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 Puron ap plicatio ns. Carefully check the
existin g su ctio n line size agains t the table for maximum size
(see Table 8); replace vertical ris er segments if neces s ary.
Check existing liquid line size against sizing data in Table 5
or 6; replace with smaller lines w hen feas ib le.
Installation –
1. Remove the existing evaporator coil or fan coil and
install the replacement coil when appropriate.
2. Drain oil from low points and traps in suction line
tubing (and hot ga s 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 ap-
proved metering device, change the metering device
to a thermal expansion valve (TXV) designed for
Puron
R
(R-410A).
4. Remove the existi ng 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 improper 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 3 psig (21kPa), 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 if neces-
sary. Never leave suction-line filter drier in system
longer than 72 hr (actual time).
38AU
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