3
Same tube sizes are capable of handling higher flowrates
(expressed as tons of cooling capacity) with Puron
refrigerant compared to R--22 at constant pressure drops.
For example, a 1/2--inch OD liquid line is rated at 33%
higher tons with PuronRthan with R--22 (at 5_F pressure
drop). A 1 1/8--inchOD suction line is rated 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 linesize againstthe table for maximum size
(see Table 7); replace vertical riser segmentsif necessary.
Check existing liquid line size againstsizing data in Table 5
or 6; replace with smaller lines whenfeasible.
Installation –
1. Remove the existing evaporator coil or fan coil and
install the replacementcoil when appropriate.
2. Drain oil from low points and traps in suction line
tubing (and hot gas bypass tubing if appropriate) and
evaporator if they were not replaced. Removing oil
from evaporator coil may require purging of the
tubing with dry nitrogen.
3. Unless indoor unit is equipped with a Puron®ap-
proved metering device, change the metering device
to a thermal expansion valve (TXV) designed for
PuronR(R-410A).
4. Remove the existing outdoor unit. Install the new out-
door unit according to these installation instructions.
5. Install a new field-supplied liquid-line filter drier at
the indoor coil just upstream of the TXV or fix orifice
metering device.
6. If a suction line filter drier is also to be installed, in-
stall suctionline drier downstream of suction line ser-
vice valve at condensing unit.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage or improper operation.
Never installsuction--line filter drier in theliquid--line
of a PuronRsystem.
CAUTION
!
7. If required, install a 100% activated al umina suction
line filter drier at the outdoor unit.
8. Evacuate and charge the systemaccording to the in-
structionsin this installation manual.
9. Operate the system for 10 hr. Monitor the pressure
drop across the suction line filter drier. If pressure
drop exceeds 3 psig (21kPa), replace suction-line and
liquid-line filter driers. Be sureto purge system with
dry nitrogen and evacuate when replacing filter
driers. Continue to monitor the pressure drop across
suction-linefilter drier. Repeat filter changes is neces-
sary. Never leave suction-line filter drier in system
longer than 72 hr (actual time).
569J