Econar GeoSource Invision 3 Q Series Installation And Operating Instructions Manual page 9

Table
2
-
Side
Flow Rates
Pressure/Temperature (P/T) ports should
be
installed
in
the
entering and
leaving water lines
of
the heat
pump on
a
closed
loop
system
(see
Figure
1). A
thermometer can be
inserted
into
the
P/T ports
to
check
entering
and
leaving
water temperatures.
A pressure gauge can also
be
inserted
into these
P/T ports to determine
the pressure
differential between the
entering and
leaving
water. This
pressure
differential
can then be
compared to the
specification
data on each
particular
heat
pump to
determine the
flow
rate
of
the system.
A
PumpPAKrM that is
individually
sized
for
each
application can
supply pumping requirements
for
the
earth loop
fluid.
The PumpPAKrM can also be used
to
purge
the
loop system. The PumpPAKrM is wired directly
to a three
pole terminal
strip
in
the
domestic hot water (-
DHW
and
-DWR)
heat
pump
and
is energized by
a
relay
each
time either compressor runs (see
Electrical Diagram
- Figure
7).
The PumpPAKrM is wired
directly
to the
contactor of
standard
(-000)
and
supplemental (-SUP)
units, and operates whenever
the
lead
compressor
runs
(see
Electrical Diagram
-
Figure
8). If
you wish to wire
the
PumpPAKrM to
a
relay
instead
of
the
contactor,
wire
the relay to
plug #2 (P2)
on the
controller
in order to
energize the
relay.
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 fused
disconnect for pumps other
than
PumpPAKsrM).
Filling
and
purging
a
closed loop
system are
very
important
steps to
assure
proper
heat
pump operation.
Each
loop
must be
purged with
enough water
flow
to
assure a two feet per
second
flow
rate in
each
circuit
on
the
loop.
This normally
requires a
7Yz
to 3 HP high
head
pump to circulate fluid
through
the loop to remove all
the
air out of
the
Ioop
and
into
a
purging
tank. Allow
the
pump
to
run
10
to
15 minutes after
the lasr air
bubbles
have been
removed.
Enough antifreeze must
be added to
give a
10oF
to
15"F freeze
protection to
the earth
loop
system. This amount should
be
calculated
and added to
the
loop after purging
is complete. After
antifreeze
has
been
installed it
should
be measured with
a
hydrometer,
refractometer or
any other device to determine
the actual
freezing point of
the solution. Remember that
a
low
antifreeze level
will
lock
the heat pump out on low
pressure during wintertime
operation.
The purge pump can be used
to pressurize the system
to
an
initial static pressure
of 30-40
psi.
Make sure the
system
is
at
this pressure after the
loop pipe
has
had
enough
time
to stretch. In order to achieve the
30 to
40
psi initial
pressure, the
loop may
need
to be
pressurized to
60 to
65
psi.
This
static
pressure
will
fluctuate
from
heating to cooling
season,
but
the pressure
should always
remain above zero
so
circulation pumps
do not cavitate
and
air cannot be
pulled into
the system.
SFor
information regarding earth
loop installations contact
your
local installer,
distributor or
factory
representative.
B.
Open Loop
Applications
An
open
system gets its name
from the open
discharge
of
water after
it
has
been used
by
the heat
pump. A
well
must be
available that can
supply
all of the water
requirements (see
Table 2) of the heat
pump along
with
any
other water
requtements drawing
off that
same
well'
The
well
must be capable
of supplying the heat
pump's
required
flow
rate
for
up
to 24 hours per day on the
coldest
winter
day.
Figure 2 shows the necessary components
for
water
piping of
an
open
system. First,
a
bladder type
pressure
tank
with
a
"draw
down" of
at least lYz times the
well
pump capacity must
be
installed on
the
supply side
of
the
heat
pump.
Shut
off
valves and
boiler drains on
the
entering
and
leaving water lines are necessary
for future
maintenance issues.
A
screen strainer is
placed
on the
supply
line with
a mesh size
of
40 or
60 and enough
surface area
to allow for particle buildup between
cleanings.
Pressure/Temperature (P/T) ports
are
placed in
the
supply
and discharge lines so that thermometers or pressure
gauges can be
inserted
into
the
water
stream.
On the
well
water discharge
side
of
the heat
pump,
a
flow
control valve must
be mounted next to
the heat
pump to
regulate
the
maximum
water
flow
through
the
unit. A
solenoid valve is then installed
and
wired to plug #2 (P2)
on the
controller of
the heat
pump.
This
valve
will
open
when
the
unit
is
running
and
close when
the
unit stops. A
visual
flow
meter is
then
installed to allow
visual
inspection of
the
flow
requirements.
The
flow
meter
can
also be
useful in
determining when maintenance is
required
(if
you can't
read the
flow,
cleaning
is required,
see
Water Coil
Maintenance).
Schedule
40 PVC piping,
copper tubing, polyethylene
or
rubber
hose can be used for
supply
and
discharge water
lines.
Make
sure line
sizes are large
enough to supply
the
required flow
with
a
reasonable pressure drop (generally
1"
diameter
minimum).
qNote:
Do not
use
plastic
female
fittings
with
metal male fittings, or
fractures may
result in
the female
fittings.
Always
use
plastic male
into
steel female!
7
8
2.9
11
4.6
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3.4
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6.3 9
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3.4
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4.0
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Q18kW6T-000,
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15
dP'
{asE}
dP
(psi)
Flor
{spm)
FIow
(sm)
Mcd&l
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