AAON M2-036 User Manual

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M2 Series

Modular Indoor Air Handling Units,

Modular Outdoor Air Handling Units,

Self Contained Units & Packaged Rooftop Units

Installation, Operation

& Maintenance

FIRE OR EXPLOSION HAZARD

Failure to follow safety warnings exactly could result in serious injury, death or property damage.

Be sure to read and understand the installation, operation and service instructions in this manual.

Improper installation, adjustment, alteration, service or maintenance can cause serious injury, death or property damage.

A copy of this IOM should be kept with the unit.

Do not store gasoline or other flammable vapors and liquids in the vicinity of this or any other appliance.

WHAT TO DO IF YOU SMELL GAS

 Do not try to light any appliance.  Do not touch any electrical switch;

 Leave the building immediately.  Immediately call you gas supplier

 If you cannot reach your gas

Installation and service must be performed by a qualified installer, service agency or the gas supplier.

do not use any phone in your building.

from a phone remote from the building. Follow the gas supplier’s instructions.

supplier call the fire department.

WARNIN

Table of Contents

Safety .............................................................................................................................................. 7

Model Number Nomenclature ...................................................................................................... 13

M2 Base Model Description ......................................................................................................... 14

Fan Module Description ............................................................................................................... 15

Filter Module Description ............................................................................................................. 16

Mixing Box Module Description .................................................................................................. 17

Heat Module Description .............................................................................................................. 18

Blank Module Description ............................................................................................................ 19

Coil Module Description............................................................................................................... 20

Control Panel Module Description ............................................................................................... 21

Energy Recovery Module Description .......................................................................................... 22

Condenser Module Description .................................................................................................... 23

Typical Configurations ................................................................................................................. 24

Unit Orientation ............................................................................................................................ 25

General Information ...................................................................................................................... 26

Codes and Ordinances ............................................................................................................... 27

Receiving Unit ........................................................................................................................... 27

Storage ....................................................................................................................................... 28

Packaged Direct Expansion (DX) Units .................................................................................... 28

Gas or Electric Heating ............................................................................................................. 29

Wiring Diagrams ....................................................................................................................... 29

Condensate Drain Pan ............................................................................................................... 29

Installation..................................................................................................................................... 30

Locating Units ........................................................................................................................... 30

Lifting the Unit .......................................................................................................................... 31

Indoor Floor Mounted Units ..................................................................................................... 34

Indoor Suspended Units ............................................................................................................ 34

Module Assembly ..................................................................................................................... 35

Refrigerant Piping ..................................................................................................................... 39

Determining Refrigerant Line Size ........................................................................................... 40

Water-Cooled Condenser .......................................................................................................... 44

Open Loop Applications ........................................................................................................ 44

Freezing Water in the Heat Exchanger .................................................................................. 45

Water Piping .......................................................................................................................... 46

Water-Cooled Condenser Safeties ......................................................................................... 49

Electrical .................................................................................................................................... 49

Cutting Electrical Openings ................................................................................................... 50

Thermostat Control Wiring .................................................................................................... 51

Condensate Drain Piping ........................................................................................................... 52

Blower Wheels .......................................................................................................................... 53

Air Adjustment ...................................................................................................................... 54

Waterside Economizer .............................................................................................................. 55

Hot Water and Steam Coils ....................................................................................................... 56

Chilled Water Coils ................................................................................................................... 56

Electric Heating ......................................................................................................................... 56

Gas Fired Duct Furnace ............................................................................................................. 57

Duct Furnace Component Identification ................................................................................... 59

Furnace Maintenance ................................................................................................................ 66

Troubleshooting ........................................................................................................................ 67

Startup ........................................................................................................................................... 68

Filters ......................................................................................................................................... 68

Check Out .................................................................................................................................. 68

Commissioning .......................................................................................................................... 69

Operation ................................................................................................................................... 70

Adjusting Refrigerant Charge ................................................................................................... 70

Maintenance .................................................................................................................................. 74

Fan Assembly ............................................................................................................................ 74

Bearings ..................................................................................................................................... 74

Belts ........................................................................................................................................... 75

Indoor Coils ............................................................................................................................... 76

Refrigeration Cycle ................................................................................................................... 76

E-Coated Coil Cleaning ............................................................................................................ 76

Recommended Coil Cleaner .................................................................................................. 77

Recommended Chloride Remover ......................................................................................... 77

Energy Recovery Wheel ............................................................................................................ 77

Electric Heating ......................................................................................................................... 79

Steam or Hot Water Heating ..................................................................................................... 79

Cleaning .................................................................................................................................... 79

Chilled Water ............................................................................................................................ 79

Lubrication ................................................................................................................................ 79

Replacement Parts ..................................................................................................................... 80

AAON-Longview Customer Service Department .................................................................... 80

Filter Replacement .................................................................................................................... 80

Appendix A - Heat Exchanger Corrosion Resistance ................................................................... 82

Refrigerant Piping Diagrams ........................................................................................................ 84

M2 Series Startup Form ................................................................................................................ 91

Maintenance Log .......................................................................................................................... 97

R40681 · Rev. B · 120509

(ACP 30752)

Index of Tables and Figures

Tables:

Table 1 - Minimum Clearances ..................................................................................................... 31

