Ulvac MS120A Instruction Manual page 61

Indication Alarm Name
ov Overvoltage in the main
（ov）
circuit
Cause
Occurrence of power outage
The motor is ground fault.
Extremely high power supply
voltage
Inverter failure
Indication Alarm Name
oH
Inverter overheating
（oH）
Cause
Excessive ambient
temperature
Ventilation fan failure
Insufficient cooling water flow
rate
Status
An overvoltage has been detected.
Measures
Check the power wiring.
Contact to ULVAC service center.
Check the supply voltage.
➡ Reduce the voltage to the power supply specifications
of this machine.
Contact to ULVAC service center.
Status
Inverter overheating was detected.
Measures
Reduce the ambient temperature.
Contact to ULVAC service center.
Check the cooling water and increase the amount of
supply.
Insufficient differential pressure at the cooling water
inlet/outlet
➡ Increase the supply pressure.
The cooling water piping is clogged, or impurities are
mixed in the cooling water.
➡ Clean the piping.
Leakage from the cooling water piping
➡ If it is in this machine, Contact to ULVAC service
center.
47
Reference
3.6.1
End of
Document
7.1
End of
Document
Reference
3.1.3
End of
Document
3.5.2
3.5.2
3.5.2
End of
Document
YO20-0938-DI-001-00