AAON WH Series Owner's manual

WH Series
Horizontal Water-Source Heat Pump Unit
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 should be kept
with the unit.
WARNING
WARNING

2
Table of Contents
AAON WSHP Series Features and Options Introduction .............................................................. 4
Safety .............................................................................................................................................. 5
WSHP Series Feature String Nomenclature................................................................................... 9
General Information...................................................................................................................... 11
Codes and Ordinances .............................................................................................................. 11
Receiving Unit.......................................................................................................................... 12
Storage ...................................................................................................................................... 12
Direct Expansion (DX) Systems............................................................................................... 12
Wiring Diagrams....................................................................................................................... 13
Installation..................................................................................................................................... 13
Locating the Unit...................................................................................................................... 13
Condensate Drain Piping.......................................................................................................... 14
Blower Assembly Removal – Side Access............................................................................... 17
Discharge Modification ............................................................................................................ 18
Lifting and Handling the Unit................................................................................................... 19
Horizontal Unit Bottom Access................................................................................................ 19
Blower Assembly Removal – Bottom Access.......................................................................... 20
Blower Motor and Fan Access.................................................................................................. 21
Refrigerant-to-Water Heat Exchanger Water Piping................................................................ 22
Electrical................................................................................................................................... 25
Optional 4-Sided Air Filter Rack Setup.................................................................................... 28
Duct Connection....................................................................................................................... 30
Waterside Economizer.............................................................................................................. 30
Startup........................................................................................................................................... 31
Supply Fans............................................................................................................................... 31
Fan Air Flow Adjustment......................................................................................................... 32
Filters ........................................................................................................................................ 32
Adjusting Refrigerant Charge................................................................................................... 32
Operation....................................................................................................................................... 36
AAON WSHP Pioneer Silver Controller.................................................................................. 36
AAON WSHP Pioneer Silver Expansion Board ...................................................................... 42
Maintenance.................................................................................................................................. 46
DX Cooling............................................................................................................................... 46
Condensate Drain Pans............................................................................................................. 46
Supply Fans............................................................................................................................... 47
Microchannel Coil Cleaning..................................................................................................... 47
Filter Replacement.................................................................................................................... 49
Replacement Parts..................................................................................................................... 49
Warranty, Service, and Parts Department................................................................................. 49
Filter Information.......................................................................................................................... 49
Appendix A - Heat Exchanger Corrosion Resistance................................................................... 51

3
Index of Tables and Figures
Tables:
Table 1 - WSHP WH Series Clearances....................................................................................... 16
Table 2 - Glycol Freezing Points................................................................................................. 23
Table 3 - Condenser Water Connections...................................................................................... 24
Table 4 - Control Wiring............................................................................................................... 27
Table 5 - Acceptable Refrigeration Circuit Values at AHRI ISO 13256 WLHP Conditions....... 33
Table 6 - R-410A Refrigerant Temperature-Pressure Chart......................................................... 35
Table 7 - LED Diagnostic Codes.................................................................................................. 40
Table 8 - Glycol Setpoints ............................................................................................................ 40
Table 9 – 006, 009, & 012 WH Unit Series Filters (A Cabinet)................................................... 49
Table 10 – 015, 018, 024, & 030 WH Series Unit Filters (B & C Cabinet)................................. 50
Table 11 – 036 & 042 WH Series Unit Filters (D Cabinet).......................................................... 50
Table 12 – 048 & 060 WH Series Unit Filters (E Cabinet).......................................................... 50
Figures:
Figure 1 – Access Panels .............................................................................................................. 12
Figure 2 - Foam Shipping Block................................................................................................... 13
Figure 3 - Mounting Horizontal Units.......................................................................................... 13
Figure 4 - Vibration Grommet Installation................................................................................... 14
Figure 5 - Condensate Drain Piping.............................................................................................. 14
Figure 6 - Drain Trap.................................................................................................................... 15
Figure 7 - WH Series Unit Orientation (Right Return Units Shown)........................................... 16
Figure 8 - Blower Assembly with Captive Panel.......................................................................... 17
Figure 9 - Blower Assembly, Shown Pulled Away From Blower Panel...................................... 17
Figure 10 - Horizontal Unit Bottom Access................................................................................. 19
Figure 11 - WH Bottom Access Panel.......................................................................................... 19
Figure 12 - Shipping Screw .......................................................................................................... 20
Figure 13 - Spade Connectors....................................................................................................... 20
Figure 14 - Filter access Doors..................................................................................................... 28
Figure 15 - Close-Up of Pre-cut Aluminum Handle..................................................................... 28
Figure 16 - Pre-cut Aluminum Handles bent to 90 degrees.......................................................... 28
Figure 17 - Filter Pull.................................................................................................................... 29
Figure 18 - Fastener Clip .............................................................................................................. 29
Figure 19 - Removing Filter Access Doors .................................................................................. 29
Figure 20 – Using the Filter Pull................................................................................................... 29
Figure 21 - Keeper Tabs ............................................................................................................... 30
Figure 22 - Filter Access Doors at 45 degree angle...................................................................... 30
Figure 23 - WSHP Series Supply Fan........................................................................................... 32
Figure 24 – Pioneer Silver Controller Layout............................................................................... 38
Figure 25 - Pioneer Silver Expansion Board Layout.................................................................... 43
V81280 · Rev. A · 170308

