Carrier 50TCQD17-D24 Service And Maintenance Instructions page 9

LPS/LOC
FILTER
DRIER
2B
FILTER
DRIER 1B
ACCUTROL
DFT1
DFT 2
OUTDOOR COIL
Fig. 12 - - Typical Unit Piping Schematic with TXV Valves on the Indoor Coils
FROM
LIQUID
HEADER
Fig. 13 - - Heat Pump — Flow as Evaporator Function
50TCQ- - D17, - - D24 Outdoor Coils Only — Converging
circuit flow in the condenser- - function operation is
accomplished with the check valve in the vapor header
and the liquid transfer header connected to the side ports
on all but one of the Accutrol tee nipples in each circuit.
During condenser- - function operation, hot gas from the
compressor discharge enters the header until it reaches the
check valve which blocks further flow. The hot gas exits
the header through the tubes above the check valve and
enters these coil circuits. At the outlet of these
desuperheating and condensing circuits, the refrigerant
1A
HPS2
COMP 2
2A
STRAINER
1C
TO
EVAPORATOR
COIL
CIRCUITS
C09229A
COOLING LIQUID LINES
HPS1
COMP 1
HEATING LIQUID LINES
STRAINER
2C
enters the Accutrol tees from the coil end. The refrigerant
exits the tee at the side port and enters the liquid transfer
header (see Fig. 14). The refrigerant moves through the
liquid transfer header and exits through the remaining
tubes, through the side ports on the Accutrol tees (see
Fig. 15) and back into the coil circuits where additional
condensing occurs. These circuits exit into the vapor
header behind the check valve and exit through the
remaining tube on the vapor header. In this last pass
through the coil, the refrigerant is subcooled. Subcooled
liquid exits at the last Accutrol tee (see Fig. 16) where the
side port is connected to the specific mode liquid line.
Fig. 14 - - Heat Pump Accutrol — Flow as Condenser
Function/ Exiting First Pass
9
2D
1D
INDOOR COIL
From
Condenser
Coil Circuits
To
Transfer
Header
TXV 2
TXV1
C12383
C09230