3707

Common Causes

• Fault in the spindle head oil cooling unit itself (no code / Code 1 for M-spindle unit)
• Cooler oil level below the lower limit (Code 2)
• Coolant/oil flow switch not detecting flow (Code 3)
• Cooler temperature switch not satisfied (Code 4)
• Low oil pressure in the spindle or M-axis cooler circuit (Codes 5, 6)

Troubleshooting Steps

1. 1Read the code number shown with the alarm: code none = Spindle head oil cooling unit error; code 1 = M-spindle oil cooling unit error; code 2 = Spindle oil cooler level lower limit switch stayed OFF (oil level low); code 3 = Spindle oil cooler flow switch stayed OFF (no flow detected); code 4 = Spindle oil cooler temperature switch stayed OFF; code 5 = Spindle oil cooler pressure low signal switch stayed OFF; code 6 = M-axis oil cooler pressure low switch is OFF
2. 2Read the code: no code = spindle head oil cooling unit error; 1 = M-spindle oil cooling unit error; 2 = oil level low; 3 = flow switch OFF; 4 = temperature switch OFF; 5 = spindle cooler pressure low; 6 = M-axis cooler pressure low.
3. 3For Code 2, check the oil level in the spindle cooler tank and top up with the specified oil; if the level is correct, test the level switch.
4. 4For Codes 3, 5 or 6, confirm the cooler pump is running, then check for clogged filters, kinked lines or a failed pump causing loss of flow or pressure.
5. 5For Code 4, verify the cooler fans/compressor are operating and the unit is actually cooling; check the temperature switch if cooling appears normal.
6. 6Verify the error input on the I/O screen: I/O check NO.24 INPUT bit 6 iOCA/ for the 1st main spindle, NO.32 INPUT bit E i2OCA/ for the 2nd main spindle, or NO.34 INPUT bit 8 iMOCAL/ for the M-spindle; if the input never changes state, check the switch and its wiring.
7. 7If it returns after these checks, record the alarm number, code and object and contact Okuma service.