Refrigeration System Components; Reversing Valve And Check Valve Position; Troubleshooting Refrigerant Pressure Problems And Check; Valves - Carrier Legacy 548J07 Installation Instructions Manual

REFRIGERATION SYSTEM COMPONENTS

Each heat pump refrigeration system includes a compressor,
accumulator, reversing valve, dual-function outdoor coil with
vapor header check valve, cooling liquid line with a filter drier
and a check valve, dual-function indoor coil with a vapor head-
er check valve, and heating liquid line with a check valve and a
strainer. See Fig. 7 for typical unit piping schematic.
Dual-function outdoor and indoor coils are designed to provide
parallel coil circuits during evaporator-function operation and
converging coil circuits during the condenser-function operation.

Reversing Valve and Check Valve Position

See Fig. 7 and Tables 2-4.
Troubleshooting Refrigerant Pressure Problems and
Check Valves
Refer to Fig. 7 and Tables 2 and 3.

REFRIGERANT SYSTEM PRESSURE ACCESS PORTS

There are two access ports on the suction tube and the dis-
charge tube near the compressor. These are brass fittings with
black plastic caps. The hose connection fittings are standard
1 / -in. SAE male flare couplings.
4
The brass fittings are two-piece High Flow valves, with a re-
ceptacle base brazed to the tubing and an integral spring-closed
check valve core screwed into the base. See Fig. 8 on page 10.
This check valve is permanently assembled into this core body
and cannot be serviced separately. Replace the entire core body
if necessary. Service tools are available from RCD that allow
the replacement of the check valve core without having to re-
cover the entire system refrigerant charge. Apply compressor
refrigerant oil to the check valve core's bottom O-ring. Install
the fitting body and torque to 96 ±10 in.-lb (10.9 ±1 Nm). Do
not exceed 106 in.-lb (11.9 Nm) when tightening.
ACUTROL
HEATING
MODE
HEATING MODE LIQUID LINES
COOLING MODE LIQUID LINES
FILTER
DRYER
LOC
Fig. 7 — Unit Piping Schematic for 548J*07
9
Table 2 — Cooling Mode (each circuit)
COMPONENT
Reversing Valve
Check Valve A
Check Valve B
Check Valve C
Check Valve D
Table 3 — Heating Mode (each circuit)
COMPONENT
Reversing Valve
Check Valve A
Check Valve B
Check Valve C
Check Valve D
Table 4 — Defrost Mode
COMPONENT
Defrost Thermostat
Outdoor Fan(s)
Reversing Valve
Check Valve A
Check Valve B
Check Valve C
Check Valve D
HPS
STATUS/POSITION
Energized
Closed
Open
Closed
Open
STATUS/POSITION
De-energized
Open
Closed
Open
Closed
STATUS/POSITION
Closed
Off
Energized
Closed
Open
Closed
Open
STRAINER