AAON ProFit WV Series Owner's manual

ProFit
WV Series
Vertical Water-Source Heat Pump Units
Installation, Operation
& Maintenance
If the information in this manual is not
followed exactly, a fire may result
causing property damage, personal
injury, or loss of life.
QUALIFIED INSTALLER
Improper installation, adjustment,
alteration, service,
or maintenance
can cause property damage, personal
injury or loss of life.
Startup and
service must be performed by a
Factory Trained Service Technician. A
copy of this IOM must be kept with the
unit.
WARNING
WARNING

3
Table of Contents
AAON ProFit Features and Options Introduction .......................................................................... 5
Safety .............................................................................................................................................. 6
WSHP Series Feature String Nomenclature ................................................................................. 10
General Information...................................................................................................................... 12
Codes and Ordinances .............................................................................................................. 12
Receiving Unit .......................................................................................................................... 13
Storage ...................................................................................................................................... 13
Direct Expansion (DX) Systems............................................................................................... 13
Wiring Diagrams....................................................................................................................... 14
Installation..................................................................................................................................... 14
Locating the Unit ...................................................................................................................... 14
Condensate Drain Piping .......................................................................................................... 14
Backward Curved Blower Removal ......................................................................................... 16
Forward Curved Blower Removal............................................................................................ 16
Lifting and Handling the Unit................................................................................................... 17
Service Access .......................................................................................................................... 17
Blower Motor and Fan Access.................................................................................................. 18
Refrigerant-to-Water Heat Exchanger Water Piping................................................................ 18
Electrical ................................................................................................................................... 22
Duct Connection ....................................................................................................................... 25
Startup........................................................................................................................................... 25
Supply Fans............................................................................................................................... 26
Fan Air Flow Adjustment ......................................................................................................... 26
Filters ........................................................................................................................................ 26
Adjusting Refrigerant Charge................................................................................................... 27
Operation....................................................................................................................................... 30
AAON WSHP Pioneer Silver Controller.................................................................................. 30
Maintenance.................................................................................................................................. 37
DX Cooling............................................................................................................................... 37
Condensate Drain Pans ............................................................................................................. 37
Supply Fans............................................................................................................................... 37
Filter Replacement.................................................................................................................... 37
Replacement Parts..................................................................................................................... 38
Warranty, Service, and Parts Department................................................................................. 38
Filter Information.......................................................................................................................... 38
Appendix A - Heat Exchanger Corrosion Resistance................................................................... 41

4
Index of Tables and Figures
Tables:
Table 1 - WSHP WV Series Clearances ....................................................................................... 15
Table 2 - Glycol Freezing Points ................................................................................................. 20
Table 3 - Water Connections ........................................................................................................ 21
Table 4 - Nameplate Voltage Markings & Tolerances ................................................................. 22
Table 5 - Control Wiring............................................................................................................... 24
Table 6 - Acceptable Refrigeration Circuit Values at AHRI ISO 13256 WLHP Conditions....... 28
Table 7 - R-410A Refrigerant Temperature-Pressure Chart......................................................... 29
Table 8 - LED Diagnostic Codes .................................................................................................. 34
Table 9 - Glycol Percentage Setpoints.......................................................................................... 35
Table 10 - 006-012 WV Unit Series Filters (A Cabinet).............................................................. 38
Table 11 - 015-030 WV Series Unit Filters (B & C Cabinet) ...................................................... 39
Table 12 - 036 & 042 WV Series Unit Filters (D Cabinet) .......................................................... 39
Table 13 - 048 & 060 WV Series Unit Filters (E Cabinet)........................................................... 40
Figures:
Figure 1 - Access Panels ............................................................................................................... 13
Figure 2 - Internal Condensate P-trap ........................................................................................... 14
Figure 3 - Vertical Configuration Orientations............................................................................. 15
Figure 4 - Blower Assembly......................................................................................................... 16
Figure 5 - Blower Assembly with Captive Panel.......................................................................... 17
Figure 6 - Blower Assembly, Shown Pulled Away From Blower Panel...................................... 17
Figure 7 - Vertical Unit Service Access ....................................................................................... 17
Figure 8 - Flattened Duct Flanges................................................................................................. 25
Figure 9 - WSHP Series Supply Fan............................................................................................. 26
Figure 10 - Pioneer Silver Controller Layout ............................................................................... 32
V01230 · Rev. A · 220720

