16.05.2025 by Viktor Siebert
Experience Report: Okuma MPR5 Power Supply (1006-2205)
For several years now, we’ve been deeply involved in repairing and maintaining Okuma CNC control systems and drive components. During this time, we frequently encounter the DC power supply unit Okuma MPR5 (1006-2205), an essential component for operating various CNC machines.
Everything began with a collaboration with one particular customer who operates dozens of Okuma CNC machines in their facility and relies heavily on dependable repair services. Thanks to this regular cooperation, we have steadily developed extensive expertise and specialized know-how in repairing these power supply units.
To ensure our repairs consistently meet high standards, we invested in our own Okuma test machine. This has enabled us to test repaired power supplies and drive modules under realistic, demanding conditions before returning them to customers. For us, this was a crucial step in guaranteeing consistently high repair quality and ensuring long-term reliability after repairs.
Over time, we expanded our repair services beyond the MPR5 power supply to other Okuma components, such as MIV servo drives and spindle drives. Our expertise has gradually become known internationally, resulting in repair requests not only from Europe but increasingly from distant countries such as Brazil, Mexico, South Africa, New Zealand, and Australia. The growing international demand confirms that our specialized approach to repairs is exactly what our customers need.
Our customers find it worthwhile to ship defective units to Germany via express delivery. Often, shipments arrive within two days, and the costs involved remain quite reasonable. This allows customers worldwide to benefit from our specialized expertise—and we are always happy to provide our assistance.
The following tasks were performed during the repair:
- Preventive overhaul: replacement of all necessary defective and worn parts.
- Intensive cleaning of the unit.
- Comprehensive final and load testing on our specialized test benches.
- Parameter adjustment or restoration of necessary parameters.
- Thorough completion of documentation and checklists.
Price and Delivery Time for Okuma MPR5 Ord. Nr. 1006-2205
For more information about our Okuma repairs, please click here.
📞 Feel free to contact us if you have any questions regarding your Mitsubishi drive technology. Our experienced team is always ready to provide you with expert advice and support.
Device Description
The MPR5 is an Okuma DC Power Supply Unit designed as a resistor-regeneration type (MPR = Multiple Power Supply Resistor type). This power supply unit has the following technical specifications:
- Product Type: MPR5 PU (DC power supply unit, resistor-regeneration type)
- Continuous Output: 5 kW (rated output, approx. 6.7 hp)
- Dimensions (H×W×D): 380 mm × 60 mm × 325 mm
- Weight: approx. 5.7 kg
- Supply Voltage: 3-phase, 200 VAC input
- Output Voltages: 300 VDC intermediate circuit voltage and 24 VDC control voltage
- Communication: Converter-Link (communication bus) connected to the MIV inverter units
Error Codes and Troubleshooting
Despite its robust design, the MPR5 may exhibit various alarm messages during operation. The unit uses a 7-segment display to indicate error conditions with a two-digit alarm code. In case of an alarm, the display initially flashes “AL” (Alarm) followed by a number. In practice, certain alarm numbers occur frequently. The following table shows typical MPR5 alarm codes and recommended troubleshooting actions.
| Alarm No. | Meaning (Error) | Recommended Action |
|---|
| 01 | Power Supply Error: Internal fault in MPR5 (e.g., voltage issue, overheating, CPU fault) | Check supply voltage; inspect operating conditions; if the error persists, replace the power supply (also consider checking/replacing the connected MIV unit). |
| 02 | Converter Link Error: Communication failure between power supply and MIV units (monitoring interrupted) | Check converter link wiring (plug connections, replace cable); if the problem persists, replace the MIV unit; if necessary, replace the power supply. |
| 03 | DC Bus Error: DC bus voltage detected as either too high or too low (overvoltage/undervoltage) | Check mains input voltage (e.g., phase loss or overvoltage); monitor for unusual load conditions; if necessary, replace faulty MIV unit or the power supply. |
| 07 | Input Voltage Error: Three-phase input voltage of the power supply outside tolerance (too high or too low) | Measure and stabilize mains supply (check voltage source, optimize cable cross-section and length); consider replacing the MPR5 unit if this issue occurs repeatedly. |
hese alarm codes can be quickly identified via the display. For example, an Alarm 01 would appear as a blinking sequence “AL–01”. In many cases, checking the supply voltages (300 V intermediate circuit and 24 V control voltage) and verifying the condition of the wiring can already resolve the issue. However, in case of persistent errors or internal defects, there’s often no alternative but to replace or professionally repair the power supply unit. Thanks to specialized test equipment such as the Okuma test machine described earlier repair service providers can thoroughly test and repair defective MPR5 units under load, quickly returning the Okuma machines to productive operation.
