Okuma MPS and MPR Power Supply Units
The Okuma Motion Control System (MCS) runs on an inverter unit and a DC power supply unit. Its DC power supply unit supplies 300 VDC and 24 VDC control power to the MIV units and talks to them over the converter link. Okuma builds two types by regeneration method. The MPS unit uses power regeneration and the MPR unit uses resistor regeneration.
Okuma power supply unit names carry codes for the regeneration method and the unit capacity. Independent drive repair shops list Okuma MPS and MPR power supplies next to MIV servo and spindle drives.
Okuma Power Supply Repair Shops
Northline Industrial
Redford, MI
Brands: Fanuc, Makino, Okuma
Paragon Technologies
Warren, MI
Brands: Okuma
Power Supply Errors and Supply Voltage
An MPS or MPR unit shows its error number on a 7-segment LED. When an MIV unit has an error at the same time the power supply error number and AA display alternately. Error 12 reports an overload in regeneration (ROH) on the MPR unit only. A heat sink overheat (FOH) shows as error 13.
Alarm 2160 MCS SUPPLY VOLTAGE FLUTTER on the OSP control reports abnormally high or low power voltage and shows up most often during heavy spindle acceleration or deceleration. Okuma clears it with power supplied to the machine’s KVA rating and a check of the power line connections. After a power outage Okuma checks the supply voltage on all three incoming legs because an outage can blow a buss fuse. A lost leg can single phase a motor and damage it.
Before the Supply Comes Out
High voltage sits on the terminal blocks of the power supply unit after power off. Okuma calls for a wait of at least 2 minutes and a dark charge indicating lamp before work starts. A replacement has to be the same unit type by regeneration method and capacity. An MPS unit gets its controller ID switch set to all OFF. The MPR unit has no ID switch.