Description
Regulating industrial motor speed with exceptional torque control, the Mitsubishi Electric FR-A740-2.2K-CHT is a high-performance three-phase 400V variable frequency drive designed for heavy-duty applications. Part of the robust FR-A700 Series, this 2.2 kW (3 HP) inverter features advanced magnetic flux vector control and real sensorless vector control, ensuring stable speed regulation even at ultra-low frequencies. Engineered to survive harsh manufacturing environments, it serves as an essential automation component for precise machinery synchronization, fan/pump speed regulation, and torque-limiting applications.
Key Features
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Real Sensorless Vector Control (RSV): Achieves high-accuracy torque and speed control without requiring an encoder feedback interface.
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Offline Auto-Tuning: Automatically characterizes motor parameters to maximize performance across different motor brands.
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Built-In Modbus RTU: Integrated RS-485 serial communication port supports standard industrial networking protocols.
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Long-Life Design: Utilizes specialized cooling fans and capacitors rated for extended service lifetimes.
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Integrated PLC Functionality: Allows custom logic control processing directly inside the drive using GX Developer software.
Applications
- Conveyors and material handling distribution systems requiring high starting torque.
- Industrial fan, blower, and exhaust ventilation systems.
- Centrifugal pumps, booster stations, and fluid processing facilities.
- Machine tool spindles, textile winding machines, and packaging equipment.
Technical Specifications
| Specification Parameter |
Value / Rating |
| Manufacturer |
Mitsubishi Electric |
| Model Number |
FR-A740-2.2K-CHT |
| Product Series |
FR-A700 (A740 Class) |
| Input Voltage / Frequency |
3-Phase 380 to 480 V AC, 50Hz / 60Hz |
| Applicable Motor Capacity |
2.2 kW (3 Horsepower) |
| Output Current Rating |
6.0 A (LD) / 5.0 A (HD) |
| Output Frequency Range |
0.2 to 400 Hz |
| Control Modes Available |
V/F Control, Advanced Magnetic Flux Vector Control, Real Sensorless Vector Control |
| Enclosure Rating |
IP20 (Open Type) |
| Ambient Operating Temperature |
-10 to 50 degC (non-freezing) |
| Terminal Screw Size |
M3 x 35 mm (Control terminals) |
| Shipping Weight (Calculated) |
4.0 kg (8.82 lbs) |
Empirical Engineering Insights
Alternative Models & Compatibility
The FR-A740-2.2K-CHT serves as a direct upgrade to the older FR-A540-2.2K series. For facilities transitioning to the newer FR-A840 series, the FR-A840-00126-2.6K is the designated replacement. When migrating configuration parameters, use the FR Configurator software to import and convert parameter tables seamlessly, but pay special attention to the terminal block mapping if relying on built-in PLC functions.
Application Pitfalls & Engineering Notes
In high-inertia fan applications, decelerating too rapidly can generate regenerative energy back into the drive, triggering an E.OV3 (Overvoltage during deceleration) safety fault. To prevent downtime under high-inertia loads, integrate a dedicated external braking resistor (FR-ABR-H2.2K) and ensure parameter 30 (Regenerative function selection) is configured correctly.
Commissioning & Wiring Tips
Always route the control signal wiring (using shielded twisted pair cables) completely separate from the main motor and power input lines to mitigate electro-magnetic interference (EMI). Terminal connections for control logical inputs are secure-clamp style; avoid using bare stranded copper wires without crimp ferrules, as this can lead to intermittent feedback signals.
Installation Guidelines
CRITICAL ELECTRICAL WARNING
Isolate and lock out all AC main line input feeds before attempting terminal wiring or mounting procedures. Internal DC-bus capacitors retain high-voltage charge after de-energization. Wait at least 10 minutes and verify with a reliable multimeter that the voltage across terminals P/+ and N/- is below 30 V DC before initiating hands-on physical contact.
1
Enclosure Mounting: Mount the inverter vertically onto a flat, non-flammable surface inside an electrical cabinet. Maintain a minimum horizontal spacing clearance of 50 mm and vertical clearance of 100 mm for unrestricted convective heat dissipation.
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Power Connections: Connect the three-phase AC input supply to terminals R/L1, S/L2, and T/L3. Connect the output motor terminals to U, V, and W. Ensure the grounding terminal (PE) is securely bonded to the plant ground grid.
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Startup Initialization: Turn on the input power. Set Parameter 9 (Electronic thermal O/L relay) to match the motor's rated plate current before executing any physical rotation tests.