ALSTOM 029.148.906 Motor Protection Relay

The ALSTOM 029.148.906 is a numerical motor protection relay designed to safeguard medium and high‑voltage AC motors against all common electrical and mechanical faults. It combines thermal modeling with extensive protection elements to ensure motor longevity and process continuity.

Key Features

• Thermal overload protection based on motor thermal model (49) with RTD biasing

• Locked rotor / starting time supervision (48/51LR)

• Stator earth fault (50N/51N) and phase fault (50/51) protection

• Negative sequence overcurrent for unbalanced supply (46)

• Undercurrent / load loss (37) and over‑power protection

• Repeated start inhibition and number of starts monitoring

• Vibration and temperature monitoring via external RTDs (optional)

Technical Specifications

• Rated current: 1 A or 5 A (software selectable)

• Thermal model accuracy: ±2% of full load current

• RTD inputs: up to 12 three‑wire RTDs (Pt100, Ni100, Cu10)

• Binary inputs: 8 (24‑250 V DC)

• Output relays: 6 (trip, alarm, control)

• Communication: Modbus RTU, Profibus DP, or IEC 61850 (optional)

• Power supply: 24‑250 V DC / 100‑240 V AC

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

Applications

The 029.148.906 is ideal for protection of induction and synchronous motors driving pumps, fans, compressors, conveyors, and mills in industries such as oil & gas, mining, water treatment, and power generation. It supports both direct‑on‑line and soft‑starter applications.

Motor Management Features

Beyond protection, the relay provides comprehensive motor management data: start‑up reports, running hours counters, number of starts, and maintenance alerts. The thermal capacity used is continuously displayed, allowing operators to optimize motor loading and prevent overheating.

With its advanced protection and monitoring capabilities, the ALSTOM 029.148.906 enhances motor reliability and reduces unplanned downtime.