MPR-341-2 digital Motor protection relay
Selec MPR-341-2 Motor Protection Relay – 3Ø, Overload, Voltage, Phase & Current Protection
Advanced 3-phase motor protection relay with overload, phase failure, voltage imbalance, under/over-voltage, and dry run protection. Features programmable trip modes, CT selection, and RS-485 (Modbus) communication.
The Selec MPR-341-2 is an intelligent 3-phase motor protection relay designed for industrial motors. It provides comprehensive protection, including overload, under-current (dry run), over/under-voltage, phase reversal, phase unbalance, and stall protection. With a built-in CT, LCD display, programmable parameters, and RS-485 Modbus communication, it offers precise control and diagnostic capability for motor safety.
Key Features
True RMS measurement for accurate motor monitoring
Protects against overload, dry run, phase loss, phase reversal, voltage imbalance
Built-in CT options: 10A / 40A / 80A (selectable)
Dual display: Motor current & settings
Programmable trip class (10, 20, 30)
Selectable auto/manual reset
RS-485 Modbus RTU communication
Wide supply voltage: 85–270V AC/DC
DPDT (5A) relay output
ON, Trip, SP status LED indications
Compact DIN-rail mounting
Technical Specifications
| Specification | Details |
|---|---|
| Input System | 3Ø, 3-wire |
| Measuring Principle | True RMS |
| CT Ranges | 10A / 40A / 80A selectable |
| Trip Class | 10 / 20 / 30 (per IEC) |
| Protections | Overload, Dry Run, Phase Loss, Phase Reversal, Phase Unbalance, Over/Under-Voltage |
| Voltage Range | 85–270V AC/DC |
| Current Accuracy | ±2% |
| Relay Output | DPDT 5A @ 250V AC / 30V DC |
| Display | Dual 7-segment LED |
| Communication | RS-485, Modbus RTU |
| Sampling Time | 300 ms |
| Operating Temperature | –10 to +55°C |
| Humidity | 95% RH non-condensing |
| Mounting | DIN Rail |
| Dimensions | 105 × 72 × 58 mm |
| Weight | 220 g |
Applications
Industrial motors & pumps
HVAC systems (compressors, blowers)
Water treatment & pumping stations
Conveyors and process machinery
MCC panels & automation equipment
Agriculture pumps (dry run protection)
What’s in the Box?
1 × Selec MPR-341-2 Motor Protection Relay
User instruction manual
Warranty card
FAQ
Q1. Can this relay protect a motor from dry run?
Yes. It includes undercurrent detection for dry run protection.
Q2. Is RS-485 communication built-in?
Yes, Modbus RTU is supported for remote monitoring and PLC/SCADA integration.
Q3. Does it require an external CT?
No, CT ranges are selectable internally: 10A, 40A, 80A.
Q4. Can it be reset automatically?
Yes. Supports manual, auto, and remote reset modes.
Q5. Is it compatible with all 3-phase induction motors?
Yes, as long as motor current falls within the selected CT range.