Description
Optimizing space-constrained motor control architectures, the Mitsubishi Electric FR-D720-0.75K micro-drive delivers precise speed regulation and high-torque performance for three-phase induction motors up to 0.75 kW (1 HP). This variable frequency drive operates on a three-phase 200V class input, utilizing advanced general-purpose magnetic flux vector control to achieve starting torques exceeding 150% at 1 Hz. Its highly compact frame makes it an ideal choice for conveyors, packaging machines, fan and pump drives, and automated material handling systems requiring high reliability and simplified integration.
Key Features
-
Magnetic Flux Vector Control: Ensures stable torque performance and precise speed response, even under varying load conditions.
-
Integrated Modbus RTU: Built-in RS-485 serial communication port enables seamless network integration without additional interface cards.
-
Safe Torque Off (STO): Supports integrated safety stop functions compliant with EN ISO 13849-1 Category 3 / PLd and IEC 61508 SIL2.
-
Spring-Clamp Control Terminals: High-reliability wiring design that resists vibration and reduces commissioning time.
-
One-Touch Digital Dial: Simplified parameter entry and real-time monitoring directly from the integrated control panel.
Typical Industrial Applications
-
Packaging Machinery: Smooth acceleration and deceleration for delicate product handling.
-
Conveyor Systems: Precise speed synchronization and high starting torque for heavy-load startup.
-
HVAC Fans and Pumps: Optimized energy saving using integrated optimum excitation control algorithms.
-
Machine Tool Auxiliaries: Reliable speed control for coolant pumps, small spindles, and chip conveyors.
Technical Specifications
| Parameter |
Specification Values |
| Manufacturer |
Mitsubishi Electric |
| Model Number |
FR-D720-0.75K |
| Product Series |
FREQROL-D700 Series |
| Applicable Motor Capacity |
0.75 kW (1 HP) |
| Rated Output Current |
4.2 A |
| Rated Output Capacity |
1.7 kVA |
| Output Voltage Rating |
3-Phase 200 to 240 VAC |
| Overload Current Rating |
150% for 60 seconds, 200% for 0.5 seconds |
| Input Voltage Class |
Three-Phase 200V Class |
| Input AC Voltage & Frequency |
3-Phase 200 to 240 VAC, 50 Hz / 60 Hz |
| Allowable Voltage Variation |
170 to 264 VAC |
| Power Supply Frequency Tolerance |
+/- 5% |
| Control Method |
Soft-PWM / High Carrier Frequency PWM (V/F Control, Magnetic Flux Vector Control selectable) |
| Output Frequency Range |
0.2 to 400 Hz |
| Cooling Method |
Self-cooling |
| Protective Structure |
Enclosed Type (IP20) |
| Ambient Operating Temperature |
-10 to +50 degC (non-freezing) |
| Ambient Operating Humidity |
90% RH or less (non-condensing) |
| Shipping Weight (Calculated) |
2.0 kg |
| Product Dimensions |
68 mm (W) x 128 mm (H) x 142.5 mm (D) |
Control Connections and Interfaces
| Terminal / Port |
Function / Circuit Assignment |
| L1, L2, L3 |
Three-phase AC power input |
| U, V, W |
Three-phase AC output to induction motor |
| Terminal 2 |
Analog frequency setting input (0 to 10 V / 0 to 5 V selectable) |
| Terminal 4 |
Analog input (0 to 10 V / 0 to 5 V / 4 to 20 mA selectable) |
| FM |
Pulse train output monitor (Up to 2.4 kHz) |
| RJ-45 Port |
RS-485 Modbus RTU interface / PU connection |
Empirical Engineering Insights
Alternative Models & Compatibility
The FR-D720-0.75K acts as a direct modern replacement for legacy FR-S520-0.75K drives. Note that control terminal layouts differ; the newer D700 series uses vibration-resistant spring-clamp terminals instead of traditional screw terminals. When migrating configurations from legacy drives, parameter maps generally align, but you must manually check Parameter 79 (Operation Mode Selection) to ensure the network or external start commands route correctly.
Application Pitfalls & Engineering Notes
Because this small frame size utilizes natural convection (self-cooling) and lacks an internal cooling fan, it is highly sensitive to ambient heat concentration. If mounted inside compact, unventilated enclosures, the drive will rapidly trigger an Overheat (E.THT or E.FIN) fault. Ensure a minimum of 50 mm clearance above and below the drive and verify that panel temperatures do not exceed 50 degC under continuous duty cycles.
Commissioning & Wiring Tips
When configuring Modbus RTU communications via the integrated RJ-45 connection, remember that standard Ethernet patch cables can be used, but you must terminate the end-of-line drive with a 120-ohm resistor between the SDA and SDB signals to prevent communication timeouts. Always route control signal lines and main power lines in separate conduits to eliminate EMI induced noise on critical analog input terminals (Terminal 2 and 4).
Installation Guidelines
CRITICAL WARNING: Hazardous voltages remain present on the drive's internal capacitors for several minutes after the main power is disconnected. Always verify that the charge lamp is fully extinguished and use a voltmeter to confirm zero voltage across terminals P/+ and N/- before touching any wiring connections.
1
Mount the inverter vertically on a flat, non-flammable surface, observing standard vertical clearance rules to allow natural heat dissipation.
2
Connect three-phase incoming AC power to terminals L1, L2, and L3. Ground the drive chassis to a dedicated earth terminal using the shortest practical path.
3
Route the motor leads directly from terminals U, V, and W to the induction motor, ensuring that shielding is properly terminated to reduce electromagnetic interference.
4
Turn on the input power. Verify that the integrated LED display lights up and indicates normal standby status before starting parameter setup.