Manual Power Quality Filter PQFS
Maintenance instructions 177
10.3
Standard maintenance procedure
10.3.1
Step 1: Check the ambient temperature conditions
With the filter running, check the ambient temperature conditions and make sure that
they are similar to the conditions at the commissioning stage. If higher temperatures
are present, this may indicate a problem with the switch room cooling/ventilation
system. Ensure that the filter derating factor ([/Welcome/Settings/Installation
set./Rating]) corresponds to the ambient conditions observed. If the ambient
temperature is higher than 40°C/104°F, the filter should be derated (Cf.
Section 5.2
).
10.3.2
Step 2: Record the filter operating status
−
With the filter running, check and note the filter load graphs ([/Welcome/PQF
Monitoring/Filter load]). Pay special attention to the temperature graph. If this one
is around 100% and the other load indicators are relatively low, this could indicate
that the filter is limiting its output because it is experiencing a cooling (fan)
problem. If in doubt, assign the ‘T Limit’ indicator to a spare digital output
([/Welcome/Settings/Customer set./Digital Outputs]). This way, the digital output
monitor at the top of the PQF-Manager screen will be on if the filter is limiting its
output current due to temperature problems. By default, the ‘T Limit’ indicator is
assigned to digital output 6 of the PQF-Manager.
−
Make a note of the PQF-operation hours ([/Welcome/PQF monitoring/PQF
operation]) and the fan-operation hours ([/Welcome/PQF Monitoring/Fan
operation]). For units up to 60A, if the fan operation indicator shows a multiple of
40000 hours, it is recommended that the fan be replaced. For units with higher
ratings than 60A, if the fan operation indicator shows a multiple of 35000 hours (for
“fan in”) or 27000 hours (for “fan out”), it is recommended that the fan be replaced
(Cf.
Section 10.4
). Pay attention to any noise that could indicate fan failure.
−
Browse the ‘event logging’ menu ([/Welcome/PQF monitoring/Event logging]) to
spot any abnormal events that may have occurred.
−
Make a note of the total number of faults that the system has recorded over time
([/Welcome/PQF monitoring/Number of errors]).
−
Inspect the filter visually for any condition that could indicate an abnormal filter
stress (e.g. abnormal noises, abnormal appearance/colour or components and
cables).
Note: In filters consisting of more than one master, the above parameters can be
reviewed for the different units.
10.3.3
Step 3: Shut the filter down
−
Switch the filter off and remove the power supply to the filter.
−
Wait at least 25 minutes for the discharge of the DC capacitors.
−
Remove the filter cover panel (right hand side). Pay attention to the PQF-Manager
connections.