HC-RFS353K MITSUBISHI AC Servo Motor

• Brand
  MITSUBISHI
• Model
  HC-RFS353K
• Product Name
  Ultra‑Low Inertia AC Servo Motor
• Place of Origin
  Japan
• HS Code
  85015220
• Dimensions
  130 mm × 185 mm × 280 mm
• Weight
  15.0 kg
• Operating Temperature
  0℃ to +40℃
• Storage Temperature
  ‑20℃ to +80℃
• Power Supply
  3.5 kW
• Warranty
  1 year
• Product Status
  new and original

HC-RFS353K MITSUBISHI Wiring

This servo motor is compatible with MR-J2S-500A and MR-J2S-500B servo amplifier units.

Motor Power Connector (U, V, W, PE)

U: Connect to the U terminal of the servo amplifier

V: Connect to the V terminal of the servo amplifier

W: Connect to the W terminal of the servo amplifier

PE: Protective earth, connect to amplifier PE terminal and cabinet protective ground

Strictly maintain correct phase correspondence for U-V-W. Motor rotation direction shall not be altered by swapping any two power-phase wires.

Contactors or relays shall not be wired between amplifier U/V/W outputs and motor power terminals.

Encoder Connector

Employ the dedicated HC-RFS series encoder cable. One end mates with the motor encoder receptacle, while the other end connects to the amplifier CN2 encoder port.

Fully fasten and lock the encoder connector. Prevent mechanical tensile stress from acting upon the connector housing.

Electromagnetic Brake Wiring (K suffix denotes built-in holding brake)

Brake terminals: BK1, BK2

Rated voltage: DC 24V

Apply DC 24V across BK1-BK2 to release the brake; cut off the 24 V supply to engage mechanical holding braking.

An isolated external 24 VDC power supply is recommended for the brake circuit. Avoid sharing the power source with control signals when noise interference is observed.

Fit a reverse-parallel surge-absorption diode across the brake coil terminals.

Grounding Requirements

Connect the motor housing PE terminal to protective earth using a short, heavy-gauge cable.

Physically separate power cables and encoder signal cables during cable routing to mitigate electromagnetic interference.

HC-RFS353K MITSUBISHI Operation Manual

1. General Specifications

The HC-RFS353K is a low-inertia AC servo motor with a rated power of 3.5 kW, a rated speed of 3000 r/min and a maximum speed of 4500 r/min. It is equipped with a keyed shaft and a built-in electromagnetic holding brake. This motor is exclusively compatible with Mitsubishi MR-J2S-500A and MR-J2S-500B servo amplifiers.

It adopts a 17-bit absolute encoder (131072 ppr). The motor protection grade is IP65 (shaft seal: IP67) with Class F insulation.

2. Safety Warnings

Disconnect all power supplies before wiring, disassembly and maintenance. Wait no less than 15 minutes for the internal capacitor discharge, and confirm zero residual voltage with a multimeter to avoid electric shock hazards.

Do not touch the motor housing, heat sink and regenerative resistor during operation or immediately after power-off, as high surface temperatures may cause scald injuries.

Keep hands, tools and foreign objects away from the rotating shaft during powered operation to prevent mechanical injury.

Do not apply over-rated voltage or incorrect polarity to any terminal, which will cause permanent damage to the motor and servo amplifier.

Reliable protective earth connection must be implemented for both the motor and the matched servo amplifier.

3. Mechanical Installation

Mounting Orientation: Horizontal and vertical installation are allowed. For vertical installation with a downward shaft, enhanced sealing measures are required to prevent oil and water ingress.

Shaft Load Requirements: Operate within the allowable radial and axial load range of the motor shaft. Avoid impact load during coupling installation, and never strike the motor shaft directly with tools.

Ambient Conditions: The operating ambient temperature ranges from 0 ℃ to +40 ℃. The installation site must be free of corrosive gas, heavy dust, oil mist and water splashing.

Reserve sufficient ventilation space around the motor to ensure effective heat dissipation.

Ensure high concentricity of the coupling. Excessive misalignment will cause vibration, abnormal noise and accelerated service life degradation.

4. Wiring Procedure

4.1 Motor Power Terminal (U, V, W, PE)

U, V, W: Connect correspondingly to the U, V, W terminals of the servo amplifier.

PE: Protective earth terminal, connected to the amplifier PE terminal and equipment cabinet protective ground.

Strictly follow the standard U-V-W phase sequence. Do not swap power phase wires to adjust motor rotation direction. No contactors or relays shall be installed between the amplifier power output terminals and the motor power terminals.

4.2 Encoder Wiring

Use a dedicated shielded encoder cable for HC-RFS series motors. Connect one end to the motor encoder interface and the other end to the CN2 encoder port of the servo amplifier.

Fully lock the encoder connector to prevent loosening, and avoid tensile stress on the connector and cable.

Separate encoder signal cables from power cables during wiring to reduce electromagnetic interference.

4.3 Built-in Holding Brake Wiring (BK1, BK2)

Rated brake voltage: DC 24 V

Apply DC 24 V power to BK1 and BK2 to release the brake; cut off the DC 24 V power to engage the mechanical holding brake.

Adopt an independent isolated DC 24 V power supply for the brake circuit. Do not share the power supply with control signals to avoid noise interference.

Install a reverse-parallel surge absorption diode across the brake coil terminals for overvoltage protection.

4.4 Grounding Specification

Use short and thick gauge cables to connect the motor housing PE terminal to protective earth. The shielding layer of all signal cables shall be grounded at the amplifier side.

5. Commissioning Steps

1. Complete mechanical installation and all wiring work. Double-check the power phase sequence, encoder connection, brake wiring and grounding condition.

2. Confirm no short circuit in the power circuit. Power on the amplifier control circuit first, then switch on the main power supply.

3. Perform absolute encoder origin reset in accordance with MR-J2S amplifier operation specifications.

4. Conduct no-load JOG operation test to check the motor rotation direction, operating noise and vibration status.

5. Connect the mechanical load after passing the no-load test, and optimize servo gain parameters according to the actual mechanical system.

6. Verify brake logic performance: The brake releases when the servo system is enabled, and engages automatically after servo power-off to hold vertical axes in position.

6. Operation Precautions

Do not install external capacitors or surge suppressors on the wiring between the amplifier and the motor.

Operate the motor within the rated speed-torque range, and avoid long-term overload operation.

For applications with frequent deceleration, install a matched regenerative resistor and set reasonable deceleration time parameters to prevent DC bus overvoltage alarms.

Stop operation immediately if abnormal noise, vibration or overheating occurs. Inspect mechanical alignment, load condition and servo parameters before restarting.

7. Common Fault Troubleshooting

Encoder Error: Check whether the CN2 connector is locked firmly, inspect the cable for breakage and confirm intact shielding and grounding.

Over-current Alarm: Check for U/V/W circuit short circuit, motor coil insulation damage and wiring errors.

Over-voltage Alarm: Verify the installation of the regenerative resistor and check the rationality of deceleration time parameters.

Brake Malfunction: Inspect the DC 24 V power supply for BK1/BK2 terminals, check the surge diode status and confirm correct wiring polarity.