ClimaCool UCR 30, 50 and 70 tons Manual - Manual (Page 53)

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Split System Interconnecting Piping
Discharge Line Piping Recommendations
All discharge lines should be kept as short as possible and the
line sizing is determined to provide for a low-pressure drop.
There should always be a gradual negative elevation change
when traversing from the remote condenser location to the
UCR module section. Avoid any reversing elevation changes
throughout this discharge line run. Horizontal liquid lines
should be sloped downward, in the direction of refrigerant
fl ow, at a pitch of 1/8” per foot. The total equivalent distance
between the condenser and the UCR section (including
allowances for U-bends and 90° elbows) should not exceed
100 feet. Vertical discharge lines greater than 5 feet required
a P- trap at the base of the riser as well as an inverted trap
at the top of the discharge line run (See Remote Condenser
Installation Guidelines – page 29).The inverted trap should
be the highest point in the discharge line. Additional P-traps
should be added at every 10 feet of additional vertical rise in
the discharge line. The maximum vertical distance between
the lower UCR module section and the higher remote
condenser location should be less than 50 feet. UCR modules
equipped with optional compressor unloading by means of
hot gas bypass require the use of double risers for vertical
discharge line runs (See Remote Condenser Installation
Guidelines – page 29).
Remote Condenser Piping Connections
The discharge and liquid line connections at the remote
condenser section are equipped with capped, stub-out tubes.
It is mandatory that isolation ball valves and check valves
are fi eld installed at both the inlet and outlet connections
locations of each remote condenser. These ball valves and
check valves are shipped loose with every ClimaCool UCR
split systems chiller package. Refer to Remote Condenser
Installation Guidelines – page 29 for schematic representation
of the isolation and check valve functions.
Leak Testing – Refrigeration Side
Prior to startup, the entire system should be leak tested using
electronic leak detection. Carefully leak test both factory and
fi eld made joints including condenser coils. Although each
unit is factory leak tested, joints do loosen and sometimes
break during shipment.
Refrigeration System Reprocessing
Once a refrigeration system has been exposed to atmosphere
for any length of time (several minutes to an hour), it is
imperative that the system undergo a thorough evacuation to
remove moisture and non-condensibles. With split systems,
provisions should be made to evacuate the interconnecting
discharge and liquid lines prior to opening the shutoff valves
provided in each section. Non-condensibles (air, nitrogen
trace gases, etc.) trapped in the systems will elevate
condensing pressures. This will result in ineffi
cient system
operation and potentially cause nuisance head pressure
trips. Moisture in the system can cause chemical reactions
with many POE oil additives resulting in the formation of
undesirable acids which corrode the system.
IMPORTANT: NEVER start the compressors while in a
vacuum. Serious damage can occur to the motor windings
in this condition. Only use a vacuum pump of known reliable
operation, specifi cally, one that can achieve a vacuum level
of 100-200 microns with the pump service port closed. Prior
to evacuation, make sure all refrigerant isolation valves
are OPEN and that the main liquid line solenoid valves are
energized (apply 24VAC to the solenoids coils using a 75VA
transformer or equivalent). Alternatively, you may choose
to manifold multiple evacuation hoses together and connect
vacuum lines to refrigeration access fi ttings on both sides of
the liquid line solenoid valves. Ensure that the vacuum pump
is connected to both high and low sides of the system with
copper tube or vacuum hoses. A vacuum gauge capable of
reading vacuum levels in microns (with readability as low as
100 microns) must be connected to the system, preferably
close to the compressor module. Ordinary gauges from a
standard charging manifold are unacceptable!
Operate the vacuum pump until a vacuum level below 500
microns is achieved. Close the vacuum pump service valves to
isolate the pump from the refrigeration system. This initiates
a “vacuum decay test” by monitoring
system pressure rise for a time period of 15 minutes. The
refrigeration system vacuum gauge should not rise more
than 200 microns within this 15 minute period. Pressures
that rise beyond this decay criteria indicate the existence
of a leak, or more likely, indicate the presence of moisture
or non-condensable in the system. If a leak is suspected, it
must be identifi ed and corrected before proceeding with
the evacuation. If moisture contamination is the suspected
problem, rapid evacuation processes may serve only to freeze
the moisture inside the system, allowing only for the slow
process of sublimation to remove all of the water. Then it is
recommended to apply heat lamps to the compressor and
receiver to elevate the temperature inside the system above
the freezing point while evacuating. Successive dry nitrogen
fi lls and purges can prove equally benefi cial in removing
excessive moisture from a system.
WARNING
To avoid the release of refrigerant into the atmosphere,
the refrigerant circuit of this unit must be serviced only by
technicians who meet local, state and federal profi ciency
requirements.
All refrigerant discharged from this unit must be recovered
WITHOUT EXCEPTION. Technicians must follow industry
accepted guidelines and all local, state and federal statutes for
the recovery and disposal of refrigerants.
If a compressor is removed from this unit, system refrigerant
circuit oil will remain in the compressor. To avoid leakage of
compressor oil, the refrigerant lines of the compressor must
be sealed after it is removed.