5
AAON ProFit Features and Options Introduction
Energy Efficiency
•Direct Drive Supply Fan
•Scroll or Rotary Compressor
•High Efficiency Electronically
Commutated (EC) Motor
•Copper Coaxial Refrigerant-to-Water-
Heat Exchanger
•AHRI Certified Performance
Indoor Air Quality
•Stainless Steel Drain Pan
Controls
•5 Wire Thermostat Control
Installation and Maintenance
•Internal P-trap
•Color-Coded Wiring and Wiring
Diagram
Environmentally Friendly
•R-410A Refrigerant
Extended Life
•Sturdy Galvanized Steel Construction
•Induction Brazing
•Stainless Steel Drain Pan
•5 Year Parts Warranty
Reduced Sound
•Compressors mounted with rubber-in-
shear isolators on an isolation plate with
rubber-in-shear isolation to the cabinet
•Sound absorbing fiberglass cabinet
insulation
•Floating water connections

6
Safety
ROTATION MUST BE CHECKED ON
ALL COMPRESSORS AND MOTORS OF
3 PHASE UNITS AT STARTUP BY A
QUALIFIED SERVICE TECHNICIAN.
Scroll compressors are directional and
will be damaged if rotated in the wrong
direction. Compressor rotation must
be checked for proper operation,
without using external refrigerant
pressure gauges.
Often, a
compressor running in reverse rotation
will be much louder than a normal
compressor, and will not develop
much of a temperature differential
between the suction and discharge
lines.
Fan motor rotation must
also be
checked for proper operation.
Alterations must only be made at the
unit power connection.
To prevent damage to the unit, do not
use acidic chemical coil cleaners. Do
not use alkaline chemical coil cleaners
with a pH value greater than 8.5, after
mixing, without first using an
aluminum corrosion inhibitor in the
cleaning solution.
Cleaning the cooling tower or the
water loop with harsh chemicals, such
as hydrochloric acid (muriatic acid) or
chlorine, can damage the refrigerant-
to-water heat exchanger. Care must
be taken to avoid allowing chemicals
to enter the refrigerant-to-water heat
exchanger. See Appendix A - Heat
Exchanger Corrosion Resistance for
more information.
Attention must be paid to the following statements:
NOTE - Notes are intended to clarify the unit installation, operation and maintenance.
CAUTION - Caution statements are given to prevent actions that may result in equipment
damage, property damage, or personal injury.
WARNING - Warning statements are given to prevent actions that could result in
equipment damage, property damage, personal injury or death.
CAUTION
CAUTION
CAUTION

7
PVC (Polyvinyl Chloride) and CPVC
(Chlorinated Polyvinyl Chloride) are
vulnerable to attack by certain
chemicals. Polyolester
(POE) oils
used with R-
410A and other
refrigerants, even in trace amounts, in
a PVC or CPVC piping system will
result in stress cracking of the piping
and fittings and complete piping
system failure.
OPEN LOOP APPLICATIONS
Failure of the refrigerant-to-water heat
exchanger
as a result of chemical
corrosion is excluded from coverage
under AAON Inc. warranties and the
heat exchanger manufacturer’s
warranties.
Some chemical coil cleaning
compounds are caustic or toxic. Use
these substances only in accordance
with the manufacturer’s usage
instructions.
Failure to follow
instructions may result in equipment
damage, injury or death.
Do not work in a closed area where
refrigerant or nitrogen gases may be
leaking. A sufficient quantity of vapors
may be present and cause injury or
death.
UNIT HANDLING
To prevent injury or death lifting
equipment capacity shall exceed unit
weight by an adequate safety factor.
Always test-lift unit not more than 24
inches high to verify proper center of
gravity lift point to avoid unit damage,
injury or death.
ELECTRIC SHOCK AND FIRE
HAZARD
Failure to follow safety warnings
exactly could result in dangerous
operation, serious injury, death or
property damage.
Improper servicing could result in
dangerous operation, serious injury,
death, or property damage.

