Mitsubishi HC-MFS23G1-UE Servo Gearmotor — 200W Ultra-Low Inertia with G1 Reduction Gear | EN & UL/C-UL Compliant | New In Box Factory Sealed

Compact assembly machines, high-speed pick-and-place units, precision packaging lines — all of them share one requirement that a bare motor often cannot satisfy on its own: the output speed is too high or the load inertia is too large for direct coupling. The Mitsubishi HC-MFS23G1-UE solves both problems in a single factory-integrated package. It combines a 200W ultra-low inertia HC-MFS23 servo motor with a G1 general industrial reduction gearhead, certified to both EN European Standard and UL/C-UL North American Standard, and supplied new in original sealed Mitsubishi Electric packaging.

Technical Specifications

One Unit, Two Problems Solved

The HC-MFS23 base motor is Mitsubishi's 200W member of the ultra-low inertia HC-MFS family. On its own, it delivers 0.64 Nm at 3,000 rpm — a motor optimized for rapid acceleration and high-cycle operation. The G1 gearhead that comes factory-fitted on the HC-MFS23G1-UE adds two things the bare motor cannot provide alone.

First, torque multiplication. The gearhead reduces output shaft speed while multiplying torque in proportion to the gear ratio, producing a far higher output torque at the gearhead shaft than the motor could generate directly. Second, inertia matching. The reduction gearhead cuts the effective reflected inertia of the load back to the motor shaft by the square of the gear ratio. This allows the ultra-low inertia motor to drive loads with substantially higher inertia than would otherwise fall within acceptable limits — which is precisely the problem that makes geared servo motors the right answer for driving heavy tooling, loaded rotary tables, or complex fixture assemblies.

Because the gearhead is factory-fitted and the assembly leaves Mitsubishi as a matched, aligned, and tested unit, the machine builder avoids the dimensional tolerance stack-ups and coupling alignment demands that come with separately mounting a gearbox on a motor shaft.

Ultra-Low Inertia — Why It Changes the Application

The defining characteristic of the HC-MFS family is rotor inertia, not just power. Ultra-low inertia means the motor accelerates and decelerates extremely quickly in response to servo commands, with minimal energy spent overcoming the motor's own rotating mass. The gearhead extends this advantage to the load: even with a heavier mechanism at the output, the servo system can execute sharp, repeatable motion profiles at the cycle rates demanded by assembly automation, packaging machinery, and semiconductor handling equipment.

This combination — low motor inertia, high output torque, fast closed-loop response — is why the HC-MFS series with reduction gears appears in applications where the number of positioning cycles per hour is the primary performance metric.

17-Bit Absolute Encoder — 131,072 ppr, Zero Homing Required

The encoder reads at the motor shaft and transmits 131,072 distinct positions per revolution to the servo amplifier via Mitsubishi's high-speed serial link. The servo system converts this motor-side position data to output shaft position by accounting for the gear ratio in the amplifier parameters.

Being absolute means the motor retains position knowledge through power cycles — with the A6BAT battery installed in the servo amplifier, multi-turn position data is maintained when the machine is shut down. No reference return routine is needed at startup. For machines running multiple shifts or frequent power cycles, eliminating the homing sequence is a real-world production advantage that compounds across every cycle over the machine's service life.

The -UE Suffix — What EN and UL/C-UL Compliance Means

The -UE designation confirms this unit has been manufactured and documented to meet:

EN Standard — the conformity framework for CE-marked electrical equipment sold and operated within the European Union and EEA, covering electrical safety, motor construction, and electromagnetic compatibility.

UL/C-UL Standard — Underwriters Laboratories safety certification covering both the US (UL) and Canadian (C-UL) markets, required for installation in North American industrial and commercial electrical systems.

Per Mitsubishi's own documentation, the electrical and mechanical performance of the -UE model is identical to the non-UE version. The suffix indicates manufacturing traceability and compliance verification, not a design change. For OEM machine builders who supply into multiple geographic markets or must satisfy customer audit requirements for regulatory documentation, the -UE variant provides the certification trail those processes require without any sacrifice in motor performance.