Table 2 - Glycol Freezing Points .................................................................................................. 46

Table 3 - Freezing Points .............................................................................................................. 48

Table 4 - Coaxial Heat Exchanger Pressure Drops (WCC- & WHP-) ......................................... 48

Table 5 - Brazed Plate Heat Exchanger Pressure Drops (WCC- & WHP-) ................................. 49

Table 6 - Control Wiring ............................................................................................................... 51

Table 7 - Drain Trap Dimensions ................................................................................................. 52

Table 8 - Blow-Through Drain Trap Dimensions......................................................................... 53

Table 9 - Gas Heater Troubleshooting .......................................................................................... 64

Table 10 - Gas Heater Troubleshooting Continued ...................................................................... 65

Table 11 - Problems, Causes and Solutions .................................................................................. 67

Table 12 - Acceptable Air-Cooled Refrigeration Circuit Values ................................................. 71

Table 13 - Acceptable Water-Cooled Refrigeration Circuit Values ............................................. 71

Table 14 - R-410A Refrigerant Temperature-Pressure Chart ....................................................... 73

Table 15 - Bearing Setscrew Torque Recommendations .............................................................. 75

Table 16 - Fan Bearing Lubrication Schedule .............................................................................. 79

Table 17 - M2-005 and M2-008 Filters ........................................................................................ 80

Table 18 - M2-011 and M2-014 Filters ........................................................................................ 80

Table 19 - M2-018 and M2-022 Filters ........................................................................................ 81

Table 20 - M2-026 Filters ............................................................................................................. 81

Table 21 - M2-032 and M2-036 Filters ........................................................................................ 81

Figures:

Figure 1 - Typical Configurations ................................................................................................. 24

Figure 2 - Unit Orientation ........................................................................................................... 25

Figure 3 - Lockable Handle .......................................................................................................... 28

Figure 4 - Service Access Clearance ............................................................................................ 31

Figure 5 - M2 Series Unit Four Point Lifting ............................................................................... 32

Figure 6 - M2 Series Unit Eight Point Lifting .............................................................................. 33

Figure 7 - Unit Suspension ........................................................................................................... 34

Figure 8 - Module Assembly Schematic ....................................................................................... 36

Figure 9 - Bulb Gasket .................................................................................................................. 37

Figure 10 - Applying Bulb Gasket ................................................................................................ 37

Figure 11 - Gasket Application ..................................................................................................... 37

Figure 12 - Bolted Base Rail ......................................................................................................... 37

Figure 13 - Bar Clamp .................................................................................................................. 38

Figure 14 - Self-Tapping Screw .................................................................................................... 38

Figure 15 - Strap Types................................................................................................................. 38

Figure 16 - Strap Locations........................................................................................................... 38

Figure 17 - Strap Installation ........................................................................................................ 39

Figure 18 - Draw-Through Drain Trap ......................................................................................... 52

Figure 19 - Blow-Through Drain Trap ......................................................................................... 53

Figure 20 - Supply Fan Banding ................................................................................................... 55

Figure 21 - Sediment Trap ............................................................................................................ 58

Figure 22 - Horizontal Configuration ........................................................................................... 59

Figure 23 - Vertical Configuration ............................................................................................... 59

Figure 24 - Gas Valve ................................................................................................................... 59

Figure 25 - 1.2” w.c. Manifold ..................................................................................................... 61

Figure 26 - 3.5” w.c. Manifold ..................................................................................................... 61

Figure 27 - Flame Sensor Current Check ..................................................................................... 62

Figure 28 - Angular Misalignment ............................................................................................... 75

Figure 29 - Parallel Misalignment ................................................................................................ 75

Figure 30 - Belt Deflection ........................................................................................................... 75

Figure 31 - Energy Recovery Wheel ............................................................................................ 78

Figure 32 - Standard Split System Piping ..................................................................................... 84

Figure 33 - Modulating Hot Gas Reheat with Hot Gas Bypass Split System Piping ................... 85

Figure 34 - Hot Gas Bypass Split System Piping ......................................................................... 86

Figure 35 - Modulating Hot Gas Reheat Split System Piping ...................................................... 87

Figure 36 - Heat Pump Split System Piping ................................................................................. 88

Figure 37 - Heat Pump with Factory Installed Modulating Hot Gas Reheat Split System Piping 89 Figure 38 - Heat Pump with Field Installed Modulating Hot Gas Reheat Split System Piping ... 90

Safety

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.

Attention should be paid to the following statements:

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

 When servicing controls, label all

 Verify proper operation after

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

wires prior to disconnecting. Reconnect wires correctly.

servicing. Secure all doors with key-lock or nut and bolt.

WARNING

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 trained, qualified installer. A copy of this IOM should be kept with the unit.

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

 Never test for gas leaks with an

 Use a gas detection soap solution

QUALIFIED INSTALLER

building.

open flame.

and check all gas connections and shut off valves.

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.

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.

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 open door containing fans until the power to the unit has been disconnected and fan wheel has stopped rotating.

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.

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.

WARNIN

CAUTIO

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.

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

UNIT HANDLING

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

Failure to properly drain and vent coils when not in use during freezing temperature may result in coil and equipment damage.

