3745

Common Causes

• Low oil-mist lubricant level in the reservoir
• Faulty or contaminated oil-mist drip sensor switch
• Loss of drive air to the oil-mist lubrication pump (air supply off, low pressure, or leak)
• Oil-mist flow sensor not detecting flow within the monitor time
• Faulty oil-mist lubrication unit itself

Troubleshooting Steps

1. 1Read the code number shown with the alarm: code 2 = Turret oil-mist drip sensor switch stayed ON for 30 seconds or longer; code 3 = Drip sensor input never turned ON across two consecutive pump air ON/OFF cycles; code 4 = Initial power-up dripping sequence by the oil-mist unit did not complete; code 5 = Oil-mist lubricant level alarm/switch stayed OFF for 3 seconds or longer (low level); code 6 = Oil-mist lubrication pressure switch turned OFF while the lubrication ON signal was active; code 7 = Oil-mist supply or flow sensor did not turn ON within the flow monitor time; code 8 = Oil-mist flow sensor did not turn ON within the flow monitor time
2. 2Read the alarm code. Code 4 (initial dripping not completed at power-up): turn the power off and back on to rerun the initial drip sequence; the control expects the drip sensor input to turn ON in three successive 1-second pump cycles within 100 cycles. If it alarms again after retry, the oil-mist unit is likely faulty.
3. 3Code 5 (level switch OFF 3 s or more): check the oil-mist lubricant reservoir level and top up with the specified oil; if the level is adequate, suspect the level switch or the lubrication unit.
4. 4Code 6 (pressure switch dropped while lubrication ON signal active): verify shop air is supplied to the oil-mist unit at the correct pressure and check for air leaks or a sticking pressure switch.
5. 5Code 2 (drip sensor stuck ON 30 s or more) or Code 3 (drip sensor never turned ON across two pump cycles): inspect the drip sensor and its wiring; a stuck-ON sensor may be contaminated, a never-ON sensor may indicate no oil reaching the drip point or a dead sensor.
6. 6Code 7 or 8 (flow sensor did not turn ON within the monitor time): confirm the pump drive air ON signal actually drives the pump, check the oil-mist line for blockage, then check the flow sensor and its input wiring.
7. 7Do not run the M-tool spindle until mist lubrication is confirmed. If the alarm persists after these checks, record the code and contact Okuma service.