STARTUP AND MAINTENANCE
MAGNITUDE WME-D MAGNETIC BEARING CHILLER
DAIKIN APPLIED
50
Chiller Maintenance
DANGER
Use approved Lock Out/Tag Out procedures to disconnect power
from the unit. Wait 20 minutes after disconnecting power from the
unit before opening any compressor access covers. The DC link
capacitors store enough energy to cause electrocution.
Electrical System
Maintenance of the electrical system involves the general
requirement of keeping connections clean and tight. Pump
interlocks and flow switches should be checked to be sure they
interrupt the control circuit when tripped.
Cleaning and Preserving
A common cause of service calls and equipment malfunction is
dirt. This can be prevented with normal maintenance. The system
components most subject to dirt are:
1 .
Strainers: Remove and clean strainers in the chilled water
system and condenser water system at every inspection.
2 .
Condenser Tubes: Inspect the condenser tubes annually
for fouling and clean if required. The standard heads
should be removed with care due to their weight. One
method for handling standard heads follows (only qualified
service personnel should perform these tasks):
•
After draining water, remove all but two head bolts at
roughly 10 o’clock and 2 o’clock.
•
Loosen the remaining two bolts to enable the head
to be separated from the tube sheet sufficiently for a
clevis pin or hook to be inserted into an open bolt hole
at the top of the head.
•
Attach a hoist to the pin or hook, lift the head to
remove weight from the two remaining bolts, remove
the bolts, and carefully remove the head.
•
Do not try to install a machine thread eyebolt into the
head vent fitting, which has pipe threads.
•
Reverse this procedure to mount the head, using a
new gasket.
3 .
Condenser Flow Sensor: The condenser sensor should
be cleaned anytime the condenser is opened. This should
typically be performed at the annual inspection; however,
more frequent cleaning may be required depending on
the conditions of the jobsite. Recommended maintenance
includes the following:
•
Check the sensor tip for buildup.
•
Clean the tip using a soft cloth. Stubborn buildup,
such as lime, can be removed using a common
vinegar cleaning agent.
4 .
Electrical Panels: Excessive accumulation of dirt within
panels can damage components, inhibit good air
circulation, and make visual inspections difficult.
Water Treatment
Special care must be taken when utilizing open system water that
is usually not treated (such as lakes, rivers, and ponds). The use
of untreated water will result in corrosion, erosion, slime buildup,
scaling, or algae formation. Water treatment service must be
used. Special tube and water head material may be required to
reduce damage from corrosion. Daikin Applied is not responsible
for damage or faulty operation from untreated or improperly
treated water. See page 14 for caution statement on water
quality.
Seasonal Shutdown
WARNING
The condenser and evaporator are not self-draining. Where the
chiller can be subject to freezing temperatures, the condenser
and evaporator must be drained of all water. Water permitted
to remain in the piping and vessels can rupture these parts if
subjected to freezing temperatures. Dry air blown through the
vessels will aid in forcing all water out.
Except for freezing conditions, it is desirable to leave water in the
vessels to avoid long term exposure to air.
Continuous forced circulation of antifreeze through the
vessels is one method of avoiding freeze up .
Seasonal Startup
Seasonal startup procedures are as follows:
1 .
Leak test the unit.
2 .
Check and tighten all electrical connections.
3 .
Replace the drain plugs (including cooling tower pump and
tower drain) if they were removed at shutdown the previous
season.
Harmonic Filter Evaluation
If the optional harmonic filter is provided with the chiller,
measuring the current in each of the three phases of the
capacitor circuit may help determine the condition of the
capacitors. If the input phase currents are within a 5% match to
each other and approximately 30% of filter current rating, the
capacitors can be assumed to be in good working condition.
Phase currents that are imbalanced, may indicate a capacitor
failure. Testing should be done whenever the unit appears to be
operating in an abnormal state.
When the unit is off, the harmonic filter may be checked for
resistance levels. Using a multi-meter (set to read 100K ohms) to
check the phase-to-phase isolation, the reading should be about
40K (total equivalent bleeder resistance value) and should be the
same for each phase. Open circuit or very low readings indicate
an issue. Also check phase-to-chassis resistance as low readings
indicate a ground fault problem.
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