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ECONOMIZER DAMPER VALVE
The damper valve operation should be inspected annually (exter-
nal inspection) and internally when the refrigerant is removed
and it has been more than 5 years since last inspection or initial
start-up. See Fig. 46 for economizer damper valve detail.
VALVE
PACKING
COMPRESSOR
SIDE
NOTE: Two Stage 19XR6-7 utilizes an electrical actuated butterfly valve as
damper valve.
Fig. 46 — Economizer Damper Valve (Two-Stage
19XRC, E Compressor Chiller)
Inspect Relief Valves and Piping
The relief valves on this chiller protect the system against the po-
tentially dangerous effects of overpressure. To ensure against
damage to the equipment and possible injury to personnel, these
devices must be kept in peak operating condition.
As a minimum, the following maintenance is required.
1.
At least once a year, disconnect the vent piping at the
valve outlet and carefully inspect the valve body and
mechanism for any evidence of internal corrosion or rust,
dirt, scale, leakage, etc.
2.
If corrosion or foreign material is found, do not attempt to
repair or recondition. Replace the valve.
3.
If the chiller is installed in a corrosive atmosphere or the
relief valves are vented into a corrosive atmosphere,
inspect the relief valves at more frequent intervals.
Compressor Bearing and Gear Maintenance
The key to good bearing and gear maintenance is proper lubrica-
tion. Use the proper grade of oil, maintained at recommended lev-
el, temperature, and pressure. Inspect the lubrication system regu-
larly and thoroughly. Annual oil analysis and vibration measure-
ments are recommended.
Excessive bearing wear can sometimes be detected through in-
creased vibration or increased bearing temperature. Gears, bab-
bitted journal bearings, and thrust bearings should be examined
for signs of wear based on the results of the annual oil analysis
and vibration levels. To inspect the bearings, a complete com-
pressor teardown is required. Only a trained service technician
should remove and examine the bearings. The frequency of ex-
amination is determined by the hours of chiller operation, load
conditions during operation, and the condition of the oil and the
lubrication system. High speed shaft rolling element bearings
cannot be field inspected; excessive vibration is the primary sign
of wear or damage. If either symptom appears, contact an expe-
rienced and responsible service organization for assistance.
Inspect
Flow Devices
COOLER AND OPTIONAL FLOW DEVICES
Inspect and clean the cooler tubes at the end of the first operating
SPRING
season. Confirm that there is no foreign debris from the system
HOUSING
that could have lodged in the tubes potentially resulting in tube
failure. Because these tubes have internal ridges, a rotary-type
tube cleaning system is needed to fully clean the tubes. Inspect the
tubes' condition to determine the scheduled frequency for future
CONNECTION
cleaning and to determine whether water treatment in the chilled
TO COOLER
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
O-RING
or remove any scale if found.
CONDENSER AND OPTIONAL FLOW DEVICES
Since this water circuit is usually an open-type system, the tubes
ECONOMIZER
SIDE
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. Confirm that there is no
foreign debris from the system that could have lodged in the tubes
potentially resulting in tube failure. Inspect the entering and leav-
ing condenser water sensors and flow devices for signs of corro-
sion or scale. Replace the sensor or Schrader fitting if corroded or
remove any scale if found.
Higher than normal condenser pressures, together with the inabili-
ty 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 refrigerant temperature
against the leaving condenser water temperature. If this reading is
more than what the design difference is supposed to be, the con-
denser tubes may be dirty or water flow may be incorrect. Because
HFC-134a is a high-pressure refrigerant, air usually does not enter
the chiller.
During the tube cleaning process, use brushes specially designed
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 re-
moval. Consult a water treatment specialist for proper treatment.
Water Leaks
The refrigerant moisture indicator on the refrigerant motor cooling
line (Fig. 3-5) indicates whether there is water leakage during
chiller operation. 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 25.
Water Treatment
Untreated or improperly treated water may result in corrosion,
scaling, erosion, or algae. The services of a qualified water treat-
ment specialist should be obtained to develop and monitor a treat-
ment program.
Water must be within design flow limits, clean, and treated to
ensure proper chiller performance and reduce the potential of
tube damage due to corrosion, scaling, erosion, and algae.
Carrier assumes no responsibility for chiller damage
resulting from untreated or improperly treated water.
49
the
Heat
Exchanger
CAUTION
CAUTION
Tubes
and
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