Technical data

24
Vacuum pump
NOTE: All equipment used on R22 systems must be kept
separate from equipment used on R407C systems. With
the outdoor unit service valves closed, the pipework and
indoor unit must be evacuated, using a suitable vacuum
pump. See diagram below regarding service valves. This
is to ensure all air, moisture and other gases are completely
removed from the system, and to confirm the leakage
testing. A vacuum of –75cmHg should be applied for at
least two hours.
Refrigerant charging
It is essential that the correct amount of additional
refrigerant is added to the system, before the system is
switched on. The length of refrigerant piping (one way)
must be measured to the nearest metre, and the additional
charge added, as detailed in the installation instructions
packed with the unit.
Electronic weighing scales
Do not attempt to add refrigerant charge unless electronic
scales are used.
Insulation
All refrigerant pipework, both liquid and gas pipes, must
be insulated, and insulation joints sealed.
The insulation material must be pre-formed Armaflex, or
similar, Class “O” fire rated, and vapour sealed. The wall
thickness should be at least 6mm for copper pipe diameter
of 1/4”, and 13mm for all larger sizes.
IMPORTANT
Manifolds and tubes for R22 systems must be kept separate
from those used on R407C systems.
Low ambient control Ref: L1220
(For FDC 6 Series OUTDOOR UNITS)
Application
The FDC 6 Series outdoor units are designed to operate,
in the cooling mode, in ambient temperatures down to
10
o
C. Below this temperature it is likely that over
condensing will occur, and the internal cooling
performance will be affected.
The low ambient kit reduces the condenser fan speed, to
prevent over condensing, and to maintain the refrigerant
pressure in the system at a level which will maintain its
cooling performance. The low ambient control is
temperature actuated, with a small thermistor fitted to
the copper tubing of the condenser coil.
Refrigerant charging Low ambient control