Specifications

8
Cooler — The cooler (also known as the evaporator) is
maintained at low temperature/pressure so that evaporating
refrigerant can remove heat from the liquid flowing through its
internal tubes.
Condenser — This vessel is located underneath the
compressor. The condenser operates at a higher temperature/
pressure than the cooler and has liquid flowing through its
internal tubes to remove heat from the refrigerant.
Motor-Compressor — The motor-compressor main-
tains system temperature/pressure differences and moves the
heat carrying refrigerant from the cooler to the condenser. See
Fig. 4.
Muffler — The muffler provides acoustical attenuation. A
check valve just downstream of the muffler prevents reverse
compressor rotation during shutdown.
Control Center — The control center is the user inter-
face for controlling the chiller and regulating the chiller’s
capacity to maintain the proper chilled liquid temperature. See
Fig. 5. The control center:
• 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 microproces-
sor control
• provides access to other Carrier Comfort Network
®
devices
• provides machine protection
Storage Vessel (Optional) — Two sizes of storage
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
/
2
-in. male flare vapor connection
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 liquid flowing through the
cooler tubes. With heat energy removed, the liquid becomes
cold enough for use in an air-conditioning circuit or process
liquid cooling.
After absorbing heat from the chilled liquid, the refrigerant
vapor is compressed. Compression adds still more energy, and
the refrigerant is quite warm (typically 90 to 130 F [32 to
54 C]) when it is discharged from compressor into condenser.
Relatively cool (typically 65 to 85 F [18 to 29 C]) liquid
flowing into the condenser tubes removes heat from the refrig-
erant and the vapor condenses to liquid, refrigerant.
The liquid refrigerant in the condenser passes through
orifices into the FLASC (Flash Subcooler) chamber (Fig. 6).
Since the FLASC chamber is at a lower pressure, part of the
liquid refrigerant flashes to vapor, thereby cooling the remain-
ing liquid. The FLASC vapor is recondensed on the tubes
which are cooled by entering condenser liquid. 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
condenser and cooler. In this case, an in-line orifice on the
economizer drain flange meters the refrigerant liquid into the
cooler. Pressure in this chamber is intermediate 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 suction cutoff (Fig. 7). Here it
is mixed with gas from the suction cut-off point to produce an
increase in the mass flow of refrigerant transported and
compressed without either an increase in suction volume or a
change in suction temperature.
The cooled liquid refrigerant in the economizer is metered
through an orifice into the cooler. Because pressure in the cool-
er is lower than economizer pressure, some of the liquid flashes
and cools the remainder to evaporator (cooler) temperature.
The cycle is now complete.
DISCHARGE
COMPRESSOR LUBRICATION BLOCK
MOTOR TERMINAL
ACCESS COVER
MOTOR COOLING
DRAIN
MOTOR TERMINALS ECONOMIZER
PORT
MOTOR
COOLING
INLET
FLANGE
Fig. 4 — Compressor
a23-1619