Operating instructions

6
• The acceptable hydronic LWT is 70
o
F to 115
o
F for
heating and 35
o
F to 50
o
F for cooling. Hydronic EWT
should remain above 50
o
F to avoid low-pressure lockouts.
• The acceptable Ground Loop EWT is 25
o
F to 50
o
F for
heating and 50
o
F to 100
o
F for cooling.
V. UNIT LOCATION / MOUNTING
CAUTION – Units must be kept in an upright position
during transportation or installation, or severe internal
damage may occur.
Important – To ensure easy removal and replacement of
access panels, leave panels secured in place until the unit is
set in place and leveled.
Important – Locate the unit in an indoor area where the
ambient temperature will remain above 45
o
F. Service is
done primarily from the front. Top and rear access is
desirable and should be provided when possible.
Important – A field installed drain pan is required under
the entire unit where accidental water discharge could
damage surrounding floors, walls or ceilings.
CAUTION – Do not use this unit during construction.
Dust and debris may quickly contaminate electrical and
mechanical components; resulting in damage.
CAUTION – Before driving screws into the cabinet,
check on the inside of the unit to ensure the screw will not
damage electrical, water, or refrigeration lines.
Important – Units must be mounted on a vibration-
absorbing pad slightly larger than the base to provide
isolation between the unit and the floor. Water supply
pumps should not be hard plumbed directly to the unit with
copper pipe; this could transfer vibration from the water
pump to the refrigeration circuit, causing a resonating
sound. Hard plumbing must be isolated from building
structures that could transfer vibration from the unit through
the piping to the living space.
CAUTION – Always use plastic male fittings into plastic
female or into metal female fittings.
Never use metal male
fittings into plastic female fittings. On metal-to-metal
fittings; use pipe thread compound, do not use pipe thread
tape, hand tighten first, and then only tighten an additional
½ turn with a tool if necessary. On plastic fittings, always
use 2 to 3 wraps of pipe thread tape, do not use pipe thread
compound, hand tighten first, and then only tighten an
additional ½ turn with a tool if necessary. Do not over-
tighten, or damage may occur.
VI. GROUND SOURCE DESIGN
Since water is the source of energy in the winter and the
energy sink in the summer, a good water supply is possibly
the most important requirement of a geothermal heat pump
system installation.
a. Ground Loop Installation
A Ground Loop system circulates the same antifreeze
solution through a closed system of high-density
underground polyethylene pipe. As the solution passes
through the pipe, it collects energy (in the heating mode)
from the relatively warm surrounding soil through the pipe
and into the relatively cold solution. The solution circulates
to the heat pump, which transfers energy with the solution,
and then the solution circulates back through the ground to
extract more energy.
The Ultra is designed to operate on either vertical or
horizontal ground loop applications. Vertical loops are
typically installed with a well drilling rig up to 200 feet
deep, or more. Horizontal loops are installed with
excavating or trenching equipment to a depth of about six to
eight feet, depending on geographic location and length of
pipe used. Loops must be sized properly for each particular
geographic area, soil type, and individual capacity
requirements. Contact Enertech Customer Support or a
local installer for loop sizing requirements in your area.
Typical winter operating EWT to the heat pump ranges
from 25
o
F to 32
o
F.
CAUTION – Ground Loops must be properly freeze
protected. Insufficient amounts of antifreeze may result in a
freeze rupture of the unit or can cause unit shutdown
problems during cold weather operation. Propylene glycol
and Geothermal Transfer Fluid (GTF) are common
antifreeze solutions. GTF is methanol-based antifreeze and
should be mixed 50% with water to achieve freeze
protection of 12
o
F. Propylene glycol antifreeze solution
should be mixed 25% with water to obtain a 15
o
F freeze
protection.
Important – Do not mix more than 25% propylene
glycol with water in an attempt to achieve lower than 15
o
F
freeze protection, since more concentrated mixtures of
propylene glycol become too viscous at low temperatures
and cannot be pumped through the earth loop. Horizontal
loops typically use GTF, and vertical loops typically use
propylene glycol. Note – Always check State and Local
codes for any special requirements on antifreeze solutions.
CAUTION – Never operate with flow rates less than
specified. Low flow rates, or no flow, may cause the unit to
shut down on a pressure lockout or may cause a freeze
rupture of the heat exchanger.
Important – Figure 2 shows that Pressure/Temperature
(P/T) ports
must be installed in the entering and leaving
water lines of the heat pump. 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 confirm the proper flow
rate of the system.
An individually-sized Enertech flow center can supply
pumping requirements for the Ground Loop fluid, and can
also be used to purge the loop system.
Note – Refer to
instructions included with the flow center for properly
purging the ground loop.
Important – the pump must be installed to supply fluid