1701

Common Causes

• Auxiliary motor (coolant, hydraulic pump, lubrication, spindle cooling) mechanically seized or overloaded
• Overload relay tripped from sustained overcurrent or a failing motor
• Wiring fault or short in the tripped motor's circuit
• Wrong motor for the load (e.g. coolant pump running dry or against a blocked line)

Troubleshooting Steps

1. 1Read the code number shown with the alarm: code 1 = EC overload relay tripped (general); code 2 = Oil pump motor overload tripped; code 3 = Coolant control motor overload tripped; code 4 = Spindle oil pump overload tripped; code 5 = Lubrication motor overload tripped; code 6 = Spindle cooling motor overload tripped; code 7 = Spindle cooling fan overload tripped; code 8 = 2nd spindle cooling motor overload tripped
2. 2Read the alarm code on screen to identify which motor's overload tripped (e.g. Code 3 = coolant control motor, Code 6 = spindle cooling motor, Code 15 = through-spindle coolant motor, Code 23 = spindle motor).
3. 3Verify the trip at I/O check NO.24, INPUT bit A (iOLA/) = 0 to confirm the EC overload input is the source.
4. 4Power down and lock out the machine before opening the electrical cabinet; locate the overload relay for the motor named by the code.
5. 5Inspect that motor and its driven load: check for a seized pump, blocked coolant line, dry-running pump, or binding before resetting anything.
6. 6Reset the tripped overload relay and run the motor briefly to confirm it starts and runs normally without re-tripping.
7. 7If the relay trips again immediately, suspect a failed motor or wiring short in that circuit; if the cause cannot be found, record the code and contact Okuma service.