New In Sealed Box Mitsubishi HC-SFS702 Servo Motor HCSFS702 HC-SFS7O2

Mitsubishi HC-SFS702 | MELSERVO J2S Series 7 kW AC Servo Motor — 2000 RPM, 17-bit Absolute Encoder, IP65

Part Number: HC-SFS702

Manufacturer: Mitsubishi Electric (Japan)

Product Type: AC Brushless Rotary Servo Motor

Product Series: MELSERVO J2S (HC-SFS series)

Rated Output: 7,000 W (7 kW)

Rated Torque: 33.4 Nm 

7 kW Medium-Inertia Servo Power

The HC-SFS702 is a 7 kW AC servo motor from Mitsubishi's HC-SFS (High-performance, Compact, Super Frame, Standard) series within the MELSERVO J2S drive platform. The SFS designation identifies the medium-inertia, medium-power capacity class within the HC family — matched to applications that demand both precision positioning and significant load force: rotary tables, axis feeds on large machining centres, presses, and heavy-duty conveyors.

At 33.4 Nm continuous and 100.0 Nm peak, the torque headroom (roughly 3× rated) gives the J2S amplifier the transient current budget it needs for fast acceleration without saturating the servo loop. The 2,000 RPM rated speed is typical for high-torque servo applications where mechanical gearing provides the final speed ratio.

The integrated 17-bit absolute encoder (131,072 counts per revolution) retains absolute position through power cycles without a homing cycle — the machine position is known immediately at power-up. This is a significant time saver on machines where re-homing is operationally disruptive.

The oil seal and IP65 protection make this motor practical in real machine tool environments where coolant splash and swarf are present on the motor surface.

HC-SFS Series Variants

The HC-SFS702 is the base variant: straight shaft, no brake. Related variants in the same frame include:

Confirm the required variant before ordering — the brake and shaft options are fixed at manufacture.

Key Specifications

FAQ

Q1: The HC-SFS702 is part of the MELSERVO J2S platform. Which servo amplifier is compatible?

The HC-SFS702 is designed for use with the MR-J2S series servo amplifiers. The specific amplifier model is selected based on the motor's rated current (35A) — the MR-J2S-350A or equivalent in the 350W class covers the 35A rated current. Confirm the amplifier-motor combination from Mitsubishi's J2S system configuration table.

Q2: The 17-bit absolute encoder retains position without homing. What happens if the battery backing the absolute position fails?

When the absolute encoder's battery voltage drops below threshold, the absolute position is lost. On the next power-up, the servo amplifier generates an absolute position lost alarm, and the axis must perform a homing operation. The encoder battery is located in the servo amplifier, not the motor. Battery replacement should follow Mitsubishi's specified maintenance interval — typically every 3–5 years.

Q3: The HC-SFS702 is listed as new in sealed box. What should be checked before installation after long storage?

Inspect the motor body for any physical damage to connectors or shaft seal. Rotate the shaft by hand to verify smooth bearing rotation — motors stored beyond 3–5 years may develop bearing stiffness. Check the encoder connector cover is intact. If the motor has been stored in humid conditions, verify the winding insulation resistance before installation.

Q4: The motor generates alarm A3 (encoder communication error) immediately at power-up. Is this a motor or amplifier fault?

Alarm A3 at power-up is typically caused by a wiring fault in the encoder cable, not a motor failure. Check the encoder cable connector is fully seated at both the motor and amplifier ends. Inspect the cable for any damage, particularly at the connector entry points. If the cable is confirmed intact, the encoder internal circuit has failed.

Q5: Is the HC-SFS702 compatible with newer Mitsubishi amplifier series, such as MR-J3 or MR-J4?

The HC-SFS series was designed for MR-J2S amplifiers. While the physical motor can be mechanically installed in any application, the encoder interface — a 17-bit serial type specific to the J2S platform — is not directly compatible with MR-J3 or MR-J4 amplifiers without an encoder adapter. For new machine builds, Mitsubishi's current servo motor series (HG-SR for J4) is recommended. The HC-SFS702 with J2S amplifiers is appropriate for maintaining existing J2S-based machine tools.