Before servicing, disconnect all
electrical power to the unit to avoid
shock hazard or injury from
rotating parts.
Follow proper
Lockout-Tagout procedures.
When servicing controls, label all
wires prior to disconnecting.
Reconnect wires correctly.

Verify proper operation after
servicing. Secure all service
panels.
CAUTION
WARNING
WARNING
WARNING
WARNING
WARNING

8
GROUNDING REQUIRED
All field installed wiring must be
completed by qualified personnel.
Field installed wiring must comply with
NEC/CEC, local and state electrical
code requirements. Failure to follow
code requirements could result in
serious injury or death. Provide proper
unit ground in accordance with these
code requirements.
During installation, testing, servicing
and troubleshooting of the equipment
it may be necessary to work with live
electrical components. Only a
qualified licensed electrician or
individual properly trained in handling
live electrical components shall
perform these tasks.
Standard NFPA-70E, an OSHA
regulation requiring an Arc Flash
Boundary to be field established and
marked for identification of where
appropriate Personal Protective
Equipment (PPE) be worn, must be
followed.
ROTATING COMPONENTS
Unit contains fans with moving parts
that can cause serious injury. Do not
remove panel containing fans until the
power to the unit has been
disconnected and fan has stopped
rotating.
WATER FREEZING
Failure of the refrigerant-to-water heat
exchanger due to freezing will allow
water to enter the refrigerant circuit
and will cause extensive damage to
the refrigerant circuit components.
Any damage to the equipment as a
result of water freezing is excluded
from coverage under AAON
warranties and the heat exchanger
manufacturer warranties.
WATER PRESSURE
Prior to connection of condensing
water supply, verify water pressure is
less than maximum pressure shown
on unit nameplate. To prevent injury
or death due to instantaneous release
of high pressure water, relief valves
must be field supplied on system
water piping.
WARNING
WARNING
WARNING
WARNING
WARNING

9
1. READ THE ENTIRE INSTALLATION,
OPERATION AND MAINTENANCE
MANUAL. OTHER IMPORTANT
SAFETY PRECAUTIONS ARE
PROVIDED THROUGHOUT THIS
MANUAL.
2. Startup and service must be performed by
a Factory Trained Service Technician.
3. The unit is for indoor use only. See
General Information section for more unit
information.
4. Every unit has a unique equipment
nameplate with electrical, operational,
and unit clearance specifications. Always
refer to the unit nameplate for specific
ratings unique to the model you have
purchased.

10
WSHP Series Feature String Nomenclature
Unit Configuration
:
Accessory Options
Gen
Major Rev
Size
Series
Minor Rev
Voltage
Eff. Level
Comp Level
Loop Type
Coil Type
Heat Type
Heat Staging
1
2
3A
3B
4
5
6A
6B
7
8
9
10
11
12
13
14
15
16
WV B
-
024
-
C
-
0
-
C
-
1
-
0
0
0
-
0
0
:
0
0
-
0
E
-
0
0
-
0
0
-
0
0
0
0
0
-
0
0
0
0
0
MODEL OPTIONS
Generation and Orientation
WV = Horizontal Water-Source Heat Pump
Major Revision
B
Unit Size
006 = 6,000 Btu/hr = ½ ton
009 = 9,000 Btu/hr = ¾ ton
012 = 12,000 Btu/hr = 1 ton
015 = 15,000 Btu/hr = 1 ¼ ton
018 = 18,000 Btu/hr = 1 ½ ton
024 = 24,000 Btu/hr = 2 ton
030 = 30,000 Btu/hr = 2 ½ ton
036 = 36, 000 Btu/hr = 3 ton
042 = 42,000 Btu/hr = 3 ½ ton
048 = 48,000 Btu/hr = 4 ton
060 = 60,000 Btu/hr = 5 ton
Series
A = A Cabinet (006, 009 & 012)
B = B Cabinet (015 & 018)
C = C Cabinet (024 & 030)
D = D Cabinet (036 & 042)
E = E Cabinet (048 & 060)
Minor Revision
0 = Minor Revision 0
Voltage
3 = 460V/3Φ/60Hz
4 = 575V/3Φ/60Hz
A = 265V/1Φ/60Hz
B = 115V/1Φ/60Hz
C = 208-230V/1Φ/60Hz
D = 208-230V/3Φ/60Hz
Efficiency Level
0 = Std Efficiency Compact Box
Compressor Style
0 = R-410A On/Off Compressor - Heat Pump
Loop Type
0 = Water Loop (Cooling Tower Only, EWT ≥ 60°F)
A = Ground Loop Application
B = Ground Water Application
Coil Type
0 = Copper Coaxial Refrigerant-to-Water Heat
Exchanger + Fin & Tube Condenser Coil
Heat Type
0 = No Heating
Heating Staging
0 = No Heating
1: Unit Orientation
0 = Right Hand Return + Left Hand Supply
A = Right Hand Return + End Supply
B = Left Hand Return + Right Hand Supply
C = Left Hand Return + End Supply
2: Supply Fan
B = Standard Fan + ECM Motor
3A: Filter Rack
0 = Open Return - Slide-Out Filter Rack
3B: Filters
A = 2” MERV 8 Pleated Filter
E = 1” MERV 8 Pleated Filter
F = 1” MERV 11 Pleated Filter
G = 1” MERV 13 Pleated Filter
I = 1” Fiberglass Filter
J = 2” Fiberglass Filter
K= 2” MERV 11 Pleated Filter
L = 2” MERV 13 Pleated Filter
4: Refrigeration and Dehumidification Options
0 = Standard

