Service Parts List ............................................................. 34
NDS OUTDOOR SPLIT INSTALLATION MANUAL
Model Nomenclature
123
DS
N
Model Type
N = Envision
Compressor Type
D = Dual Capacity
Cabinet Configuration
S = Outdoor Split
Unit Capacity
026
038
049
064
072
NOTE: *026-049 uses the FC1-GL and 060-072 uses
the FC2-GL, the flow center is factory installed. If these
flow centers do not meet the flow requirements, select
A = None for digit 10.
4-6
0497A819010A11C
Coax Options
C = Copper
N = Cupronickel
Flow Center
A = None
B = Flow Center*
IntelliStart Options
0 = No IntelliStart
3 = IntelliStart
Voltage
1 = 208-230/60/1
Vintage
A = Current
4
General Installation Information
NDS OUTDOOR SPLIT INSTALLATION MANUAL
Safety Considerations
WARNING: Before performing service or
maintenance operations on a system, turn off main
power switches to both units. Turn off accessory
heater power switch if applicable. Electrical
shock could cause personal injury. Installing and
servicing heating and air conditioning equipment
can be hazardous due to system pressure and
electrical components. Only trained and qualified
service personnel should install, repair or service
heating and air conditioning equipment.
Installing and servicing heating and air conditioning
equipment can be hazardous due to system pressure and
electrical components. Only trained and qualified service
personnel should install, repair or service heating and air
conditioning equipment. Untrained personnel can perform
the basic maintenance functions of cleaning coils and
cleaning and replacing filters. All other operations should
be performed by trained service personnel. When working
on heating and air conditioning equipment, observe
precautions in the literature, tags and labels attached to the
unit and other safety precautions that may apply, such as
the following safety measures:
• Follow all safety codes.
• Wear safety glasses and work gloves.
• Use a quenching cloth for brazing operations.
• Have a fire extinguisher available for all brazing
operations.
Moving and Storage
Move units in the normal “up” orientation. Units may be
moved and stored per the information on the packaging.
Do not stack more than three units in total height. Do not
attempt to move units while stacked. When the equipment
is received, all items should be carefully checked against
the bill of lading to be sure all crates and cartons have been
received. Examine units for shipping damage, removing
the units from the packaging if necessary. Units in question
should also be internally inspected. If any damage is noted,
the carrier should make the proper notation on the delivery
receipt, acknowledging the damage.
Condensate Drain
Follow the blower coil manufacturer’s instructions.
Duct System
All blower coil units/air coils must be installed as specified
by the manufacturer’s installation instructions; however, the
following recommendations should considered to minimize
noise and service problems.
An air filter must always be installed upstream of the air coil
on the return air side of the air handler or furnace. If there
is limited access to the filter rack for normal maintenance, it
is suggested that a return air filter grill be installed. Be sure
that the return duct is properly installed and free of leaks
to prevent dirt and debris from bypassing the filter and
plugging the air coil.
In applications using galvanized metal ductwork, a flexible
duct connector is recommended on both the supply and
return air plenums to minimize vibration from the blower. To
maximize sound attenuation of the unit blower, the supply
and return plenums should include an internal duct liner
of 1-inch thick glass fiber or be constructed of ductboard.
Insulation is usually not installed in the supply branch
ducts. Ducts in unconditioned areas should be wrapped
with a minimum of 1-inch duct insulation. Application of
the unit to uninsulated ductwork in an unconditioned
space is not recommended as the unit’s performance will
be adversely affected. If the air handler is connected to
existing ductwork, a previous check should have been
made to assure that the duct system has the capacity to
handle the air required for the unit application. If ducting
is too small, as in replacement of heating only systems,
larger ductwork should be installed. All existing ductwork
should be checked for leaks and repairs made accordingly.
The duct systems and diffusers should be sized to handle
the design airflow quietly. If air noise or excessive airflow
is a problem, the blower speed can be changed to a lower
speed to reduce airflow. This will reduce the performance
of the unit slightly in heating; however, it will increase the
temperature rise across the air coil. Airflow must still meet
minimum requirements.
Split Unit Location
Locate the split compressor section away from areas that
may disturb the customer and in a way that allows easy
removal of the access panels and the top of the cabinet.
Provide sufficient room to make water, electrical and
refrigerant line connections and allow space for service
personnel to perform maintenance. The NDS split is
approved for outdoor installation when properly installed.
Air Coil Location
Refer to the air handler manufacturer’s instructions for the
blower coil unit for details on installing the air handling
portion of the system.
