Hybrid
Vertical
Stack
–
Installation
Operation
Maintenance
Manual
OPERATION
‐
DETAILED
R090303
Installation
Operation
Maintenance
Manual
is
subject
to
change
without
notice
Page
11
FAN
1.
A
call
on
“G”
for
fan
on
the
thermostat
terminal
strip
will
cause
the
fan
to
operate
continuously
on
low
fan
speed
through
K5
on
multi
speed
units.
2.
A
call
on
“W”
for
heat
on
the
thermostat
terminal
strip
will
also
cause
the
fan
to
operate
on
low
speed.
After
10
minutes
of
a
continuous
heating
call,
the
multi
speed
units
will
be
switched
to
high
speed
through
Relay
K6.
3.
A
call
on
“Y”
for
cooling
on
the
thermostat
terminal
strip
will
cause
the
fan
on
multi
speed
units
to
step
up
to
high
speed
through
Relay
K6.
4.
Fan
operation
will
terminate
whenever
heating
or
cooling
calls
are
dropped.
5.
Both
relays
and
their
associated
LED’s
are
energized
when
the
fan
is
in
high
speed.
HEAT
1.
A
call
on
“W”
for
heat
will
turn
on
the
fan
at
low
speed.
Simultaneously,
it
will
energize
the
heat
relay
K2
and
it’s
LED.
The
relay
K2
will
provide
24V
AC
fused
power
directly
to
the
heat
valve.
COOL
START
UP
1.
A
call
on
“Y”
for
cooling
initiates
a
series
of
checks
prior
to
the
start
up
of
the
compressor.
These
checks
include:
a.
Power
ON
timer
–
Compressor
operation
is
delayed
for
approximately
5
minutes
after
restoration
of
power.
This
prevents
all
units
coming
on
‐
line
at
the
same
time
once
power
is
restored.
It
also
prevents
compressor
jolting
as
a
result
of
intermittent
power.
b.
Anti
‐
Recycle
timer
–
There
is
a
5
‐
minute
anti
‐
recycle
delay
timer
that
allows
the
refrigeration
cycle
to
achieve
pressure
equalization
so
that
the
compressor
is
unloaded
upon
start
up.
c.
High
Pressure
Switch
–
The
high
refrigerant
pressure
switch
must
be
closed
prior
to
start.
LED
11
will
be
ON.
d.
Low
Pressure
Switch
–
The
low
pressure
switch
operates
primarily
as
a
loss
of
charge
protector.
It
must
be
closed
for
compressor
start
up
and
LED
12
will
be
ON.
The
pressure
switch
has
a
5
minute
ignore
subsequent
to
start
‐
up.
In
some
situations,
particularly
when
the
unit
is
cold,
the
pressure
switch
will
open
during