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.

WATER PRESSURE

Always use a pressure regulator, valves and gauges to control incoming pressures when pressure testing a system. Excessive pressure may cause line ruptures, equipment damage or an explosion which may result in injury or death.

CAUTIO

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.

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

Door compartments containing hazardous voltage or rotating parts are equipped with door latches to allow locks. Door latch are shipped with nut and bolts requiring tooled access. If you do not replace the shipping hardware with a pad lock always re-install the nut & bolt after closing the door.

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.

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.

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.

WARNIN

OPEN LOOP APPLICATIONS

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 coverage under AAON warranties and the heat exchanger manufacturer warranties.

WATER FREEZING

Disconnect all power, close all isolation valves and allow equipment to cool before servicing equipment to prevent serious injury. Equipment may have multiple power supplies. Electric resistance heating elements and hot water or steam heating coils may have automatic starts. Hot water will circulate even after power is off.

HOT PARTS

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.

Do not weld or cut foam panel with plasma cutters or a cutting torch – When burnt the foam produces dangerous fumes.

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.

Never attempt to open an access door or remove a panel while the unit is running. Pressure in the unit can cause excessive force against the panel.

Ensure that sufficient dampers will be open to provide air path before fan is allowed to run.

1. Use only with type of the gas approved

for the furnace. Refer to the furnace rating plate.

2. Provide adequate combustion ventilation

air to the furnace. If a vent duct extension is used, a class III approved vent is required. See the Locating Units and Gas Heating sections of the Installation section of the manual.

3. Always install and operate furnace

within the intended temperature rise range and duct system external static pressure (ESP) as specified on the unit nameplate.

4. The supply and return air ducts must be

derived from the same space. It is recommended ducts be provided with access panels to allow inspection for duct tightness. When a down flow duct is used with electric heat, the exhaust duct should be an L shaped duct.

5. Clean furnace, duct and components

upon completion of the construction setup. Verify furnace operating

conditions including input rate, temperature rise and ESP.

6. 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.

7. READ THE ENTIRE INSTALLATION,

OPERATION AND MAINTENANCE MANUAL. OTHER IMPORTANT SAFETY PRECAUTIONS ARE PROVIDED THROUGHOUT THIS MANUAL.

8. Keep this manual and all literature

safeguarded near or on the unit.

Model Number Nomenclature

Base Model Number Individual Module Model Numbers

Identifies the main unit features and options. Identifies module configurations, features and

options.

M2-H-011-R-2-A-A-0-C-0

Complete Model Number

A complete unit model number consists of a base model number followed by a series of individual module numbers. In the individual module model number, the three numbers after the three letter Module ID indicate the position of the module in unit assembly, increasing in value from the

MBH-101-A-00-00000-00000-0-0 FTA-102-P-A0-00000-00000-0-0 SFA-103-F-B0-A000C-00000-0-0 CLF-104-C-00-210F0-410F0-0-0 SFA-105-0-AA-CPTB0-00000-0-0 PEC-201-K-BI-A0000-00000-0-0 FTE-203-P-B0-00000-00000-0-0

return/outside air section to the discharge air section and from the bottom to the top. In the above example, the cooling coil module, CLF-104-C-00-CPTB0-00000-0-0, would be the fourth module on the bottom row of the unit.

Series and

Generation

Type

011

Unit Size

BASE MODEL

SERIES AND GENERATION

M2 = Modular 2

TYPE

H = Horizontal V = Vertical

UNIT SIZE

005 = 5 ft 008 = 8 ft 011 = 11 ft2 Coil 014 = 14 ft2 Coil 018 = 18 ft 022 = 22 ft 026 = 26 ft 032 = 32 ft 036 = 36 ft

SUPPLY AIRFLOW

L = Left Hand R = Right Hand

VOLTAGE

1 = 230V/1Φ/60Hz 2 = 230V/3Φ/60Hz 3 = 460V/3Φ/60Hz 4 = 575V/3Φ/60Hz 6 = 380-415V/3Φ/50Hz 7 = 265V/1Φ/60Hz 8 = 208V/3Φ/60Hz 9 = 208V/1Φ/60Hz

Coil

Generation

M2 Base Model Description

Model Numbe

Supply

Airflow

Voltage Assembly Wiring Paint

ASSEMBLY

A = Factory Assembled B = Loose Boxes

WIRING

0 = None A = Control Wiring in Fan Box B = Control Wiring in Control Box

PAINT

0 = None A = Standard White Exterior B = Special Color Exterior

BASE RAIL

B = 8” High C = 6” High D = 10” High

SPECIAL

0 = None A = Special Pricing Authorization

Base

Rail

Special

Fan Module Description

SFA

Module ID Position

MODULE ID

SFA = Belt Driven Supply, Control Panel SFB = Vertical Belt Driven Supply, Control Panel SFC = Belt Drive Supply, Top Discharge, Control Panel SFD = Belt Driven Supply, No Control Panel SDB = Direct Drive Supply, Control Panel SDD = Direct Drive Supply, Top Discharge, Control Panel PEA = Belt Driven Power Exhaust PEC = Belt Driven Power Exhaust, Top Discharge EDB = Direct Drive Power Exhaust EDD = Direct Drive Power Exhaust, Top Discharge RFA = Belt Driven Power Return RDB = Direct Drive Power Return

