24
S&C Instruction Sheet 653-506
Warning Alarms
Description
Utility Over Freq
Indicates the system is sensing a utility frequency
greater than 1 Hz above the nominal frequency
Troubleshooting Tip:
The system will respond based
on the over-frequency settings . The frequency threshold
can be changed if desired .
Utility Over Voltage
Indicates the system is sensing a utility voltage greater
than 110% of the nominal voltage
Troubleshooting Tip:
The system will respond based
on the overvoltage settings . The voltage threshold can
be changed if desired .
Utility Under Freq
Indicates the system is sensing a utility frequency more
than 1 .5 Hz below the nominal frequency
Troubleshooting Tip:
The system will respond based
on the under-frequency settings . The frequency
threshold can be changed if desired .
Utility Under Voltage
Indicates the system is sensing a utility voltage less
than 90% of the nominal voltage
Troubleshooting Tip:
The system will respond based
on the undervoltage settings . The voltage threshold can
be changed if desired .
Operation
Table 3. Warning alarms—continued.