related measurements and controls.

Other characteristics
Data recording and display: with data recording function, it can record the operating hours of the generator, the demand (current MW, Mvar, MVA) and other data, and can also record the fault event in detail, including the time, type, and related electrical parameters of the fault. These data are of great significance for fault analysis, equipment maintenance and power system operation evaluation. At the same time, the relay is equipped with an enhanced display, with a larger LCD display, which can display the set point, actual value, diagnostic message and default message, etc., which is convenient for field operation and maintenance personnel to directly view the operating status of the generator, protection parameters and fault information.