Description
Regulating three-phase asynchronous and synchronous motors in demanding industrial environments, the Mitsubishi Electric FR-A840-11K-1 is a high-performance FR-A800 series variable frequency drive engineered for high-torque applications. This inverter features an integrated FM pulse train output terminal, delivering real-world precision in speed and torque regulation across a wide 400V input range. Equipped with dynamic torque vector control and built-in PLC functionality, it coordinates complex motion sequences directly at the drive level, minimizing communication latency and system overhead.
Key Features
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Advanced Vector Control: Supports Real Sensorless Vector (RSV) control and closed-loop vector control for exceptional speed accuracy and starting torque.
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FM Pulse Output Terminal: Provides a high-speed pulse train output channel for accurate monitoring of operating frequency, output current, or motor speed.
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Integrated PLC Engine: Allows custom control algorithms, localized IO handling, and decentralized logic control without an external controller.
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Multi-Protocol Serial Interface: Built-in RS-485, RS-232, and RS-422 networks provide robust integration options for existing SCADA and DCS configurations.
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Comprehensive Protection: Built-in features protect against overcurrent, overvoltage, motor overload, and heatsink overheating.
Applications
- Heavy-duty cranes, hoists, and material handling systems requiring high static starting torque.
- Industrial fan, blower, and centrifugal pumping configurations with quadratic load profiles.
- Extrusion lines, compounding systems, and material mixing equipment.
- Winding and tension-controlled unwinding systems in paper, textile, and metal processing.
Technical Specifications
| Specification |
Value |
| Manufacturer |
Mitsubishi Electric |
| Model Number |
FR-A840-11K-1 |
| Product Series |
FR-A800 Series |
| Applicable Motor Capacity |
11 kW |
| Input Voltage Class |
Three-Phase 400 V Class |
| Rated Input Power Supply |
Three-phase 380 to 500 V AC, 50/60 Hz |
| Output Rated Current |
23 A |
| Output Capacity |
18 kVA |
| Output Configuration |
Three-Phase |
| External Communications |
RS-232, RS-422, RS-485 |
| Standards |
CE, UL, cUL, RoHS Compliant |
| Enclosure Protection Rating |
IP20 (Open Type) |
| Dimensions (W x H x D) |
220 mm x 300 mm x 190 mm |
| Shipping Weight (Calculated) |
9.5 kg |
Connections and Interfaces
| Terminal / Connector |
Circuit Assignment / Function Description |
| R/L1, S/L2, T/L3 |
Main AC power input terminals (Three-phase 380-500 V) |
| U, V, W |
Variable frequency three-phase output to the induction or PM motor |
| FM |
Pulse train output terminal (Monitors frequency, current, or voltage) |
| SD |
Common terminal for contact input and 24 V DC external power supply |
| STF / STR |
Forward Rotation Start / Reverse Rotation Start control inputs |
Empirical Engineering Insights
Alternative Models & Compatibility
The FR-A840-11K-1 is the direct technological successor to the legacy FR-A740-11K series in 400V industrial networks. When transitioning legacy machinery to the FR-A800 architecture, parameter lists can be converted using Mitsubishi's FR Configurator2 software. Although physical mounting dimensions are compatible, always cross-reference control terminal blocks as the FR-A800 series utilizes spring clamp terminals for control wiring compared to the screw terminals on older models.
Application Pitfalls & Engineering Notes
When deploying the drive in sealed electrical panels, proper thermal management is critical. The unit generates approximately 330 Watts of heat under full-load conditions. Ensure a minimum lateral spacing of 50 mm and vertical clearance of 100 mm from adjacent equipment to avoid thermal derating. If the drive is run at high carrier frequencies (exceeding 14.5 kHz) to minimize motor acoustic noise, the rated output current must be derated by 15 percent to prevent premature thermal fault (E.THT) trips.
Commissioning & Wiring Tips
For motor applications requiring high starting torque at low speeds, execute an offline auto-tuning sequence (Parameter 96 set to 1) with the motor completely uncoupled. This maps the stator resistance and transient inductance, optimizing the dynamic torque vector control algorithms. Additionally, to avoid high-frequency capacitive leakage currents and EMC disruption on analog feedback loops, always use symmetrically shielded motor power cables, and ground the shielding braid 360 degrees directly at the drive grounding clamp.
Installation Guidelines
CRITICAL WARNING:
Risk of electric shock and lethal discharge. Disconnect all main power inputs (R/L1, S/L2, T/L3) before opening the terminal cover or executing any maintenance. Wait at least 10 minutes for internal capacitors to discharge completely, and verify that the charge lamp is fully extinguished prior to working on internal electrical terminals.
1
Mount the inverter vertically to a flat, rigid vertical wall or internal panel backplate using appropriate M5 mounting fasteners. Do not install the unit horizontally or upside down.
2
Connect the input power lines to R/L1, S/L2, and T/L3 terminals. Connect the motor supply cables to U, V, and W terminals. Ensure proper phase configuration and torque connections. Do not apply AC power to the motor output terminals.
3
Establish a solid low-impedance safety ground connection utilizing the ground terminal provided on the chassis. Do not daisy-chain ground lines with nearby equipment.
4
Wire control signals (such as start/stop commands and the FM analog monitoring output) using shielded twisted-pair cables, keeping control routing physically isolated from high-voltage motor lines.