S&C PureWave SMS-250 Operation And Maintenance page 38

Operation
38 S&C Instruction Sheet 659-520
Table 7. PureWave SMS-250 Inhibit Alarms—continued
Alarm
Time Current Indicates the current is too high for too long, risking damage
Curve Overload to the IGBTs
Troubleshooting Tip: Reduce island load.
Under Frequency Indicates the line frequency at the ac connection is below the
Underfrequency threshold
Troubleshooting Tip: The inverter will respond based on
the under frequency settings. To change the sensitivity,
time delay on or the frequency threshold can be changed.
Under Voltage Indicates the RMS line-to-line voltage of any of the
three phases at the inverter ac connection is below the
Undervoltage threshold (This alarm is used to prevent
unintentional islanding .)
Troubleshooting Tip: The inverter will respond based on
the voltage settings. To change the sensitivity, time delay
on or the voltage threshold can be changed.
Very Over Indicates the line frequency at the inverter ac connection is
Frequency above the Very Overfrequency threshold
Troubleshooting Tip: The inverter will respond based on
the Very Overfrequency settings. To change the sensitivity,
time delay on or the frequency threshold can be changed.
Very Over Voltage Indicates the line-to-line voltage at any of the three phases
at the inverter ac connection is above the Very Overvoltage
threshold .
Troubleshooting Tip: The inverter will respond based on
the voltage settings. To change the sensitivity, time delay
on or the voltage threshold can be changed.
Very Under Indicates the line frequency at the inverter ac connection is
Frequency under the Very Underfrequency threshold
Troubleshooting Tip: The inverter will respond based
on the Very Underfrequency settings. To change the
sensitivity, time delay on or the frequency threshold can
be changed.
Very Under Indicates the line-to-line voltage at any of the three phases
Voltage at the inverter ac connection is under the Very Undervoltage
threshold
Troubleshooting Tip: The inverter will respond based on
the voltage settings. To change the sensitivity, time delay
on or the voltage threshold can be changed.
Description Reset Type
MANUAL
SELF
SELF
SELF
SELF
SELF
SELF