Installation Procedure

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Condensing Unit - Operational Limits

When the Condensing Unit is being used, check with the final test data of the application product to see whether or not, the following standards are being maintained:

  1. Refrigerant used -> For Bitzer compressor with “Y” uses only R134a and R404a and without “Y” use R22
  2. Evaporating temperature range -> Please refer the Blue Cold technical sheet
  3. Discharge gas temperature -> Not exceed 115 °C (239 °F), This temperature should be measured at the surface of the heat-insulated discharge pipe at 150 mm distance from the shell surface
  4. Suction gas temperature -> Amount of refrigerant charge should be just sufficient to obtain at least 3 K of superheat to avoid any liquid flood-back
  5. Amount of refrigerant charged -> Amount of refrigerant charged should be just sufficient to obtain at least 3 K of superheat to avoid any liquid flood back. To prevent flood-back a proper accumulator must be installed in the suction pipe side according to the refrigerant charging amount
  6. ON/OFF frequency ->   The time between two successive compressor starts should be at least 5 min. The run time of compressor should be at least 3 min before stop
  7. Pipe stress -> The piping must be designed so that no damage will result from transporting of the product and the ON/OFF of the compressor. Recommendable tolerance of piping stress.
  1. At starting and stopping: 34.3N/mm2‍
  2. During operation:                 17.7N/mm2 
  1. Piping -> The unit pipes should be piped inside of discharge and suction pipes of the compressor
  2. Pipe clearance -> A clearance of at least 13mm must be left between the piping and active parts (compressor, fan, anti-resonance rubber, piping, etc.). A clearance of at least 10mm must be left between the piping and inactive parts

The unit should be designed to satisfy above operational standard and operational limit in any condition.

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The following conditions are hazard-causing example in particular.

  1. In case of high or low supply voltage at the high ambient temperature (e.g. 43 °C)
  2. Flood-back at the low ambient temperature (e.g. -5 °C)
  3. In case of hard condition such as closing fan filter
  4. In case of transitional condition such as pull-down and defrost
  5. The phenomenon of abnormal low pressure to be caused by bad defrosts

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