Aaon CN-090 Installation Manual

CN Series

Condensing Units

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

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

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

Installation, Operation,

& Maintenance

Table of Contents

Codes and Ordinances ............................................................................................................... 13

Receiving Unit ........................................................................................................................... 13

Storage ....................................................................................................................................... 13

Wiring Diagrams ....................................................................................................................... 15

General Maintenance ................................................................................................................. 15

Unit Placement .......................................................................................................................... 16

Curb and Steel Mount Installation ............................................................................................ 16

Lifting and Handling ................................................................................................................. 17

End Flashing Installation ........................................................................................................... 17

Mounting Isolation .................................................................................................................... 19

Access Doors ............................................................................................................................. 19

Low Ambient Operation ............................................................................................................ 19

Expansion Valve Operation ...................................................................................................... 19

Determining Refrigerant Line Size ........................................................................................... 19

Liquid Line ............................................................................................................................ 20

Suction Line ........................................................................................................................... 21

Hot Gas Bypass Line ............................................................................................................. 22

Hot Gas Reheat ...................................................................................................................... 23

LAC Valve ................................................................................................................................ 24

Condenser Flooding .................................................................................................................. 25

Electrical .................................................................................................................................... 25

Axial Flow Condenser Fans ...................................................................................................... 27

General ...................................................................................................................................... 31

Compressors .............................................................................................................................. 31

Refrigerant Filter Driers ............................................................................................................ 31

Adjusting Refrigerant Charge ................................................................................................... 31

Lubrication ................................................................................................................................ 35

Air-Cooled Condenser ............................................................................................................... 35

E-Coated Coil Cleaning ............................................................................................................ 35

Microchannel Coil Cleaning ..................................................................................................... 36

Service ....................................................................................................................................... 38

Replacement Parts ..................................................................................................................... 38

AAON Warranty, Service and Parts Department ...................................................................... 38

Index of Tables and Figures

Tables:

Table 1 - Service Clearances......................................................................................................... 16

Table 2 - Condenser Flooding....................................................................................................... 25

Table 3 - Condenser Fan Pin Location ......................................................................................... 29

Table 4 - Condenser Fan Pin Location ......................................................................................... 29

Table 5 - Fan Assembly Bushing Torque Specifications.............................................................. 30

Table 6 - Filter Drier Maximum Pressure Drop............................................................................ 31

Table 7 - Acceptable Refrigeration Circuit Values ....................................................................... 32

Table 8 - R-410A Refrigerant Temperature-Pressure Chart ......................................................... 34

Figures:

Figure 1 - Curb Mounting with Dimensions ................................................................................. 17

Figure 2 - Steel Mounting Rail with Dimensions ......................................................................... 17

Figure 3 - Concrete Pad Mounting with Dimensions ................................................................... 17

Figure 4 - Lifting Points ................................................................................................................ 17

Figure 5 - CN Series A Cabinet Top Lifting Detail ...................................................................... 18

Figure 6 - CN Series B and C Cabinet Bottom Lifting Detail ...................................................... 18

Figure 7 - Piping Schematic of Example System Using the LAC Valve. .................................... 24

Figure 8 - Front View of Utility Entry and Power Switch from Control Compartment ............... 26

Figure 9 - Fan with the HUB on the top and RET on the bottom. ................................................ 27

Figure 10 - Bushing Mount Location............................................................................................ 28

Figure 11 - RET with Pin in Groove 4 .......................................................................................... 28

Figure 12 - Fan HUB and RET Castings ...................................................................................... 28

Figure 13 - Pitch Insert ................................................................................................................. 29

Figure 14 - A/C Only Piping, AHU Above CU ............................................................................ 39

Figure 15 - A/C Only Piping, AHU Below CU ............................................................................ 40

Figure 16 - Modulating Hot Gas Reheat Piping, AHU Above CU .............................................. 41

Figure 17 - Modulating Hot Gas Reheat Piping, AHU Below CU ............................................... 42

Figure 18 - Hot Gas Bypass Piping, AHU Above CU .................................................................. 43

Figure 19 - Hot Gas Bypass Piping, AHU Below CU .................................................................. 44

Figure 20 - Modulating Hot Gas Reheat with Hot Gas Bypass Piping, AHU Above CU............ 45

Figure 21 - Modulating Hot Gas Reheat with Hot Gas Bypass Piping, AHU Below CU ............ 46

V28960 · Rev. A · 151208

AAON® CN Series Features and Options Introduction

Energy Efficiency

 Double Wall Rigid Polyurethane Foam

Injected Panel Construction, R-13 Thermal Resistance

 VFD Controlled Variable Speed R-410A

Scroll Compressors

 VFD Controlled Variable Speed

Condenser Fans

 High Efficiency Microchannel Air-

Cooled Condenser

Humidity Control

 Modulating Hot Gas Reheat Humidity

Control

Safety

 Phase and Brownout Protection  Suction Pressure Transducer  Condenser Coil Guard

Installation and Maintenance

 Isolated Compressors and Controls

Compartment

 Access Doors with Hinges and Lockable

Handles

 Compressors Installed on Rubber

Isolation Mounts

 Run Test Report and Installation Manuals

Included in Controls Compartment

 Color Coded Wiring and Wiring

Diagrams

System Integration

 Split System Matching  Single Point Power

Environmentally Friendly

 R-410A Refrigerant

Extended Life

 2,500 Hour Salt Spray Tested Exterior

Corrosion Paint

 Optional 5 Year Non-Prorated

Compressor Warranty

 Polymer E-Coated Condenser Coils

Safety

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.

