KeepRite K40-CU-IM-13, Инструкция по установке и обслуживанию

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Leak Testing
IMPORTANT: All system piping, including the condensing unit and accessories should be thoroughly tested for
leaks prior to start up and charging. The system should be initially pressurized to a maximum of 150 psig (1136
kPa) with dry nitrogen to ensure that the system is free of major leaks. With the system free of major leaks, a
more detailed leak check should be performed. Discharge the initial dry nitrogen charge and add enough
refrigerant to raise the system pressure up to 10 psig (170 kPa) (tracer amount). Add dry nitrogen to increase
the system pressure to a maximum of 150 psig (1136 kPa). It is recommended that an electronic leak detector
be used when checking for leaks because of its greater sensitivity to small leaks. As a further check it is
recommended that this pressure be held for a minimum of 12 hours and then rechecked. The system must be
leak free for satisfactory operation.
WARNING
HFC-134a has been shown to be combustible at pressures as low as 5.5 psig (140 kPa) at 350
o
F (176.7
o
C)
when mixed with air at concentrations more than 60% air by volume. At lower temperature, higher pressures
are required to support combustion. Therefore, air should never be mixed with HFC-134a for leak detection.
IMPORTANT ENVIRONMENTAL NOTE
When conventional leak detection methods are employed using HCFC or CFC tracer gas, all of the tracer gas
must be reclaimed and disposed of in a proper manner.
Evacuation and Dehydration
When the system is completely free of refrigerant leaks, an evacuation of the entire system should be completed
by using a “high vacuum” pump. This evacuation, if completed correctly, will ensure long life for the system as
well as elimination of moisture and non-condensable gas problems.
Moisture problems causing compressor
failure will void warranty. Follow the recommended procedure carefully.
CAUTION
Do not use the refrigeration compressor to evacuate the system. Never start the compressor or perform a
megger insulation test while the system is in a vacuum.
Dehydration Procedure
Use only a “high vacuum” pump capable of drawing a vacuum of 100 microns. Change the vacuum pump oil
frequently. Gauges or vacuum measuring instruments should be suitable to measure conditions at any stage of
the process in order to give the operator indications of progress. For specific recommendations, refer to the
vacuum pump supplier for these instruments.
Copper jumper lines should be used to interconnect both high and low-pressure sides of the system. These
lines should be at least 3/8” O.D. in order to handle the light density vapor at high vacuum obtained at
completion of operation. Lines smaller than 3/8” O.D. will slow down the process considerably as well as making
final system vacuum questionable. The entire system temperature should be over 60
o
F (16
o
C) for evacuation to
be effective. If the temperature is less than 60
o
F (16
o
C) the final vacuum should be 50 microns. Double
evacuation with a “sweeping “ of dry nitrogen is recommended. First evacuation should be to at least 750-micron
depth. When this point is reached, break the vacuum with refrigerant or dry nitrogen to melt any moisture, which
may have frozen during the first vacuum stage.
IMPORTANT ENVIRONMENTAL NOTE
When conventional leak detection methods are employed using HCFC or CFC tracer gas, all of the tracer gas
must be reclaimed and disposed of in the proper manner.
Reclaim any tracer gas from the system and re-evacuate to a final vacuum of at least 100 microns at a minimum
60
o
F (16
o
C) system temperature. With this degree of evacuation, all moisture and non-condensables will be
removed from the entire system.