4
2.1.3
Master
and
slave
unit
positioning
In
systems
with
multiple
outdoor
units,
the
units
should
be
placed
in
order
from
largest
capacity
unit
to
smallest
capacity
unit.
The
largest
capacity
unit
must
be
placed
on
the
first
branch,
and
be
set
as
the
master
unit,
while
the
others
should
be
set
as
slave
units.
Refer
to
the
V5
X
Service
Manual,
Control
Manualfor
details
of
how
to
set
units
as
master/slave.
The
example
in
Figure
3
‐
2.4
illustrates
the
placing
of
units
in
a
48HP
combination:
Place
the
22HP
unit
on
the
first
branch
and
set
it
as
the
master
unit.
Place
the
16HP
and
10HP
units
on
the
next
branches
and
set
them
as
slave
units.
Figure
3
‐
2.4:
Positioning
of
master
and
slave
units
2.1.4
Base
structures
Outdoor
unit
base
structure
design
should
take
account
of
the
following
considerations:
A
solid
base
prevents
excess
vibration
and
noise.
Outdoor
unit
bases
should
be
constructed
on
solid
ground
or
on
structures
of
sufficient
strength
to
support
the
units’
weight.
Bases
should
be
at
least
200mm
high
to
provide
sufficient
access
for
installation
of
piping.
Either
steel
or
concrete
bases
may
be
suitable.
A
typical
concrete
base
design
is
shown
in
Figure
3
‐
2.5.
A
typical
concrete
specification
is
1
part
cement,
2
parts
sand
and
4
parts
crushed
stone
with
Φ
10mm
steel
reinforcing
bar.
The
edges
of
the
base
should
be
chamfered.
To
ensure
that
all
contact
points
are
equally
secure,
bases
should
be
completely
level.
Base
design
should
ensure
that
the
points
on
the
units’
bases
designed
for
weight
‐
bearing
support
are
fully
supported.
Bolt
spacings
should
be
as
per
Figure
3
‐
2.6
and
Table
3
‐
2.1.
A
drainage
ditch
should
be
provided
to
allow
drainage
of
condensate
that
may
form
on
the
heat
exchangers
when
the
units
are
running
in
heating
mode.
The
drainage
should
ensure
that
condensate
is
directed
away
from
roadways
and
footpaths,
especially
in
locations
where
the
climate
is
such
that
condensate
may
freeze.
Outdoor
units
(48HP)
A
(22HP)
B
(16HP)
C
(10HP)
Indoor
unit
A
Indoor
unit
B
Indoor
unit
C
First
outdoor
branch
joint