4
AAON WSHP Features and Options Introduction
Energy Efficiency
•Direct Drive Forward Curved Supply Fan
•Scroll or Rotary Compressor
•Closed Cell Neoprene Foam or 1” Foil
Faced Cotton Fiber Cabinet Insulation
•Waterside Economizer with 3-Way
Motorized Valve
•Electronically Commutated Motors
(ECM) or Permanent Split Capacitor
Motors (PSC)
•Copper Coaxial Heat Exchanger or
Cupronickel Coaxial Refrigerant-to-
Water-Heat Exchanger
•Microchannel Air Coils
•Waterside Economizer
Indoor Air Quality
•Multiple High Efficiency Filters up to
MERV 14 Rating
•Stainless Steel Drain Pan
•Closed Cell Neoprene Foam or 1” Foil
Faced Cotton Fiber Cabinet Insulation
Humidity Control
•ECM Fan Speed Dehumidification
•Hot Gas Reheat Dehumidification
Controls
•5 Wire Thermostat Control
Installation and Maintenance
•Tool-Less Access Panels
•Bottom Service Access
•Color-Coded Wiring and Wiring
Diagram
•Non-Fused Service Disconnect
System Integration
•Waterside Economizer
•Hot Gas Reheat Humidity Control
Environmentally Friendly
•R-410A Refrigerant
•Recyclable Sheet Metal Shipping Pallet
Extended Life
•Induction Brazing
•Aluminum Cabinet
•Stainless Steel Drain Pan
•Cupronickel Coaxial Refrigerant-to-
Water Heat Exchanger
•Microchannel Air Coil
Reduced Sound
•Sound Absorbing Cabinet Insulation
•Compressors mounted with rubber-in-
shear isolators on an isolation plate with
rubber-in-shear isolation to the cabinet
•Sound Absorbing Blower Insulation
•Compressor Sound Blanket

5
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 can 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 should also be
checked for proper operation.
Alterations should only
be made at
the unit power connection.
CAUTION
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.
CAUTION
Cleaning the cooling tower or the
condenser water loop with harsh
chemicals, such as hydrochloric acid
(muriatic acid) or chlorine, can
damage the water-cooled condenser.
Care should be taken to avoid
allowing chemicals to enter the
water-
cooled condenser. See
Appendix A -
Heat Exchanger
Corrosion Resistance for more
information.
CAUTION
Attention should 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.

