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I
C,q,UffON-
miswiring of control
voltage on
system
controls
can
result
in
transformer burnout.
cNote: If
a
single thermostat controls
multiple
heat
pumps,
the
control wiring of
the heat
pumps must
be
isolated
from
each
other. This
will
prevent
the heat
pumps
from
receiving high voltage through
the
common
wiring
if it
is turned
off
at the
circuit
breaker
for
service.
A
GeoSource
DualTEK
heat
pump requires
at least
two
thermostats. The
flrst
thermostat
is
a
forced air
heat
pump thermostat
connected
to
the
terminal
strip on
the
controller.
This
thermostat controls forced air heating
and
cooling
as
any thermostat
would.
The
second
thermostat
is
a
heating
aquastat,
which
is
wired
to
H
and
R on
the
terminal
strip.
The
aquastat
tells
the heat
pump when
hydronic
side water heating is required
and
when
the
hydronic
side
is
satisfied.
The
heat
pump
can
only
run
in
one
mode
at
a
time,
so there
is
a
priority
switch on
the
controller
to regulate
mode changes
(see
Forced
Air/llydronic
Priority).
Power is supplied to
the
thermostat by connecting
the
R
and
X
terminals to
the heat
pump
terminal
sfip.
The G
terminal
energizes the
blower
relay.
The
Y
terminal
energizes the
compressor
for
forced air heating
and
cooling.
The
unit
is
put into
the
cooling
mode when
the
thermostat
energizes the
O
terminal, which
operates the
4-way
reversing
valve.
The
L
terminal
is
used
to power
a
lockout LED
on the
thermostat, which indicates
a
compressor lockout.
The
heat
pump's
controller
regulates
compressor
operation when
there
is
an
auxiliary
heat
(W2) or
an
emergency
heat
(E)
call from
the
thermostat. With
forced
air
priority,
a
W2 call
will
energize
the elements,
along
with
the
blower
and
compressor
in
forced
air. With
hydronic
priority,
if
the
unit
is
running
in hydronic
mode
and
receives
a
W2 call,
the
blower
and
electric elements
will
energize along
with
the
compressor
in hydronic
mode. During
emergency heating,
the
compressor
will
be
shut
down,
and
not allowed to run.
When
a
single
stage
electric
heater is used,
wire
it
to
the
W2
and
X
terminals on
the
left terminal
strip on
the
controller.
Also,
wire E
and
W2 from
the
thermostat to
the heat
pump. This
will
cause the
electric
heater
to
energize
when
the
thermostat gives
an
emergency
heat
or
second stage heat
call.
The
aquastat closes and
passes
power to
the
H
terminal,
energizing
the
compressor
and
circulation
pumps
in
the
hydronic heating
mode.
The pump relay
is
connected to
the
circulation
pump's
3
pole, high voltage
terminal block
(BP).
The
hydronic
side
circulation
pump receives power
from
BP, which is energized by
M6.
When mounting
an
aquastat
inside
a
storage
tank, always
use a
submersible
type aquastat. The
aquastat
should
be
installed
approximately
1/3
of
the way down
into
the
tank.
Set
the
aquastat
differential to
15nF
to
avoid
short
cycling
cNote:
The
aquastat
should
be
set
to give
a
maximum
leaving water temperature from
the heat
pump
of
115T.
This
means
that
the
actual setting
of
the aquastat
will
be
lower
than
this
(typically
100
to
105T).
Any
number or
types
of
thermoslats,
aquastats,
or
switches
can be used
with
an
independent power supply
(typically aZ{-volt
transformer) to activate specific
zone
controls.
These zone
controls
are
normally
either
zone
pumps (Figure 3)
or
zone
valves
(Figure
l).
End switches
on the zone
valves
can be used
to
pass
a
signal to
a
pump
relay when
the zone
valve
is
open.
The pump relay then
activates
a
common pump,
which
supplies any number
of
zones.
If
a
thermostat
is
equipped
with
an
anticipator
it
should
be
set
to its
maximum
setting to avoid
interfering with
heat
pump
operation.
The anticipator is
a
resistor
in
the
thermostat
that heats
up
as
current is drawn through
and
satisfies
the
thermostat
prematurely.
This
reduces system
capacity by
restricting
run time.
C.
Controller
The
controller
receives
a
signal
from
the
thermostat
and
initiates
the
correct
sequence
ofoperations for
the heat
pump.
The
controller
performs
the
following
functions:
1)
Blower
Operation
2)
Earth
L,oop Pump
Initiation
3)
CompressorOperation
4)
4-Way
Valve Control
5)
Compressor Lockouts
6)
CompressorAntishort-Cycle
7)
System
Diagnostics
8)
Forced
Air/Hydronic
Priority
9)
Overflow
Detection
1.
Blower Operation
A
signal on
the
G terminal
from
the
thermostat to
the
controller
will tell
the
conroller
to
energize the
blower
The
confroller
then energizes
its
M7
output
to
send
control
voltage
directly
to
the
blower
motor relay.
To
change
blower
speeds,
move
the
wire
on the
fan
terminal sffip
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.
For more
information
on the
blower, including
the
optional
ECM Variable
Speed
Blower
(-DxVx),
see
section
III,
Duct
System/Blower.
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
separate
pump
can be used
which
is energized
with
a
pump
relay
(Note: electrical
code
will
require
a
l5
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