Table of Contents
Advertisement
WARNING
UNIT OPERATION AND SAFETY HAZARD
Failure to follow this warning could cause personal injury,
death and/or equipment damage.
Puron (R-410A) refrigerant systems operate at higher pres-
sures than standard R-22 systems. Do not use R-22 service
equipment or components on Puron refrigerant equipment.
WARNING
PERSONAL INJURY AND ENVIRONMENTAL HAZ-
ARD
Failure to follow this warning could cause personal injury or
death.
Relieve pressure and recover all refrigerant before system
repair or final unit disposal.
Wear safety glasses and gloves when handling refrigerants.
Keep torches and other ignition sources away from refriger-
ants and oils.
CAUTION
CUT HAZARD
Failure to follow this caution may result in personal injury.
Sheet metal parts may have sharp edges or burrs. Use care
and wear appropriate protective clothing, safety glasses and
gloves when handling parts and servicing air-conditioning
equipment.
WARNING
CARBON-MONOXIDE POISONING HAZARD
Failure to follow instructions could result in severe personal
injury or death due to carbon-monoxide poisoning, if com-
bustion products infiltrate into the building.
Check that all openings in the outside wall around the vent
(and air intake) pipe(s) are sealed to prevent infiltration of
combustion products into the building.
Check that furnace vent (and air intake) terminal(s) are not
obstructed in any way during all seasons.
INSTALLATION GUIDELINES
Replacement/Retrofit
Refrigerant
Replacement/retrofit installations require change-out of
outdoor unit, metering device, and filter driers. Change-out
of indoor coil (evaporator) and interconnecting tubing is
recommended.
EXISTING EVAPORATOR COIL
If the existing evaporator coil may be re-used, check with
the coil manufacturer to verify the coil construction is suit-
able for operation with the higher pressures of Puron refrig-
erant (R-410A). Also determine if the existing TXV valve is
compatible with R-410A, replace if necessary. The minimum
factory test pressure rating must be 250 psig (1725 kPa). Ex-
isting coil will need to be purged with Nitrogen to remove as
much mineral oil as possible to eliminate cross contamina-
tion of oils.
ACID TEST
If the existing system is being replaced because of a compres-
sor electrical failure, assume acid is in system. If system is being
replaced for any other reason, use an approved acid test kit to de-
termine acid level. If even low levels of acid are detected, install
a 100 percent activated alumina suction-line filter drier in addi-
tion to the replacement liquid-line filter drier. Remove the suc-
tion line filter drier as soon as possible, with a maximum of 72 hr
of operation. Recommendation: Install a ball valve in the liquid
line at the filter drier location when installing a suction filter in
the suction line.
EXISTING REFRIGERATION PIPING
Reuse of existing refrigerant piping involves three issues:
quality (strength) of existing tubing, cleanliness and tube size.
Inspect all tube segments and joints for signs of damage, corro-
sion or poor brazing. Flush the interconnecting piping system
with dry Nitrogen to eliminate as much trace of mineral oil as
possible.
Same tube sizes are capable of handling higher flowrates (ex-
pressed as tons of cooling capacity) with Puron refrigerant com-
pared to R-22 at constant pressure drops. For example, a
OD liquid line is rated at 33% higher tons with Puron than with
R-22 (at 5°F pressure drop). A 1
at 53% higher tons with Puron than with R-22 (at 2°F pressure
drop). Refrigeration lines selected for R-22 use are typically
oversized for Puron applications. Carefully check the existing
suction line size against the table for maximum size; replace ver-
tical riser segments if necessary. Check existing liquid line size
against sizing data in Table 1 or 2; replace with smaller lines
when feasible.
Table 1 — Evaporator Coil Connections
EVAPORATOR
CONNECT TO
COIL HAS
Single Circuit
38AUZ ONLY
Two Circuits
2
—
R-22
to
Puron®
1
/
-inch OD suction line is rated
8
NOTES
MODEL
—
Manifold evaporator circuits
38AUZ
into single piping system.
or
Use two separate piping
38AUD
systems
1
/
-inch
2
Hide quick links:
Advertisement
Table of Contents
