5 - 6
Sigma 2 Load Bank Status Display
The load bank status is displayed on the seven segment LED located on the Sigma 2 load
bank module.
Figure 5-1
The Sigma 2 control unit showing LED display
During operation the LED decimal point flashes every second.
If the decimal point is not flashing then a software problem is likely. Cycle the fans and
controls power supply off and on to restart the Sigma 2 controller and clear the fault.
Chapter Five
Fault
Possible Causes
Possible Solutions
Incorrect or wrong load is applied
Supply-on-test voltage and/or Frequency.
•
Ensure the Supply-on-Test settings are
correct.
Excessive volt drop.
•
Check rating of cables or if an MV test,
transformer.
•
Check AVR droop setting.
Single phase operation or phase missing
•
When testing a single phase generator,
check the method of connection. Refer to
Chapter two
•
For three phase operation verify that all
of the phases are present.
Loading problem.
•
Check the load fuses.
•
Check the load contactors.
•
Check the load elements.
Ring main unit (RMU) tripped
Bund is full of liquid.
•
Check the bund is clear of debris and
without liquid.
Cargo doors are open.
•
Close the cargo doors.
Transformer is over temperature.
•
Check the fans are running.
•
Check the oil level in the transformer.
Control circuit is not energised.
•
Energise the control circuit.
