What causes Okuma OSP alarm 2856?

Coolant pump motor mechanically seized or running against a blocked/restricted line (clogged filter, closed valve, kinked hose). Overload relay trip setting too low or a faulty/worn overload relay. Low coolant level causing the pump to run dry and overheat. Motor winding failure, phase loss, or wiring fault in the motor power circuit.

How do I fix Okuma OSP alarm 2856?

1. Read the code number shown with the alarm: code None = Coolant motor overload detected from motor overheating or malfunction, no specific motor identified; code 3 = Overload relay of the lower right saddle coolant motor has tripped; code 4 = Overload relay of the lower left saddle coolant motor has tripped; code 5 = Pump-up motor overload tripped while the washing gun command was active; code 6 = Pump-up motor overload tripped while the through-spindle coolant command was active; code 7 = Overload relay of the ANG head coolant motor has tripped; code 8 = Overload relay of the pump-up motor has tripped 2. Read the code on the alarm screen to identify the tripped motor: 3 = lower right saddle coolant motor, 4 = lower left saddle coolant motor, 5 = pump-up motor during washing gun command, 6 = pump-up motor during through-spindle coolant command, 7 = ANG head coolant motor, 8 = pump-up motor. 3. Check the coolant tank level and the pump intake filter/screen; a dry pump or clogged suction makes the motor overheat and trip the overload. 4. Inspect the delivery line for that motor (washing gun line, through-spindle coolant line, or ANG head line per the code) for a closed valve, kinked hose, or blocked nozzle that dead-heads the pump. 5. Lock out power, then reset the tripped overload relay on the identified motor's starter and try running the pump; if it trips again immediately, check the motor for free rotation by hand and measure winding continuity/phase balance. 6. If the motor and line are clear, verify the overload relay trip current setting matches the motor nameplate and replace the relay if it trips below rated current. 7. If the overload keeps tripping after these checks, record the alarm number and code and contact Okuma service.

Okuma OSP codes

axismd.ai

Okuma OSP Controller

Coolant · Intermediate

Alarm 2856

Okuma OSP Alarm B 2856 - Coolant motor overload

The control detected that a coolant pump motor's overload relay (thermal trip) has opened, meaning the motor drew excessive current or overheated. The code on screen identifies which motor tripped: a saddle coolant motor, the pump-up motor for the washing gun or through-spindle coolant, or the ANG head coolant motor.

Okuma OSPCoolantIntermediate

2856

Okuma OSP Alarm B 2856 - Coolant motor overload

Coolant motor overload

Common Causes

Coolant pump motor mechanically seized or running against a blocked/restricted line (clogged filter, closed valve, kinked hose)
Overload relay trip setting too low or a faulty/worn overload relay
Low coolant level causing the pump to run dry and overheat
Motor winding failure, phase loss, or wiring fault in the motor power circuit

Troubleshooting Steps

1Read the code number shown with the alarm: code None = Coolant motor overload detected from motor overheating or malfunction, no specific motor identified; code 3 = Overload relay of the lower right saddle coolant motor has tripped; code 4 = Overload relay of the lower left saddle coolant motor has tripped; code 5 = Pump-up motor overload tripped while the washing gun command was active; code 6 = Pump-up motor overload tripped while the through-spindle coolant command was active; code 7 = Overload relay of the ANG head coolant motor has tripped; code 8 = Overload relay of the pump-up motor has tripped
2Read the code on the alarm screen to identify the tripped motor: 3 = lower right saddle coolant motor, 4 = lower left saddle coolant motor, 5 = pump-up motor during washing gun command, 6 = pump-up motor during through-spindle coolant command, 7 = ANG head coolant motor, 8 = pump-up motor.
3Check the coolant tank level and the pump intake filter/screen; a dry pump or clogged suction makes the motor overheat and trip the overload.
4Inspect the delivery line for that motor (washing gun line, through-spindle coolant line, or ANG head line per the code) for a closed valve, kinked hose, or blocked nozzle that dead-heads the pump.
5Lock out power, then reset the tripped overload relay on the identified motor's starter and try running the pump; if it trips again immediately, check the motor for free rotation by hand and measure winding continuity/phase balance.
6If the motor and line are clear, verify the overload relay trip current setting matches the motor nameplate and replace the relay if it trips below rated current.
7If the overload keeps tripping after these checks, record the alarm number and code and contact Okuma service.

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