Page 6Boreal Geothermal Inc. 02 JULY 2009
UNIT DESCRIPTION
The W-Series unit is a high efficiency two-stage geother-
mal heat pump with R410a refrigerant. Two-stage units offer a
significant efficiency increase over single stage units when oper-
ating in the reduced capacity mode (stage 1).
The unit has several key features that are described in the
specifications document for the particular heat pump. Please
request a copy if desired or visit www.boreal-geothermal.com
UNPACKING THE UNIT
When the heat pump reaches its destination it should be
unpacked to determine if any damage has occurred during
shipment. Any visible damage should be noted on the carrier's
freight bill and a suitable claim filed at once.
The heat pump is well constructed and every effort has been
made to ensure that it will arrive intact, however it is in the
customer's best interest to examine the unit thoroughly when it
arrives.
OPTIMUM PLACEMENT
The placement of a hydronic unit has negligible effects on
the operation of the system. For ground water systems, the unit
can be placed near the well water system, ground loop system
units can be place near where the header pipes enter the struc-
ture to keep the ground loop piping, heat pump and circulator
pump module in one location. The hydronic layout may make a
particular location ideal for the unit installation.
If possible the access panels should remain clear of
obstruction for a distance of two feet to facilitate servicing and
general maintenance. DO NOT STACK UNITS ON TOP OF
EACH OTHER. The cases are not designed to hold the weight
of another unit. Stacking should only be done with a proper rack
system able to hold a minimum of 2x the weight of the unit.
Raising the heat pump off the floor a few inches is
generally a good practice since this will prevent unnecessary
rusting of the bottom panel of the unit. We recommend that the
heat pump be placed on a piece of 2'' Styrofoam covered with
1/4'' plywood. The Styrofoam will smooth out any irregularities in
the cement floor while the plywood will distribute the weight of
the unit evenly over the Styrofoam. This process will also
deaden the compressor noise emitted from the bottom of the
cabinet.
ELECTRICAL PROVISIONS
The heat pump has a concentric 1.093” / 0.875” knockout
for power supply connection to the electrical box. There are
also two other 0.875” knockouts: one for connections to the in-
door circulator; the other for connections to the circulator pump
module for ground loop applications. There are three 1/2” open-
ings with plastic grommets (grommet hole is 3/8”) in the upper
section of the electrical box for connections to the controls.
A schematic diagram and electrical box layout diagram
(ELB) can be found inside the electrical box cover of the unit as
well as in the Model Specific section of this manual. The Electri-
cal Tables in the Model Specific section and the ELB diagram
contain information about the size of wire for the connections, as
well as the recommended breaker size.
A properly qualified electrician should be retained to
make the connections to the heat pump and associated
controls. The connections to the heat pump MUST CON-
FORM TO LOCAL CODES.
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 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 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.
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 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 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.
CONTROL REQUIREMENTS
The heat pump requires a two-stage heating (and two
stage cooling for reversing units) control system for proper op-
eration. The stages are S1 = Stage 1 compressor, and S2 =
Stage 2 compressor.
Two-stage aquastats can be purchased with the unit, or
other system controllers with dry contacts may be used. This
manual covers operation of the heat pump with aquastats.
The electrical box diagram on the electrical box cover pro-
vides a description of the signal connections in the heat pump.
They are also listed in TABLE 1 below.
NOTE: Some models are not available in two-stage at the pre-
sent time (see Electrical Tables). The Y2 signal is not used for
these units.
The aquastat(s) can be placed anywhere within the range
of the probe cable. The probe(s) should be inserted into a dry
well in or near the top of the tank for optimal operation (refer to
drawing 000533PDG) . If a dry well is not available, it may be
possible to fix the probe to the tank inside the insulation.
TABLE 1 - Control Signal Description
Signal Description
C 24VAC Common (Ground)
R 24VAC Hot
Y1Heat Pump Stage 1
O Cooling Mode (reversing valve)
Y2Heat Pump Stage 2 (if applicable to unit)
Installation Information
