Description
ABB M4A-AT
Technical Specifications
- Product type: Motor temperature monitoring module
- Input: Pt100 RTD
- Channels: Multi-channel bearing and winding temperature
- Output: Alarm and trip relay contacts
- Contact rating: AC250 V 3 A
- Supply: From M101/M102 unit
- Temperature: -25 °C to +70 °C
- Storage: -40 °C to +85 °C
- Humidity: 5 % to 95 %, non-condensing
- Protection: IP20
- Installation: DIN rail / paired with control unit
- Accuracy: ±1 °C
Functional Features
- Receives motor Pt100 temperature signals
- Multi-channel bearing and winding monitoring
- Temperature alarm and trip output
- Communication with M101/M102
- Front panel LEDs per temperature channel
- Threshold set via protection unit
- Sensor wire-break detection
- Modular, easy expansion
- Industrial-grade components
- Motor cabinet environment
Application Scenarios
- Medium/high-voltage motor bearing temperature protection
- Motor winding overheating monitoring
- Pump, fan, compressor motor temperature
- With ABB M101/M102 motor protection
- Petrochemical motor temperature interlock trip
Materials and Construction
- Housing: Flame-retardant engineering plastic
- PCB: FR4 board
- Input: Pt100 signal conditioning
- Relays: Industrial electromagnetic relays
- Terminals: Screw-fastened terminals
- Passive components: Metal film resistors, capacitors
Structural Features
- Compact DIN rail module
- Top and bottom terminals
- Status LEDs
- Dedicated connector to M101/M102
- Fanless cooling
- Modular plug-in design
Working Principle Motor Pt100 signals enter input channels; conditioning circuitry converts resistance to temperature values. The module sends temperature data over a communication bus to the M101/M102 protection unit. On exceeding alarm threshold the alarm relay operates; on exceeding trip threshold the trip relay operates to shut down the motor. Sensor wire-break lights the channel fault LED.
Installation Requirements
- DIN rail or paired with M101/M102
- Three-wire Pt100 compensating wire connection
- Alarm/trip contacts wired to motor circuit
- Temperature wires shielded away from power
- Temperature -25 °C to +70 °C
- Set temperature thresholds in protection unit after power-up
Precautions
- Pt100 three-wire wiring must be correct
- Temperature thresholds match motor insulation class
- Wire-break faults handled promptly
- Periodically calibrate temperature accuracy
- Store spares in dry environment
- Disconnect temperature wires before service
