Power Supply Module A06B-6081-H103 A06B6081H103 AO6B-6O81-H1O3

A06B-6081-H103 | FANUC Alpha Power Supply Module — PSMR-3 / 200–230V AC / 283–325V DC / 3.8kW / CNC and Robot Servo Drive Power

PSMR-3 — Regenerative Power Supply for Alpha Servo Systems

The A06B-6081-H103 is the PSMR-3 — the third-capacity model in FANUC's PSMR (Power Supply Module with Regenerative capability) series. The "R" in PSMR identifies the defining characteristic: this power supply module can return regenerated energy to the AC supply during servo motor braking, rather than dissipating it as heat in brake resistors.

In a FANUC Alpha servo drive system:

During motor acceleration: The PSMR-3 rectifies the incoming three-phase AC (200–230V AC) to a regulated 283–325V DC bus. This DC bus supplies the connected servo (SVM) and spindle (SPM) amplifier modules, which in turn generate the variable-frequency AC that drives the motors.

During motor deceleration: As servo motors brake, they act as generators — returning kinetic energy as electrical energy back to the DC bus. A standard power supply cannot handle this regenerated energy; it must be dissipated in braking resistors. The PSMR-3, by contrast, inverts the regenerated DC back to AC and returns it to the mains supply.

Key Specifications

Alarm Codes

The A06B-6081-H103 generates specific alarm codes when faults occur:

Applications — CNC Machines and Robots

The A06B-6081-H103 is confirmed for use in both FANUC CNC machine tools and FANUC industrial robots:

CNC machine tool application: The PSMR-3 serves as the central power supply for the complete Alpha servo drive system on machining centres, turning centres, and grinding machines — supplying regulated DC power to all servo axis drives and the spindle drive simultaneously.

Robot application: FANUC robots equipped with Alpha series drive systems use the PSMR-3 to supply power to the robot's multiple joint servo axes. The regenerative capability is particularly valuable in robot applications with high-inertia movements — large robots decelerating heavy payloads generate significant regenerated energy.

FAQ

Q1: What is the significance of "PSMR" versus "PSM" in FANUC power supply module naming?

PSM = Power Supply Module (standard — cannot return regenerated energy to AC supply; requires brake resistors). PSMR = Power Supply Module with Regenerative feedback (can invert regenerated energy from braking motors back to the AC supply). The PSMR-3 (A06B-6081-H103) is the regenerative variant — it eliminates the need for brake resistors in most applications and reduces energy consumption in high-cycle drive systems.

Q2: What FANUC Alpha servo amplifiers does A06B-6081-H103 power?

The A06B-6081-H103 PSMR-3 provides the DC bus power for FANUC Alpha series servo modules (SVM — single and multi-axis) and spindle modules (SPM) in the Alpha drive system. The specific combination of SVM and SPM modules the PSMR-3 can support is determined by the total connected drive power not exceeding the 3.8kW output rating of the module.

Q3: What does the AL-05 alarm ("capacitor not recharged in time") indicate?

AL-05 appears when the PSMR-3's internal DC bus capacitors fail to charge to the required voltage within the expected time after power-up. Possible causes: input voltage too low, a capacitor within the module has degraded (reduced capacitance or increased leakage), a fault in the precharging circuit, or a short circuit on the DC bus from a connected amplifier. Distinguish from AL-04 (DC voltage dropped during operation) — AL-05 occurs at power-up, AL-04 during running.

Q4: Can the two internal PCBs (A20B-2001-0890 and A16B-2202-0542) be replaced independently?

Yes — both the A20B-2001-0890 control board and A16B-2202-0542 wiring board are separately available as spare parts. If the fault is diagnosed as specific to one PCB (control alarm patterns versus power stage fault patterns), replacing the faulty PCB alone is viable and less costly than replacing the complete A06B-6081-H103 module. The applicable FANUC Alpha power supply maintenance documentation provides guidance on isolating faults to specific internal boards.

Q5: What safety precautions apply when replacing A06B-6081-H103?

Power the servo drive system completely down and isolate all mains supplies. The PSMR-3's DC bus capacitors retain hazardous voltage (283–325V DC) for a period after mains removal — wait the discharge time specified in the B-65162E manual and verify DC bus voltage is at safe levels before handling internal components. The module is physically compact (171mm × 59mm × 367mm) but its internal voltages are potentially lethal.