11
WSHP Series Feature String Nomenclature
Unit Configuration
:
Accessory Options
Gen
Major Rev
Size
Series
Minor Rev
Voltage
Eff. Level
Comp Level
Loop Type
Coil Type
Heat Type
Heat Staging
1
2
3A
3B
4
5
6A
6B
7
8
9
10
11
12
13
14
15
16
WV B
-
024
-
C
-
0
-
C
-
1
-
0
0
0
-
0
0
:
0
0
-
0
E
-
0
0
-
0
0
-
0
0
0
0
0
-
0
0
0
0
0
5: Service Disconnect
0 = Standard - 5 kAIC
D = 5 kAIC Standard / 100 kAIC w/ Field Installed
Fusing
F = 100 kAIC Fusing w/ Fused Disconnect - 30 Amp
G = 100 kAIC Fusing w/ Fused Disconnect - 60 Amp
6A: Control Sequence
0 = Terminal Block for Thermostat + Pioneer Silver
Controller
A = Terminal Block for Thermostat + Pioneer Silver
Controller + Expansion Board
6B: Control Options
0 = Standard - No Communication
7: Cabinet Options
G = 1/2” Fiberglass Cabinet Insulation + Stainless
Steel Drain Pan
H = 1/2” Fiberglass Cabinet Insulation + Stainless
Steel Drain Pan + Low Sound Package + MLV
8: WSE
0 = Standard - None
9 & 10: Blank
00 = Standard - None
11: Code Options
0 = Standard - ETL USA Listing
B = ETL USA + Canada Listing
12: Shipping Options
0 = Standard
13: Cabinet Access
0 = Standard
14 & 15: Blank
00 = Standard - None
16: Cabinet & Specials
0 = Galvanized Steel Cabinet Construction

12
General Information
AAON WV Series Water-Source Heat Pump
units (WSHP) are designed for indoor
installation only. Units are assembled, wired,
charged and run-tested at the factory.
Certification of Cooling Models
a. Certified as a commercial central air
conditioner with electrically operated
compressors.
b. Certified for indoor installation only.
c. Certified with refrigerant R-410A coils.
Codes and Ordinances
WSHP Series units have been tested and
certified, by ETL, in accordance with UL
Safety Standard 1995/CSA C22.2 No. 236.
System must be sized in accordance with the
American Society of Heating, Refrigeration
and Air Conditioning Engineers Handbook.
Installation of units must conform to the ICC
standards of the International Mechanical
Code, the International Building Code,
Installation of Air Conditioning and
Ventilating Systems Standard, NFPA 90A,
and local building, plumbing and waste water
codes. All appliances must be electrically
grounded in accordance with local codes, or
in the absence of local codes, the current
National Electric Code, ANSI/NFPA 70 or
the current Canadian Electrical Code CSA
C22.1.
Improper installation, adjustment,
alteration, service or maintenance can
cause property damage, personal
injury or loss of life.
Startup and
service must be performed by a
Factory Trained Service Technician. A
copy of this IOM must be kept with the
unit.
These units must not be used as a
“construction heater” at anytime
during any phase of construction.
Very low return air temperatures,
harmful vapors, and misplacement of
the filters can damage the unit and its
efficiency.
The Clean Air Act of 1990 bans the
intentional venting of refrigerant as of
July 1, 1992. Approved methods of
recovery, recycling, or reclaiming
must be followed.
Coils and sheet metal surfaces
present sharp edges and care must
be
taken when working with
equipment.
CAUTION
WARNING
CAUTION
WARNING

