5 - 4
In addition, carry out a load check to ensure that load contactors and elements are
operating correctly:
1. Connect a supply (at the load bank’s rated voltage) to the load bank.
2. Set and apply loads at 30%, 60%, and 100%, and make a note of the power value shown
on the instrumentation (or external metering).
3. Check that the power values are within 5% of the load set on the controller.
Annually
Verify the load bank instrumentation’s calibration. If adjustment is required contact
Froment for advice.
Air Circuit Breaker (Option) Maintenance
Annually
• The inspection procedure according to NEMA AB4, section 3 must be performed once
a year.
• The arc chutes and contact system must be inspected according to manufacturer’s
manual operation instructions
Five Yearly
• Manufacturer’s advise a full service
Fault Condition
• If a fault condition opens the circuit breaker, the circuit breaker should be inspected
before it is re-placed into service
• Optional arc chute covers must be replaced at least after three short circuit interruptions
Refer to the Manufacturer’s operation manual for further details.
Note: The recom-
mended interval for a
calibration check is one
year, unless the equip-
ment has been subject
to misuse or damage. If
adjustment is not nec-
essary the calibration
check interval could
be increased to three
years.
Chapter Five
Fault Finding
The following chart covers some of the typical faults you might encounter and some
possible solutions.
Fault Possible Causes Possible Causes
Cooling fan does not start or run Correct operation • 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 control and fans
supply selector switch and the Fan
and Controls Supply Isolator are in the
correct position and the Start button
has been pressed.
• Confirm that the control supply fuses
are not blown.
Fan thermal overload tripped
• Allow the load bank to cool, and then
press the Stop button followed by the
Start button to reset.
• 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 cir-
cuit 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 then
reset.
• 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.
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 genera-
tor, 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
5 - 5
Maintenance & Troubleshooting
To Next Page
Loading...
