AAON CF Series Owner's manual

CF Series
Condenser and Condensing Units
Installation, Operation,
& Maintenance
If the information in this manual is not
followed exactly, a fire or explosion
may result causing property damage,
personal injury or loss of life.
WARNING
QUALIFIED INSTALLER
Improper installation, adjustment,
alteration, service or maintenance
can cause property damage,
personal injury or loss of life.
Installation and service must be
performed by
a Factory Trained
Service Technician. A copy of this
IOM should be kept with the unit.
WARNING
FOR YOUR SAFETY
Do not store or use gasoline or other
flammable vapors and liquids in the
vicinity of this or any other appliance.
WARNING

2
Table of Contents
AAON CF Series Features and Options Introduction..................................................................... 5
Safety .............................................................................................................................................. 6
CF Series Feature String Nomenclature ....................................................................................... 11
General Information...................................................................................................................... 14
Codes and Ordinances............................................................................................................... 14
Receiving Unit........................................................................................................................... 14
Storage....................................................................................................................................... 15
Wiring Diagrams....................................................................................................................... 16
General Maintenance................................................................................................................. 16
Installation..................................................................................................................................... 17
Forklifting the Unit.................................................................................................................... 17
Lifting the Unit.......................................................................................................................... 18
Locating the Unit....................................................................................................................... 18
Mounting Isolation.................................................................................................................... 19
Access Doors............................................................................................................................. 19
Low Ambient Operation............................................................................................................ 19
Fan Cycling Low Ambient........................................................................................................ 20
Variable Speed Low Ambient................................................................................................... 20
Flooded Condenser Low Ambient ............................................................................................ 20
LAC Valve ................................................................................................................................ 20
Condenser Flooding .................................................................................................................. 21
Refrigerant Piping ..................................................................................................................... 22
Determining Refrigerant Line Size........................................................................................ 22
Liquid Line ............................................................................................................................ 23
Suction Line........................................................................................................................... 24
Discharge Line....................................................................................................................... 26
Hot Gas Bypass Line............................................................................................................. 28
Hot Gas Reheat...................................................................................................................... 29
Electrical.................................................................................................................................... 30
Startup........................................................................................................................................... 32
Compressor Operation............................................................................................................... 32
Variable Capacity Compressor Controller................................................................................ 33
Low Voltage Terminals............................................................................................................. 33
High Voltage Terminals............................................................................................................ 33
Compressor Lockouts................................................................................................................ 35
Maintenance.................................................................................................................................. 36
General ...................................................................................................................................... 36
Compressors.............................................................................................................................. 36
Refrigerant Filter Driers............................................................................................................ 36
Adjusting Refrigerant Charge ................................................................................................... 36
Lubrication ................................................................................................................................ 40
Condenser Tube Inspection....................................................................................................... 40
Maintenance Recommendations ............................................................................................... 40
E-Coated Coil Cleaning ............................................................................................................ 41
Service....................................................................................................................................... 43

