What causes Okuma OSP alarm 2734?

Coolant (or oil-mist oil) level genuinely low or overflowing in the tank. Flow switch set in the wrong position. Faulty or stuck float switch (failed ON or OFF). A coolant ON signal from the high-pressure unit persisting longer than the parameter-set time, indicating a level switch or wiring problem.

How do I fix Okuma OSP alarm 2734?

1. Read the code number shown with the alarm: code none = Coolant level low switch (I/O check NO.34 input bit 0, iCOL/) stayed OFF over 1 second - tank level low.; code 2 = Coolant lowest level switch (NO.43 bit A, iCLLST/) OFF over 1 second - tank nearly empty.; code 3 = Coolant overflow switch (NO.43 bit B, iCLOF/) OFF over 1 second - tank overflowing.; code 4 = Coolant upper limit switch (I.035F) OFF over 1 second.; code 5 = Coolant lower limit switch (I.035E) OFF over 1 second.; code 6 = High-pressure coolant unit kept sending its coolant ON signal longer than the parameter-set time.; code 7 = Coolant level low switch (NO.34 bit 0, iCOL) stuck ON over 1 second - switch or wiring fault.; code 8 = Level shortage input (NO.36 bit 9, iCLLD/) OFF for 1 second or more. 2. Read the code on screen to identify which switch tripped: e.g. code 2 = lowest level switch (I/O check NO.43 bit A, iCLLST/), code 3 = overflow switch (NO.43 bit B, iCLOF/), codes 25-28 = A/B turret oil-mist oil low or overflow, code 30 = low level during through-spindle coolant. 3. Open the coolant tank (or oil-mist reservoir for codes 25-28) and check the actual level; replenish coolant or oil if low, or drain to the correct level if overfilled. 4. Watch the corresponding input bit on the I/O check screen (e.g. NO.34 bit 0 iCOL/, NO.43 bits A/B, NO.36 bits 6/9/A) while manually moving the float to confirm the switch signal changes state. 5. If the level is correct but the input does not toggle, inspect the float switch for sludge, chips, or a stuck float, and check the flow switch position; clean or reposition as needed. 6. Replace the float switch if it still fails to change state after cleaning. 7. For codes 6, 40, 41, or 42 (signal persisting while coolant motor / through-spindle / high-pressure coolant is ON), check that the level-normal switch wiring is not shorted and the switch is not stuck closed.

Okuma OSP codes

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Okuma OSP Controller

Coolant · Intermediate

Alarm 2734

Okuma OSP Alarm B 2734 - Coolant level

A coolant tank level or flow monitoring switch stayed in an abnormal state longer than its allowed time, telling the control the coolant supply is low, overflowing, or that a level switch itself has failed. The exact switch and condition are identified by the code shown on screen, covering the machine tank, additional tank, high-pressure/through-spindle coolant, and turret oil-mist units.

Okuma OSPCoolantIntermediate

2734

Okuma OSP Alarm B 2734 - Coolant level

Coolant level

Common Causes

Coolant (or oil-mist oil) level genuinely low or overflowing in the tank
Flow switch set in the wrong position
Faulty or stuck float switch (failed ON or OFF)
A coolant ON signal from the high-pressure unit persisting longer than the parameter-set time, indicating a level switch or wiring problem

Troubleshooting Steps

1Read the code number shown with the alarm: code none = Coolant level low switch (I/O check NO.34 input bit 0, iCOL/) stayed OFF over 1 second - tank level low.; code 2 = Coolant lowest level switch (NO.43 bit A, iCLLST/) OFF over 1 second - tank nearly empty.; code 3 = Coolant overflow switch (NO.43 bit B, iCLOF/) OFF over 1 second - tank overflowing.; code 4 = Coolant upper limit switch (I.035F) OFF over 1 second.; code 5 = Coolant lower limit switch (I.035E) OFF over 1 second.; code 6 = High-pressure coolant unit kept sending its coolant ON signal longer than the parameter-set time.; code 7 = Coolant level low switch (NO.34 bit 0, iCOL) stuck ON over 1 second - switch or wiring fault.; code 8 = Level shortage input (NO.36 bit 9, iCLLD/) OFF for 1 second or more.
2Read the code on screen to identify which switch tripped: e.g. code 2 = lowest level switch (I/O check NO.43 bit A, iCLLST/), code 3 = overflow switch (NO.43 bit B, iCLOF/), codes 25-28 = A/B turret oil-mist oil low or overflow, code 30 = low level during through-spindle coolant.
3Open the coolant tank (or oil-mist reservoir for codes 25-28) and check the actual level; replenish coolant or oil if low, or drain to the correct level if overfilled.
4Watch the corresponding input bit on the I/O check screen (e.g. NO.34 bit 0 iCOL/, NO.43 bits A/B, NO.36 bits 6/9/A) while manually moving the float to confirm the switch signal changes state.
5If the level is correct but the input does not toggle, inspect the float switch for sludge, chips, or a stuck float, and check the flow switch position; clean or reposition as needed.
6Replace the float switch if it still fails to change state after cleaning.
7For codes 6, 40, 41, or 42 (signal persisting while coolant motor / through-spindle / high-pressure coolant is ON), check that the level-normal switch wiring is not shorted and the switch is not stuck closed.

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