Compatible Servo Amplifiers

The HC-MFS23G1-UE pairs with the MR-J2S-20A (analog/pulse-train command) or MR-J2S-20B (SSCNET network command) servo amplifiers, both rated at 200W in the MELSERVO J2S platform. The gear ratio must be entered into the amplifier's electronic gear ratio parameter during commissioning so the servo system correctly translates motor encoder counts into output shaft position. Mitsubishi's MR-J2S amplifiers provide dedicated parameters for this, making setup straightforward.

Application Fit

The HC-MFS23G1-UE is specified for precision automation where reduced output speed, higher output torque, and certified standards compliance are all required in the same unit:

Assembly machines — rotary indexing stations and multi-axis assembly cells where the G1 gearhead provides the output torque needed for loaded fixtures and tooling at controlled, repeatable speeds

Packaging and labeling equipment — format adjustment axes and registration drives where precise positioning at moderate speed is more critical than maximum velocity

Pick-and-place and handling systems — linear and rotary transport axes where the gearhead brings load inertia within an acceptable range, improving dynamic response across the full motion profile

Medical and laboratory automation — systems destined for European or North American markets where EN and UL/C-UL compliance is a hard procurement requirement

Semiconductor and electronics production — wafer transport, component placement, and inspection positioning axes where low inertia, position accuracy, and standards documentation all appear on the specification sheet simultaneously

FAQ

Q1: What servo amplifier is compatible with the HC-MFS23G1-UE?

The correct amplifiers are the MR-J2S-20A (analog or pulse-train command from an external PLC or controller) or MR-J2S-20B (SSCNET fiber-optic network for multi-axis Mitsubishi motion controllers). Both are 200W-rated within the MELSERVO J2S platform. During initial setup, the gear ratio must be programmed into the amplifier's electronic gear parameters to ensure the position feedback reflects output shaft movement accurately.

Q2: What does the G1 gearhead provide compared to using the bare HC-MFS23 motor?

The G1 gearhead reduces output shaft speed while multiplying torque in proportion to the gear ratio, and it reduces the reflected inertia of the load back to the motor shaft by the square of that ratio. This allows the 200W ultra-low inertia motor to drive loads with higher inertia or requiring higher output torque than the bare motor could handle within its recommended operating limits. For applications requiring low output speed, high output torque, or better load inertia matching, the integrated G1 gearhead is the engineering solution.

Q3: What is the difference between G1, G5, and G7 gearhead configurations on the HC-MFS series?

The G1 designation is Mitsubishi's general industrial reduction gear — a spur gear type suitable for typical assembly, handling, and automation applications where moderate output shaft accuracy is acceptable. G5 and G7 are precision reduction gears with significantly tighter backlash specifications, intended for applications requiring high angular accuracy at the gearhead output, such as precision rotary tables or measurement equipment. G1 is appropriate for the majority of automation and handling applications; G5/G7 are specified when the machine's angular accuracy requirement demands it.

Q4: What does the -UE suffix mean, and is it required for my application?

The -UE suffix indicates the motor has been manufactured and certified to comply with both EN European Standard (required for CE-marked equipment in EU markets) and UL/C-UL Standard (required for North American installations). Motor performance is identical to the non-UE version — the difference is regulatory documentation and manufacturing traceability. If your machine will be CE-marked for European sale or must satisfy UL requirements for a North American customer, specify the -UE variant. For internal use in non-regulated environments, both versions perform identically.

Q5: Does the 17-bit encoder read position at the motor shaft or the gearhead output shaft?

The encoder reads the motor shaft directly. The servo amplifier uses the programmed electronic gear ratio to translate motor-side position counts into the corresponding output shaft angle. This approach preserves the full 131,072 ppr resolution of the encoder while correctly representing the output shaft position in the control loop. From the machine controller's perspective, all position commands and feedback are expressed in terms of the output shaft — the gear ratio calculation happens transparently inside the amplifier.