Maritime Geothermal WH-Series, Installation And Service Manual

Page: 8 / 77

Page 8 002028MAN-01 1-Oct-2015
INDOOR LOOP WATER LINES
The port connections for the Indoor Loop circuit are heavy
duty 1” brass FPT fittings. They are labelled as INDOOR IN
and INDOOR OUT. The ports are located on the front of the
unit.
A typical 2 port buffer tank system is shown in drawing
001981PDG . This diagram shows all of the recommended
components as well as where they should be placed. A typical 4
port buffer tank system is shown in
drawing 001046PDG . Un-
ions or some other form of disconnect should be used so that
the coaxial heat exchanger may be accessed should it require
cleaning.
NOTE: It is recommended that the water lines between the heat
pump and the buffer tank be copper piping.
NOTE: Care should be taken when routing the water lines to
ensure that adequate access to the heat pump is maintained so
as to not compromise ease of serviceability.
The minimum buffer tank size should follow the rule of
8USGAL per ton of heat pump capacity. TABLE 4 shows the
minimum buffer tank size for each heat pump along with the
recommended size. The recommended size will minimize the
number of starts per hour and provide longer runtimes for im-
proved efficiency.
CIRCULATOR PUMP MODULE WIRING
(GROUND LOOP ONLY)
The heat pump has provisions for connecting the circulator
pump module so that the pumps will be turned on whenever the
compressor operates. Connect the circulator pump module to
the appropriate two terminals (115V or 230V) of the terminal
strip marked
OUTDOOR - INDOOR CIRCULATORS in the heat
pump, as per the voltage of the circulator pump module. Ensure
that the total current draw of all circulators connected to the ter-
minal strip does not exceed the value indicated on the label in
the heat pump electrical box. Refer to the electrical box draw-
ing on the electrical box cover for more information.
INDOOR LOOP CIRCULATOR WIRING
The Indoor Loop circulator provides flow between the heat
pump and the buffer tank. The heat pump has provisions for
connecting the Indoor Circulator so that it will be turned on
whenever the compressor operates. Connect the Indoor Loop
circulator to the appropriate two terminals (115V or 230V) of the
terminal strip marked
OUTDOOR - INDOOR CIRCULATORS in
the heat pump, as per the voltage of the circulator pump mod-
ule. Ensure that the total current draw of all pumps connected
to the terminal strip does not exceed the value indicated on the
label in the heat pump electrical box. Refer to the electrical box
drawing on the electrical box cover for more information.
THERMOSTAT REQUIREMENTS
(
Setpoint Control & Hard Wired Options
)
NOTE: If controlling the system via the BACNet interface,
skip this section as no connections are required.
The unit has an advanced control board with several fea-
tures that are described in the Control Board section of the man-
ual. One of these features is built in Aquastat functionality (with
optional Outdoor Reset) known as “Setpoint Control”; refer to
the Setpoint Control section of this manual for more information.
It is recommended that this feature be used to operate the heat
pump system as it eliminates the need for an external aquastat
and temperature probe in the tank(s) and provides a three stage
system along with delay timer for the hydronic auxiliary heat.
No external signals are required with this mode of operation.
If electing to use the hardwired option with an external
aquastat, a 2-stage aquastat is required. The stage settings are
S1 = compressor and S2 = Hydronic Auxiliary.
An aquastat may be purchased with the unit, or other aq-
uastats with the same number of stages may be used. The
electrical box diagram on the electrical box cover provides a
description of the signal connections as does
TABLE 6 . All
signal connections are located on the top right side of the con-
trol board, on the screw terminal connector section marked AQ-
UASTAT.
TABLE 3 - Aquastat Connections
Signal Description
CA 24VAC common (ground)
RA 24VAC hot
Y1A* Compressor
Y2A* Electric Backup Heat
TABLE 4 - Buffer Tank Size
Heat Pump Size
Minimum Size
USGAL (Litres)
Recommended Size
USGAL (Litres)
25 16 (61) 20 (76)
45 24 (91) 30 (114)
55 32 (121) 40 (151)
65 40 (151) 50 (189)
75/80 48 (182) 60 (227)
If a tank size is not available take the next size larger tank.