POSITION

### = Level and Position of Module in Air Handling Unit

MOTOR SIZE

E = 1 hp F = 2 hp G = 3 hp H = 5 hp J = 7.5 hp K = 10 hp L = 15 hp M = 20 hp N = 25 hp

BLOWER

0 = None A = 15” Backward Curved Plenum B = 18” Backward Curved Plenum C = 22” Backward Curved Plenum D = 27” Backward Curved Plenum E = 30” Backward Curved Plenum F = 33” Backward Curved Plenum G = 37” Backward Curved Plenum H = 24” Backward Curved Plenum J = 15” BC Plenum - 50% Width K = 18” BC Plenum - 30% Width L = 2 x 18” Backward Curved Plenum M = 2 x 22” Backward Curved Plenum N = 2 x 24” Backward Curved Plenum P = 2 x 27” Backward Curved Plenum

103

Motor

Size

B 0

Blower Isolation

Model Numbe

A 00 0C

Motor

Type

ISOLATION

I = Fan Isolation

- Rubber-in-Shear Isolation on 005, 008, 011 & 014

- Spring Isolation on 018, 022, 026, 032 & 036

MOTOR TYPE

A = Standard Efficiency 1760 rpm B = Premium Efficiency 1760 rpm C = Premium Eff. 1760 rpm with VFD D = Premium Eff. 1760 rpm with VFD and Bypass E = Premium Efficiency 1170 rpm F = Premium Eff. 1170 rpm with VFD

BLANK

00 = Standard

PULLEYS

## = Pulley Combination

SAFETY CONTROL

0 = None A = Phase & Brownout Protection

BLANK

0000 = Standard

BLANK

0 = Standard

TYPE

0 = None X = Special Pricing Authorization

Blank Pulleys

Control

0 0000

Safety

Blank Blank Type

Filter Module Description

FTA

Module ID Position

MODULE ID

FTA = Small Flat Filter FTC = Cartridge Filter FTE = Medium Flat Filter FTF = Large Flat Filter FTG = G Flat Filter FTH = Cartridge Filter with Flat Pre-Filter FTI = I Flat Filter FTK = Extra Large Flat Filter

POSITION

### = Level and Position of Module in Air Handling Unit

FILTER TYPE

P = Pleated C = Cartridge

FILTERS

A0 = 2” Pleated, 30% Eff. B0 = 4” Pleated, 30% Eff. C0 = 4” Pleated, 65% Eff. or 12” Cartridge, 65% Eff. D0 = 4” Pleated, 85% Eff. or 12” Cartridge, 85% Eff. E0 = 4” Pleated, 95% Eff. or 12” Cartridge, 95% Eff.

SAFETY CONTROL

0 = None 2 = Firestat

BLANK

0000 = Standard

102

Filter Type

Filters

Model Numbe

0 0000

Safety

Control

0 00 00

Blank

Filter Type

Second

Filters

SECOND FILTER TYPE

Blank

Options

Second

0 = Type C = Cartridge

SECOND FILTERS

C0 = 12” Cartridge, 65% Eff. D0 = 12” Cartridge, 85% Eff. E0 = 12” Cartridge, 95% Eff.

BLANK

00 = Standard

FILTER OPTIONS

0 = None A = Magnehelic Gauge B = Clogged Filter Switch C = Magnehelic Gauge & Clogged Filter Switch

TYPE

0 = None X = Special Pricing Authorization

Filter

Type

Mixing Box Module Description

MBH

Module

MODULE ID

MBA = Vertical Damper MBB = Horizontal Top Damper MBC = Vertical & Horizontal Top Damper MBD = Vertical Damper with Filter MBE = Horizontal Top Damper with Filter MBF = Horizontal Bottom Damper MBH = Vertical & Horizontal Bottom Damper MBI = Horizontal Bottom Damper with Filter MBJ = Vertical & Horizontal Top Damper with Filter MBK = Vertical & Horizontal Bottom Damper with Filter

POSITION

### = Level and Position of Module in Air Handling Unit

ACTUATOR

0 = None A = Two Position Actuator B = DDC Actuator

FILTERS

00 = None A0 = 2” Pleated, 30% Eff. B0 = 4” Pleated, 30% Eff. C0 = 4” Pleated, 65% Eff. D0 = 4” Pleated, 85% Eff. E0 = 4” Pleated, 95% Eff.

101

Position Position Filters

Model Numbe

0 0000

Safety

Control

0 0000

Blank

Bypass

Open

SAFETY CONTROL

0 = None 2 = Firestat

BLANK

0000 = Standard

BYPASS OPEN

0 = None A = Top Open B = Bottom Open

BLANK

0000 = Standard

FILTER OPTIONS

0 = None A = Magnehelic Gauge B = Clogged Filter Switch C = Options A + B

TYPE

0 = None X = Special Pricing Authorization

Blank

Filter

Options

Type

PHA

Module

MODULE ID

PHA = Electric Heat PHB = Hot Water Coil PHC = Hot Water Coil with Filter PHD = Electric Heat with Filter RHC = Hot Gas Reheat Coil

POSITION

### = Level and Position of Module in Air Handling Unit

FUNCTION

H = Heating D = Dehumidification B = Heating and Dehumidification

FILTERS

00 = None A0 = 2” Pleated, 30% Eff. B0 = 4” Pleated, 30% Eff. C0 = 4” Pleated, 65% Eff. D0 = 4” Pleated, 85% Eff. E0 = 4” Pleated, 95% Eff.

