Mitsubishi Mazak PD14B-1 DC Power Supply Unit
The Mitsubishi Mazak PD14B-1 is a regulated DC power supply specifically designed for Mazak CNC machine tools that use Mitsubishi CNC controllers (e.g., Meldas 50, 60, 500 series). It provides stable 24 V DC for relays, sensors, and I/O modules, and 5 V DC for logic circuits and CNC processor boards. The unit is a drop-in replacement for the original PD14B power supply in Mazak turning centers and machining centers.
Output Specifications
Output1: +24 V DC, 6 A (peak 8 A for 1 second). Output2: +5 V DC, 4 A. Output3: +24 V auxiliary (unregulated, 1 A for fan). Ripple and noise: < 100 mVpp on 24V, < 50 mVpp on 5V. Load regulation: ±2% from 10-100% load. Overcurrent protection: hiccup mode with auto-recovery. Overvoltage protection: clamp at 28 V (24V rail) and 6 V (5V rail). Efficiency: 82% typical. The unit is fan cooled (internal 40 mm fan, variable speed).
Input and Environmental
Input voltage: single-phase 100-120 V AC or 200-240 V AC (selectable via jumper), 50/60 Hz, current 3 A max. Input fuse: 6.3 A (slow blow, accessible on rear panel). Operating temperature: 0°C to 50°C (derate above 40°C). Storage: -20°C to 70°C. Humidity: 20% to 85% non-condensing. Dimensions: 250 mm x 110 mm x 150 mm (W x H x D). Weight: 2.2 kg. The enclosure is metal with vent slots, protection IP20.
Connectors and Indication
Output terminals: 6-position screw barrier strip (marked +24V, COM, +5V, COM, FAN+, FAN-). A green LED on the front panel indicates power OK. A red LED lights when overload or overvoltage occurs. A remote ON/OFF control is provided via a 2-pin header (short to enable). The unit includes a relay contact (rated 24 V / 1 A) that closes when outputs are within regulation, used to signal the CNC that power is ready.
Compatibility and Installation
The PD14B-1 is a direct replacement for PD14B (previous revision) and is compatible with Mazak models from 1995 to 2005: Quick Turn, VTC, FJV, and Horizontal Center series. Mounting holes align with existing chassis. The input voltage jumper (J1) must be set correctly for local mains (115 V or 230 V) – incorrect setting will damage the unit. A mating output connector is included. Ventilation clearance: 50 mm on all sides.
Troubleshooting and Maintenance
No outputs: check input fuse and input voltage jumper. Overload: reduce load or check for shorted I/O devices. Fan noise: replace fan (12 V, 0.1 A, 40x40x10 mm). For capacitor replacement, the unit contains four 1000 µF/35V and two 3300 µF/10V electrolytic capacitors. Service life typically 5-7 years in continuous operation. Spare part: Mitsubishi part number PD14B-1 (original) or aftermarket equivalents.
