4-Way Valve Control; Startup - Econar GeoSurce Vara 2 Plus GV Series Lnstallation And Operating Lnstructions

3. Compressor
Operation for
l't
Stage
HeaUCool
A
Yl
signal
from
the
thermostat
will
ask the
controller
to
initiate
l't
stage
heating or
cooling. The controller
then
decides, based
on
lockout
and
anti-short-cycle periods,
when to
bring
the
compressor
on. With
a
Yl
call from
the thermostat, the
compressor
will
operate
with
its
bypass
ports open. This
means that the
unit
will
be
running
at
7
5Vo
of
full
capacity, thereby increasing
efficiency
and
comfort. When
the heat
pump is operating
in
l'1
stage
heating
or cooling,
the
blower
will
be
running
on medium-low
speed.
4. Compressor
Operation for
2'd Stage
HeaUCool
A Y2
signal
from
the thermostat
will
ask the
controller to
initiate
2nd
stage
heating or
cooling.
The
unit
will
then
energize
the solenoid coil
on the
compressor. When
the
solenoid
coil is energized,
the bypass
ports in
the
compressor close, allowing
full
compressor
capacity.
Also,
the
controller
will
energize
the
medium-high
speed
output on the
blower.
5.
Electric Element Operation
A
Wl
signal
from
the thermostat
will
make the
unit
energize
5
kW of
the
electric elements.
These elements
will
stay energized
until Y2
is
satisf,red
on the thermostat.
The blower
will
increase
to
the
High
speed
output.
An E (Emergency Heat) signal from
the
thermostat
will
energize
all
10
kW of
the
electric elements. This
also
locks out the compressor signal
from
the
thermostat. The
blower
will
run on
high
speed.
6.
4-Way Valve Control
When the thermostat calls
for cooling on
the
O terminal,
the
controller
energizes
its O output to
send
control power
to the 4-way reversing valve
(VR)
in order
to
switch the
refrigerant
circuit
to
the
cooling
mode.
7.
Compressor Lockouts
A
compressor lockout occurs
if
the
high-pressure, low
pressure
(in
the
heating mode), or
freeze
protection
pressure switches
open.
The
controller
blocks the signal
from
the thermostat to the contactor that
normally would
energize
the
compressor. In
the event
of
a
compressor
lockout,
the
controller
will
send
a
signal from
L
on the
terminal
strip to
an
LED
on the thermostat to indicate
a
lockout condition. This lockout condition
means that
the
unit
has shut
down to protect
itself,
and
will
not come
back on
until power
has
been disconnected
(via
the
circuit
breaker) to the heat
pump for
one
minute. Problems that
could cause
a
lockout
situadon include:
1.
Water
flow
or temperature problems
2.
Air flow
or temperature problems
3.
Cold ambient air temperature conditions
4. Internal heat
pump operation problems
3If
a
lockout condition
exists, the heat
pump should not
be reset
more than once;
a service
technician should
be
called
immediately. VThe
cause
of
the
lockout
must
be
determined.
Repeated reset may
cause damage
to
the
system.
8.
Compressor Anti-Short-Cycle
An
anti-short-cycle
is a
delay period between
the
time
a
compressor
shuts down and
when that compressor
is
allowed to come on
again. This protects
the
compressor
and
avoids nuisance
lockout conditions. Anti-short-
cycles occur after
these three
conditions;
L
A
30 second to one
minute time-out period
occurs
on
a
compressor before
it will
start
after its last
shutdown.
2.
A
four minute 35
second
delay is incorporated
into
the
timing function immediately
after power is
applied to
the heat
pump.
This occurs only after
reapplying power to
the
unit.
To
avoid this
timeout while servicing
the
unit,
apply power,
disconnect
and
reapply power very
quickly.
This
can sometimes
eliminate
the
waiting period.
3.
A
four-minute anti-short-cycle
will
occur after
a
low-pressure switch
opens
in
the
cooling
mode.
This
is done
to eliminate
nuisance
lockout
conditions.
tlf
the compressor continuously
short cycles
in
the
cooling
mode, shut the
thermostat
off
and
call your
sen,ice technician.
cNote:
The thermostat supplied with
the heat
pump is
factory programmed to
have
a
five-minute delay period
after compressor shutdown before
it
will
start
again.
A
"Wait"
indicator on
the
thermostat
shows
this delay. This
delay
can be
reprogrammed to
be
from
zero
to
5
minutes.
9. System Diagnostics
The controller is equipped with
diagnostic
LED lights,
which
indicate the system status at any
particular
time.
The lights indicate
the
following
conditions:
l.
24Yolt
system
power
GREEN
2. Faultorlockout
YELLOW
3.
Anti-short-cycle
mode
RED
X.
STARTUP
Before applying power to
the heat
pump, check
the
following
items:
o
Water supply
plumbing
to
the heat
pump is
completed
and
operating. Manually
open the
water valve on well
systems
to check
flow.
Make
sure
all valves
are open and air
has been
purged from
a
closed
loop
system. Never
operate the system
without correct water
flow.
r
All
construction dust
has been cleaned up and
all
sheet-rocking
is
completed. Consffuction
dust,
especially sheet-rock dust, can
plug the air coil
and
block
airflow.
Make sure the
filter
is
clean
before starting
the
unit.
o
f.ow voltage wiring of
the thermostat and any
11