Test Operation
SiENBE28-901
58
Air Cooled Refrigeration Condensing Unit
5.1.1 To Piping Work Contractors
Never open the shutoff valve until the steps specified in “
5.2 FIELD WIRING
” and “
5.3.3
Checking of device and installation conditions
” of piping.
Do not use flux at the time of brazing and connecting refrigerant pipes. Use phosphorous
copper brazing filler metal (BCuP-2), which does not require flux. Chlorine-based flux
causes piping corrosion. Furthermore, if fluoride is contained, the flux will have adverse
influences on the refrigerant piping line, such as the deterioration of refrigerating machine
oil.
Caution
All field piping must be installed by a licensed refrigeration technician and must comply with
relevant local and national regulations.
[Precautions for reuse of existing refrigerant piping / heat exchangers]
Keep the following points in mind for the reuse of existing refrigerant piping / heat
exchangers.
A malfunction may result if there is deficiency.
Do not use the existing piping in the following cases. Perform new piping instead.
• The piping is different in size.
• The strength of the piping is insufficient.
• The compressor of the condensing unit previously used caused a malfunction.
An adverse influence of residual substances, such as the oxidation of refrigerant oil and the
generation of scale, is considered.
• If the indoor unit or outdoor unit is disconnected from the piping for a long time.
The intrusion of water and dust into the piping is considered.
• The copper pipe is corroded.
• The refrigerant of the condensing unit previously used was other than R410A (e.g., R404A /
R507 or R407C).
The contamination of the refrigerant with heterogeneity is considered.
If there are welded connections midway on the local piping, make gas leakage checks on the
welded connections.
Be sure to insulate the connection piping.
The liquid and gas pipe temperatures are as follows:
Liquid pipe arrival minimum temperature: 0°C
Gas pipe arrival minimum temperature:
–26°C (Refrigeration Series)
–46°C (Freezer Series)
In the case of thickness insufficiency, add additional insulation material or renew the existing
insulation material.
Renew the insulation material if the insulation material is degraded.
Keep the following points in mind for the reuse of existing heat exchangers
Units with insufficient design pressure (since this product is an R410A unit) require a lower-
stage design pressure of 2.5 MPa [25 bars].
Units for which the path to the heat exchanger has been routed so that the flow of refrigerant
is from bottom to top
Units with copper tubing or fan corrosion
Units that may be contaminated with foreign matter such as rubbish or other dirt
