Description
Managing heavy-duty motor operations requires precise speed regulation and high torque response. The Mitsubishi Electric FR-A840-5.5K-1 variable frequency drive delivers exceptional vector control and real-time sensorless control for three-phase induction and permanent magnet motors. This inverter is engineered for highly demanding automation layouts, providing reliable performance, structural durability, and multi-protocol network capabilities within a compact chassis.
Key Features
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Advanced Vector Control: Supports real-time sensorless vector control and closed-loop vector control for high-accuracy positioning and speed stability.
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Built-In PLC Functionality: Allows localized logic processing and sequence control directly inside the drive without an external controller.
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Comprehensive Network Integration: Native RS-485 serial interfaces with support for Modbus-RTU, alongside expansion capabilities for CC-Link, Profibus-DP, and EtherCAT.
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Energy-Saving Algorithms: Optimum excitation control continuously monitors load conditions to minimize energy consumption during operation.
Applications
- Industrial fan and ventilation fan control.
- Centrifugal and positive displacement pump systems.
- Conveyor networks and automated material handling equipment.
- Extruders, mixers, and heavy machinery requiring high starting torque.
Technical Specifications
| Manufacturer |
Mitsubishi Electric |
| Model Number |
FR-A840-5.5K-1 |
| Applicable Motor Capacity |
5.5 kW |
| Input Voltage Class |
Three-phase 400 V AC (380 to 500 V at 50/60 Hz) |
| Output Rated Voltage |
Three-phase 380 to 500 V AC |
| Output Rated Current |
12 A |
| Output Capacity |
9.1 kVA |
| Serial Communications |
RS-232, RS-422, RS-485 |
| Enclosure Protection Class |
IP20 |
| Standards |
CE, UL, cUL |
| Dimensions (H x W x D) |
260 mm x 220 mm x 170 mm |
| Shipping Weight (Calculated) |
8.0 kg |
Connections and Interfaces
| Terminal / Port |
Function / Circuit Assignment |
| R/L1, S/L2, T/L3 |
Three-phase AC power input |
| U, V, W |
Three-phase AC output to induction/PM motor |
| P/+, PR |
External brake resistor connection |
| PU Connector |
RJ-45 port for parameter unit (FR-PU07) or RS-485 connection |
| SD, PC, 5 |
Control circuit common and power supply lines |
Alternative Models & Compatibility
The FR-A840-5.5K-1 belongs to the flagship A800 inverter range, succeeding the legacy FR-A740 series. While physical footprints are largely compatible, wiring terminal alignments differ slightly. Parameter migration from older installations is streamlined via the FR Configurator2 software, allowing automatic conversion of legacy registers to the newer, high-resolution parameters of the current platform.
Application Pitfalls & Engineering Notes
When mounting this drive within closed electrical panels, adequate ventilation is essential. Under continuous 12 A load conditions, heat dissipation can lead to thermal tripping if localized temperatures rise above 50 degC. Ensure a minimum clearance of 50 mm on both sides and 100 mm top and bottom. Avoid routing high-voltage motor output cables parallel to low-voltage sensor cables to prevent electromagnetic coupling.
Commissioning & Wiring Tips
When using dynamic braking configurations, ensure that the parameter settings for brake deceleration duty cycles match the thermal ratings of the external resistors. Always connect a dedicated ground wire directly from the drive's ground terminal to the main system ground bus to mitigate leakage currents and transient voltage spikes.
Installation Guidelines
CRITICAL WARNING:
De-energize all primary and secondary power sources prior to installation. Internal main circuit capacitors hold highly lethal residual voltage. Wait a minimum of 10 minutes after disconnecting power, and verify that the charge LED indicator has extinguished before touching any terminals or wiring structures.
1
Mount the drive vertically to flat, solid surfaces in a well-ventilated enclosure.
2
Connect three-phase input power lines to R/L1, S/L2, and T/L3 terminals. Do not apply input power to output terminals.
3
Wire motor leads to U, V, and W terminals using shielded, low-impedance cabling.
4
Secure all cover plates, apply power, and initiate the motor parameter auto-tuning function through the keypad.