3
Warranties ................................................................................................................................. 43
Replacement Parts..................................................................................................................... 43
AAON - Longview Warranty, Service, and Parts Department................................................. 43
Split System Refrigerant Piping Diagrams................................................................................... 44
Index of Tables and Figures
Tables:
Table 1 –Clearances for Proper Operation.................................................................................... 18
Table 2 –Clearances for Coil Pull................................................................................................ 18
Table 3 - Condenser Flooding....................................................................................................... 21
Table 4 - Demand Signal vs. Compressor Capacity Modulation.................................................. 34
Table 5 - Thermistor Temperature vs. Resistance Values............................................................ 35
Table 6 - Max Filter Drier Pressure Drops ................................................................................... 36
Table 7 - Acceptable Refrigeration Circuit Values....................................................................... 37
Table 8 - R-410A Refrigerant Temperature-Pressure Chart......................................................... 40
Figures:
Figure 1 - Forklifting a CF Series A Cabinet................................................................................ 17
Figure 2 - Forklifting a CF Series B and C Cabinet ..................................................................... 17
Figure 3 –Lifting Details and Orientation of a CF Series 9-70 ton Condensing Unit................. 18
Figure 4 - Orientation of Series 2-7 ton Condensing Unit............................................................ 18
Figure 5 - Adjustable Fan Cycling Switch.................................................................................... 20
Figure 6 - Piping Schematic of Example System using the LAC Valve ...................................... 21
Figure 7 - Double Suction Riser Construction.............................................................................. 25
Figure 8 –Heat Pump Piping Schematic of Suction Vapor Flow Down in Double Riser ........... 27
Figure 9 –Heat Pump Piping Schematic of Discharge Vapor Flow Up in Double Riser............ 27
Figure 10 –Oil Return Line.......................................................................................................... 29
Figure 11 - Variable Capacity Compressor Controller................................................................. 33
Figure 12 - Compressor Controller Flash Code Details................................................................ 34
Figure 13 - Adjustable compressor lockout.................................................................................. 35
Figure 14 - Ambient sensor cover................................................................................................. 35
Figure 15 - A/C Split System Piping, Suction Down ................................................................... 44
Figure 16 - A/C Split System Piping, Suction Up........................................................................ 45
Figure 17 - A/C with LAC Split System Piping, Suction Down .................................................. 46
Figure 18 - A/C with LAC Split System Piping, Suction Up....................................................... 47
Figure 19 - A/C with Modulating Hot Gas Reheat Split System Piping, Suction Down............. 48
Figure 20 - A/C with Modulating Hot Gas Reheat Split System Piping, Suction Up.................. 49
Figure 21 - A/C with Modulating Hot Gas Reheat Split + LAC System Piping, Suction Down. 50
Figure 22 - A/C with Modulating Hot Gas Reheat Split + LAC System Piping, Suction Up...... 51
Figure 23 - A/C with Hot Gas Bypass Split System Piping, Suction Down ................................ 52
Figure 24 - A/C with Hot Gas Bypass Split System Piping, Suction Up ..................................... 53
Figure 25 - A/C with Hot Gas Bypass + LAC Split System Piping, Suction Down.................... 54
Figure 26 - A/C with Hot Gas Bypass + LAC Split System Piping, Suction Up......................... 55

4
Figure 27 - A/C with Modulating Hot Gas Reheat and Hot Gas Bypass Split System Piping,
Suction Down................................................................................................................................ 56
Figure 28 - A/C with Modulating Hot Gas Reheat and Hot Gas Bypass Split System Piping,
Suction Up .................................................................................................................................... 57
Figure 29 - A/C with Modulating Hot Gas Reheat and Hot Gas Bypass + LAC Split System
Piping, Suction Down................................................................................................................... 58
Figure 30 - A/C with Modulating Hot Gas Reheat and Hot Gas Bypass + LAC Split System
Piping, Suction Up........................................................................................................................ 59
Figure 31 - Heat Pump Split System Piping, Suction Down........................................................ 60
Figure 32 - Heat Pump Split System Piping, Suction Up............................................................. 61
Figure 33 - Heat Pump with Modulating Hot Gas Reheat Split System Piping, Suction Down.. 62
Figure 34 - Heat Pump with Modulating Hot Gas Reheat Split System Piping, Suction Up....... 63
Figure 35 - Heat Pump with Hot Gas Bypass Split System Piping, Suction Down..................... 64
Figure 36 - Heat Pump with Hot Gas Bypass Split System Piping, Suction Up.......................... 65
Figure 37 –Heat Pump with Modulating Hot Gas Reheat and Hot Gas Bypass Split System
Piping, Suction Down................................................................................................................... 66
Figure 38 –Heat Pump with Modulating Hot Gas Reheat and Hot Gas Bypass Split System
Piping, Suction Up........................................................................................................................ 67
V45040 · Rev. A · 180319
(ACP J00424)