13
Receiving Unit
When received, check the unit for damage
that might have occurred in transit. If damage
is found, it must be noted on the carrier’s
freight bill. A request for inspection by
carrier’s agent must be made in writing at
once. Check nameplate to ensure the correct
model sizes and voltages have been received
to match the job requirements.
All units are shrink-wrapped in blue wrap. If
a unit shows up with any other color wrap,
the unit has been opened and it must be
thoroughly checked for damage that
necessitated re-wrapping.
If repairs must be made to damaged goods,
notify the factory before any repair action is
taken in order to protect the warranty. Certain
equipment alteration, repair, and
manipulation of equipment without the
manufacturer’s consent may void the product
warranty. Contact the AAON Warranty
Department for assistance with handling
damaged goods, repairs, and freight claims:
918-382-6450.
Note: Upon receipt check shipment for items
that ship loose. Consult order and shipment
documentation to identify potential loose-
shipped items.
Figure 1 - Access Panels
Storage
If installation will not occur immediately
following delivery, store equipment in a dry
protected area away from construction traffic
and in the proper orientation as marked on the
packaging with all internal packaging in
place. Secure all loose-shipped items.
Direct Expansion (DX) Systems
All systems are factory assembled, leak
tested, charged with R-410A refrigerant, and
run tested.
All systems include air coil, reversing valve,
liquid line filter dryer, thermal expansion
valve (TXV), and compressor.
Always control the unit from the thermostat,
or control panel, never at the main power
supply, except for emergency or complete
shutdown of the unit.
During the cooling season, if the airflow is
reduced due to dirty air filters or any other
reason, the cooling coils can get too cold
which can cause excessive liquid to return to
the compressor. As the liquid concentration
builds up, oil is washed out of the
compressor, leaving it starved for lubrication.
The compressor life will be seriously
shortened by reduced lubrication and the
pumping of excessive amounts of liquid oil
and refrigerant.
Failure to observe the following
instructions will result in premature
failure of your system and possible
voiding of the warranty.
WARNING

14
Wiring Diagrams
Unit specific wiring diagrams are affixed
inside the control compartment panel.
Installation
AAON equipment has been designed for
quick and easy installation.
Locating the Unit
Placement of the unit relative to ductwork,
electrical and plumbing must be carefully
considered. Supply and return air plenum or
duct can be mounted directly to the duct
connection flanges. Use a properly sized duct
transition to connect supply duct to unit
supply air opening. Return duct flanges are
only included on units with the optional 4-
sided filter rack. Use flexible gasket material
to seal the duct to the unit.
Verify floor, or foundation can support the
total unit weight, including accessory
weights.
Note: Ductwork must be supported
independently from the unit. The unit must
not support supply and/or return ductwork.
Allow adequate service clearances as shown
on the unit nameplate and unit drawing.
Consult your local building codes for
additional service clearance requirements.
Allow adequate space for piping access and
panel removal. Water piping and condensate
drain connections are located on the front of
the unit.
Floor Mounted Units
Make sure the unit is level. Other installation
provisions may be necessary according to job
specifications.
It is recommended that a vibration isolation
pad be used when floor mounting a unit
Condensate Drain Piping
An internal P-trap is provided on WV Series
units. Drain line must pitch downward
toward drain. An air break must be used with
long runs of condensate lines.
Condensate drain trapping and piping must
conform to all applicable governing codes.
Drain connection is a ¾” FTP.
Figure 2 - Internal Condensate P-trap
Emergency drain pan is
recommended for all applications
where a risk of water damage to
surrounding structure or furnishings.
Refer to local codes.
Installing contractor is responsible for
leak checking internal condensate
trap during installation. Failure to
check condensate trap and drain
operation may result in damage to the
unit and property.
CAUTION
CAUTION

