Mitsubishi HC-SFS502B AC Servo Motor — New In Box, Factory Sealed

Condition: Brand New · Original Packaging · Factory Sealed

Part Number: HC-SFS502B / HCSFS502B

Series: HC-SFS | Compatible Amplifiers: MR-J2S / MR-J3 / MR-J4

Overview

Five kilowatts. Built-in electromagnetic brake. Factory sealed.

The Mitsubishi HC-SFS502B is a 5.0 kW AC servo motor with an integrated electromagnetic brake — the "B" designation that makes it the go-to choice for vertical axis applications, gravity-loaded slides, and any setup where the load needs to stay put when power drops. Rated at 23.9 N·m continuous torque at 2,000 rpm, it covers a broad range of industrial motion control requirements without being oversized for the job.

Shipped new, sealed, and uninstalled. Original Mitsubishi carton. No field history, no rework, no exceptions.

Key Specifications

The Case for the 502B Over the Standard 502

The integrated electromagnetic brake is what sets this variant apart. When current is cut — whether by design or by fault — the brake engages automatically, holding the shaft in position. No external brake module. No added wiring complexity. No relying solely on the amplifier's dynamic brake.

That matters in:

• Vertical Z-axes on machining centers and gantries, where a de-energized motor without mechanical braking means a falling load
• Welding positioners and tilt tables that need to lock in place between cycles
• Robotic joints where gravity acts on the arm during e-stop or power interruption
• Clamping and pressing mechanisms that must hold force after the servo is disabled

For horizontal applications where a brake isn't required, the standard HC-SFS502 is the right call. If there's any vertical load in the system, the 502B is the safer specification.

Performance You Can Count On

Absolute position, no homing required. The 17-bit encoder retains position across power cycles. On a restart after an e-stop or outage, the controller knows exactly where the axis is — no slow homing routine, no lost production time.

Sealed against the environment. IP65 shaft sealing keeps cutting fluid, coolant mist, and airborne particulates out of the motor. It's a meaningful difference in real shop environments compared to motors with lower ingress protection ratings.

Thermal durability in continuous duty. Class F insulation is rated to withstand higher operating temperatures than Class B or Class E — relevant in applications running extended shifts with limited forced cooling.

Drop-in compatibility across amplifier generations. The HC-SFS502B works with MR-J2S, MR-J3, and MR-J4 amplifiers, which simplifies sourcing for maintenance teams managing mixed-generation equipment on the same floor.

Where This Motor Gets Installed

CNC Vertical Machining Centers — Z-axis drives where the spindle head must hold position during tool changes and power interruptions without relying on the amplifier alone.

Industrial Robots — Shoulder and elbow joints in 6-axis arms where gravity loading demands a reliable mechanical hold on e-stop.

Automated Assembly Systems — Lift and press stations that need position-holding between cycles without continuous current draw through the amplifier.

Conveyor & Material Handling — Inclined conveyor drives and lifting mechanisms where brake-on-power-loss is a basic safety requirement.

Injection Molding & Press Equipment — Clamping axes that benefit from a mechanical lock during the hold phase of the cycle.

Frequently Asked Questions

Q: What does the "B" suffix mean in HC-SFS502B?

 A: It indicates the motor includes a built-in electromagnetic brake. The brake engages automatically when power is removed, holding the shaft in position — essential for vertical axes and gravity-loaded applications.

Q: How does the electromagnetic brake work during normal operation?

A: The brake is spring-applied and electrically released. When the motor is powered and running, current holds the brake open. When power is cut — intentionally or by fault — the spring engages the brake immediately. It is a holding brake, not a dynamic stopping brake.

Q: Which amplifiers are compatible with the HC-SFS502B?

A: The HC-SFS502B is compatible with Mitsubishi MR-J2S, MR-J3, and MR-J4 series servo amplifiers. Confirm the amplifier's rated output matches the motor's 5.0 kW / 200V specification and that brake power supply connections are properly configured.

Q: Is this unit genuinely new, or refurbished stock?

A: Genuinely new. Factory sealed in original Mitsubishi packaging — never installed, never powered on, no rework performed. The seals, documentation, and packaging are intact as shipped from the factory.

Q: Does the encoder require a battery for absolute position retention?

A: In single-turn absolute mode, no battery is required. For multi-turn absolute operation (retaining position across multiple shaft revolutions), a battery backup on the amplifier side is needed — this is an amplifier-level requirement, not specific to the motor itself.