5
AAON CF Series Features and Options Introduction
Energy Efficiency
•Staged, Two-Step, 10-100% Variable
Capacity, or Tandem R-410A Scroll
Compressors
•Air-Source Heat Pump
•VFD Controlled or ECM Driven
Condenser Fans
Humidity Control
•Modulating Hot Gas Reheat
Safety
•Phase and Brownout Protection
•Adjustable Compressor Lockout
Installation and Maintenance
•Isolated Controls and Compressor
Compartment
•Access Doors with Full Length Stainless
Steel Piano Hinges
•Molded Lockable Handles
•Run Test Report and Installation Manual
Included in Controls Compartment
•Color-Coded Wiring and Wiring
Diagrams
•Factory Installed Convenience Outlet
•Service Access Lights
•Remote Start/Stop Terminals
•Liquid Line Sight Glass
•Compressor Isolation Valves
System Integration
•Complete Split System with AAON DX
Air Handling Units
•Single Point Non-Fused Disconnect
Power Switch
•Labeled Split System Piping Stub Outs
with Shut-Off Valves
•Flooded Condenser 0°F Low Ambient
Controls
•Terminal Block for Thermostat with
Isolation Relays
•Constant Air Volume (CAV), Makeup
Air (MUA), Variable Air Volume
(VAV), and Single Zone Variable Air
Volume (SZ VAV)
Environmentally Friendly
•R-410A Refrigerant
Extended Life
•Optional 5 Year Compressor Warranty
•G90 Galvanized Steel Construction
•2,500 Hour Salt Spray Tested Exterior
Corrosion Protection
•6,000 Hour Salt Spray Tested Polymer
E-Coated Condenser Coils
•Copper Fin and Stainless Steel Casing
Coils
•Condenser Coil Guards

6
ELECTRIC SHOCK
Electric shock hazard. Before
servicing, shut off all electrical power
to the unit, including remote
disconnects, to avoid shock hazard
or injury from rotating parts. Follow
proper Lockout-Tagout procedures.
WARNING
Safety
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.
DANGER - Danger statements are given to prevent actions that will result in equipment
damage, property damage, severe personal injury or death.
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
ELECTRIC SHOCK, FIRE OR
EXPLOSION 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.

When servicing controls, label all
wires prior to disconnecting.
Reconnect wires correctly.

Verify proper operation after
servicing. Secure all doors with
key-lock or nut and bolt.
WARNING

7
ROTATING COMPONENTS
Unit contains fans with moving parts
that can cause serious injury. Do not
remove grill containing fans until the
power to the unit has been
disconnected and fan has stopped
rotating.
WARNING
LIVE ELECTRICAL
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
FIRE, EXPLOSION OR CARBON
MONOXIDE POISONING HAZARD
Failure to replace proper controls
could result in fire, explosion or
carbon monoxide poisoning. Failure
to follow safety warnings exactly
could result in serious injury, death or
property damage. Do not store or use
gasoline or other flammable vapors
and liquids in the vicinity of this
appliance.
WARNING
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
VARIABLE FREQUENCY DRIVES
Do not leave VFDs unattended in
hand mode or manual bypass.
Damage to personnel or equipment
can occur if left unattended. When in
hand mode or manual bypass mode
VFDs will not respond to controls or
alarms.
WARNING

8
LEAK TESTING
Do not use oxygen, acetylene or air
in place of refrigerant and dry
nitrogen for leak testing. A violent
explosion may result causing injury or
death.
WARNING
VARIABLE FREQUENCY DRIVES
Electric motor over-current protection
and overload protection may be a
function of the Variable Frequency
Drive to which the motors are wired.
Never defeat the VFD motor overload
feature. The overload ampere setting
must not exceed 115% of the electric
motors FLA rating as shown on the
motor nameplate.
CAUTION
PVC PIPING
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
3-PHASE ROTATION
Rotation must be checked on all
MOTORS AND COMPRESSORS 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 using suction and
discharge gauges. Fan motor rotation
should be checked for proper
operation. Alterations should only be
made at the unit power connection
CAUTION
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
DOOR LATCHES
Door compartments containing
hazardous voltage or rotating parts
are equipped with door latches that
allow locks. Door latches are shipped
with a nut and bolt requiring tooled
access. If the shipping hardware is
not replaced with a pad lock, always
re-install the nut and bolt after closing
the door to maintain tooled access.
CAUTION

9
ENCLOSED AREA
Do not work in an enclosed area
where refrigerant or nitrogen gases
may be leaking. A sufficient quantity
of vapors may be present and cause
injury or death.
WARNING
COMPRESSOR LUBRICANT
Polyolester (POE) and Polyvinylether
(PVE) oils are two types of lubricants
used in hydrofluorocarbon (HFC)
refrigeration systems. Refer to the
compressor label for the proper
compressor lubricant type.
CAUTION
COIL CLEANERS
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
COIL CLEANERS
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
COIL CLEANING
Do not clean DX refrigerant coils with
hot water or steam. The use of hot
water or steam on refrigerant coils
will cause high pressure inside the
coil tubing and damage to the coil.
CAUTION
CONVENIENCE OUTLETS
Factory installed convenience outlets
are not intended for use while the unit
is operating.
WARNING

