EN - 12
For Effectively Using the Refrigeration Unit
Cautions for Installation Work
This refrigeration unit has been designed exclusively for R744 (CO
2
refrigerant).
Refrigeration oil and each component including the compressor have been exclusively designed for the refrigeration
unit.
Please use suf
fi
cient caution for maintaining the reliability of the product.
(1) Since CO
2
refrigeration cycle becomes high pressure during operation, use the piping material and other
components particularly designed for CO
2
refrigerant with suf
fi
cient strength.
(2) As the refrigeration oil has high moisture absorption property, make the opening time as short as possible.
Connection of the piping to the refrigeration unit should be made at the last stage of piping installation work.
Avoid outdoor work on a rainy day.
(3) For piping work, use “phosphorous-deoxidized copper pipe” of refrigeration grade, clean, dehydrated and
“phosphor-copper brazing solder”.
If “silver brazing solder” is to be used, do not use any
fl
ux containing chlorine. During pipe brazing it is a must to
use nitrogen over pressure.
(4) Do not use pipe joints made for HFC refrigerant, because they do not have the required strength. In addition,
absolutely do not use
fl
ared joints.
(5) For the purpose of protecting the refrigeration unit and refrigeration cycle, be sure to install the included
fi
lter dryer
at the liquid line of the refrigeration unit.
(6) Gas leak detector used for airtight test should be foaming liquid or soap water. Do not use kitchen detergent.
Kitchen detergent may corrode metals.
For Economically Using the Refrigeration Unit
For the purpose of using the refrigeration unit economically, consider the following.
Cooling capacity largely vary by the method of use.
Reduction of evaporating temperature (unit inlet pressure converted to temperature) reduces cooling capacity by 3 to
4%, and increase of discharge pressure decreases cooling capacity and increases power consumption.
In order to fully extract the unit performance, compressor suction pressure should be increased as high as possible,
and discharge pressure should be made as low as possible. For this reason, caution should be used in the following
points.
(1) Make the piping resistance as small as possible.
Ref: Capacity change rate per 1 °C pressure loss of suction line
Evaporating temperature
Capacity change rate per 1 °C
-45 °C to -5 °C
3 % to 4 %
(2) Select an evaporator of suf
fi
cient capacity for raising evaporating temperature as high as possible.
(3) Do not block the cold air outlet in a refrigerator, freezer, or showcase with food items.
(4) Operate door opening of a refrigerator or freezer as quick as possible. (To avoid leak of cold air, reduce the time
of door opening)
(5) Periodically perform cleaning of the gas cooler to avoid clogging.
01̲OCU-CR200VF5.indd 12
01̲OCU-CR200VF5.indd 12
2018/12/28 15:17:06
2018/12/28 15:17:06
