Vfd Refrigerant Strainer - Carrier 19XRV Start-Up, Operation And Maintenance Instructions Manual

VFD Refrigerant Strainer —
located in the 5/8 in. line that supplies refrigerant to the VFD.
The strainer should be replaced once a year or more often if the
strainer condition indicates a need for more frequent replace-
ment. Change the filter by closing the refrigerant cooling line
isolation valves. Refrigerant pressure can be relieved through
access valves on the strainer housing. Tighten 5/8 flare nuts to
55 to 66 ft-lb (75 to 89 Nm).
Inspect Refrigerant Float System —
inspection every 5 years or when the condenser is opened for
service.
1. Transfer the refrigerant into the cooler vessel or into a
pumpout storage tank.
2. Remove the float access cover.
3. Clean the chamber and valve assembly thoroughly. Be
sure the valve moves freely. Ensure that all openings are
free of obstructions.
4. Examine the cover gasket and replace if necessary.
See Fig. 42 for a view of the float valve design. For linear
float valve designs, inspect the orientation of the float slide pin.
It must be pointed toward the bubbler tube for proper operation.
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.
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
lubrication. Use the proper grade of oil, maintained at
recommended level, temperature, and pressure. Inspect the
lubrication system regularly and thoroughly.
Excessive bearing wear can sometimes be detected through
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-
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 compressor high speed shaft only) cannot be field in-
spected; excessive vibration is the primary sign of wear or
damage. If either symptom appears, contact an experienced
and responsible service organization for assistance.
Inspect the Heat Exchanger Tubes and Flow
Devices
COOLER AND OPTIONAL FLOW DEVICES — Inspect and
clean the cooler tubes at the end of the first operating season.
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 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
A refrigerant strainer is
Perform this
The relief valves
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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.
Inspect 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
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.
During the tube cleaning process, use brushes specially
designed to avoid scraping and scratching the tube wall.
Contact a Carrier representative to obtain these brushes. Do not
use wire brushes.
Hard scale may require chemical treatment for its preven-
tion or removal. Consult a water treatment specialist for
proper treatment.
The refrigerant moisture indicator on the
Water Leaks —
refrigerant motor cooling line (Fig. 2) 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.
See Chiller Dehydration section, page 61.
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LEGEND
1 — Refrigerant Inlet from FLASC Chamber
2 — Linear Float Assembly
3 — Float Screen
4 — Bubbler Line
5 — Float Cover
6 — Bubbler Line Connection
7 — Refrigerant Outlet to Cooler
8 — Gasket
Fig. 42 — 19XRV Float Valve Design
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