74
CVHE-SVX005C-EN
CAUTION
Hot Surface!
Failure to follow instructions below could result in
moderate injury.
Surface temperatures can reach 150°F (66°C). To
avoid possible skin burns, stay clear of these
surfaces. If possible, allow surfaces to cool before
servicing. If servicing is necessary while surface
temperatures are still elevated, you MUST put on all
Personal Protective Equipment (PPE).
To ensure proper lubrication and prevent refrigerant from
condensing in the oil tank, a 750-watt heater is in a well in
the oil tank. The heater is used to warm the oil while the
unit is off. With the default settings for R-123, the oil heater
is de-energized when the unit starts. With the default
settings for R-514A, Running Oil Temperature Control is
enabled, and the Running Oil Temperature Setpoint is
factory-programmed at 100°F (37.8°C). With either
refrigerant, the heater energizes as needed to maintain
140°F to 145°F (60.0°C to 62.8°C) when the chiller is not
running.
With R-123 and mineral oil, when the chiller is operating,
the temperature of the oil tank is typically 100°F to 160°F
(37.8°C to 71.1°C). With R-514A, solid state oil heater
control is installed and enabled. The oil return lines from
the thrust and journal bearings transport oil and some seal
leakage refrigerant. The oil return lines are routed into a
manifold and separator under the motor. Gas flow exits the
top of the manifold and is vented to the evaporator. Oil exits
the bottom of the manifold and returns to the tank.
Separation of the seal leakage gas in the separator keeps
this gas out of the tank.
A dual eductor system is used to reclaim oil from the
suction cover and the evaporator, and deposit it back into
the oil tank. These eductors use high-pressure condenser
gas to draw the oil from the suction cover and evaporator to
the eductors and then discharge into the oil tank. The
evaporator eductor line has a shut-off valve mounted by the
evaporator. The position of the shut-off valve will be set at
three-quarters of a turn open during commissioning, but
may be adjusted later by a qualified technician as
necessary for oil return. A normal operating setting for the
valve may range from full closed to two turns open.
Note: Depending on operating conditions, the oil sump’s
normal operating oil level may vary from just below
the bottom sight glass to near the top of the upper
sight glass.
Liquid refrigerant is used to cool the oil supply to both the
thrust bearing and journal bearings. On refrigerant pump
units, the oil cooler is located inside the economizer and
uses refrigerant passing from the condenser to evaporator
to cool the oil. Oil leaves the oil cooler and flows to both the
thrust and journal bearings.
Motor Cooling System
Compressor motors are cooled with liquid refrigerant (refer
to the figures in “Compressor Lubrication System,” p. 71).
The refrigerant pump is located on the front of the oil tank
(motor inside the oil tank). The refrigerant pump inlet is
connected to the well at the bottom of the condenser. The
connection is on the side where a weir ensures a
preferential supply of liquid refrigerant. Refrigerant is
delivered to the motor via the pump. An in-line filter is
installed (replace the in-line filter only with major service).
Motor refrigerant drain lines are routed to the condenser.
Tracer
®
AdaptiView™ Display
Information is tailored to operators, service technicians,
and owners.
When operating a chiller, specific information is needed
you needed on a day-to-day basis—setpoints, limits,
diagnostic information, and reports.
Day-to-day operational information is presented at the
display. Logically organized groups of information—chiller
modes of operation, active diagnostics, settings, graphs,
and reports put information conveniently at your fingertips.
For more information, refer to Tracer
®
AdaptiView™
Display for Water-cooled CenTraVac™ Chillers with
Symbio™ Controls User Guide (CTV-SVU004*-EN).
Operating Principles
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