Equipment Selection
The following guidelines should be used when mating an
Envision Split to an air handler/coil.
• Select R-410A components only.
• Match the air handler to the air handler coil data table.
• Indoor matching adjustable TXV is factory installed on
every NAH air handler/coil. Fixed orifice or cap tube
systems should not be used.
• Minimum of two (2) blower speeds
Utilizing Existing Coil or Air Handler
It is recommended that a new R-410A air handler be
installed with an Envision Split considering the long term
5
NDS OUTDOOR SPLIT INSTALLATION MANUAL
General Installation Information cont.
benefits of reliability, warranty, etc. versus the short term
installation cost savings. However, the existing air handler
may be retained provided the following:
• Coil currently is R-410A rated
• Coil uses a TXV. No capillary or fixed orifice systems
should be used
• A life expectancy of more than 7 years remaining for the
air handler and components
• Flush air coil and line set
When utilizing the existing air coil or line set, only flushing
compounds that vaporize should be used; which means
they are packaged in a pressurized disposable cylinder. It is
preferable to use a flushing agent that removes oil, water,
and acid, plus, is biodegradeable and non-toxic. The flushing
agent should be safe to use with both HCFC and HFC
refrigerants. Once a flushing agent has been selected, follow
the instructions provided with the product.
The first step should be purging the lines or air coil with
nitrogen. Purging with nitrogen first will remove some of
the particulate and residual oil which will allow the flushing
agent to work better. Never blow the flushing agent
through a compressor, filter drier, or txv as it will cause the
components to fail.
When flushing is complete and the final system is assembled,
an acid check should be preformed on the system. Acid test
kits are available from most HVACR distributors.
An air filter must always be installed upstream of the air coil
on the return air side of the air handler or furnace. If there
is limited access to the filter rack for normal maintenance,
it is suggested that a return air filter grille be installed. Be
sure that the return duct is properly installed and free of
leaks to prevent dirt and debris from bypassing the filter
and plugging the air coil.
Ensure that the line set size is appropriate to the capacity
of the unit (refer to Line Set Sizes table). Line sets should
be routed as directly as possible, avoiding unnecessary
bends or turns. All wall penetrations should be sealed
properly. Line set should not come into direct contact
with water pipes, floor joists, wall studs, duct work, floors,
walls and brick. Line set should not be suspended from
joists or studs with a rigid wire or strap which comes into
direct contact with the tubing. Wide hanger strips which
conform to the shape of the tubing are recommended.
Isolate hanger straps from line set insulation by using metal
sleeves bent to conform to the shape of insulation. Line
set insulation should be pliable, and should completely
surround the refrigerant line.
NOTE: Improper installation of equipment may result in
undesirable noise levels in the living areas.
Typical Split System Application Remote Blower Coil
Connection to Air Coil
Typical Split System Application - Remote Blower Coil
and Typical Split System Heat Pump Coil Add-on Fossil
Fuel Furnace illustrations show typical Envision Split
installations. The Line Set Sizes table shows typical line
set diameters and maximum length. Line sets over 60 feet
are not recommended. If the line set is kinked or deformed
and cannot be reformed, the bad section of pipe should be
replaced. A restricted line set will affect unit performance.
As in all R-410A equipment, a reversible liquid line filter
drier is required to ensure all moisture is removed from the
system. This drier should be replaced whenever “breaking
into” the system for service. All line sets should be insulated
with a minimum of 1/2” closed cell insulation. All exterior
insulation should be painted with UV resistant paint or
covering to ensure long insulation life.
Air Handler Installation
Air handlers used with dual capacity units must be capable
of operating with a minimum of 2 blower speeds. Refer to
the manufacturer’s instructions for the blower coil unit for
details on installing the air handling portion of the system.
All blower coil units/air coils must be installed as specified
by the manufacturer’s installations instructions. However,
the following recommendations should be considered to
minimize noise and service problems.
Insulated
Suction Line
Lineset
To Air Handler
Condensate Drain
(must be trapped)
Disconnect
Low
Voltage Wire
Remote Air Handler
(Maximum Recommended Distance is
60' Between Units)
Supply
Duct
Air
Handler
Return
Duct
6
General Installation Information cont.
NDS OUTDOOR SPLIT INSTALLATION MANUAL
Dual Fuel Systems
Envision units can be connected to fossil fuel furnaces that
include an A-coil or slab coil. Dual fuel installations utilize
the Envision heat pump for heating until the point that
auxiliary heat is called for on the thermostat. At that point,
the furnace will be enabled and the heat pump will be
disabled. The Envision heat pump provides air conditioning
through the furnace’s refrigerant coils.
