12
VRF-SVX26D-EN
Installation
Installing Refrigerant Piping
Connect field-supplied piping using flared connections (not supplied) or by brazing.The large unit
port is for gas refrigerant; the small one is for liquid refrigerant.
Cut or extend field-supplied piping as needed. Use the following procedures.
•
Before connecting the pipes, make sure they are free of dirt and debris.
•
Use insulated, unwelded, degreased, and deoxidized copper pipe (Cu-DHP type according to
ISO 1337 or UNI EN 12735-1) suitable for an operating pressure of at least 609.15 psi and a burst
pressure of at least 3002.28 psi. Copper pipe for hydro-sanitary applications is unsuitable.
•
For sizing and limits (height difference, line length, maximum bends, refrigerant charge, and
so on) see the outdoor unit installation manual.
•
All refrigerant connections must be accessible for servicing and maintenance.
Pipe Cutting
Required tools:
•
Pipe cutter
•
Reamer
•
Pipe holder
1.
Using a pipe cutter, cut the pipe so that the cut edge is at 90° to the side of the pipe.
2. Use a reamer to remove all burrs at the cut edge.
See examples of correctly and incorrectly cut pipes.
Nitrogen Flushing While Brazing
While brazing refrigerant pipes, flush them with nitrogen gas. Use a pressure regulator to maintain
a flow rate of 1.76 ft
3
/h or more.
NOTICE
System Failure!
If brazing is used for pipe connections, a nitrogen purge is required to prevent the formation of
copper oxides inside the piping. Failure to follow this procedure could damage the system.
Correct: 90º
Oblique
Rough
Burr
NOTICE
Avoid Unit Damage!
Never braze pipe connections without performing nitrogen flushing. Failure to perform this
procedure will damage the unit, resulting in capacity loss and reduced long-term reliability.