10
1. Startup and service must be performed
by a Factory Trained Service
Technician.
2. The unit is for outdoor use only. See
General Information section for more
information.
3. 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
purchased.
4. READ THE ENTIRE INSTALLATION,
OPERATION AND MAINTENANCE
MANUAL. OTHER IMPORTANT
SAFETY PRECAUTIONS ARE
PROVIDED THROUGHOUT THIS
MANUAL.
5. Keep this manual and all literature
safeguarded near or on the unit.
COMPRESSOR CYCLING
5 MINUTE MINIMUM OFF TIME
To prevent motor overheating
compressors must cycle off for a
minimum of 5 minutes.
5 MINUTE MINIMUM ON TIME
To maintain the proper oil level
compressors must cycle on for a
minimum of 5 minutes.
The cycle rate must not exceed 6
starts per hour.
WARNING

CF Series Feature String Nomenclature
Model Options
:
Unit Feature Options
GEN
MJREV
SIZE
SERIES
MNREV
VLT
A1
A2
A3
A4
A5
1
2A
2B
3A
3B
4
5
6A
6B
6C
7
8A
8B
8C
8D
9
10
11
12
13
14
15
CF
A
-
015
-
B
-
A
-
3
-
D
C
0
0
K
:
0
-
A
0
-
E
0
-
C
0
-
A
N
0
-
B
-
D
E
0
0
-
0
0
A
0
E
0
0
0
0
0
0
0
D
B
16
17
18
19
20
21
22
11
CF Series Feature S tring Nomenc lature
MODEL OPTIONS
Series and Generation
CF
Major Revision
A
Unit Size
002 = 2 ton Capacity
003 = 3 ton Capacity
004 = 4 ton Capacity
005 = 5 ton Capacity
006 = 6 ton Capacity
007 = 7 ton Capacity
009 = 9 ton Capacity
011 = 11 ton Capacity
013 = 13 ton Capacity
015 = 15 ton Capacity
016 = 16 ton Capacity
018 = 18 ton Capacity
020 = 20 ton Capacity
025 = 25 ton Capacity
026 = 26 ton Capacity
030 = 30 ton Capacity
031 = 31 ton Capacity
040 = 40 ton Capacity
050 = 50 ton Capacity
060 = 60 ton Capacity
070 = 70 ton Capacity
Series
A = 2-7 ton units
B = 9-15 ton units
C = 16-25 & 30 ton units
D = 26 & 31-70 ton units
Minor Revision
A
Voltage
1 = 230V/1Φ/60Hz
2 = 230V/3Φ/60Hz
3 = 460V/3Φ/60Hz
4 = 575V/3Φ/60Hz
8 = 208V/3Φ/60Hz
9 = 208V/1Φ/60Hz
A1: Compressor Style
0 = Air-Cooled Condenser - No Compressors
(1 Circuit)
A = R-410A Scroll Compressors
B = R-410A Two Step Capacity Scroll Compressors
D = R-410A Variable Capacity Scroll Compressors
E = R-410A Tandem Scroll Compressors
G = R-410A Tandem Variable Capacity Scroll
Compressors
P = Air-Cooled Condenser - No Compressors
(2 Circuits)
Q = Air-Cooled Condenser - No Compressors
(4 Circuits)
A2: Condenser Style
C = Air-Cooled Condenser
J = Air-Source Heat Pump
A3: Configuration
0 = Standard
A4: Coating
0 = Standard
E = Polymer E-Coated Condenser Coil
G = Copper Fin + Stainless Steel Casing - Condenser
Coil
A5: Staging
0 = No Cooling
G = 1 On/Off Refrigeration System
H = 1 Variable Capacity Refrigeration System
J = 2 On/Off Refrigeration Systems
K = 1 Variable Capacity Refrigeration System + 1
On/Off Refrigeration System
L = 2 Variable Capacity Refrigeration System
R = 4 On/Off Refrigeration Systems
T = 2 Variable Capacity Refrigeration Systems + 2
On/Off Refrigeration Systems
U = 4 Variable Capacity Refrigeration Systems

