5 m or less
22 m or less
Evaporator
Suction pipe
Liquid pipe
Suction pipe
Liquid pipe
Position the liquid solenoid
valve closer to the expansion
valve more than the main unit.
Trap to prevent standing
liquid in the heat sensing
tube
Step to prevent standing
liquid in the heat sensing
tube
Secure a downward
slope of 1/200 to
1/250
Loop to prevent oil return
during operation stop
Heat insulate the liquid, suction
pipes over entire length.
Evaporator
5 m or less
Insulate the liquid, suction pipes
over entire length.
Oil U trap at every 5 m of pipe length
Oil return trap
Use Ø19.05 pipe for
vertical pipe going up
• The suction piping connected to the compressor must be flexible in 3 dimensions to dampen vibrations. Furthermore piping has to
be done in such a way that oil return for the compressor is ensured and the risk of liquid slug over in compressor is eliminated.
• Take care to avoid direct contact between suction and liquid pipes without insulation material too large temperature difference.
• The condensing unit is charged with Nitrogen gas at approx. 0.1 bar at shipping from the factory. Make sure to keep the seal intact till
just before connecting pipes in order to keep out dirt or moisture. Release to the atmosphere must be made through service ports at
the high, medium and low sides.
*Dryer (accessory of refrigerant machine) is recommended to install in liquid pipe. Also strainer is recommended to install before the low
pressure expansion valve.
Typical instillation
4. Installation
Note on R744
Refrigeration cycle pressures (airtight test pressure, operation pressure, etc.) become approx. 4 times larger than the same of R410A.
Wall thickness of refrigerant pipes varies depending on the refrigerant and pipe size. Check if specified thickness is observed, and correct if necessary.
It could vary depending on pipe materials as well.
Ester oil is used as the condensing unit oil for the refrigeration cycle of R744.
In order to avoid contamination with impurities such as moisture, dirt, etc., as much as possible, the same fundamental control as Freon is required at the
installation of refrigerant piping.
Practice thorough control on the storage and curing of pipes to protect them from dirt or moisture.
Make sure to practice the nitrogen blowing before brazing to prevent oxide scale.
Fig. 14
Fig. 15
25
AB408540130380en-000102
© Danfoss | Climate Solutions | 2023.02
Application Guidelines