6
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.
CAUTION
OPEN LOOP APPLICATIONS
Failure of the condenser as a result
of chemical corrosion is excluded
from coverage under AAON Inc.
warranties and the heat exchanger
manufacturer’s warranties.
WARNING
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.
WARNING
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.
WARNING
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.
WARNING
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.
WARNING

7
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.
WARNING
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, should be
followed.
WARNING
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.
WARNING
WATER FREEZING
Failure of the condenser 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 condenser is excluded
from co
verage under AAON
warranties and t
he heat exchanger
manufacturer warranties.
WARNING
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 should be field supplied on
system water piping.
WARNING

8
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.

9
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
WH A
-
024
-
C
-
0
-
1
-
1
-
0
0
0
-
0
0
:
0
0
-
0
A
-
0
0
-
0
0
-
0
0
0
0
0
-
0
0
0
0
0
MODEL OPTIONS
Generation and Orientation
WH = Horizontal Water-Source Heat Pump
Major Revision
A
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
1 = Std Efficiency Compact Box with PSC Motor
2 = Std Efficiency Compact Box with ECM Motor
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 + Microchannel Air Coil
B = Cupronickel Coaxial Refrigerant-to-Water Heat
Exchanger + Microchannel Air 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
0 = Standard Fan + PSC Motor
A = Standard Fan + ECM Motor

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
WH A
-
024
-
C
-
0
-
1
-
1
-
0
0
0
-
0
0
:
0
0
-
0
A
-
0
0
-
0
0
-
0
0
0
0
0
-
0
0
0
0
0
3A: Filter Rack
*0 = Open Return – Slide-Out Filter Rack
A = 4-Sided 2” Filter Rack - Return Duct Flange and
Access Panel
B = 4-Sided 2” Filter Rack + High MERV Filter Seal
- Return Duct Flange and Access Panel
C = 4-Sided 4” Filter Rack + High MERV Filter Seal
- Return Duct Flange and Access Panel
D = 4-Sided 1” Filter Rack + Access Panel - Return
Duct Flange and Access Panel
E = 4-Sided 1” Filter Rack + High MERV Filter Seal
- Return Duct Flange and Access Panel
3B: Filters
0 = No Filter
A = 2” MERV 8 Filter
B = 4” MERV 11 Filter
C = 4” MERV 13 Filter
D = 4” MERV 14 Filter
E = 1” MERV 8 Filter
F = 1” MERV 11 Filter
G = 1” MERV 13 Filter
4: Refrigeration and Dehumidification Options
0 = Standard
A = ECM Fan Speed Dehumidification
B = On/Off Hot Gas Reheat Dehumidification
5: Service Disconnect
0 = Standard - None
A = Non-Fused Service Disconnect
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
* 1” Filter Rack for A Cabinet Only
2” Filter Rack for B, C, D, & E Cabinets
7: Cabinet Options
B = Closed Cell Neoprene Foam Cabinet Insulation +
Stainless Steel Drain Pan
C = Low Sound Package - Closed Cell Neoprene
Foam Cabinet and Blower Insulation + Compressor
Sound Blanket + Stainless Steel Drain Pan
0 = 1” Foil Face Cotton Fiber Cabinet Insulation +
Stainless Steel Drain Pan
A = Low Sound Package – 1” Foil Face Cotton Fiber
Cabinet and Blower Insulation + Compressor Sound
Blanket + Stainless Steel Drain Pan
8: WSE
0 = Standard - None
B = Waterside Economizer + 3-Way Motorized
Valve
9: Blank
0 = Standard - None
10: Blank
0 = Standard - None
11: Code Options
0 = Standard - ETL USA Listing
B = ETL USA + Canada Listing
12: Shipping Options
0 = Standard - Sheet Metal Pallet with Forklift Slots
and AAON Blue Shrink Wrap
13: Blank
0 = Standard - None
14: Blank
0 = Standard - None
15: Blank
0 = Standard - None
16: Cabinet & Specials
0 = All Aluminum Cabinet Construction

11
General Information
AAON WH 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 should 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 should be kept
with the unit.
WARNING
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.
CAUTION
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.
CAUTION
Coils and sheet metal surfaces
present sharp edges and care must
be taken
when working with
equipment.
WARNING