CF Series Feature String Nomenclature
Model Options
:
Unit Feature Options
GEN
MJREV
SIZE
SERIES
MNREV
VLT
A1
A2
A3
A4
A5
1
2A
2B
3A
3B
4
5
6A
6B
6C
7
8A
8B
8C
8D
9
10
11
12
13
14
15
CF
A
-
015
-
B
-
A
-
3
-
D
C
0
0
K
:
0
-
A
0
-
E
0
-
C
0
-
A
N
0
-
B
-
D
E
0
0
-
0
0
A
0
E
0
0
0
0
0
0
0
D
B
16
17
18
19
20
21
22
12
UNIT FEATURE OPTIONS
1: Unit Orientation
0 = Vertical Condenser Discharge - Standard Access
A = Horizontal Condenser Discharge - Standard
Access
2A: Refrigeration Control
0 = Standard
A = 5 Minute Compressor Off Timer + 20 Second
Compressor Stage Delay
C = Adjustable Fan Cycling
D = Adjustable Compressor Lockout
G = Option A + Adjustable Fan Cycling
H = Option A + Adjustable Compressor Lockout
M = Adjustable Fan Cycling + Adjustable
Compressor Lockout
W = Option A + Adjustable Fan Cycling +
Adjustable Compressor Lockout
2B: Blank
0 = Standard
3A: Refrigeration Options
0 = Standard
A = Hot Gas Bypass Lead Stage [HGB]
B = HGB Lead + HGB Lag
D = Hot Gas Bypass Non-Variable Capacity
Refrigeration Systems [HGBNV]
E = Modulating Hot Gas Reheat [MHGR]
H = HGB + MHGR
J = HGB Lead + HGB Lag + MHGR
L = HGBNV + MHGR
3B: Blank
0 = Standard
4: Refrigeration Accessories
0 = Standard
A = Sight Glass
B = Compressor Isolation Valves
C = Options A + B
D = Flooded Condenser 0°F Low Ambient Controls –
One Circuit
E = Options A + D
F = Options B + D
G = Options A + B + D
4: Refrigeration Accessories Continued
H = Flooded Condenser 0°F Low Ambient Controls-
Two Circuits
J = Options A + H
K = Options B + H
L = Options A + B + H
R = Flooded Condenser 0°F Low Ambient Controls –
Four Circuits
S = Options A + R
T = Options B + R
U = Options A + B + R
5: Blank
0 = Standard
6A: Unit Disconnect Type
0 = Single Point Power Block
A = Single Point Power Non-Fused Disconnect
6B: Disconnect 1 Size
0 = Standard
N = 100 amps
R = 150 amps
V = 250 amps
Z = 400 amps
6C: Blank
0 = Standard
7: Accessories
0 = Standard
B = Phase & Brown Out Protection
D = Suction Pressure Transducer on Each
Refrigeration Circuit
E = Compressor Sound Blanket
L = Options B + D
M = Options B + E
Q = Options D + E
1 = Options B + D + E

CF Series Feature String Nomenclature
Model Options
:
Unit Feature Options
GEN
MJREV
SIZE
SERIES
MNREV
VLT
A1
A2
A3
A4
A5
1
2A
2B
3A
3B
4
5
6A
6B
6C
7
8A
8B
8C
8D
9
10
11
12
13
14
15
CF
A
-
015
-
B
-
A
-
3
-
D
C
0
0
K
:
0
-
A
0
-
E
0
-
C
0
-
A
N
0
-
B
-
D
E
0
0
-
0
0
A
0
E
0
0
0
0
0
0
0
D
B
16
17
18
19
20
21
22
13
8A: Control Sequence
A = Terminal Block for Thermostat w/ Isolation
Relays
D = VAV Unit Controller - VAV Cool + CAV Heat
E = CAV Unit Controller
F = Makeup Air Unit Controller - CAV Cool + CAV
Heat
H = Constant Volume HP Unit Controller - CAV
Cool + CAV Heat
J = Makeup Air HP Unit Controller - CAV Cool +
CAV Heat
N = Field Installed DDC Controls by Others with
Isolation Relays
8B: Control Suppliers
0 = Standard
E = WattMaster VCC-X (Main Controller in Air
Handling Unit)
H = AAON Touchscreen Controller (Main Controller
in Air Handling Unit)
8C: Control Supplier Options
0 = Standard
8D: BMS Connection & Diagnostics
0 = Standard
9: Blank
0 = Standard
10: Blank
0 = Standard
11: Maintenance Accessories
0 = Standard
A = Factory Wired 115VAC Convenience Outlet
B = Field Wired 115VAC Convenience Outlet
C = Service Lights
E = Remote Unit Start/Stop Terminals
F = Options A + C
H = Options A + E
J = Options B + C
L = Options B + E
N = Options C + E
R = Options A + C + E
U = Options B + C + E
12: Code Options
0 = Standard ETL USA Listing
B = ETL USA + Canada Listing
13: Air-Cooled Condenser Accessories
0 = Standard
A = Condenser Coil Guard
C = ECM Condenser Fan Head Pressure Control
E = VFD Condenser Fan Head Pressure Control
G = Options A + C
J = Options A + E
14: Blank
0 = Standard
15: Blank
0 = Standard
16: Electrical Options
0 = Standard
17: Shipping Options
0 = Standard
A = Crating
B = Export Crating
18: Blank
0 = Standard
19: Blank
0 = Standard
20: Cabinet Material
0 = Galvanized Steel Cabinet
21: Warranty
0 = Standard
D = Compressor Warranty - Years 2-5
22: Type
B = Premium AAON Gray Paint Exterior
E = Premium AAON Gray Paint Ext + Shrink Wrap
X = SPA + Premium AAON Gray Paint Exterior
1 = SPA + Premium AAON Gray Paint Exterior +
Shrink Wrap

