5 - 4
Chapter Five
Fault Finding
The following chart covers some of the typical faults you might encounter and some
possible solutions.
Fault
Possible Causes
Possible Solutions
Cooling fan does not start or run
No load applied
•
The cooling fan may not run until load
is applied. Apply the load and verify
that the fan starts.
No power to fan
•
Check that the Fan and Controls
Supply Isolator is turned on.
•
Confirm that the control supply fuse is
not blown.
Fan thermal overload tripped
•
Check that the fan is not obstructed
and that it is free to rotate.
•
Check the motor current and overload
setting.
No load is being applied
Supply-on-test is not switched on.
•
Confirm that the Supply-on-Test
circuit breaker is switched on.
•
If fitted, ensure that the load bank
circuit breaker(s) is switched on.
Load bank over temperature trip
•
Allow the load bank to cool and reset
over temperature trip.
•
Check that the airflow through load
bank is unobstructed.
•
Check for any signs of hot air re
circulation.
Faulty or damaged connecting lead
•
Check that the hand-held lead and
connectors are not damaged. Use
local operation for testing.
Incorrect or wrong load is applied
Supply-on-test voltage
•
Ensure the working voltage and
connection settings are correct.
Excessive volt drop
•
Check rating of cables.
•
Check generator AVR droop settings.
Single phase operation or phase missing
•
When testing a single phase
generator, check the method of
connection in the hand-held or digital
toggle switch control settings.
•
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.
Error Type
Display
Possible Causes
Communications Loss (transmit error)
err Conn t
•
Unplugged cable from load bank to hand-held
•
Damaged cable
Communications Loss (receive error)
err Conn r
•
Unplugged cable from load bank to hand-held
•
Damaged cable
Over Voltage
err OUer UoLt
•
Voltage applied is too high for the load bank
Low airflow (if fitted)
err AIr FAIL
•
Check that the fan is not obstructed and that it is free to
rotate.
Motor Overload
err FAn OUEr
•
Check that the fan is not obstructed and that it is free to
rotate.
•
Check the motor current and overload setting.
Over Temperature “1”
err OUER TC 1
•
Allow the load bank to cool and reset over temperature
trip.
•
Check that the airflow through load bank is unobstructed.
•
Check for any signs of hot air re circulation.
•
Check all fans and filters on the load bank are
unobstructed
Supply line error
err SPLY LInE
•
Error in supply connection, check wiring according to
single phase connection mode
Internal Software Error
err SoFt FaIL
•
Software fault. Please contact our support team.
Firmware update required
Info UPd sys
•
Firmware update required in either the hand-held, SIGMA
gateway or PC system.
5 - 5
Sigma LT Load Bank Status Display
The load bank status is displayed on the seven segment LED located on the Sigma LT front
control panel.
Figure 5-1
The Sigma LT digital toggle switch panel LED display
Sigma LT Digital Toggle Switches - Error Messages
Maintenance & Troubleshooting
