Installation and Maintenance Manual
12
3.
REFRIGERATION PIPING
(Applicable to PCU-D Systems only)
IMPORTANT
The unit is designed for use with specific refrigerants (R-410A or R-407C). Check
serial number plate for type of refrigerant. The use of other refrigerants is not
authorised or approved by Air Change, and may cause operational problems such as
poor performance and efficiency, loss of capacity, degradation of materials, and
refrigerant leaks.
DANGER
The use of flammable or explosive materials as a refrigerant creates the additional
risks of fire and explosion which may result in property damage, personal injury or
death.
General
Design pipe work to prevent drainage of liquid refrigerant into the compressor during off cycle, and
to ensure return of oil to the compressor.
Piping
Pipe diameters vary with unit capacity.
Use only clean sealed refrigeration grade piping and cut only with a pipe cutter.
Insulate the gas line and seal all insulation joints.
Charging
Evacuate the indoor unit and interconnecting pipe work to a standard pressure of 500 microns
which is to be held for minimum of 15 minutes.
Open the service valve at both the indoor and outdoor unit to allow refrigerant to flow through the
system.
Start by altering the refrigerant charge to match the nominal amount specified for the total line
length installed.
Check the superheat on the suction line is in the 3°C – 5°C range under the following conditions:
̵
21°C – 27°C (indoor temperature)
̵
24°C – 35°C (outdoor temperature).
Cooke Industries - Phone: +64 9 579 2185 Email: [email protected] Web: www.cookeindustries.co.nz