Inspect Relief Valves And Piping; Compressor Bearing And Gear; Maintenance; Inspect The Heat Exchanger Tubes - Carrier AquaEdge 19XRV series Operation, Maintenance And Installation Manual

ECONOMIZER FLOAT SYSTEM (TWO-STAGE COM-
PRESSORS) — For two-stage compressors, the economizer
has a low side ball type float system. The float refrigerant level
can be observed through the two sight glasses located on the
float cover under the condenser. See Fig. 52 for float detail. In-
spect the float every five years. Clean the chamber and the float
valve assembly. Be sure that the float moves freely and the ball
bearings that the float moves on are clean.
ECONOMIZER DAMPER VALVE (TWO-STAGE COM-
PRESSORS) — The damper valve should be inspected every
5 years or when the condenser is opened for service. With the
refrigerant transferred, remove the spring housing from the
valve (Fig. 53). The valve spring will exert 50 lb force upward.
Check the valve and linkage for free travel and loose parts.
Clean the assembly thoroughly. Replace the valve packing and
the housing o-ring if necessary.
2
LEGEND
1 — Float Ball
2 — Refrigerant Exit
3 — Bearings
Fig. 52 — Economizer Float System
(Two-Stage Compressor Chiller)
VALVE
PACKING
COMPRESSOR
SIDE
Fig. 53 — Economizer Damper Valve
(Two-Stage Compressor Chiller)
Inspect Relief Valves and Piping —
on this chiller protect the system against the potentially danger-
ous effects of overpressure. To ensure against damage to the
equipment and possible injury to personnel, these devices must
be kept in peak operating condition.
Compressor Bearing and Gear Maintenance —
The key to good bearing and gear maintenance is proper
lubrication. Use the proper grade of oil, maintained at
recommended level, temperature, and pressure. Inspect the
lubrication system regularly and thoroughly. Annual oil
analysis and vibration monitoring is recommended.
increased vibration or increased bearing temperature. Gears,
babbitted journal, and thrust bearings should be examined ap-
proximately every five years for signs of wear based on the re-
sults of the annual oil analysis. To inspect the bearings, a com-
plete compressor teardown is required. Only a trained service
technician should remove and examine the bearings. The fre-
1
quency of examination is determined by the hours of chiller op-
eration, load conditions during operation, and the condition of
the oil and the lubrication system. Rolling element bearings
(Frame 3, Frame 4, Frame 5, and Frame E compressor high
speed shaft only) cannot be field inspected; excessive vibration
is the primary sign of wear or damage. If either symptom ap-
3
pears, contact an experienced and responsible service organiza-
tion for assistance.
Inspect the Heat Exchanger Tubes and Flow
Devices
COOLER AND OPTIONAL FLOW DEVICES —
and clean the cooler tubes at the end of the first operating sea-
son. 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
SPRING
HOUSING 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
CONNECTION
if corroded or remove any scale if found.
TO COOLER
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
O-RING
condenser tubes with a rotary tube cleaning system at least
once per year and more often if the water is contaminated.
Inspect the entering and leaving condenser water sensors and
flow devices for signs of corrosion or scale. Replace the sensor
ECONOMIZER
SIDE
or Schrader fitting if corroded or remove any scale if found.
inability 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 or water flow
may be incorrect. Because HFC-134a is a high-pressure refrig-
erant, air usually does not enter the chiller.
designed to avoid scraping and scratching the tube wall.
91
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.
Excessive bearing wear can sometimes be detected through
Higher than normal condenser pressures, together with the
During the tube cleaning process, use brushes specially
The relief valves
Inspect