101

Position Function Filters Rows FPI Circuiting Coating kW Stages Blank

HEATING COIL

ROWS

1 = 1 Row 2 = 2 Rows

FPI

08 = 8 Fins Per Inch 10 = 10 Fins Per Inch 12 = 12 Fins Per Inch

CIRCUITING

F = Single Serpentine H = Half Serpentine

COATING

0 = Standard P = Polymer E-Coating S = Stainless Steel Coil Casing H = Stainless Steel Coil Casing & Copper Fins

Heat Module Description

Model Numbe

0 00 0 0

ELECTRIC HEAT

A = 7 kW (5.25 kW) B = 14 kW (10.5 kW) C = 21 kW (15.75 kW) D = 28 kW (21.0 kW) E = 42 kW (31.5 kW) F = 56 kW (42.0 kW) G = 70 kW (52.5 kW) H = 35 kW (26.25 kW) J = 84 kW (63 kW) K = 112 kW (84.0 kW) L = 126 kW (94.5 kW) M = 168 kW (126 kW) N = 10 kW (7.5kW) P = 20 kW (15 kW) Q = 30 kW (22.5 kW) R = 40 kW (30 kW) S = 50 kW (37.5 kW) T = 80 kW (60 kW) U = 100 kW (75 kW) V = 120 kW (90 kW) W = 160 kW (120 kW)

STAGES

01 = 1 Stage 02 = 2 Stage 03 = 3 Stage 04 = 4 Stage

BLANK

00 = Standard

FILTER OPTIONS

0 = Standard A = Magnehelic Gauge B = Clogged Filter Switch C = Options A + B

TYPE

0 = None X = Special Pricing Authorization

E 02 00

Filter

Options

Type

Blank Module Description

BBA

Module

MODULE ID

BBA = Small BBB = Medium BBC = Large BBD = XL BBE = XXL BBF = XXXL CBA = Small with Drain Pan CBB = Medium with Drain Pan CBC = Large with Drain Pan CBD = XL with Drain Pan CBE = XXL with Drain Pan CBF = XXXL with Drain Pan

POSITION

### = Level and Position of Module in Air Handling Unit

DRAIN PAN TYPE

0 = None A = Auxiliary

AIRWAY TYPE

AR = Top Open, Right Hand End Panel AL = Top Open, Left Hand End Panel

101

Position

Drain

Pan

Type

Airway

Type

Model Numbe

0 0000

Safety

Control

0 0000

Blank

SAFETY CONTROL

0 = None 2 = Firestat

BLANK

0000 = Standard

BYPASS OPENING

0 = None A = Top Opening B = Bottom Opening

BLANK

0000 = Standard

BLANK

0 = Standard

TYPE

0 = None X = Special Pricing Authorization

Bypass

Opening

Blank Blank Type

CBL

Module

Coil Module Description

101

Position

MODULE ID

CBL = Chilled Water or DX CLC = DX + Hot Gas Reheat CLF = Hot Water + Chilled Water or DX CLG = Electric Heat + Chilled Water or DX CLI = Hot Water or Chilled Water Face Bypass CLM = Chilled Water or DX, Optional Size

POSITION

### = Level and Position of Module in Air Handling Unit

COOLING TYPE

0 = None C = Chilled Water D = DX E = DX or Hot Gas Bypass

ELECTRIC HEAT

A = 7 kW (5.3 kW) B = 14 kW (10.5 kW) C = 21 kW (15.8 kW) D = 28 kW (21.0 kW) H = 35 kW (26.3 kW) E = 42 kW (35.0 kW) F = 56 kW (42.0 kW) G = 70 kW (52.5 kW) J = 84 kW (47.7 kW) K = 112 kW (53.0 kW) L = 126 kW (58.3 kW) M = 168 kW (63.6 kW)

STAGES

1 = 1 Stage 2 = 2 Stage 3 = 3 Stage 4 = 4 Stage

HEATING COIL

ROWS

1 = 1 Row 2 = 2 Rows

FPI

08 = 8 Fins Per Inch 10 = 10 Fins Per Inch 12 = 12 Fins Per Inch

Cooling

Type

0 0

kW Stages Rows FPI Circuiting Coating Rows FPI Circuiting Coating

Model Numbe

0 00 0 0

CIRCUITING

F = Single Serpentine H = Half Serpentine

COATING

0 = Standard P = Polymer E-Coating S = Stainless Steel Coil Casing H = Stainless Steel Coil Casing & Copper Fins

COOLING COIL

ROWS

4 = 4 Rows 6 = 6 Rows 8 = 8 Rows

FPI

08 = 8 Fins Per Inch 10 = 10 Fins Per Inch 12 = 12 Fins Per Inch

CIRCUITING

F = Single Serpentine H = Half Serpentine S = DX Single Circuit I = DX Dual Circuit, Interlaced

