Applicable Systems
OSP-P300S
OSP-P300L
OSP-P200
Symptoms
The Okuma OSP control displays a power supply error. The control or servo power is unstable.
Possible Causes
- OSP input voltage out of range
- OSP power supply module fault
- OSP DC bus voltage fault
- OSP phase loss detected
- OSP power supply overload
- OSP software needs update
Troubleshooting Steps
- Step 1: Record the Okuma alarm code A-557 and note the machine operating state
Alarm code and context are documented - Step 2: Access the alarm detail screen on the Okuma OSP control for additional information
Detailed alarm information is retrieved - Step 3: Inspect the Power subsystem for visible faults
No visible damage or abnormal conditions found - Step 4: Check parameters, programs, and offsets per the Okuma service manual
Values match expected settings or discrepancies are identified - Step 5: Reset the alarm per the OSP procedure and test machine operation
Alarm clears and machine operates normally, or alarm returns
How to Reset
To reset Okuma alarm A-557: 1) Resolve the underlying fault per the troubleshooting steps. 2) Press the RESET key on the Okuma OSP control panel. 3) If the alarm persists, press EMERGENCY STOP, release it, then press RESET. 4) If still present, power cycle the machine (main breaker off, wait 30 seconds, on). 5) Contact Okuma service if the alarm persists after reboot.
Frequently Asked Questions
- Q: What does Okuma alarm A-557 mean?
Alarm A-557 indicates: OSP Power Supply Error #58. This is an Okuma OSP control system alarm related to Power.
- Q: How do I clear Okuma alarm A-557?
Fix the root cause, press RESET. If persistent, cycle E-STOP and RESET. If still present, power cycle the machine. Contact Okuma service if it returns.
- Q: Is Okuma alarm A-557 critical?
Severity: Major. Reduce operations and service promptly.
Source: Okuma OSP Operation/Maintenance Manual / helmancnc.com
Category: CNC