12
Receiving Unit
When received, the unit should be checked
for damage that might have occurred in
transit. If damage is found it should be noted
on the carrier’s Freight Bill. A request for
inspection by carrier’s agent should be made
in writing at once.
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 should be
thoroughly checked for damage that
necessitated re-wrapping.
Nameplate should be checked to ensure the
correct model sizes and voltages have been
received to match the job requirements.
If repairs must be made to damaged goods,
then the factory should be notified 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: [phone].
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.
Failure to observe the following
instructions will result in premature
failure of your system and possible
voiding of the warranty.
WARNING

13
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.
Wiring Diagrams
Unit specific wiring diagrams are affixed
inside the control compartment panel.
Installation
AAON equipment has been designed for
quick and easy installation.
Before startup of the unit, remove the foam
shipping block that supports the blower
assembly before installation, or damage may
occur.
Figure 2 - Foam Shipping Block
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. 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 ceiling, floor, or foundation can
support the total unit weight, including
accessory weights.
To properly support the horizontal WSHP
unit and reduce sound and vibration, it must
be mounted level in both horizontal
directions. These units are designed to be
suspended via threaded rod (field provided)
through all four hanger brackets using the
four (4) vibration grommets and 3/8”
washers provided and as shown in Figure 3.
Figure 3 - Mounting Horizontal Units
Caution should be taken to assure the top of
the vibration grommet is inserted into (or
through) the hole provided in the hanger
bracket, as pointed out in Figure 4.
Threaded Rod
(Field Provided)
Nut
(Field Provided)
3/8” Washer
Vibration
Grommet

14
Figure 4 - Vibration Grommet Installation
The threaded rod and nut should be
adequately sized to support the total unit
weight. Care should be taken to avoid
installing units directly above or adjacent to
sound-sensitive areas. Note: Only the
required supply and/or return air ducts
should be supported by or from the
horizontal WSHP unit.
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. Condenser water piping is on
the compressor end and condensate drain
connections are located on the opposite end.
Figure 5 - Condensate Drain Piping
Floor Mounted Units
Make sure the unit is level and mounted on a
field supplied platform with a minimum
height to allow for proper depth of the
condensate line p-trap. 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
A p-trap and drain line must be installed on
horizontal units, with the p-trap not to
exceed 6” from the drain connection. The
lines should be the same pipe size or larger
as/than the drain connection and pitch
downward toward drain. An air break should
be used with long runs of condensate lines.
Note: All horizontal units require a field
installed 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.
CAUTION
Unit should not be operated without
p-traps. Failure to install a p-trap may
result in overflow of condensate
water.
CAUTION
Condensate
Drain

15
Draw-through cooling coils will have a
negative static pressure in the drain pan area.
This will cause an un-trapped drain to back
up due to air being pulled up through the
condensate drain piping.
Condensate drain trapping and piping should
conform to all applicable governing codes.
Note:The drain pan connection is an
unthreaded 7/8” stainless steel pipe stub.
Figure 6 - Drain Trap
The total height from the trap inlet to the top
of the bottom bend of the trap must be 2”
minimum.
The height from top of the bottom bend of
the trap to the bottom of the leaving pipe
must be at least equal to 1”. This ensures
that enough water is stored in the trap to
prevent losing the drain seal during unit
startup.
2"
1"

16
Table 1 - WSHP WH Series Clearances
Minimum Clearances Required
Capacity
Front/Control
Panel
Back
(Optional) Air Intake *Bottom
006, 009, 012
20
24
6
14
015, 018
20
20
6
20
024, 030
20
20
6
20
036, 042
20
20
6
24
048, 060
20
20
6
24
072, 084
20
24
6
20
*Note: If bottom access is not available, optional dimensions become required.
Water Connections
Air Intake
(Filters)
End
Discharge
Straight
Discharge
End Discharge (Optional)
Air Intake
(Filters)
Straight
Discharge
Figure 7 - WH Series Unit Orientation (Right Return Units Shown)

