Ulvac MS120A Instruction Manual page 62

Indication Alarm Name
PF Abnormal voltage in the
（PF）
main circuit
Cause
An open-phase has occurred in the
input power.
Excessive fluctuations in voltage
of the input power supply.
Phase voltage imbalance
Inverter failure
Indication Alarm Name
Inputting external
STo
（STo）
interlock signals
Cause
An external interlock signal is
input.
The external interlock is broken or
not wired.
Indication
LT-2
（LT-2）
LT-3
（LT-3）
LT-4
（LT-4）
Cause
The period that the inverter
needs to be replaced has
expired.
Measures
Check the input power supply wiring for breaks
and miss-wiring.
➡ Install wiring for the power supply correctly.
Check the power supply voltage.
➡ Take measures to stabilize the power supply.
Contact to ULVAC service center.
Measures
Check the external interlock conditions.
➡ Release the external interlocks.
Check the wiring for remote control for breaks and
miss-wiring.
For local operation, check that pins 13 and 14 are
short-circuited.
➡ Install wiring for remote control correctly.
Alarm Name
Expiration of maintenance
period
Measures
It is recommended to overhaul including
replacement of the inverter.
➡ Contact the ULVAC service center.
48
Status
Main-circuit DC voltage fluctuates excessively more
than that during regeneration.
Status
An external interlock signal was input to the wiring
for remote operation.
Status
The period that the inverter needs to be
replaced has expired.
YO20-0938-DI-001-00
Reference
3.6.1
3.6.1
End of
Document
Reference
3.6.2
3.6.2
Reference
Last page of
this manual