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

(example, 230).
ff
connected
to
a
power supply having
the
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 GW37-87 heat pump
series uses a
single-compressor,
and
the
GW240 has
a
tandem
(two
compressors
connected
together). The GW240 is configured
as 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 controls for proper mounting
and operation.
Slmportant -
If
one remote hydronic control
operates
multiple
heat
pumps, the control wiring of
the heat
pumps
must be isolated
with
isolation relays
to
avoid
excessive
voltages
or
overheating
and premature failure
of
the
control
components.
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
all
that
is
required
for
simple heat-only
systems. The contact
on
the
hydronic control closes and provides 24Yac to the
Y
terminal. When using
a
hydronic control, insert
the
'*1
temperature sensor
approximately 1/3
of
the way
down
into the
storage
tank.
Set
the
hydronic control
setpoint to
1
10-1 15oF
typical,
and set
the differential
to
15oF
to
avoid
short
cycling.
eCAUTION
- The setpoint
of
the
hydronic control
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
low 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 sirrgle pole/double
throw relay
to
select
the
heating hydronic
conffol
(normally
closed contact)
or
the cooling hydronic control
(normally
open contact).
eNote
-
Always wire the
system
to
shut
down (Anti-
short-cycle)
between
a
heating and cooling
mode
changeover,
or
nuisance
trip-outs could occur
from
changing modes
"on
the
fly."
For
Zoning
applications,
any
number
or
types of
thermostats, Aquastats,
or
switches can be used
with
an
independent
power supply (typically
a
24-volt
traasformer) 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 common pump,
which
supplies any number
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
of
operation
for
the
heat
pump. The confroller 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 Control
6)
4-Way Valve Control
7)
Compressor Lockouts
8)
System
Diagnostics
9)
24Vac
Fuse
10)
Plug Accessory
11) Alarm
Output
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-minutelZ5-second to 4-minute/45-second random-
start
delay
occurs
immediately after power
is
applied
to the
heat
pump. This
occurs only after reapplying
power
to
the unit. To
bypass
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
compressor on. The M1
output
of
the
controller
energizes
the
compressor contactor, and the
compressor stays on
until
ttre
24Yac
is removed
from
the
Y
terminal.
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'?lug
Accessory" connector.
4.
Compressor Staging
The
GW240
has
staged compressors controlled with
separate
Y
and
Y2
inputs. The
Ml
output of
the
controller
energizes
the
flrst
compressor contactor and begins
the
time-out of
the
time
delay (adjustable
10
to
1000
seconds
and factory
set
at 10).
After
the
time-out,
a
Y2 input
can
11
l