17
Blower Assembly Removal – Side Access
1) Using a ¼” socket drive, remove the
shipping screw on the outside of the
right or discharge side of the unit as
shown in the figure below.
2) Remove the side blower access panel
using the panel handle and lift the panel
upwards about ½” or until it clears the
captive panel at the bottom of the blower
panel.
3) Pull the bottom of the blower panel out
about 10 degrees then down and away
from the unit
4) Grip the blower assembly with both
hands and lift it about ½” or until it
clears the captive panel at the assembly.
Figure 8 - Blower Assembly with Captive
Panel
Figure 9 - Blower Assembly, Shown Pulled
Away From Blower Panel
5) Pull the lower half of the blower mount,
away from the blower panel about 10
degrees.
Handle

18
6) Once the blower assembly is clear of the
blower panel, turn the blower assembly,
90 degrees, counter clockwise.
Caution: At any time, DO NOT rest
blower assembly on bottom access
panel, as damage may occur to the unit
7) Pull the blower assembly out of the unit.
Discharge Modification
The AAON WSHP discharge direction can
be selected in ECat and is also designed so
that the discharge direction can be field
modified if needed. (Note: DO NOT
perform this action while unit is hanging. It
MUST be done on a solid working surface.
Otherwise, serious unit damage may occur)
Remove the blower assembly as outlined in
the “Blower Assembly Removal – Side
Access” section before modifying the
discharge.
Once complete, proceed to the following:
1) Use a ¼” socket to remove the four (4)
screws holding the blower panel in place.
2) Firmly grip the blower panel and lift it
approximately ½” or until the bottom of the
blower panel clears the WSHP unit.
3) Pull the bottom of the blower panel out
about 10 degrees then down and away from
the unit.
4) Remove the side access panel as shown
in the “Blower Assembly Removal – Side
Access” section, step 2.
5) Swap the two panels keeping note of
which side is up. (Note: Installing blower
panel upside down will result in damage to
the unit.)

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Ensure both the blower panel and side
access panels are installed correctly as
outlined in the “Blower Assembly Removal
– Side Access” section.
Lifting and Handling the Unit
Before lifting unit, be sure that all shipping
material has been removed from unit.
Horizontal Unit Bottom Access
Several components are accessible through
the bottom access panel of the WSHP unit.
Accessible components include: Blower
housing, blower motor, TXV, reversing
valve, and filter drier.
Figure 10 - Horizontal Unit Bottom Access
In order for the unit to be bottom accessible,
adequate bottom clearance is needed.
Bottom clearance required for the unit can
be found on Table 2– WSHP Series
Clearances.
To access the bottom panel, use a *flat*
head screw driver to remove the screws that
hold the panel in place;
In order to eliminate door stress as these
screws are removed, start with the ones
closest to the hinged side of the cover. Note:
The nuts will remain captive within the unit.
After the screws are removed, the bottom
access panel will drop or swing down and
remain attached to the unit as shown in
Figure 11 .
While leaving the bottom access panel in
this position 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 should 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
Figure 11 - WH Bottom Access Panel

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To do this, grasp both sides of the panel and
using a moderate amount of force, pull the
compressor side of the panel, approximately
30 degrees, towards the opposite side of the
unit.
At this point, the end that was just pulled
will be low enough to clear the bottom
access hole and slide the panel out of the
unit.
Blower Assembly Removal – Bottom
Access
1) Using a ¼” socket drive, remove the
shipping screw on the outside of the
right or discharge side of the unit as
shown in Figure 12.
Figure 12 - Shipping Screw
2) Open the bottom access panel section as
described in the “Blower Assembly
Removal – Side Access”, steps 3 and 4.
3) Remove the five (5) spade connectors on
the blower motor as shown in Figure 13.
Figure 13 - Spade Connectors
4) Firmly grip the blower assembly with
both hands and push it upwards about
½” or until it clears the captive panel at
the bottom of the blower panel.
5) Pull the lower half of the blower mount,
away from the blower panel (about 10
degrees).