15
Table 1 - WSHP WV Series Clearances
Minimum Clearances Required
Front/Control Panel Air Intake/Return Back/Compressor Access*
24
12
0
* Compressor replacement access is through the service access panel on the rear of the unit. Compressor wiring
terminals can be accessed from the front of the unit.
Figure 3 - Vertical Configuration Orientations

16
Backward Curved Blower Removal
1) Using a 5
16
�”socket, remove the screw
from the controls access panel; Access
panel can now be removed.
2) Using a 5
16
�”socket, remove the screws
on the outside of the control panel.
3) The hinged control compartment can now
be opened to access the blower.
4) Grip the blower assembly and pull it until
it clears the compartment.
Figure 4 - Blower Assembly
Forward Curved Blower Removal
1) Using a 5
16
�”socket, remove the screw
from the controls access panel; Access
panel can now be removed.
2) Grip the blower assembly with both
hands and pull it about ½” or until it
clears the captive panel at the assembly.

17
Figure 5 - Blower Assembly with Captive
Panel
3) Pull the blower assembly out of the unit.
Figure 6 - Blower Assembly, Shown Pulled
Away From Blower Panel
Lifting and Handling the Unit
Before lifting unit, be sure that all shipping
material has been removed from unit.
Unit may be lifted with a pallet jack.
Service Access
Several components are accessible through
the service access panels of the WV unit.
Accessible components include: Blower
housing, blower motor, TXV, reversing valve,
and filter drier.
Figure 7 - Vertical Unit Service Access
Service access is provided through access
panels to the controls and compressor
compartment, an additional removable panel
to the compressor compartment, and a hinged
door to the blower section accessible through
the controls compartment.
While leaving the access panel opened is
acceptable for most service / maintenance
conditions, occasionally it will be necessary
for the panel to be completely removed.
UNIT HANDLING
Incorrect lifting can cause damage to
the unit, injury or death. Lifting
equipment capacity must exceed unit
weight by an adequate safety factor.
Always test lift unit not more than 24
inches high to verify proper center of
gravity lift point.
WARNING

18
Blower Motor and Fan Access
To access the blower motor and fan, first
remove the blower assembly as outlined in
the appropriate “Blower Assembly Removal”
for your unit.
Once the blower assembly is on a working
surface:
1) Remove the five (5) screws that secure
the blower motor to the blower assembly.
2) Pull the motor and blower up and out of
the blower assembly.
3) Separate the motor from the blower sub
assembly, place the sub assembly (motor
side down) and remove the set screw as
shown below.
4) The blower can now be separated from
the motor.
Refrigerant-to-Water Heat Exchanger
Water Piping
Open Loop Applications
This product contains refrigerant-to-water
heat exchanger made of cupronickel or
copper and is subject to severe corrosion and
failure when exposed to chlorides.
Do not allow water containing any form of
chlorides to enter this heat exchanger.
Common forms of chlorides include:
1. Sea water mist entering an open cooling
tower system.
2. Contaminated make-up water containing
salt water.
OPEN LOOP APPLICATIONS
Failure of the refrigerant-to-water heat
exchanger
as a result of chemical
corrosion is excluded from coverage
under AAON Inc. warranties and the
heat exchanger manufacturer’s
warranties.
WARNING

