3
Same tube sizes are capable of hand lin g higher flow r ates
(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 Puron
R
than with R--22 (at 5_F pressure
drop). A 1
1
/
8
--inch OD suction line is rated at 53% higher
tons with Puron than with R--22 (at 2_F pressure drop).
Refrig eratio n lines selected for R--22 use are typically
oversized for P ur on ap plicatio ns. Car efu lly check the
existin g su ctio n line size against the table for maximu m size
(see Tab le 7); replace vertical riser seg men ts if neces s ar y.
Check existing liquid line s ize again s t s izing data in Table 5
or 6; replace with smaller lines wh en feas ible.
Installation –
1. Remove the exi sting evaporator coil or fan coil and
install the replacement coil when appropriate.
2. Drain oil from low points a nd traps in suction line
tubing (a nd hot gas bypass tubing if appropriate) and
evaporator if they were not replaced. Removing oil
from evaporator coil may re quire purging of the
tubing with dry nitrogen.
3. Unless indoor unit is equipped with a Puron
approved metering device, change the metering
device to a thermal expansion valve (TXV) designed
for Puron
R
(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 suction line 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 i mproper operation.
Never install suction--line filter drier in the liquid--line
of a Puron
R
system.
CAUTION
!
7. If required, install a 100% activated alum ina suction
line filter drier at the outdoor unit.
8. Evacuate and charge the system according to the in-
structions in this installation manual.
9. Operate the system for 10 hr. Monitor the pressure
drop across the suction line filter drier. If pressure
drop exceeds 21kPa (3 psig), replace suction-line and
liquid-line filter driers. Be sure to purge system with
dry nitrogen and evacuate when replacing filter
driers. Continue t o monitor the pressure drop ac ross
suction-line filter drier. Repeat filter changes is neces-
sary. Never leave suction-line filter drier in system
longer than 72 hr (actual time).
38AU
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