Controller - Econar GeoSource 2000 GW Series Installation And Operating Instructions Manual

lower
voltage, change
the wiring
to
the
transformer
primary to
the correct lead; otherwise premature
failure,
or
inability to operate the
control
components may occur'
B. Remote
Hydronic Controls
The GW29-67 heat
pump series uses a
single-compressor,
and
the GW98, GW120 and
GW380
use
a
[andem
compressor
(two
compressors connected
together). The
GW98,
120,
or 380 can be
ordered either as;
1)
controlled
as
one system
with a
single
Y
input
with
an
adjustable
time
delay
for
the
2od
compressor contactor,
or 2)
stage-
controlled
with
separate
Y
and
Y2
inputs
with
an
adjustable
time delay
for
the Y2-controlled
contactor.
Consult
the instructions packaged
with the
remote
hydronic conffols
for proper
mounting
and
operation-
Vlmportant
-
If
one remote hydronic
control
operates
multiple heat
pumps,
the
conffol
wiring of
the heat
pumps
must be
isolated with isolation relays
to
avoid excessive
voltages
or
overheating
and premature
failure
of
the
conftol
compononts.
Power
is
supplied
to
the
remote
hydronic control from
the
R and
X
terminals on the heat
pump
terminal
strip.
A
single-stage
hydronic control
(heating Aquastat)
on
a
storage
tank or
a
wall
mounted thermostat may be
a1l
that
is required
for simple heat-only
systems.
The
contact on
the
hydronic control
closes and
provides 24Vac to
the
Y
terminal.
When using
a
hydronic control, insert
the
temperature sensor
approximately 1/3
of
the way
down
into the storage
tank.
Set
the
hydronic control setpoint to
1
l0-1
15"F
typical, and set the
differential
to
15oF
to avoid
short
cycling.
eCAUTION
- The setpoint
of
the
hydronic conffol must
limit
the
LWT from
the heat
pump
to
a
maximum
of
120oF
to avoid premature
failure of
the compressor.
A
cooling hydronic control
(Aquastat)
can
be mounted on
the
water supply
line,
as
shown
in Figure 4. This control
acts as
a
1ow
limit,
which shuts the heat
pump down when
the
cooling water reaches
the setpoint
(e.g. 45"F).
Changeover
from heating
to
cooling can
be achieved
in
two ways: 1)
a
manual
toggle switch to select the heating
or the cooling
hydronic control
(Aquastat), or 2)
a
cooling
thermostat
which powers the
coil of a single pole/double
throw relay
to
select
the heating hydronic
control
(normally
closed contact)
or
the
cooling hydronic control
(normally
open
contact).
eNote
-
Always
wire the
system
to
shut
down (Anti-
short-cycle) between
a
heatiag
and cooling
mode
changeover,
or
nuisance
trip-outs
could occur from
changing modes
"on
the
fly".
For
Zoning
applications,
any number
or
rypes
of
thermostats, Aquastats,
or
switches can
be
used
with
an
independent
power supply (typically
a
24-volt
transformer) to activate specific zone
controls. These zone
controls are
normally either
a
zone
pump (Figure
4)
or
zone
valves (Figure 5). End
switches
on the zone valves
can
be used
to control
a
pump relay when the zone valve
is open.
The pump relay then activates a
coulmon pump,
which
supplies
any nurnber
of
zones.
Example: the fan
coil
in
Figure
4 could be
supplied
by
the
same
pump
as
the radiant
floor
system
if
zone
valves were used
instead
of two pumps.
C.
Controller
The
controller receives
a
signal from
the
thermostat and
initiates
the
correct sequence
ofoperation for
the
heat
pump. The conffoller
performs
the
following
functions:
1)
Compressor
Anti-Short Cycle
2)
Compressor
Control
3)
Ground Loop Pump
/
Ground Water
Initiation
4)
Compressor Staging
5)
Hydronic Circulator Pump
Conffol
6)
4-Way Valve Control
7)
Compressorl,ockouts
8)
System
Diagnostics
9)
24Vac Fuse
10)
Plug Accessory
11)
AlarmOuput
1.
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
for
these
two
conditions;
1.
A
70
to
130-second
random time-out
period
occurs
before
a
re-start after the
last shutdown.
2-
A
4-minute/25-second
to 4-sinutel45-second random-
start
delay
occurs
immediately after power
is
applied
to the
heat
pump. This occurs
only
after reapplying
power
to
the unit.
To
blpass
this timeout
while
servicing
the unit, apply power,
disconnect
and
reapply power very
quickly to
shorten
the delay.
2.
Compressor Control
When 24Vac
is
applied
to the
Y
terminal on the
wiring
terminal
block,
the
controller
then
decides, based on
lockout
and anti-short-cycle periods, when
to bring
the
eompressor on. The
Ml
output
of
the
controller
energizes
the
compressor
contactor, and
the compressor stays on
until the 24Yacis removed
from
the
Y termhal.
3.
Ground Loop Pump / Ground Water
Initiation
On
ground loop
systems, a
Ml
output
from the controller
will
energize
the contactor, starting the compressor and
the ground loop pump. On ground water
systems,
a M1
output
from
the
controller
will
energize the ground water
solenoid valve through
the "P1ug Accessory" connector.
4.
Compressor Staging
GW98, GW120, and
GW380 can be ordered
with
staged
compressors
controlled
with
separate
Y
and
Y2
inputs.
The
Mi
output
of
the controller
energizes
the
flrst
11