Description

GE Multilin SR745-W3-P5-G5-HI-A-E

I. Overview

The GE Multilin SR745-W3-P5-G5-HI-A-E is an integrated protection relay, focusing on the protection and monitoring of transformers, motors, and distribution lines, and serving as a "safety sentinel" for industrial power networks. Its core function is to capture equipment operating parameters in real time. When faults such as short circuits, overloads, and ground faults occur, it triggers protection actions within milliseconds to cut off the faulty circuit and minimize losses. At the same time, it records fault data to support operation and maintenance work.

With the advantages of "accurate protection + flexible adaptation + stable operation", this device is widely used in scenarios such as transformer protection in chemical parks, motor control in metallurgical workshops, and distribution line monitoring in commercial buildings. It is suitable for both single-machine protection and integration into systems for centralized management and control, making it a cost-effective choice for power safety assurance in small and medium-sized enterprises.

II. Technical Parameters

III. Functional Features

1. Comprehensive Accurate Protection: It has 12 core protection functions built-in, including overload, short circuit, ground fault, overvoltage, and undervoltage protection. It supports two overload protection modes: definite time and inverse time. For example, when a motor is locked, the inverse time protection can intelligently adjust the action time according to the current magnitude to avoid false tripping.
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3. Multi-Dimensional Monitoring for Easy Traceability: It collects 8 parameters in real time, such as three-phase current, voltage, and power, with a data update rate of 10 times per second. A 200-event recorder is built-in, which automatically stores the fault type, time, and parameters when a fault occurs, facilitating cause traceability.
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5. Flexible Adaptation with Low Cost: It can switch between transformer/motor protection modes via software without hardware modification, and supports custom protection thresholds. The wide-voltage power supply is suitable for different power supply scenarios, reducing the cost of accessory replacement.
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7. Strong Anti-Interference for Stable Operation: It has passed EMC anti-interference tests and can resist interference from equipment such as frequency converters and contactors in industrial sites. It still operates stably in dusty and high-temperature environments, with a mean time between failures (MTBF) of over 200,000 hours.

IV. Working Principle

The device operates through a closed-loop process of "collection - judgment - action - recording":First, current/voltage transformers collect on-site signals, which are transmitted to the AD conversion chip after isolation and filtering.The chip converts analog signals into digital signals, and the microprocessor judges the operating status by comparing the signals with preset thresholds.If a fault is detected (e.g., current reaches the short-circuit threshold), it immediately drives the relay to trip and trigger an alarm.At the same time, it records fault information and uploads it to the monitoring system via the communication interface, achieving "rapid fault handling + data traceability".

V. Usage Precautions and Fault Handling

Usage Precautions

• During installation, keep it away from high-interference equipment, with a minimum distance of ≥10cm.
• The secondary side of the CT (Current Transformer) must not be open-circuited, and the secondary side of the VT (Voltage Transformer) must not be short-circuited.
• Before wiring, the power must be cut off and voltage tested. Use twisted-pair shielded wires for communication lines, with one end grounded.
• Calibrate parameters regularly (every six months) and clean dust on the device.

Common Faults, Cause Analysis and Solutions