Fanuc A16B-1212-0100-01 Power Supply Unit

The Fanuc A16B-1212-0100-01 is a power supply unit (PSU) used in Fanuc CNC control systems, specifically for the Series 15, 16, and 18 controllers. This module is installed in the CNC rack and supplies regulated DC voltages to the main CPU, memory, I/O, and axis control boards. The PSU converts 200-240V AC input to +5V, +12V, -12V, and 24V DC outputs, ensuring stable operation of the CNC system. It is a critical component for maintaining legacy Fanuc-controlled machine tools. The unit is designed for continuous operation and includes overvoltage, overcurrent, and short-circuit protection.

Technical Specifications

Input voltage: 200-240V AC, 50/60 Hz (single phase). Outputs: +5V DC (typical 10A), +12V DC (2A), -12V DC (1A), +24V DC (4A). Output power: approx. 150W. Protection: Overvoltage (crowbar), overcurrent (hiccup), and short-circuit on all outputs. Cooling: Forced air via internal fan. Dimensions: 200 mm × 100 mm × 150 mm (approx.). Weight: 2 kg. Operating temperature: 0°C to 45°C. Storage: -20°C to 60°C. Front panel LEDs: POWER (green), ALARM (red). Connection: via edge connector to rack backplane. The unit is hot-swappable? Not typically; power off before replacement.

Key Features

• Power supply for Fanuc CNC racks (Series 15/16/18)

• Input: 200-240V AC, 50/60Hz

• Multiple DC outputs: +5V, ±12V, +24V

• Overvoltage and overcurrent protection

• Internal cooling fan with tachometer monitoring

• LED indicators for power and fault status

• Rugged design for industrial environments

• Direct replacement for original Fanuc part

Operation and Output Specifications

The PSU supplies the main CNC backplane. The +5V rail powers TTL logic and processors. The +12V and -12V are used for RS-232 drivers and analog circuits. The +24V is used for I/O modules, relays, and field power. The total load must not exceed the rated current per rail; overloading may trigger the overcurrent protection. The internal fan runs continuously; a fan failure will cause a thermal alarm and eventual shutdown. The PSU monitors output voltages; if any output deviates beyond ±5%, the ALARM LED lights and the CPU may receive a system fault.

Applications

This power supply is used in Fanuc-controlled machine tools such as machining centers, lathes, and grinders. It is essential for maintaining older Fanuc CNC equipment where original power supplies have failed. Suitable for replacement in Fanuc Series 15, 16, 18, and some 21 systems.

Installation and Replacement

Turn off the CNC main power and disconnect the machine from the mains. Open the CNC rack cabinet. Locate the existing power supply unit (usually the leftmost or rightmost module). Remove the mounting screws and slide the unit out of the rack. Insert the replacement A16B-1212-0100-01, ensuring the edge connector aligns with the backplane slot. Secure with screws. Reconnect any external power cables (if present). Close the cabinet and restore power. Check that the POWER LED lights and the ALARM LED is off.

Maintenance and Troubleshooting

If the POWER LED is off, check the AC input fuse (internal or external). If the ALARM LED is on, measure output voltages; if missing, the unit may have failed. The internal fan should spin; if not, replace the fan or the entire PSU. Dust accumulation inside the unit can cause overheating; periodically blow out dust with compressed air. The power supply is not user-serviceable beyond fuse replacement; replace the entire unit for other failures.

Environmental and Compliance

The A16B-1212-0100-01 is a genuine Fanuc part, compliant with original safety standards. Operating temperature: 0-45°C. Humidity: 30-95% non-condensing. The unit is RoHS compliant (depending on manufacturing date).

Conclusion

The Fanuc A16B-1212-0100-01 power supply unit is a direct replacement for failed PSUs in Fanuc Series 15/16/18 CNC controls. Its robust design and comprehensive protection ensure reliable power distribution to the CNC rack components.