Refer to the furnace manufacturer’s installation manual
for the furnace installation, wiring and coil insertion. A
WaterFurnace Dual Fuel thermostat or a field-installed
DPST relay is required. See the Typical Split System Heat
Pump Coil Add-on Fossil Fuel Furnace illustration for
typical Dual Fuel application.
Typical Split System Heat Pump Coil
Add-on Fossil Fuel Furnace
Disconnect
Insulated
Suction Line
In add-on Envision Split applications, the coil should
be located in the supply side of the furnace to avoid
condensation damage to the furnace heat exchanger. A
high temperature limit should be installed upstream of the
coil to de-energize the compressor whenever the furnace
is operating. Without this switch, the Envision Split will trip
out on high pressure. A dual fuel thermostat can remove
the Y1 and Y2 calls when a W call is energized to allow gas
furnace backup on an Envision Split application. Refer to
the Thermostat Wiring section for details.
In ground water situations where scaling could be heavy
or where biological growth such as iron bacteria will be
present, a closed loop system is recommended. The heat
exchanger coils in ground water systems may, over a period
with extremely hard water, the owner should be informed
that the heat exchanger may require occasional flushing.
Failure to adhere to the guidelines in the water quality table
could result in loss of warranty.
of time, lose heat exchange capabilities due to a buildup
of mineral deposits inside. These can be cleaned, but only
by a qualified service mechanic, as special solutions and
pumping equipment are required. Hot water generator coils
can likewise become scaled and possibly plugged. In areas
pHAcidity/Alkalinity9 - 7 9 - 7 9 -7
ScalingCalcium and Magnesium Carbonate (Total Hardness) less than 350 ppm(Total Hardness) less than 350 ppm(Total Hardness) less than 350 ppm
Residential NDS split units are supplied standard with
GeoLink swivel connections with P.T. ports.
CAUTION: Water piping exposed to outside
temperatures may be subject to freezing.
Water Piping
The proper water flow must be provided to each unit
whenever the unit operates. To assure proper flow, use
pressure/temperature ports to determine the flow rate.
These ports should be located at the supply and return
water connections on the unit. The proper flow rate cannot
be accurately set without measuring the water pressure
drop through the refrigerant-to-water heat exchanger.
Closed Loop - Earth coupled Systems
(Outdoor Installations)
Locate unit on an air pad with access hole as shown below.
When mounting on an existing concrete pad, holes must
be bored through to accommodate 1 1/4-inch P.E. pipe with
1/2-inch insulation.
Connecting To Earth Loop
The earth loop trench should be continued directly under
the unit as shown in the Typical Split System Outdoor
Installation Using Closed Loop. Make the connections to
optional fittings from the loop circulator pump(s) and
ensure proper backfill to support the loop pipe during
trench settling. All 1 1/4-inch piping should be insulated
with a minimum of 1/2-inch closed cell insulation from
below the ground surface to the loop circulator.
Flow Center Installation
Flow centers FC1-GL or FC2-GL, as needed, may be
internally mounted on the NDS splits, Two stub tubes with
barbs are pre connected to the coax. Two tubes with brass
fittings, to adapt to the flow center, 2 hoses to connect
between the two sets of tubes, and four hose clamps are
included with each NDS unit. The brass adapter fittings
have plastic swivel connectors that also accept 1 in. O.D.
copper pipe (sweat).
NOTE: For ease of installation, attach provided hoses to
coax first and then trim to fit to elbows on flow center.
Typical Split System Outdoor Installation
Using Closed Loop
IMPORTANT: A freeze detection thermostat is
installed in the unit to automatically start loop
circulator pump if loop temperature drops
below 20°F. Loop freeze detection should also
be maintained to the lowest temperature the
insulated loop may encounter in the case of
power failure.
Open Loop (Indoor Installations)
NDS Splits can be installed on an open loop system, but
only indoors. All NDS Splits are supplied with GeoLink
swivel connectors. The swivel connectors will also accept a
1 in. O.D. copper pipe (sweat) which can be connected in an
open loop system.
Loop Supply
and Return
Piping
9
NDS OUTDOOR SPLIT INSTALLATION MANUAL
Typical EZ Wiring Diagram
Electrical Data
General
Be sure the available power is the same voltage and phase
as that shown on the unit serial plate. Line and low voltage
wiring must be done in accordance with local codes or the
National Electric Code, whichever is applicable. See unit
electrical data for fuse or cicuit breaker sizing information.