COATING

0 = Standard P = Polymer E-Coating S = Stainless Steel Coil Casing H = Stainless Steel Coil Casing & Copper Fins

DRAIN PAN

S = Stainless Steel

TYPE

0 = None X = Special Pricing Authorization

4 10 F 0

Drain

Pan

Type

Control Panel Module Description

Model Numbe

TRA

Module

MODULE ID

TRA = Small TRB = Medium TRC = Large TRD = XL TRE = XXL TRF = XXXL

POSITION

### = Level and Position of Module in Air Handling Unit

BLANK

0 = Standard

BLANK

00 = Standard

101

Position Blank Blank

0 0000

Safety

Options

Blank Blank Blank Type

SAFETY OPTIONS

0 = None 2 = Firestat

BLANK

0000 = Standard

BLANK

00000 = Standard

BLANK

0 = Standard

TYPE

0 = None X = Special Pricing Authorization

00000

Energy Recovery Module Description

Model Numbe

HRA

Module

MODULE ID

HRA = AAONAIRE Energy Recovery Wheel

POSITION

### = Level and Position of Module in Air Handling Unit

WHEEL SIZE

A = Standard

BLANK

00 = Standard

101

Position

Wheel

Size

Blank Blank Blank Blank Type

00000

BLANK

00000 = Standard

BLANK

00000 = Standard

BLANK

0 = Standard

TYPE

0 = None X = Special Pricing Authorization

00000

Condenser Module Description

WCC

Module

MODULE ID

WCC = Water-Cooled Condenser WHP = Water-Source Heat Pump

POSITION

### = Level and Position of Module in Air Handling Unit

COMPRESSOR TYPE

A = Scroll B = Two Step D = Variable Capacity Compressor T = Tandem Compressors

TONNAGE

06 = 6 Ton Capacity 08 = 8 Ton Capacity 10 = 10 Ton Capacity 13 = 13 Ton Capacity 16 = 16 Ton Capacity 20 = 20 Ton Capacity 25 = 25 Ton Capacity 30 = 30 Ton Capacity 35 = 35 Ton Capacity 40 = 40 Ton Capacity 45 = 45 Ton Capacity 50 = 50 Ton Capacity 60 = 60 Ton Capacity

HEAT EXCHANGER TYPE

A = Copper Coaxial Heat Exchanger B = Cupronickel Coaxial Heat Exchanger C = Brazed Plate Heat Exchanger

101

Position

Compressor

Type

Tonnage

Model Numbe

Exchanger

A 000 A

Heat

Type

A 0000

Blank Glycol

BLANK

000= Standard

GLYCOL

A = 0-10%, Standard Heat Exchanger B = 20-50%, Oversized Heat Exchanger

SAFETY CONTROL

A = WattMaster WSHP Control C = Phase & Brown Out Protection

BLANK

0000 = Standard

SOUND BLANKET

0 = None A = Special Pricing Authorization

TYPE

0 = None X = Special Pricing Authorization

Safety

Control

Blank

Sound

Blanket

Type

M2 Series Typical Configurations

M2 Series units have been designed as practical, high performance alternative to expensive custom air handling equipment.

Figure 1 - Typical Configurations

Fan Only

AAONAIRE® (HRU) Energy Recovery Unit

AAONAIRE®(HRU) with:

- DX or Chilled Water Cooling

- Hot Water, Steam or Electric Heat

Filter and Fan

Blow-Through

Draw-Through

Top Discharge

AAONAIRE®(HRU) with:

- DX or Chilled Water Cooling

- Hot Water, Steam or Electric Heat

- Outside Air and Return Air Mixing

AAONAIRE®(HRU) with:

- DX or Chilled Water Cooling

- Hot Water, Steam or Electric Heat

- Outside Air and Return Air Mixing

- Return Air Bypass

Unit Orientation

Determine left hand or right hand orientation/connections:

M2 Series Top View

Right Hand Side

Return Air Supply Air

Connections & service

access on left side for

left hand orientation

AIRFLOW

Filter Coil Supply Fan

Left Hand Side

Consider the airflow to be

hitting the back of your head.

Figure 2 - Unit Orientation

General Information

M2 Series modular indoor air handling units, modular outdoor air handling units, self contained units and packaged rooftop units have been designed for either indoor or outdoor installation. Flexible connectors are required on all duct connections to minimize air leaks.

M2 Series units are designed for safe operation when installed, operated and maintained within design specifications and the instructions in this manual. It is necessary to follow these instructions to avoid personal injury or damage to equipment or property during equipment installation, startup, operation and maintenance.

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 trained, qualified installer or service agency. A copy of this IOM should be kept with the unit.

These units must not be used as a “construction heater” at anytime during any phase of construction. Very low return air temperatures, harmful vapors, and misplacement of the filters will damage the unit and its efficiency.

This equipment is protected by a standard limited warranty under the condition that initial installation, service, startup and maintenance is performed according to the instructions set forth in this manual. This manual should be read in its entirety prior to installation and before performing any service or maintenance work.

