What causes Okuma OSP alarm 3151?

Inverter unit control board failure (#1, #20-44 internal errors). Control board battery voltage drop: ±12 V (#2) or 5 V (#11). Inverter bridge shorted, IPM protection activated, or motor overcurrent (#12, #13, #14). Optional program file error or file incompatible with the inverter unit (#3). Power unit failure when the alarm appears on several inverter units at once (#2/#11).

How do I fix Okuma OSP alarm 3151?

1. Read the code number shown with the alarm: code #1 = Control board error; code shows board error content; code #2 = ±12 V control board battery voltage drop; code #3 = Optional program file (OPF) error; code: 1=ID code error, 2=end code error, 3=sum check error, 4=board name error; code #11 = 5 V control board battery voltage drop; code #12 = Inverter bridge shorted; code #13 = IPM protective function activated; code #14 = Motor overcurrent; code #20 = INT loop error 2. Read the character string on screen to identify the cause (#1 control board, #2 ±12 V battery drop, #3 OPF error, #11 5 V battery drop, #12 bridge short, #13 IPM protection, #14 motor overcurrent, #20-44 internal CPU/loop errors). 3. For #12, #13 or #14: lock out main power and allow the DC bus to discharge before touching anything. Check the motor power cable and motor winding for shorts to ground, then suspect the inverter unit itself. 4. For #2 or #11 (battery voltage drop): if several inverter units alarm together, suspect the power unit supplying them; if only one unit alarms, replace that inverter unit's battery/board. 5. For #3 (OPF error), read the code: 1=identification code "OPF1" error, 2=end code "ED" error, 3=sum check error, 4=board name error — the optional program file is corrupt or incompatible with the inverter unit; reload the correct file. 6. For #1 and the internal errors (#20-44), the code shows the control board error content or error status register data; record it and replace the inverter unit. 7. If the fault returns after unit replacement, record the alarm number, character string and code and contact Okuma service.

Okuma OSP codes

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Okuma OSP Controller

Drive · Intermediate

Alarm 3151

Okuma OSP Alarm C 3151 - MCS Inverter unit fault

A fatal internal error occurred in the MCS inverter unit or its software for the indicated axis or spindle. The character string identifies the cause, ranging from control board hardware faults and battery voltage drops to inverter bridge shorts, IPM protection trips and motor overcurrent.

Okuma OSPDriveIntermediate

3151

Okuma OSP Alarm C 3151 - MCS Inverter unit fault

MCS Inverter unit fault

Common Causes

Inverter unit control board failure (#1, #20-44 internal errors)
Control board battery voltage drop: ±12 V (#2) or 5 V (#11)
Inverter bridge shorted, IPM protection activated, or motor overcurrent (#12, #13, #14)
Optional program file error or file incompatible with the inverter unit (#3)
Power unit failure when the alarm appears on several inverter units at once (#2/#11)

Troubleshooting Steps

1Read the code number shown with the alarm: code #1 = Control board error; code shows board error content; code #2 = ±12 V control board battery voltage drop; code #3 = Optional program file (OPF) error; code: 1=ID code error, 2=end code error, 3=sum check error, 4=board name error; code #11 = 5 V control board battery voltage drop; code #12 = Inverter bridge shorted; code #13 = IPM protective function activated; code #14 = Motor overcurrent; code #20 = INT loop error
2Read the character string on screen to identify the cause (#1 control board, #2 ±12 V battery drop, #3 OPF error, #11 5 V battery drop, #12 bridge short, #13 IPM protection, #14 motor overcurrent, #20-44 internal CPU/loop errors).
3For #12, #13 or #14: lock out main power and allow the DC bus to discharge before touching anything. Check the motor power cable and motor winding for shorts to ground, then suspect the inverter unit itself.
4For #2 or #11 (battery voltage drop): if several inverter units alarm together, suspect the power unit supplying them; if only one unit alarms, replace that inverter unit's battery/board.
5For #3 (OPF error), read the code: 1=identification code "OPF1" error, 2=end code "ED" error, 3=sum check error, 4=board name error — the optional program file is corrupt or incompatible with the inverter unit; reload the correct file.
6For #1 and the internal errors (#20-44), the code shows the control board error content or error status register data; record it and replace the inverter unit.
7If the fault returns after unit replacement, record the alarm number, character string and code and contact Okuma service.

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