3159

Common Causes

• Overload operation: cutting load, feed rate or acceleration beyond what the axis/spindle can sustain
• Mechanical binding or excessive friction on the reported axis increasing motor load
• Faulty inverter unit misreading or failing under normal load

Troubleshooting Steps

1. 1Read the code number shown with the alarm: code YYYY = Gamma of the protection curve used to detect the overload; code ZZZZ = Internally calculated overload data at the time of the trip
2. 2Note the object (axis name or spindle) and record the YYYYZZZZ code for reference when reporting to service.
3. 3Identify the operation running when it tripped and lighten it: reduce cut depth, feed, or rapid/acceleration rates on that axis or spindle.
4. 4Check the reported axis for mechanical drag: inspect way lubrication, ball screw condition, and for chips or debris binding the slide; for a spindle, check for bearing noise or heat.
5. 5If the alarm trips with the axis unloaded, suspect the inverter unit; lock out power and let the DC bus discharge before inspecting or swapping the unit.
6. 6If it returns after these checks, record the alarm number, code and object and contact Okuma service.