Equipment described in this manual is available with many optional accessories. If you have questions after reading this manual in its entirety, consult other factory documentation or contact your AAON Sales Representative to obtain further information before manipulating this equipment or its optional accessories

Certification of Gas Heat Models

a. Certified as a Category III forced air

furnace with or without cooling.

b. Certified for indoor and outdoor

installation.

c. Certified for installation on a

combustible roof with a minimum of 12” high curb.

Certification of Steam or Hot Water Heat Models

a. Certified as a forced air heating system

with or without cooling.

b. Certified for indoor and outdoor

installation.

Certification of Electric Heat Models

a. Certified as an electric warm air furnace

with or without cooling.

b. Certified for indoor and outdoor

installation only.

c. Certified for installation on a

combustible roof with a minimum of 12” high curb.

Certification of Cooling Models

a. Certified as a commercial central air

conditioner with or without electrically operated compressors.

b. Certified for indoor and outdoor

installation only.

c. Certified for installation on a

combustible roof with a minimum of 12” high curb.

d. Certified with refrigerant R-410A coils

or with chilled water cooling coils.

Codes and Ordinances

System should be sized in accordance with the American Society of Heating, Refrigeration and Air Conditioning Engineers Handbook.

Installation of M2 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. In the absence of local codes installation must conform to the current (United States) National Fuel Gas Code ANSI-Z223.1/NFPA 54 or the current (Canada) National Fuel & Propane Installation Code CSA B149.1 or B149.2, and Mechanical Refrigeration Code CSA B52. 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.

The Clean Air Act of 1990 bans the intentional venting of refrigerant as of July 1, 1992. Approved methods of recovery, recycling, or reclaiming must be followed.

Coils and sheet metal surfaces present sharp edges and care must be taken when working with equipment.

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

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 the AAON-Longview Warranty Department for assistance with handling damaged goods, repairs, and freight claims: (903) 236-4403.

Note: Upon receipt check shipment for items that ship loose such as filters and remote sensors. Consult order and shipment documentation to identify potential looseshipped items. Loose-shipped items may have been placed inside unit cabinet for security. Installers and owners should secure

all doors with locks or nuts and bolts to prevent unauthorized access.

Figure 3 - Lockable Handle

The warranty card must be completed in full and returned to AAON not more that 3 months after 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.

Packaged Direct Expansion (DX) Units

All DX refrigeration systems are factory assembled, leak tested, charged with refrigerant, and run tested.

All DX refrigerant systems include an evaporator, condenser, liquid line filter driers, thermal expansion valves (TXV) and scroll compressors. Compressors are equipped with a positive pressure forced lubrication system.

Some 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.

CRANKCASE HEATER

OPERATION

Never cut off the main power supply to the unit, except for servicing, emergency, or complete shutdown of the unit. When power is cut off from the unit crankcase heaters cannot prevent refrigerant migration into the compressors. 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 power to the unit must be off for more than an hour, turn the thermostat system switch to "OFF", or turn the unit off at the control panel, and leave the unit off until the main power switch has been turned on again 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 started.

Always control the unit from the thermostat, or control panel, never at the main power supply, except for servicing, emergency or complete shutdown of the unit.

During the cooling season, if the air flow is reduced due to dirty air filters or any other reason, the cooling coils can get too cold which will 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 shorted by reduced lubrication and the pumping of excessive amounts of liquid oil and refrigerant.

Note: Low Ambient Operation Air-cooled DX units without a low ambient option, such as condenser fan cycling, ECM driven condenser fans or the 0°F low ambient option, will not operate in the cooling mode of operation properly when the outdoor temperature is below 55°F. Low ambient and/or economizer options are recommended if cooling operation below 55°F is expected.

Gas or Electric Heating

The unit is designed to heat a given amount of air while operating. If this amount of air is greatly reduced, approximately 1/3 during the heating season, the gas heat exchanger or electric heating coil may overheat, and may cut the burner or heater off entirely by action of the safety high temperature limit devices which are factory mounted at the heat exchanger and supply fan areas.

Airflow should be adjusted after installation to obtain an air temperature rise within the range specified on the unit rating plate at the required external static pressure.

Should overheating occur with a gas heat exchanger, or the gas supply fail to shut off, shut off the manual gas valve to the furnace before shutting off the electrical supply.

Prolonged overheating of the heat exchanger will shorten its life.

If unit has not been selected as a 100% outside air unit (make up air unit) the return air duct must be sealed to the unit and the return air temperature must be maintained between 55°F and 80°F.

Wiring Diagrams

Unit specific wiring diagrams are laminated and affixed inside the controls compartment door.

Condensate Drain Pan

Unit requires drain traps to be connected to the condensate drain pan of the unit.

For condensate drain lines, the line should be the same pipe size or larger than the drain connection, include a p-trap, and pitch downward toward drain. An air break should be used with long runs of condensate lines.

Unit should not be operated without a p-trap. Failure to install a p-trap may result in overflow of condensate water.

An auxiliary / emergency drain pan is recommended for all indoor applications where there is a risk of water damage to surrounding structure or furnishings. Refer to local codes.

Installation

AAON equipment has been designed for quick and easy installation.

Locating Units

Verify rooftop, foundation or mounting frame can support the total unit weight, including accessory weights.

Before setting the unit into place, caution must be taken to provide clearance for unit doors that must be accessible for periodic service. These areas contain the controls, safety devices, refrigerant or water piping, shut-off valves and filters.

