EDM SYSHP MINI SPLIT 06 16

Table Of Contents
72
3.8 Pipe Flushing
3.8.1 Purpose
To remove dust, other parcles and moisture, which could cause compressor malfuncon if not ushed out before the system is
run, the refrigerant piping should be ushed using nitrogen. As described in Part 3, 3.3.1 “Installaon procedure”, pipe ushing
should be performed once the piping connecons have been completed with the excepon of the nal connecons to the hydronic
box. That is, ushing should be performed once the outdoor unit have been connected but before the hydronic box is connected.
3.8.2 Procedure
Notes for installers
Warning
Only use nitrogen for ushing. Using carbon dioxide risks leaving condensaon in the piping. Oxygen, air, refrigerant,
ammable gases and toxic gases must not be used for ushing. Use of such gases may result in re or explosion.
Procedure
The liquid and gas sides can be ushed simultaneously; alternavely, one side can be ushed rst and then Steps 1 to 6
repeated, for the other side. The ushing procedure is as follows:
1. Aach a pressure reducing valve to a nitrogen cylinder.
2. Connect the pressure reducing valve outlet to the inlet on the liquid (or gas) side of the outdoor unit.
3. Start to open the nitrogen cylinder valve and gradually increase the pressure to 0.5MPa.
4. Allow me for nitrogen to ow as far as the opening at hydronic box.
5. Flush the opening:
a) Using suitable material, such as a bag or cloth, press rmly against the opening at hydronic box.
b) When the pressure becomes too high to block with your hand, suddenly remove your hand allowing gas to
rush out.
c) Repeatedly ush in this manner unl no further dirt or moisture is emied from the piping. Use a clean cloth
to check for dirt or moisture being emied. Seal the opening once it has been ushed.
6. Once ushing is complete, seal the opening to prevent dust and moisture from entering.
Figure 3-3.9: Pipe ushing using nitrogen
liquid pipe
gas pipe
Outdoor
unit
Hydronic
box
nitrogen gas cylinder