Compressor Bearing Maintenance; Inspect The Heat Exchanger Tubes; And Flow Devices; Water Leaks - Carrier AquaEdge 19DV Series Start-Up, Operation And Maintenance Instructions Manual

2. If corrosion or foreign material is found, do not attempt to
repair or recondition. Replace the safety relief device.
3. If the chiller is installed in a corrosive atmosphere or the
relief devices are vented into a corrosive atmosphere,
inspect the safety relief devices at more frequent intervals.

Compressor Bearing Maintenance

The key to good bearing maintenance is proper lubrication. In-
spect the lubrication system regularly and thoroughly. Annual
vibration measurements are recommended to monitor overall
compressor status. Annual refrigerant analysis is recommended
to monitor refrigerant acid and moisture levels over time.
Excessive bearing wear can often be detected through in-
creased vibration or increased bearing temperature. To inspect
the bearings, a complete compressor teardown is required.
Only a trained service technician should perform a compressor
disassembly. Bearings cannot be field inspected; excessive vi-
bration is the primary sign of wear or damage. If either symp-
tom appears, contact an experienced and responsible service
organization for assistance. Annual compressor vibration anal-
ysis and trending is recommended for compressor preventative
monitoring and maintenance.
CAUTION
If compressor requires disassembly, cleanliness is of critical
importance to avoid contamination. Small amounts of con-
tamination can result in damage to ceramic bearings.

Inspect the Heat Exchanger Tubes

and Flow Devices

EVAPORATOR AND OPTIONAL FLOW DEVICES
Inspect and clean the evaporator tubes at the end of the first op-
erating season. Because these tubes have internal ridges, a rota-
ry-type tube cleaning system is needed to fully clean the tubes.
Inspect the tubes' condition to determine the scheduled fre-
quency for future cleaning and to determine whether water
treatment in the chilled water/brine circuit is adequate. Inspect
the entering and leaving chilled water temperature sensors and
flow devices for signs of corrosion or scale. Replace a sensor
or Schrader fitting if corroded or remove any scale if found.
CONDENSER AND OPTIONAL FLOW DEVICES
Since this water circuit is usually an open-type system, the
tubes may be subject to contamination and scale. Clean the
condenser tubes with a rotary tube cleaning system at least
once per year and more often if the water is contaminated. In-
spect the entering and leaving condenser water sensors and
flow devices for signs of corrosion or scale. Replace the sensor
or Schrader fitting if corroded or remove any scale if found.
Higher than normal condenser pressures, together with the in-
ability to reach full refrigeration load, usually indicate dirty
tubes or air in the chiller. If the refrigeration log indicates a rise
above normal condenser pressures, check the condenser refrig-
erant temperature against the leaving condenser water tempera-
ture. If this reading is more than what the design difference is
supposed to be, the condenser tubes may be dirty, water flow
may be incorrect, or non-condensables have contaminated the
refrigerant circuit. To resolve, check the purge status. If purge
is operating normally and does not have excessive run time,
that may be an indication to double check pressure transducer
and temperature readings along with flow.
During the tube cleaning process, use brushes specially de-
signed to avoid scraping and scratching the tube wall. Contact
your Carrier representative to obtain these brushes. Do not use
wire brushes. Hard scale may require chemical treatment for its
prevention or removal. Consult a water treatment specialist for
proper treatment.

Water Leaks

The refrigerant moisture indicator on the refrigerant motor
cooling line along with the moisture indicator located in the
liquid refrigerant feeding the compressor bearings (Fig. 2) indi-
cates whether there is water or air leakage during chiller opera-
tion. Water leaks should be repaired immediately.
The chiller must be dehydrated after repair of water leaks or
damage may result. See Chiller Dehydration section, page 20.

Water Treatment

Untreated or improperly treated water may result in corrosion,
scaling, erosion, or algae. The services of a qualified water
treatment specialist should be obtained to develop and monitor
a treatment program.
Water must be within design flow limits, clean, and treated
to ensure proper chiller performance and reduce the poten-
tial of tube damage due to corrosion, scaling, erosion, and
algae. Carrier assumes no responsibility for chiller damage
resulting from untreated or improperly treated water. If the
unit is going to be stored for an extended period of time,
Carrier has specific long-term storage requirements that are
documented and available from the chiller sales group.

Inspect the VFD

Before working on any starter, shut off the chiller, then open
and tag all disconnects supplying power to the starter.
The motor leads must be disconnected from the VFD be-
fore an insulation test is performed. The voltage generated
from the tester can damage the drive components.
Failure to follow these procedures may result in personal
injury or damage to equipment.
TO AVOID an electric shock hazard, verify that the voltage
on the bus capacitors has discharged completely before ser-
vicing. Check the DC bus voltage at the power terminal
block by measuring between the +DC and –DC terminals,
between the +DC terminal and the chassis, and between the
–DC terminal and the chassis. The voltage must be zero for
all three measurements.
DC bus capacitors retain hazardous voltages after input
power has been disconnected. An isolated multimeter will
be needed to measure DC bus voltage and to make resis-
tance checks.
After disconnecting input power, wait 5 minutes for the DC
bus capacitors to discharge and then check the voltage with
a voltmeter rated for the DC bus voltage to ensure the DC
bus capacitors are discharged before touching any internal
components. Failure to observe this precaution could result
in severe bodily injury or loss of life.
The disconnect on the starter front panel does not always de-
energize all internal circuits. Open all internal and remote
disconnects before servicing the starter. Failure to follow this
procedure may result in personal injury by electric shock.
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CAUTION
CAUTION
CAUTION
CAUTION
WARNING
WARNING