 Before servicing, disconnect all

electrical power to the furnace. More than one disconnect may be provided.

 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

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

WARNING

WHAT TO DO IF YOU SMELL GAS

 Do not try to turn on unit.  Shut off main gas supply.  Do not touch any electric switch.  Do not use any phone in the

building.

 Never test for gas leaks with an

open flame.

 Use a gas detection soap solution

and check all gas connections and shut off valves.

CAUTION

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.

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

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

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

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

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 (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

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 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

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

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

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

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 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

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

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

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 you have 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.

CN Series Feature String Nomenclature

Model Options

Unit Feature Options

GEN

MJREV SIZE SERIES MNREV VLT A1

1 2A

2B 3A

3B 4 5

6C 7 8A

8D 9

CN A -

055

- A - 0 -

3 - C A 0 0 E : 0 - 0 0 - E 0 - D 0 - 0 0 0 - 0 - D A 0 0 - 0

0 0 J 0 0

0 0 0 0 0 0 B

CN Series Feature String Nomenclature

MODEL OPTIONS

Series and Generation

Major Revision

Unit Size

055 = 55 ton Capacity 065 = 65 ton Capacity 075 = 75 ton Capacity 090 = 90 ton Capacity 105 = 105 ton Capacity 120 = 120 ton Capacity 130 = 130 ton Capacity 140 = 140 ton Capacity

Series

A = 55-75 ton units B = 90-105 ton units C = 120-140 ton units

Minor Revision

Voltage

2 = 230V/3Φ/60Hz 3 = 460V/3Φ/60Hz 4 = 575V/3Φ/60Hz 8 = 208V/3Φ/60Hz

A1: Compressor Style

C = R-410A VFD Compatible Scroll Compressor F = R-410A VFD Compatible Tandem Scroll Compressor

A2: Condenser Style

A = Air-Cooled Microchannel Condenser

A3: Configuration 0 = Standard

A4: Coating

0 = Standard E = Polymer E-coated Condenser Coil

A5: Staging A = 1 Variable Capacity Comp + 1 On/Off Comp B = 2 Variable Capacity Comp + 2 On/Off Comp E = All Variable Capacity Compressors J = 2 On/Off Refrigeration Systems K= 1 Variable Capacity Refrigeration Systems + 1 On/Off Refrigeration System L= 2 Variable Capacity Refrigeration Systems

UNIT FEATURE OPTIONS

1: Unit Orientation

A = Vertical Condenser Discharge with End Control Panel

2A: Refrigeration Control

0 = Standard B = Fan Cycling C = Adjustable Fan Cycling D = Adjustable Compressor Lockout K = Options B + D M = Options C + D

2B: Blank 0 = Standard

3A: Refrigeration Options

0 = None D = Hot Gas Bypass Non-Variable Compressors [HGBNV] E = Modulating Hot Gas Reheat [MHGR] L = Options D + E

3B: Blank 0 = Standard

CN Series Feature String Nomenclature

Model Options

Unit Feature Options

GEN

MJREV SIZE SERIES MNREV VLT A1

1 2A

2B 3A

3B 4 5

6C 7 8A

8D 9

CN A -

055

- A - 0 -

3 - C A 0 0 E : 0 - 0 0 - E 0 - D 0 - 0 0 0 - 0 - D A 0 0 - 0

0 0 J 0 0

0 0 0 0 0 0 B

4: Refrigeration Accessories

0 = None 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 H = Flooded Condenser 0°F Low Ambient Controls Two Circuit J = Options A + H K = Options B + H L = Options A + B + H M = Flooded Condenser 0°F Low Ambient Controls Three Circuit N = Options A + M P = Options B + M Q = Options A + B + M R = Flooded Condenser 0°F Low Ambient Controls Four Circuit S = Options A + R T = Options B + R U = Options A + B + R

5: Blank 0 = Standard

6A: Unit Disconnect Type 0 = Standard Single Point Power Block A = Single Point Power Non-Fused Disconnect

6B: Disconnect Size J = 60 amps N = 100 amps R = 150 amps U = 225 amps Z = 400 amps 3 = 600 amps 5 = 800 amps 7 = 1200 amps

6C: Blank 0 = Standard

7: Accessories 0 = None B = Phase & Brown Out Protection D = Suction Pressure Transducer All Refrigeration Circuits L = Options B + D

