1155

Common Causes

• Loose or damaged converter link cable or connector
• Failed power unit
• Failed inverter unit control board

Troubleshooting Steps

1. 1Read the code number shown with the alarm: code X=0 = Communication error on the converter link; code X=1 = Time-out error; communication was interrupted; code YY = Communication status value; always 0 when X=1
2. 2Read the code on screen: X=0 indicates a communication error, while X=1 means a time-out where communication was interrupted entirely; YY shows the communication status (always 0 when X=1).
3. 3Power down, lock out, and allow the DC bus to discharge, then inspect the converter link cables and connectors between the power unit and inverter unit; reseat connectors and replace any cable with damaged shielding or pins.
4. 4If the link hardware is good and the error persists, the power unit is the next suspect; have it tested or exchanged.
5. 5If a known-good power unit does not clear the alarm, replace or have the inverter unit control board checked.
6. 6If it returns after these checks, record the alarm number, code and object and contact Okuma service.