19
3. Water loop systems that have been
disinfected.
Chlorides will result in a premature failure of
the refrigerant-to-water heat exchanger.
Failure of the refrigerant-to-water heat
exchanger as a result of chemical corrosion is
excluded from coverage under AAON
warranties and the heat exchanger
manufacturer warranties.
Failure of the refrigerant-to-water heat
exchanger may allow water to enter the
refrigerant circuit and may cause extensive
damage to the refrigerant circuit components.
Any damage to the equipment as a result of
refrigerant-to-water heat exchanger failure
from chemical corrosion due to the fluid in
the refrigerant-to-water heat exchanger is
excluded from coverage under AAON
warranties and the heat exchanger
manufacturer warranties.
Freezing Water in the Heat Exchanger
This product contains one refrigerant-to-
water heat exchanger. A refrigerant-to-water
heat exchanger contains refrigerant in one
passage and water in another passage. Water
is subject to freezing at 32°F. When water
freezes in a heat exchanger significant forces
are exerted on the components of the heat
exchanger where the water is confined.
Failure of the refrigerant-to-water heat
exchanger due to freezing will allow water to
enter the refrigerant circuit and will cause
extensive damage to the refrigerant circuit
components. Any damage to the equipment
as a result of water freezing in the refrigerant-
to-water heat exchanger is excluded from
coverage under AAON warranties and the
heat exchanger manufacturer warranties.
Unit is capable of operating with Entering
Water Temperatures (EWT) as low as 57°F
during cooling mode without the need for an
automatic flow regulating water valve. If the
EWT is expected to be lower than 57°F or
more stable operation is desired, an automatic
flow regulating water valve must be installed.
OPEN LOOP APPLICATIONS
Cupronickel refrigerant-to-water heat
exchangers are recommended with all
open loop applications. Failure to use
a Cupronickel heat exchanger may
result in premature failure of your
system and possible voiding of the
warranty.
Cleaning the cooling tower or water
loop with harsh
chemicals such as
hydrochloric acid (muriatic acid),
chlorine or other chlorides, can
damage the refrigerant-to-water heat
exchanger. Care must be taken to
avoid allowing chemicals to enter the
refrigerant-to-
water heat exchanger.
See Appendix A - Heat Exchanger
Corrosion Resistance for more
information.
WARNING
CAUTION

20
Glycol solution must be used if ambient
temperatures are expected to fall below
freezing or if the loop water temperature is
below 50°F while operating in the heating
mode (heat pump units only). Adding glycol
causes an increase in pressure drop resulting
in a decrease in unit performance. A
minimum concentration of 20% glycol
solution is recommended. The unit controller
contains dip switches to set the loop glycol
percentage. Set the glycol percentage to the
closest option available, rounding down if
needed.
The option selected will reset the Leaving
Water Temperature safety for the unit.
AAON will not be responsible for frozen
coaxial coils due to improper selection of
glycol percentage. See Leaving Water
Temperature Alarm section for more details.
Table 2 - Glycol Freezing Points
% Glycol
Ethylene
Glycol
Propylene
Glycol
20
18°F
19°F
30
7°F
9°F
40
-7°F
-6°F
50
-28°F
-27°F
Water loop piping runs through unheated
areas or outside the building must be
insulated.
Never operate the unit in heat pump mode
with a saturated suction temperature below
35°F for pure water systems or below the
freezing point +3°F of the aqueous solution
of water and glycol.
Water Piping
Only use approved water pipe material.
Avoid using galvanized material for water
lines/fittings.
WATER FREEZING
Failure of the refrigerant-to-water heat
exchanger due to freezing will allow
water to enter the refrigerant circuit
and will cause extensive damage to
the refrigerant circuit components.
Any damage to the equipment as a
result of water freezing is excluded
from coverage under AAON
warranties and the heat exchanger
manufacturer warranties.
WATER PRESSURE
Prior to connection of the water
supply, verify water pressure is less
than maximu
m pressure shown on
unit nameplate. To prevent injury or
death due to instantaneous release of
high pressure water, drain valves
must be field supplied on water piping.
Supply water connection may require
a backflow preventer to prevent
supply makeup water from backing up
into the public water system.
PVC (Polyvinyl Chloride) and CPVC
(Chlorinated Polyvinyl Chloride) are
vulnerable to attack by certain
chemicals. Polyolester (POE) oils
used with R-
410A and other
refrigerants, even in trace amounts, in
a PVC or CPVC piping system will
result in stress cracking of the piping
and fittings and complete piping
system failure.
WARNING
WARNING
CAUTION