14
General Information
AAON CF Series air-cooled condensers and
condensing units have been designed for
outdoor use only. They are factory
assembled, wired, charged, and run-tested.
Codes and Ordinances
CF 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 CF Series units must conform
to the ICC standards of the International
Mechanical Code, the International Building
Code, and local building, plumbing and
electrical 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.
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. 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 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. Loose-shipped items
may have been placed inside the unit cabinet
SHARP EDGES
Coils and sheet metal surfaces
present sharp edges and care must
be taken when working with
equipment.
WARNING
QUALIFIED INSTALLER
Improper installation, adjustment,
alteration, service or maintenance
can cause property damage,
personal injury or loss of life.
Installation and service must be
performed by a Factory Trained
Service Technician.
WARNING
Failure to observe the following
instructions will result in premature
failure of your system and possible
voiding of the warranty.
WARNING

15
for security. Installers and owners should
secure all doors with locks or nuts and bolts
to prevent unauthorized access.
The warranty card must be completed in full
and returned to AAON not more than 3
months after the unit is delivered.
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.
Failure to observe the following instructions
will result in premature failure of your
system, and possible voiding of the
warranty.
Never turn off the main power supply to the
unit, except for complete shutdown. When
power is cut off from the unit, any
compressors using crankcase heaters cannot
prevent refrigerant migration. This means
the compressor will cool down, and liquid
refrigerant may accumulate in the
compressor. The compressor is designed to
pump refrigerant gas and damage may occur
if liquid enters the compressor when power
is restored.
Before unit operation, the main power
switch must be turned on for at least
twenty-four hours for units with compressor
crankcase heaters. This will give the
crankcase heater time to clear any liquid
accumulation out of the compressor before it
is required to run.
Always control the system from the control
panel, never at the main power supply
(except for emergency or for complete
shutdown of the system).
CLEAN AIR ACT
The Clean Air Act of 1990 bans the
intentional ven ting of refrigerant as
of July 1, 1992. Approved methods of
recovery, recycling, or reclaiming
must be followed.
CAUTION
CRANKCASE HEATER
OPERATION
Units are equipped with compressor
crankcase heaters, which should be
energized at least 24 hours prior to
cooling operation, to clear any liquid
refrigerant from the compressors.
CAUTION
3-PHASE ROTATION
Rotation must be checked on all
MOTORS AND COMPRESSORS of
three phase units. All motors, to
include and not be limited to pump
motors and condenser fan motors,
should all be checked by a qualified
service technician at startup and any
wiring alteration should only be made
at the unit power connection.
CAUTION

