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Cooler —
This vessel (also known as the evaporator) is
located underneath the compressor. The cooler is maintained at
low temperature/pressure so that evaporating refrigerant can
remove heat from water/brine flowing through its internal
tubes.
Condenser —
The condenser operates at a higher
temperature/pressure than the cooler and has water flowing
through its internal tubes to remove heat from the refrigerant.
Motor-Compressor —
tains system temperature/pressure differences and moves the
heat carrying refrigerant from the cooler to the condenser.
Muffler-Oil Separator —
cal attenuation.
Refrigerant/oil separation is accomplished by the oil separa-
tor. Discharge gas enters near the midsection and leaves near
the top, while the separated oil drains out through the bottom
and flows through a horizontal oil sump/filter assembly (TC
frame 1 and 2 chillers).
TC frame 1 and 2 chillers have an oil separator and a muf-
fler assembly. On TD frame 4 chiller, the muffler is located in-
side the oil separator.
Control Panel —
The control panel is the user interface
for controlling the chiller and regulating the chiller's capacity
to maintain the proper chilled water temperature. The control
panel:
• registers cooler, condenser, and lubricating system
pressures
• shows chiller operating condition and alarm shutdown
conditions
• records the total chiller operating hours, starts, and the
number of hours the chiller has been currently running
• sequences chiller start, stop, and recycle under micro-
processor control
• provides access to other Carrier Comfort Network
devices
Factory-Mounted Starter (Optional Acces-
sory) —
The starter allows for the proper starting and dis-
connecting of electrical energy for the compressor-motor, oil
heater (TC frame 1 and 2 chillers), and control panel.
Storage Vessel (Optional) —
vessels are available. The vessels have double relief valves,
a magnetically coupled dial-type refrigerant level gage, a
1-in. FPT drain valve, and a
1
for the pumpout unit. A 30-in.-0-400 psi (–101-0-2750 kPa)
gage is also supplied with each unit.
NOTE: If a storage vessel is not used at the jobsite, factory-
installed optional isolation valves may be used to isolate the
chiller charge in either the cooler or condenser. An optional
pumpout compressor system is used to transfer refrigerant
from vessel to vessel.
REFRIGERATION CYCLE
The compressor continuously draws refrigerant vapor from
the cooler. As the compressor suction reduces the pressure in
the cooler, the remaining refrigerant boils at a fairly low tem-
perature (typically 38 to 42 F [3 to 6 C]). The energy required
for boiling is obtained from the water flowing through the cool-
er tubes. With heat energy removed, the water becomes cold
enough for use in an air-conditioning circuit or process liquid
cooling.
After taking heat from the water, the refrigerant vapor is
compressed. Compression adds still more energy, and the re-
frigerant is quite warm (typically 130 to 160 F [54 to 71 C])
when it is discharged from compressor into condenser.
The motor-compressor main-
The muffler provides acousti-
Two sizes of storage
/
-in. male flare vapor connection
2
Relatively cool (typically 65 to 85 F [18 to 29 C]) water
flowing into the condenser tubes removes heat from the refrig-
erant and the vapor condenses to liquid.
The liquid refrigerant passes through orifices into the
FLASC (Flash Subcooler) chamber (Fig. 3 and 4). Since the
FLASC chamber is at a lower pressure, part of the liquid refrig-
erant flashes to vapor, thereby cooling the remaining liquid.
The FLASC vapor is recondensed on the tubes which are
cooled by entering condenser water. The liquid then passes
through a float valve assembly which forms a liquid seal to
keep FLASC chamber vapor from entering the cooler.
An optional economizer can be installed between the con-
denser and cooler. In this case, the float valve meters the refrig-
erant liquid into the economizer. Pressure in this chamber is in-
termediate between condenser and cooler pressures. At this
lower pressure, some of the liquid refrigerant flashes to gas,
cooling the remaining liquid. The flash gas, having absorbed
heat, is returned directly to the compressor at a point after suc-
tion cutoff (Fig. 5). Here it is mixed with gas from the suction
cut-off point to produce an increase in the mass flow of refrig-
erant transported and compressed without either an increase in
suction volume or a change in suction temperature. Rather than
providing the same capacity with less power, the compressor
provides substantially increased capacity with only a slight in-
crease in power requirements.
The cooled liquid refrigerant in the economizer is metered
through a linear float valve into the cooler. Because pressure in
the cooler is lower than economizer pressure, some of the liq-
uid flashes and cools the remainder to evaporator (cooler) tem-
perature. The cycle is now complete.
MOTOR COOLING CYCLE
The motor is cooled by liquid refrigerant taken from the
bottom of the condenser vessel. The flow of refrigerant is
maintained by the pressure differential that exists due to com-
pressor operation. The refrigerant flows through an isolation
valve, in-line filter/drier, and a sight glass/moisture indicator
(dry-eye), into the motor through the motor spray nozzle. See
Fig. 3 and 4.
The motor spray nozzle is orificed to control refrigerant
flow through the gaps in the rotor and axial vent holes. The re-
frigerant collects in the bottom of the motor casing and then
drains into the cooler through the motor cooling drain line.
The motor is protected by a temperature sensor imbedded
in the stator windings. Motor temperatures above the MOTOR
WINDING TEMPERATURE OVERRIDE THRESHOLD
(see Capacity Override section, page 38) will override the
chilled water temperature capacity control to hold. If the motor
temperature rises 10 F (5.5 C) above this threshold, the slide
valve will unload. If the motor temperature rises above the
safety limit, the compressor will shut down.
LUBRICATION CYCLE
Summary —
The 23XL does not require an oil pump. Oil
flow is driven by differential pressure between condenser and
evaporator. This system pressure difference holds the potential
to push the oil through the oil separator and filter into the com-
pressor rotors, bearings, and slide valve. The cycle is referred
to as a "high side" oil system. See Fig. 3, 4, and 5.
Details —
The oil system:
• lubricates the roller bearings which support the male
and female rotors, and the ball bearings of the 23XL
compressor.
• positions the slide valve for capacity control. The slide
valve is connected to a piston via a rod. The position of
the piston, which rides in a cylinder, is determined by
energizing one of two solenoids which function to
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