Refrigerant Line Sizing; Liquid Shutoff Valve And Sight Glass; Pressure Relief; Refrigerant Receiver - Carrier 09DK Series Installation, Start-Up And Service Instructions Manual

REFRIGERANT LINE SIZING — Sizing depends on length
of lines between various sections of the refrigerant system.
Consider the amount of liquid lift and drop in the system as
well as proper compressor oil return. Consult Carrier System
Design Manual, Part 3, for proper piping sizes and design.
LIQUID SHUTOFF VALVE AND SIGHT GLASS — A
shut-off valve is not supplied with 09DK condensers. It is
strongly recommended that a full line size liquid shutoff valve
(see Fig. 18 and 19) be field supplied near condenser to allow
for servicing parts of the refrigerant circuit. A field-supplied
moisture indicating sight glass is recommended for use in
charging and servicing the system. Refer to Fig. 20.
PRESSURE RELIEF — The American National Standards
Institute and American Society of Heating, Refrigeration, and
Air Conditioning Engineers Safety Code for Mechanical
Refrigeration (ANSI/ASHRAE) 15 states the following:
"Every refrigerant system shall be protected by a pressure
*Field supplied.
NOTES:
1. Hot gas lines should rise above refrigerant level in condenser
circuit.
2. Trap should be installed on hot gas lines to prevent condenser
oil and refrigerant vapor migration from accumulating on com-
pressor heads during off cycle.
3. Refer to Carrier System Design Manual, part 3 for proper pip-
ing sizes and design.
4. For piping lengths greater than 50 ft (15.2 m), provide support
to liquid and gas lines near the connections to the coil.
Fig. 18 — Typical Piping for 09DK Condenser with a Single Compressor
relief device unless so constructed that the pressure due to fire
conditions will be safely relieved by some part of the system."
Since 09DK condensers have no pressure relief device, one
should be field supplied and installed just before the liquid line
service valve. (See Fig. 18 and 19.) When the split coil is used
with multiple systems, each system must have its own pressure
relief.
REFRIGERANT RECEIVER — A refrigerant receiver is not
furnished with 09DK condensers and is not recommended for
normal applications as its use will be detrimental to the desired
effects of subcooling. However, if a particular application
requires a receiver to increase refrigerant holding capacity of
the condenser, a receiver can be used. When a receiver is to be
used all year, it should be installed indoors. Carrier recom-
mends the following installation in such a case (see Fig. 20).
Locate valves on each side of the receiver so receiver may be
isolated from system for normal operation.
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