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82
NETWORK
OPTIONS
REMOTE
CCN SITE
AUTODIAL
GATEWAY
NON CARRIER
HVAC
EQUIPMENT
TERMINAL
SYSTEM
MANAGER
TCU
ROOFTOP
UNIT
DAV AIR
TERMINAL
TCU
TCU
DAV AIR
TERMINAL
AIR DISTRIBUTION-DIGITAL AIR VOLUME CONTROL (DAV)
DAV FAN
POWERED
MIXING
BOX
TO
ADDITIONAL
TERMINALS
HEATING/COOLING UNITS
BUILDING SUPERVISOR
ROOFTOP
UNIT
CL
ROOFTOP
UNIT
CL
ROOFTOP
UNIT
CL
ROOFTOP
UNIT
CL
CCN BUS
CL
COMFORT
CONTROLLER
LEGEND
CCN -- Carrier Comfort Network
r
CL --
Comfort
Link
t
Controls
DAV -- Digital Air Volume
HVAC -- Heating, Ventilation, and
Air Conditoning
TCU -- Terminal Control Unit
C07030
Fig. 51 -- CCN System Architecture
Subcooler Heat Exchanger
(SHX -- 48/50PG20--28 Only)
The purpose of the subcooler heat exchanger (SHX) and the
subcooler TXV is to increase the capacity of the evaporator by
sending subcooled liquid refrigerant into the evaporator. Normally,
the condenser subcools the liquid refrigerant by approximately
10
_
F. The SHX adds another 10
_
F to 15
_
F degrees of subcooling
before the refrigerant reaches the evaporator. This allows the
refrigerant to absorb more heat from the mixed air, thereby
providing more cooling capacity.
The subcooler functions by taking a small percentage of the high
pressure, medium temperature liquid refrigerant which exits the
condenser and converting it into a low pressure, low temperature
gas. This is accomplished by using the subcooler TXV. The gas is
then routed through a reverse--flow heat exchanger (SHX), which
transfers heat from the remaining liquid refrigerant in the liquid
line to the reverse flow gas refrigerant. The moderate temperature
gas is then sent to the compressor to complete the loop and the
cooler liquid refrigerant continues its normal path to the main TXV
and the evaporator. (See Fig. 52.)
COND
COMPRESSOR
SUBCOOLER
HX
SUBCOOLER TXV
MAIN TXV
EVAP
C07202
Fig. 52 -- Subcooler Operation
48/
50P
G
and
P
M
Summary of Contents for 48/50PG Series
Page 32: ...32 C07009 Fig 20 Air Baffle Dimensions 48 50PG03 16 48 50PG and PM...
Page 33: ...33 C08077 Fig 21 Air Baffle Dimensions 48 50PG20 28 and 48 50PM16 28 48 50PG and PM...
Page 58: ...58 C08549 Fig 28 48PG03 16 Control Wiring Schematic 48 50PG and PM...
Page 59: ...59 C08550 Fig 29 50PG03 16 Control Wiring Schematic 48 50PG and PM...
Page 64: ...64 C08471 Fig 34 Typical 48PG and PM16 28 Control Schematic 48PM16 28 Shown 48 50PG and PM...
Page 66: ...66 C08557 Fig 36 Typical 50PG and PM16 28 Control Schematic 50PG20 28 Shown 48 50PG and PM...
Page 68: ...68 C08558 Fig 38 Typical 48 50PG and PM16 28 Power Schematic 48 50PM16 28 Shown 48 50PG and PM...
Page 72: ...72 C08565 Fig 42 Typical 48 50PG20 28 Component Arrangement 48 50PG20 24 Shown 48 50PG and PM...
Page 73: ...73 C08067 Fig 43 48 50PM16 28 Component Arrangement 48 50PG and PM...
Page 74: ...74 C08562 Fig 44 48 50PM16 28 with Humidi MiZert Component Arrangement 48 50PG and PM...
Page 208: ...208 48 50PG and PM...