Manual

48
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REFRIGERATION SYSTEM REPROCESSING
All ClimaCool remote air-cooled modular chillers leave the
factory with both refrigeration circuits pressurized with 50 psig of
dry nitrogen These split system chillers require interconnecting
refrigeration piping between the ClimaCool AR2 compressor/
evaporator module section and the remote condenser section
The condenser section provided by ClimaCool is typically a
remote air-cooled condenser conguration Contact the factory
for guidelines for customer supplied, eld integration to other
permissible condenser types, such as evaporative condenser
congurations The refrigerant charge will be weighed-in in the
eld based on the condenser conguration and condenser model
The ClimaCool AR2-25 and AR2-30 models are equipped with
a 72 pound liquid receiver capacity per compressor circuit The
AR2- 50 and AR2-65 models have an 84 pound liquid receiver
installed per circuit The installing contractor MUST make the
determination of refrigerant type to be charged in the eld All
ClimaCool AR2 module systems can be charged with either
refrigerant R-22 or R-407C Field installation of additional
receiver capacity may be required depending on the refrigerant
retaining volume of the remote condenser and interconnecting
piping After the total refrigerant amount is charged into each
circuit (weighed in using an appropriate refrigeration scale at
+/- 2 pound accuracy), the resultant weight should be recorded
on the AR2 module data plate for future reference See “System
Refrigerant Charging” section for specic charging guidelines
AR2 Module Refrigeration Piping Connections
The discharge and liquid line stub-out connections at the AR2
module section are equipped with shut-off valves with capped
leads Never uncap these leads without checking the shutoff
valves to be sure that they are fully closed and the units are ready
for piping All scroll compressors in ClimaCool AR2 modules are
equipped with POE refrigeration oil Systems with compressors
using POE oils must be kept closed at all times except when the
interconnecting piping is being directly installed POE oils are
extremely hydroscopic in nature and will absorb an undesirable
amount of moisture from normal ambient air within a few
minutes
Copper Tubing, Brazing and System Reprocessing
Recommendations
Copper tubing must be refrigeration grade (ACR type “L”)
Be sure to install appropriate copper ttings rated for ACR
applications Never leave refrigerant lines open when they are
not directly being installed Never rely on the last refrigerant
connection joint at a specic section (AR2 module or condenser
section) to provide structural support for the interconnecting
piping Line pulsation may occur at start-up and shut down of
scroll compressors Additional line support may be required to
prevent vibration transmission or movement in the line Ensure
that all interconnecting piping is properly and independently
braced at 7’ minimum intervals, and within 2’ from each section’s
nal connection location, to prevent joint fracture due to line
vibrations or liquid hammering
Use 15% silver-phosphorus braze ller rod when brazing copper-
to-copper joints, When brazing copper-to-brass joints, apply
“sta-silv” brazing paste (or equivalent) sparingly to the joint
areas, and use 45% silver-phosphorus braze ller rod Always
purge a generous ow of dry nitrogen (approx 10 CFH) through
the lines while brazing to prevent internal scaling of copper oxide
on heated copper surfaces exposed to air
When sizing the interconnecting refrigerant lines, never use the
stub-out sizes at the AR2 module section as your determining
factor For proper operation, all discharge and liquid lines must
be sized in accordance with the recommendations provided in
the following piping sections After installing the interconnecting
piping, proper system evacuation and reprocessing guidelines
are provided in the section titled, “Refrigeration System
Reprocessing”
Liquid Line Piping Recommendations
All liquid lines should be kept as short as possible, and the line
sizing is determined to provide for a low-pressure drop to prevent
liquid line ashing There should always be a gradual negative
elevation change when traversing from the remote condenser
location to the AR2 module section Avoid any reversing
elevation changes throughout this liquid line run Horizontal
liquid lines should be sloped downward in the direction of
refrigerant ow at a pitch of 1/8” per foot The total equivalent
distance between the condenser and the AR2 section (including
allowances for U-bends and 90o elbows) should not exceed 100
feet Avoid routing liquid lines through heated spaces which may
result in undesirable ash gas generated at the TXV inlet Avoid
insulating liquid lines
Refrigeration System Reprocessing