16
The standard compressors must be on a
minimum of 5 minutes and off for a
minimum of 5 minutes. The cycle rate must
be no more than 6 starts per hour.
The variable capacity compressors must be
on a minimum of 3 minutes and off for a
minimum of 3 minutes. The cycle rate must
be no more than 6 starts per hour.
The compressor life will be seriously
shortened by reduced lubrication, and the
pumping of excessive amounts of liquid oil
and liquid refrigerant.
Wiring Diagrams
A complete set of unit specific wiring
diagram in point-to-point form is laminated
in plastic and located inside the control
compartment door.
General Maintenance
When the initial startup is made, and on a
periodic schedule during operation, it is
necessary to perform routine service checks
on the performance of the condensing unit.
This includes reading and recording suction
pressures and checking for normal sub-
cooling and superheat.
COMPRESSOR ROTATION
Scroll compressors are directional
and will be damaged by operation in
the wrong direction. Low pressure
switches on compressors have been
disconnected after factory testing.
Rotation should be checked by a
qualified service technician at startup
using suction and discharge pressure
gauges and any wiring alteration
should only be made at the unit
power connection.
COMPRESSOR CYCLING
5 MINUTE MINIMUM OFF TIME
To prevent motor overheating
compressors must cycle off for a
minimum of 5 minutes.
5 MINUTE MINIMUM ON TIME
To maintain the proper oil level
compressors must cycle on for a
minimum of 5 minutes.
The cycle rate must not exceed 6
starts per hour.
WARNING
CAUTION

17
Installation
Forklifting the Unit
CF Series condensing unit sizes 2-25 & 30
tons can be lifted using a forklift. 2-7 ton
units must have forks at least 48” in length.
9-25 & 30 ton units must have forks 72” in
length, or the forks must have 72” fork
extensions. Standard units can be lifted from
all sides except the condenser coil side. CF
Series condensing unit sizes 26 & 31-70
tons cannot be lifted using a forklift. They
can be lifted as shown in Figure 3.
Forks must be perpendicular to the unit and
they must be in far enough that the back of
the forks are no more than 6” away from the
edge of the unit.
Figure 1 - Forklifting a CF Series A Cabinet
Figure 2 - Forklifting a CF Series B and C
Cabinet
FORKLIFTING
2-7 TON UNITS
Forks or Fork Extensions must be at
least 48” in length.
CAUTION
FORKLIFTING
9-25 & 30 TON UNITS
Forks or Fork Extensions must be at
least 72” in length.
CAUTION

18
Lifting the Unit
If cables or chains are used to hoist the unit
they must be the same length. Minimum
cable length is 99” for CF Series 9-70 ton
units. CF Series 2-7 ton units do not include
factory installed lifting lugs and should be
lifted by forklift only. Care should be taken
to prevent damage to the cabinet, coils, and
condenser fans.
Before lifting unit, be sure that all shipping
material has been removed from unit. Secure
hooks and cables at all lifting points / lugs
provided on the unit.
Figure 3 –Lifting Details and Orientation of
a CF Series 9-70 ton Condensing Unit
Locating the Unit
The CF Series condenser and condensing
unit is designed for outdoor applications and
mounting at ground level or on a rooftop. It
must be placed on a level and solid
foundation that has been prepared to support
its weight. When installed at ground level, a
one-piece concrete slab should be used with
footings that extend below the frost line.
Also with ground level installation, care
must be taken to protect the coil fins from
damage due to vandalism or other causes.
The first clearance table below gives the
clearance values for proper unit operation.
The second clearance table gives the
clearance necessary for removing the coil
without disassembling a large part of the
condensing unit. For ease of removing the
condenser coil, use the second table
clearances for the right hand side of the unit.
Table 1 –Clearances for Proper Operation
Location
Unit Size
2-7 tons
9-70 tons
Front -
(Controls
Side)
Unobstructed
36”
Left Side
6”
30”
Right Side
6”
36”
Top
3”
Unobstructed
Back
18”
6”
Table 2 –Clearances for Coil Pull
Unit Size
Right Hand Side
2-7 tons
42”
9-15 tons
42”
16-25 & 30 tons
54”
26 & 31-70 tons
66”
Figure 4 - Orientation of Series 2-7 ton
Condensing Unit

