Airedale BluCube 10-48kW - Manual (Page 26)

BluCube
™
Condensing Unit
26
Condensing Units
Technical Manual : 7206188 V1.6.0_07 2014
Refrigeration Information
Pipework Installation
General Special consideration should be given to vertical pipe runs and heat pump installation.
When insulating refrigerant lines, cut approximately 30 – 50mm longer than the distance
between the units to ensure the insulation goes right up to the unit. Leave connections
uncovered for leak testing.
Remove burrs to the ends of the copper tube, holding the tube downward to avoid
allowing dirt to contaminate the tube.
The installation of a sight glass close to the indoor unit is recommended.
Pressure Testing When installation is complete, the system should be pressure tested.
Fill the system with dry nitrogen to a pressure of between 45 bar/250 psig and 45 bar/
500 psig.
NOTE: The LP switch must be disconnected for pressures above 17 bar/250 psig.
Record the pressure over a minimum of 60 minutes to detect major leaks (a 24 hour
period should preferably be allowed).
If a reduction in pressure is detected, trace the leak and repair before conducting a further
pressure test and charging.
Evacuation Evacuation for systems operating with R410A refrigerant to be carried out as follows.
Use a high vacuum pump and connect to the high and low pressure sides of the system
via a gauge manifold fitted with compound gauges. A high vacuum gauge should be fitted
to the system at the furthest point from the vacuum pump.
Triple evacuation should be used to ensure that all contaminants are removed.
Operate the vacuum pump until a pressure of 1.5 torr (200 Pa) absolute pressure is
reached, then stop the vacuum pump. To break the vacuum using Nitrogen (Oxygen free)
until the pressure rises above zero.
The above operation should be repeated a second time.
The system should then be evacuated a third time but this time to 0.5 torr absolute
pressure.
Break with the correct refrigerant, until pressures equalise between the charging bottle
and the system.
IMPORTANT Ensure all valves within the system are open during pressure testing / evacuation.