York MHC-MHH, Installation Manual

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HIGH WALL 11
- Evacuate the piping. This operation, which should last
at least 15 minutes if there are large piping lengths and
changes in elevation, should be followed by a leak test.
To this effect, when the piping has been evacuated,
close the pressure gauge tap, note the value on the
gauge, then wait for 15 minutes. If the needle moves,
there is a leak in the system. Make the necessary
adjustments or repairs and repeat this procedure until
the needle no longer moves.
- Open the service valves and top up the refrigerant
charge if necessary.
This unit is shipped complete with a charge of R22 refrigerant
that will be sufficient for an interconnecting piping length of
5 meters.
Installation
Minimum thickness 6 mm
Low pressure
Gas valve
Liquid valve
Pressure tap
OUTDOOR UNIT
■
Fixing and Piping
• Piping must be performed by qualified personnel
according to good refrigeration systems practices.
• Piping materials and insulation materials must be of
refrigerant quality.
• Select the pipe diameters according to the size of unit
and cut the pipe to design length by using pipe cutter.
• Install the flare nuts and flare the end of the pipes.
• Check that no foreign bodies are inside the piping.
• Align the central of the connecting pipes and tighten
the flare nut.
• Fix piping with pipe clamps and check that any pipe
vibrations cannot be transmitted to the building
structure.
Notes
• Connect the pipe correctly.
• Do not apply the excessive torque.
• Use an appropriate bending tool to form curves and
avoid over-tightening the refrigerant tubes.
• To prevent heat loss, the two lines must be insulated
separately.
■
Maximum piping lengths
Note : Where the difference in elevation between the indoor
unit and the outdoor unit is greater than 5 meters,
install an oil trap every 5 meters.
The suction line must have a 2% gradient up to the
compressor on horizontal sections.
Where piping lengths are unusually long and include a
large number of oil traps, it may be necessary to adjust
to compressor charge.
Refrigerant charge to be added per extra
metre of piping length when more than 7.5
meters.
■
Refrigerant piping connections
(FLARE connections)
To avoid alteration of unit capacities, check that piping
lengths and changes in elevation are kept to a strict
minimum.
Before connectiong the refrigerant lines, follow the
procedures below (if pre-charged connection lines are
not supplied):
- Select copper pipe diameters according to the size of
unit to be installed.
- Install the refrigeration lines, checking that no foreign
boodies get inside the piping.
- Install the flare connectors and flare the ends of the
pipes.
Unit size 7 9 12 18 25
D (m) 10 12 15 15 22
L (m) 12 15 18 18 25
H (m) 7 10 12 12 20
MHC-MHH/BOC-BOH
Unit size
7 9 12 18 25
g/m
15 15 15 40 40
Outdoor Unit Indoor Unit
Gas Line
Liquid Line
R22
High pressure
Manifold
Heat pump
(discharge)
Cooling
(suction)
Heat pump
Liquid
Cooling
Heat pump
(discharge)
Heat pump
Liquid
Cooling
GASS
Cooling
(suction)
D
L
L
H
03_MHC/BOH 07-25.p65 18/3/02, 16:31 11