The FR-D720S-042-NA is a 0.75 kW single-phase 200 V AC variable frequency drive from Mitsubishi Electric, belonging to the FREQROL-D700 series — a compact sensorless vector inverter range optimised for general-purpose pump, fan, and conveyor applications in North American market configurations. Atlantech Drives holds stock of the FR-D720S-042-NA. Contact us for fast worldwide delivery and competitive pricing.
What Is the Mitsubishi FR-D720S-042-NA?
The FR-D720S-042-NA is the 0.75 kW model of the FR-D720S sub-series, specifically designed for single-phase 200–240 V AC input supply — making it the correct selection for installations without three-phase power availability, such as small commercial buildings, light industrial facilities, and retrofit applications on single-phase distribution systems. The -042 designation refers to the rated output current of 4.2 A. The -NA suffix confirms UL and cUL certification for North American markets. As part of the D700 series, the FR-D720S-042-NA integrates PID control, auto-tuning, and built-in EMC filter as standard features, delivering a self-contained variable speed solution without requiring external filter components.
Key Technical Specifications
- Rated output power: 0.75 kW (1 HP)
- Rated output current: 4.2 A
- Input voltage: 200–240 V AC, single-phase, 50/60 Hz
- Output voltage: 0–240 V AC, 3-phase
- Output frequency range: 0.2–400 Hz
- Control method: Advanced magnetic flux vector (sensorless), V/F control
- Overload capacity: 150% for 60 seconds, 200% for 0.5 seconds
- Built-in brake transistor: Yes
- Built-in EMC filter: Yes
- Communication: RS-485 (Modbus RTU) via PU connector
- Certifications: UL, cUL (North America), CE
- Enclosure rating: IP20
- Operating temperature: –10 to +50°C
- Dimensions (W × H × D): 68 × 128 × 114 mm
Compatibility & System Integration
The FR-D720S-042-NA accepts single-phase 200–240 V AC input and outputs three-phase variable voltage/frequency to drive standard three-phase induction motors up to 0.75 kW. This single-phase-in / three-phase-out capability is one of the defining advantages of the D720S sub-series — it eliminates the need for a phase converter or three-phase supply in single-phase installations, allowing standard three-phase motors to be used with single-phase supply infrastructure. For RS-485 Modbus RTU integration with a MELSEC-Q or MELSEC-F PLC, use the FR-A7DP or compatible PU connector adapter to access the RS-485 terminals — the PU connector pinout on D700 series drives is proprietary and does not accept standard RJ-45 or DB-9 connectors directly without the correct adapter. The FR-D720S-042-NA supports remote operation via the optional FR-PA07 parameter unit or via Modbus RTU commands for speed reference, run/stop, and fault reset from a host controller. Built-in PID control enables closed-loop process variable regulation (pressure, flow, temperature) using a 4–20 mA or 0–10 V DC process sensor signal connected to the analog input terminals, without requiring an external PID controller.
Troubleshooting Guide
- E.OC1 / E.OC2 / E.OC3 (Overcurrent trip): The most common fault on D700 series drives at commissioning. OC1 occurs during acceleration, OC2 during constant speed, OC3 during deceleration. For OC1, extend the acceleration time (Pr.7) — the default is often too aggressive for high-inertia loads. For OC3, extend the deceleration time (Pr.8) or connect an external braking resistor to the P/+ and PR terminals to absorb regenerative energy. For OC2 at constant speed, check for sudden load increases or motor insulation faults.
- E.THM (Motor thermal protection trip): The electronic thermal relay has operated. Verify that Pr.9 (Electronic thermal relay function) is set to the motor’s rated current. If the motor runs hot under normal load, check that the motor cooling fan is functioning — totally enclosed fan-cooled (TEFC) motors rely on shaft-driven fans that provide minimal cooling at low speeds during extended low-frequency operation.
- E.GF (Ground fault trip): Indicates current leakage between motor phases and earth. Disconnect the motor cable at the drive output terminals and measure insulation resistance between each phase and PE with a 500 V megohmmeter — readings below 1 MΩ confirm motor insulation failure. Also inspect the motor cable for physical damage.
- PU display shows parameter values but motor does not start: Verify that the STF (forward run) or STR (reverse run) terminal is connected to SD (common) and that the run command source (Pr.79 Operation mode) matches the actual control method — a common commissioning error is having Pr.79 set to PU operation mode while attempting external terminal control.
Frequently Asked Questions
Q: Can the FR-D720S-042-NA drive a single-phase motor?
A: No. The output of the FR-D720S-042-NA is three-phase variable frequency. Single-phase motors (capacitor-start, shaded-pole) are not compatible with VFD output waveforms. The drive is designed exclusively for three-phase induction motors (and permanent magnet motors in sensorless vector mode with auto-tuning).
Q: What is the difference between FR-D720S-042-NA and FR-D720-042-NA?
A: The FR-D720S accepts single-phase 200–240 V AC input. The FR-D720 (without the S suffix) requires three-phase 200–240 V AC input. Both produce three-phase output at equivalent ratings. Specify FR-D720S when only single-phase supply is available at the installation point.
Q: Is an external braking resistor included with the FR-D720S-042-NA?
A: No. The drive includes a built-in brake transistor but no braking resistor. An external resistor must be ordered separately and connected to the P/+ and PR terminals. For 0.75 kW applications with infrequent braking, a resistor rated at approximately 200 Ω / 100 W is typically sufficient — calculate the exact rating using the braking duty cycle tables in the FR-D700 instruction manual.
Do you need more references from this brand? Explore our full catalog of Mitsubishi here: https://atlantechdrives.com/manufacturers/mitsubishi/