8A: Control Sequence

B = VAV Single Zone Unit Controller - VAV Cool + CAV Heat C = VAV Single Zone Unit Controller - VAV Cool + VAV Heat D = VAV Unit Controller - VAV Cool + VAV Heat E = CAV Unit Controller - CAV Cool + CAV Heat F = MUA Unit Controller - CAV Cool + CAV Heat M = Field Installed DDC Controls by Others N = Field Installed DDC Controls w/ Isolation Relays P = Factory Installed DDC Controls Furnished by Others w/ Isolation Relays (SPA)

8B: Control Supplier 0 = AAON Refrigeration System Supervisory Controls A = WattMaster Orion Control System C = WattMaster Orion Control System (Main Controller in Air Handler)

8C: Control Supplier Options 0 = Standard

8D: BMS Connection & Diagnostics

0 = Standard

9: Blank 0 = Standard

10: Blank 0 = Standard

CN Series Feature String Nomenclature

Model Options

Unit Feature Options

GEN

MJREV SIZE SERIES MNREV VLT A1

1 2A

2B 3A

3B 4 5

6C 7 8A

8D 9

CN A -

055

- A - 0 -

3 - C A 0 0 E : 0 - 0 0 - E 0 - D 0 - 0 0 0 - 0 - D A 0 0 - 0

0 0 J 0 0

0 0 0 0 0 0 B

11: Maintenance Accessories 0 = None A = 115VAC Convenience Outlet - Factory Wired B = 115VAC Convenience Outlet - Field Wired C = Service Access 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 US Listing A = Chicago Code B = ETL US + Canada Listing

13: Air-Cooled Condenser H = Condenser Coil Guards + Three Phase Condenser Fan Motor J = Condenser Coil Guards + Three Phase Condenser Fan Motor + VFD Controlled Condenser Fans (35°F Low Ambient

14: Blank 0 = Standard

15: Blank 0 = Standard

16: Electrical Options 0 = Standard

17: Blank 0 = Standard

18: Blank 0 = Standard

19: Blank 0 = Standard

20: Cabinet Material

0 = Double Wall Galvanized Steel Cabinet + R-13 Foam Insulation

21: Warranty 0 = Standard Warranty D = Extended Compressor Warranty Years 2-5

22: Paint and Special Pricing Authorization B = Premium AAON Gray Paint Exterior E = Premium AAON Gray Paint Exterior + Shrink Wrap X = SPA + Option B 1 = SPA + Option E 4 = SPA + Special Exterior Paint Color 7 = SPA + Special Exterior Paint Color + Shrink Wrap

WARNING

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.

Failure to observe the following instructions will result in premature failure of your system and possible voiding of the warranty.

WARNING

General Information

AAON CN Series condensing units are complete air-cooled condensing units ranging from 55 to 140 tons of cooling capacity. They are assembled, wired, and tested.

Codes and Ordinances

CN 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 CN Series units must conform to the ICC standards of the International Mechanical Code, the International Building Code, 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.

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.

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.

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.

CRANKCASE HEATER

OPERATION Units may be 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

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

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.

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 when power is restored if liquid enters the compressor.

Before unit operation, the main power switch must be turned on for at least 24 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.

Never cut off the main power supply to the unit, except for complete shutdown. Always control the system from the building management system, or control panel, never at the main power supply (except for emergency or for complete shutdown of the system).

Scroll 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.

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 diagrams in both ladder and point-to-point form are 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 subcooling and superheat. See the air-cooled condenser sections in this manual for specific details.

Location

Unit Size

55-140 tons

Front -

(Controls Side)

60”

Left Side

72”

Right Side

72”

Top

Unobstructed

All roofing work should be performed by competent roofing contractors to avoid any possible leakage.

CAUTION

The base beneath the condenser section is open and must be considered when mounting on a curb.

CAUTION

Installation

Unit Placement

The AAON CN Series 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.

The placement relative to the building air intakes and other structures must be carefully selected. Be sure to observe the dimensions that are on the rating plate of the condensing unit for operational and service clearances.

Table 1 - Service Clearances

Condenser coils and fans must be free of any obstructions in order to start and operate properly with a correct amount of airflow. 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.

Curb and Steel Mount Installation

Make openings in the roof decking large enough to allow for water piping, electrical penetrations, and workspace only. Do not make openings larger than necessary. Set the curb to coincide with the openings. Make sure curb is level.

Unit specific curb drawing is included with job submittal. See SMACNA Architectural Sheet Metal Manual for curb installation details.

Units require rail support along all four sides of the unit base.

When installed at ground level, a one-piece concrete slab should be used with footings that extend below the frost line. Care must also be taken to protect the coil and fins from damage due to vandalism or other causes.

If unit is elevated a field supplied catwalk is recommended to allow access to unit service doors.

This unit ships with a curb gasket that is

1¼” wide and 1½” tall. It is recommended

that this or another similar gasket be used between the curb and the unit to reduce vibration from the unit to the building.

+ 36 hidden pages

Aaon CN-090 Installation Manual

Specifications and Main Features

Frequently Asked Questions

User Manual