Vli. Electricalservice - Econar GeoSurce Vara 2 Plus GV Series Lnstallation And Operating Lnstructions

1.
Closed Loop Systems
Closed loop
systems use
a
heat exchanger of
high density
polyethylene pipe buried underground to supply
a
tempered water solution back to
the heat
pump.
Closed
loops
operate at higher
flow
rates
than
open loops
since
the
entering water temperature (EWT)
is
lower.
The loop
EWT
supplied to
the heat
pump
has
a
great effect
on the
capacity of
the
unit in
the heating mode. Earth loops in
cold climates
are
normally
sized
to
supply
a
wintertime
EWT to
the heat
pump from
32oF down to 25oF,
which
minimizes
the
installation
cost of
the earth
loop
and
still
maintains proper
system
operation.
The unit GPM
requirements
and pressure drops for loop pump sizing
is
available in Table
3.
When selecting
the heat
pump,
choose
a
unit that
will
supply
the necessary heating or cooling
capacify at the
minimum
and
maximum
earth
loop temperature
conditions respectively. Example;
if
a
residential
system
requires 45,000
Btu/tr
to heat
a
house on an
earth loop
system (designed for
32"F minimum wintertime EWT),
and 40,000
Btu/tr
to cool
the house on
an earth
loop
(designed forTT'F
summertime
EWT),
a
GV48x-1-V020
GeoSource
Yara
2
Plus'"
heat
pump
is required.
1.Open Loop
Systems
eNote:
If
a
heat
pump is installed on
an open
loop,
it
should
have
a
Cupro-Nickel
water
coil (GVxxx-x-V02N)
Cupro-Nickel coils
withstand
open loop water much
better than
standard water coils.
On
an
open
loop
system the design water temperature
will
be the
well water temperature in your geographic region.
Many cold climates
are
in
the 50oF range
for
well
water
temperatwe. Flow
rate
requirements
(in GPM)
and
unit
water-side pressure drops (in PSI)
at
50oF
EWI
are
available in
Table
3. If
your well
water
temperatures are
lower
than 50oF,
for
instance Canadian well
water can be
as
low
as
43oF, the
flow
rate must
be
ilcreased to
avoid
leaving water
temperatures
below
the freezing
point.
If
well
water
temperatures are above 50oF,
as
in
some
southern
states
where
well
water
temperatures are above
70oF, the
flow
rates may need to
be increased to dump
heat
more efficiently in
the
cooling
mode.
Varying well
water temperatures
will
have
little
effect on
unit
capacity in
the
cooling
mode (since the well is
connected to the heat pump condenser), but
can
have
large effects on
the
capacity in
the
heating mode
(since
the
well
is
connected to the
evaporator).
If
well water
temperatures are
to exceed 70oF, special considerations,
such as closed
loop
systems, should
be addressed.
B.
Building
Heat Loss/Ifeat Gain
The space load must be
estimated accurately
for
any
--\
successful
HVAC installation.
There
are
many guides or
computer programs available
for load estimation
including
the
ECONAR
GeoSource Heat Pump
Handbook, Manual
J, and
others. After
the heat
loss/heat
gain is completed
and loop
EWT
are established, the heat
pump
can now be selected using the specifications
data.
Choose the capacity of
the heat pump
based on both
heating
and
cooling
load.
V[I.
ELECTRICAL
SERVICE
The main electrical service must
be
protected by
a
fuse
or
circuit
breaker,
and be capable
ofproviding
the amperes
required by
the unit
at
nameplate voltage.
All
wiring
shall comply with
the national electrical
code and/or
any
local
codes that may
apply.
Access to the
line
voltage
contactor is gained through
the knockouts
provided
on
either
side
of
the heat
pump next to
the
front corner.
Route
EMT
or
flexible
conduit
with
appropriate 3-
conductor wire to
the contactor
and
to
the
electric
elements.
9WARNING - The unit
must
be
pronerly erounded!9
When supplying power to external water pumps
with
the
heat
pump's power supply,
use
only
impedance
protected
motors. ECONAR
PumpPAKsrM
can be
wired directly
to
the contactor
in
the
electrical box.
The
relay
will
energize
the PumpPAKrM with
a
call for
heating or
cooling.
The
use
of
impedance
protected pumps eliminates
the need
for
additional fusing
on the PumpPAKrM.
rX.
a
YOLT
CONTROL
CIRCUIT
The
wiring
diagram
in
Figure 4
shows the
low
voltage
controls of
the heat
pump.
This
section
will
break down
the three basic components
of
the
low
voltage circuit;
ftansformer, thermostat,
and
controller.
A. Transformer
An
electrical diagram is provided
in Figure 4,
and on the
electrical box cover panel
of
the heat
pump.
An internal
24-vo1t,55 VA
ftansformer
is
provided to
operate
all
confrol
features
of
the heat
pump.
Table 4
shows the
trarsformer
usage
for
GeoSource
Yara
2
plust'
heat
pumps.
Table4-TransformerUr
If
any system's external controls require more
than t}le
VA
available for external
use
from
the transformer,
a
Contactor
7
4
Compressor Solenoid
4
Contro'ller
2
Thermostat
1
Blower Motor
2
Elec. Heat Relay
6
Total
26
Available
29
9
Component VA
4-Wav Valve