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The anticipator
has
the
effect
ofreducing
system
capacity
by
restricting
run time.
The thermostat should
never
be
set
back to
less than
60nF,
Ai-r temperatures less than 60oF
to
the heat
pump
in
residential applications
can
cause
difficult
starting
conditions
and
lock
the
unit
out.
Commercial
applications
can be designed
to
use
lower entering
air
temperafures,
but
60nF
is
a
safe
low
operating
point in
residential applications.
C.
Controller
The
controller
receives
a
signal
from
the
thermostat
and
initiates
the
correct
sequence
of
operation
for
the heat
pump.
The
controller
performs
the
following
functions:
1)
Blower
Operation
2)
Earth
Loop
Pump
lnitiation
3)
CompressorOperation
4)
4-Way Valve Control
5)
Compressor
Lockouts
6)
CompressorAnti-Short-Cycle
7)
System
Diagnostics
8)
Overflow
Detection
L.
Blower Operation
A
signal on
the
G terminal
from
the
thermostat to
the
controller
will
tell
the
controller
to
ener,eize
the
blower.
The
controller
then energizes
its G output to
send
control
voltage
directly
to
the
blower
motor relay.
To
change
blower
speeds,
move
the
wire on
the
fan
terminal
strip to
the
desired
setting.
Changing the
speed
from
the
factory
setting
can
cause
problems
with
output
air temperature or reduced
airflow, locking
out
the
unit.
2.
Earth Loop Pump
Initiation
If
a
PumpPAKrM is
used,
it
should
be
wired
directly
to
the
contactor
of
the
compressor.
If
a
PumpPAKrM is not
used,
a
sepa.rate
pump
can be used
which is
ener-qized
with
a
pump relay (Note: electrical
code
will
require
a
fused
disconnect
for
pumps other
than
PumpPAKsrM).
When
there
is
a
call
for
an
Ml
output
from
the
controller,
the
contactor
will
energize, starting
the
compressor
and earth
loop pump.
3. Compressor
Operation
A
Yl
signal
from
the
thermostat
will
ask the
controller
to
initiate
heating or
cooling.
The
controller
then decides,
based on
lockout
and
antishort-cycle
periods, when to
bring
the
compressor
on.
The
Ml
output
of
the
controller
energizes the
compressor. This compressor
stays
on
until
on
the
thermostat is satisfied.
4.
4-Way Yalve
Control
The
controller
energizes the
4-way
reversin-e
valve to
direct
the
flow
of refrigerant.
When
the
thermostat calls
for
cooling
on the
O terminal,
the
controller
energizes
its
O output to
send
control
power to
the
reversing valve
(VR)
to switch
the
refrigerant
circuit
to
the
cooling
mode.
5. Compressor Lockouts
A
compressor
lockout
occurs
ifthe
high-pressure,
low
pressnre
(ia
heating mode), orfreeze protection
pressure
switches
open.
The
controller
blocks
the
signal
from
the
thermostat to
the
contactor that
normally would
energize
the
compressor.
In
the event
ofa
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
itself
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
situation include:
1.
Water
flow
or temperature problems
2. Air
flow
or temperature problems
3.
Internal
heat
pump operation problems
4.
Cold
ambient air temperature conditions
tlf
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.
6.
Compressor
Anti-Short-Cycle
An
anti-short-cycle is
a
delay period
between the
time
a
compressor
shuts
down and when
it
is allowed to come
on
again.
This protects
the
compressor
and
avoids
nuisance
lockout
conditions. Anti-short-cycles
occur after
these
three
conditions;
1.
A
30
second
to
one
minute time-out period
occurs
on
the
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.
If
the
compressor
continuously
short
cycles
in
the
cooling
mode,
shut the
thermostat
off
and
call
your service technician.
7. 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
8.
Overflow Detection
An
optional
overflow
detection
sensor
may
be added
to
the
GeoSource 2000
heat
pumps. This
sensor
is located
in
the
drain pan,
and
monitors
the
amount
of
water
accumulated
in
the
pan.
If
the condensate
drain
becomes
10
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