19
The placement relative to the building air
intakes and other structures must be
carefully selected. Airflow to and from the
condenser or condensing unit must not be
restricted to prevent a decrease in
performance and efficiency.
The installation position for 9-70 ton units
must provide at least 30” of left and right
side clearance for proper airflow to the
condenser coils. When units are mounted
adjacent to each other, the minimum right
and left side clearance required between the
units is 60” or 5 feet. Similarly, when 2-7
ton units are mounted adjacent to each other,
the minimum clearance required between
the back side of the units is 36” or 3 feet.
Units should not be installed in an enclosure
or pit that is deeper than the height of the
unit. When recessed installation is
necessary, the clearance to maintain proper
airflow is at least 5 feet (3 feet for 2-7tons).
CF Series condensers and condensing units
that have a vertical air discharge must have
no obstruction above the equipment. Do not
place the unit under an overhang. CF Series
condensers and condensing units that have a
horizontal discharge must have no
obstruction in front of the unit.
For proper unit operation, the immediate
area around condenser must remain free of
debris that may be drawn in and obstruct
airflow in the condensing section.
Consideration must be given to obstruction
caused by snow accumulation when placing
the unit.
Mounting Isolation
For roof mounted applications or anytime
vibration transmission is a factor, vibration
isolators may be used.
Access Doors
Access doors are provided to the compressor
and electrical compartment.
Low Ambient Operation
During low ambient temperatures, the vapor
refrigerant will migrate to the cold part of
the system and condense into liquid. All CF
Series compressors are provided with
factory installed crankcase heaters to help
prevent liquid refrigerant from slugging the
compressors during startup in low ambient
conditions. The condenser or condensing
unit must have continuous power 24 hours
prior to startup. This ensures the compressor
will receive sufficient refrigerant vapor at
startup. Standard units can operate down to
55°F ambient temperature.
AAON head pressure control units can
operate down to 35°F ambient temperature.
Three different head pressure control
options available are adjustable fan cycling,
ECM condenser fan, or VFD controlled
condenser fans. See detailed information
following.
The AAON low ambient (condenser flood-
back) system is used to operate a refrigerant
PVC PIPING
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

20
system down to 0°F outside air temperature.
See detailed information following.
Fan Cycling Low Ambient
Adjustable fan cycling is a low ambient
head pressure control option that cycles the
condenser fans to maintain refrigerant
circuit head pressures at acceptable levels
during cooling operation. The head pressure
set point (100-470 psi) and pressure
differential (35-200 psi) can be field
adjusted using a flathead screwdriver. For
example, if the head pressure is set to
300psi, and the differential is set to 100psi,
then fans will cut in at 300psi and cut out at
200psi. Fan cycling and variable speed
condenser fan head pressure control options
allow mechanical cooling with ambient
temperatures down to 35°F.
Figure 5 - Adjustable Fan Cycling Switch
Variable Speed Low Ambient
Variable speed condenser fan head pressure
control is a low ambient head pressure
control option that sends a variable signal in
relation to the refrigerant circuit head
pressure of the system to an electronically
commutated motor or VFD. The motor
either speeds up or slows down air flow
accordingly in order to maintain constant
head pressure. Fan cycling and variable
speed condenser fan head pressure control
options allow mechanical cooling with
ambient temperatures down to 35°F.
Flooded Condenser Low Ambient
Flooded condenser low ambient control
maintains normal head pressure during
periods of low ambient. When the ambient
temperature drops, the condensing
temperature and therefore pressure drops.
Without ambient control, the system would
shut down on low discharge pressure. The
flooded condenser method of low ambient
control fills the condenser coil with liquid
refrigerant, decreasing the heat transfer
capacity of the coil, which allows the coil to
operate at an acceptable discharge pressure.
The condenser coil will not be flooded
during summer ambient temperatures, so a
receiver is included to store the additional
liquid refrigerant required to flood the
condenser coil in low ambient.
The low ambient system maintains normal
head pressure during periods of low ambient
by restricting liquid flow from the condenser
to the receiver, and at the same time
bypassing hot gas around the condenser to
the inlet of the receiver. This reduces liquid
refrigerant flow from the condenser,
reducing its effective surface area, which in
turn increases the condensing pressure. At
the same time the bypassed hot gas raises
liquid pressure in the receiver, allowing the
system to operate properly. CF Series
condensers and condensing units use an
LAC valve for low ambient operation.
LAC Valve
The Low Ambient Control (LAC) valve is a
non-adjustable three way valve that
modulates to maintain receiver pressure. As
the receiver pressure drops below the valve
setting (295 psig for R-410A), the valve
modulates to bypass discharge gas around
the condenser. The discharge gas warms the
liquid in the receiver and raises the pressure
to the valve setting. The following
schematic shows an example system using
the LAC valve.