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INSTALLATION GUIDELINE
Replacement /Retrofit – R22 to Puron
Split system heat pumps are intended to be installed with
matching indoor sections only. The 38AUQ heat pump
outdoor units are matched only with same-size 40RUQ
indoor sections. Existing R-22 indoor coils cannot be
R
converted to Puron
R-410A heat pump duty. Only the
existing refrigerant piping is a candidate for retrofit use.
Acid test – If the existing system is being replaced
because of a compressor electrical failure, assume acid is
in system. If system is being replaced for any other
reason, use an approved acid test kit to determine acid
level. If even low levels of acid are detected, install a 100
percent activated alumina suction line filter drier in
addition to the replacement liquid-line filter drier. Operate
this system in COOLING ONLY. Remove the suction 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.
Evaluate existing refrigerant piping – Reuse of existing
refrigerant piping involves three issues: quality (strength) of
existing tubing, cleanliness and tube size. R- - 410A operates
at pressures that are 50 to 70% higher than the operating
pressures in R- - 22 systems. It is important that the existing
piping set be in excellent physical condition to be considered
suitable for re- - use with R- - 410A. If the physical condition of
the existing piping set is not excellent, then remove the
existing piping and replace with new piping. Refer to Step 5
for a discussion on selecting pipe sizes for these 38AUQ
heat pumps; refer to Table 2 for recommended pipe sizes.
If the existing piping set is suitable for re- - use with
R- - 410A based on its condition, determine the relative
locations and elevation differences between outdoor
section (38AUQ) and indoor section (40RUQ) and then
check the sizes of the existing lines against the
recommended pipe sizes in Table 2 and the MAXIMUM
vapor riser pipe size use data in Table 3. Do not use pipe
sizes that exceed these maximum vapor riser sizes as oil
return at part load conditions in vertical rises may be an
issue. Replace any riser sections with reduced pipe sizes
if existing pipe sizes exceed these maximum tube size
limits.
Installation –
1. Remove the existing evaporator coil or fan coil and
install the replacement coil.
2. Drain oil from low points and traps in vapor line
tubing if they were not replaced.
3. Remove the existing outdoor unit. Install the new out-
door unit according to these installation instructions.
4. Flush the interconnection piping system with dry
Nitrogen to eliminate as much trace of mineral oil as
possible.
5. Install the factory-supplied liquid-line filter drier at
the indoor coil just upstream of the TXV.
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
6. If required, install a 100% activated alumina suction
line filter drier at the outdoor unit.
7. Evacuate and charge the system according to the in-
structions in this installation manual.
8. Operate the system for 10 hr. In COOLING MODE
ONLY. 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 to
monitor the pressure drop across suction-line filter
drier. Repeat filter changes is necessary. Never leave
suction-line filter drier in system longer than 72 hr
(actual time).
Rated Indoor Airflow (cfm)
The table below lists the rated indoor airflow used for the
AHRI efficiency rating for the units covered in this
document.
38AUQ with 40RUQ
Model Numbers
38AUQA/B07 --- 40RUQ*07
38AUQD/E07 --- 40RUQ*07
38AUQ*08 --- 40RUQ*08
38AUQA/B12 --- 40RUQ*12
38AUQD/E12 --- 40RUQ*12
3
CAUTION
!
R
system.
Full Load Airflow (cfm)
2400
2400
3000
3000
3000
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