Product Overview

The REF541 (REF541KM115AAAA) is a high-performance, multifunctional feeder protection and control terminal designed for advanced medium-voltage distribution systems. As a key Intelligent Electronic Device (IED) in the ABB power protection portfolio, the REF541 (REF541KM115AAAA) integrates comprehensive protection, measurement, monitoring, and control capabilities within a single numerical unit. This revision A module is engineered to provide deterministic fault detection for feeders, transformers, and industrial motors, facilitating seamless integration into automated substation environments. Its robust hardware design ensures reliable operation in demanding electrical infrastructures, providing the precision required for grid stability and asset protection.

Detailed Technical Specifications

• Manufacturer: ABB

• Model Designation: REF541

• Ordering Code: REF541KM115AAAA

• Hardware Revision: Rev. A

• Device Type: Feeder Protection and Control Terminal

• Primary Protection: Three-phase overcurrent, directional/non-directional earth-fault, thermal overload, and voltage protection

• Secondary Protection: Phase imbalance, underfrequency/overfrequency, and broken conductor detection

• Measurement Precision: High-accuracy monitoring of phase current, voltage, frequency, power factor, and energy

• Rated Current Input: 1 A or 5 A (Software/Hardware selectable)

• Rated Voltage Input: Up to 110 V AC (Standard VT secondary circuit)

• Nominal Frequency: 50 / 60 Hz

• Auxiliary Power Supply: Wide-range universal 24–250 V DC or 48–240 V AC

• Binary I/O Configuration: Multiple programmable digital inputs and outputs for local status feedback and trip logic

• Communication Protocols: SPA bus, Modbus RTU, and IEC 60870-5-103

• Interface: Integrated HMI with a multi-line LCD display and navigational keypad

• Fault Diagnostics: Disturbance recorder (COMTRADE format) and extensive sequence-of-events log

• Operating Temperature: -25°C to +70°C

• Storage Temperature: -40°C to +85°C

• Dimensions (WxHxD): 160 mm x 180 mm x 200 mm

• Weight: 2.5 kg

• Compliance Standards: IEC 60255 series for power system protection