A minimum clearance equal to the width of the unit is required on the access panel side of the unit to ensure there is enough room to slide out coils and energy recovery wheels, and to access filters, fans and other internal components.

Depending on natural gas and propane heating module orientations, the combustion air inlets or vent (flue) gas discharges may be located in the unit roof or sides. There must be 6 feet of clearance between these roofs/sides and building walls, parapets, adjacent buildings, or equipment. If equipment is for replacement and required clearances are not available, contact AAON for recommendations.

When locating gas fired units, it is recommended the unit be installed so that the flue discharge vents are located at least 120 inches away from any opening through which combustion products could enter the building.

Distances from adjacent public walkways, adjacent buildings, operable windows and building openings, shall conform to local codes and/or the National Fuel Gas Code, ANSI Z223.1/NFPA 54, or the National Gas & Propane Code, CSA B149.1

For gas fired unit, do not position flue opening to discharge into a fresh air intake of any other piece of equipment. Unit should also be installed so that the flow of combustion intake air is not obstructed from reaching the furnace.

Outdoor vent opening must not be blocked by snow. A minimum 12” curb must be used or the vent outlet shall be greater than 12” off the ground/roof.

Flue gas is dangerously hot and contains containments. The user is responsible for determining if vent gases may degrade building materials.

The National Gas and Propane Installation Code, B149.1 specifies a 6 ft. horizontal vent terminal clearance to gas and electric meters and relief devices.

Local codes may supersede or further place

CAUTIO

restrictions on vent termination locations.

Energy

Recovery

Wheel

Coil

Energy

Recovery

Wheel

Module

Coil Module

Fan

Figure 4 - Service Access Clearance

Table 1 - Minimum Clearances

Minimum Required

Unit Size

Service Clearance

X = M2-005 50” M2-008 50” M2-011 62” M2-014 62” M2-018 84” M2-022 84” M2-026 84” M2-032 96” M2-036 96”

Lifting the Unit

Units may be delivered in separate module components or completely factory assembled with all modules connected. In the latter case, if the unit was received fully assembled on a skid, then the equipment should be lifted into place using the shipping skid to prevent damage to the modules.

Incorrect lifting can cause damage to the unit.

If cables or chains are used to hoist the unit they must be the same length. 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.

Hoist unit to a point directly above the duct openings.

Carefully lower and align the unit with utility and duct openings. Make sure the unit is properly seated and level.

Refer to the following unit lifting figures.

Figure 5 - M2 Series Unit Four Point Lifting

Figure 6 - M2 Series Unit Eight Point Lifting

Indoor Floor Mounted Units

Indoor M2 Series units can be floor mounted.

Dual path units, self contained units and units over size M2-014 must be floor mounted. Make sure the unit is level, and installed with a minimum height of 6” to allow for proper drainage of the condensate line. Other installation provisions may be necessary according to job specifications.

Indoor Suspended Units

Indoor M2 Series units can be can be suspended. Only single path units of size M2-005 to M2-014 should be suspended. Suspension of dual path units, self contained units or units over size M2-014 is not recommended.

A ceiling suspended mounting frame must be provided for unit suspension. It is the responsibility of the engineer or installing contractor to design and build a suitable structure based on the load distribution of individual modules. C-channels, or similar structural members, are suggested to be placed parallel to airflow under each base rail of the unit, with appropriate structural cross members as required by weight and design. A 4” minimum c-channel size is recommended. The unit is not designed to be suspended directly from the base rails. An appropriate structural support is required for suspension.

The air handling unit must be installed level as the internal drain pan is manufactured with a slope toward the drain. Other installation provisions may be necessary according to job specifications and requirements.

Cross members

perpendicular to airflow

Figure 7 - Unit Suspension

Supports positioned

under base rails

parallel to airflow

Ceiling/roof

structure

Suspension

lines or rods

Base rail

Field supplied

support structure

Suspension lines or rods

tied to support structure

(not to the unit base rail)

Module Assembly

Although M2 Series modular units are shipped factory assembled as standard, they may be ordered unassembled for certain applications such as for assembly in existing structures where modules must be manipulated separately. If the unit was ordered unassembled, then you will need to connect the modules in the field.

Locate the configuration schematic in the equipment’s literature packet. The schematic will have CONFIGURATION written in the top left hand corner followed by the unit model number and then the module configuration numbers listed in order.

1. Identify and Situate Modules

Use the Model Number descriptions at the beginning of this manual for assistance identifying module types by their three-letter codes.

It is advisable to situate all required modules in the installation location as near as possible to the order in which they will be connected. Be sure to leave enough space to work between modules before connection. Bulb gasket will be applied in the next step.

Identify each module by the configuration number on its label. For example, if a module has a configuration number of FTF101-P-A0-00000-00000-0-0, then it is a large flat filter module “FTF”, and should be placed in the first position “101” of the lower tier - the bottom left as you face the access side of a right hand unit, or the bottom right as you face the access side of a left hand unit.

Although you should have a schematic available, the configuration numbers have been created so that correct assembly order

can be determined without the need for a schematic.

Modules are arranged in order with 100 series modules on the first tier and 200 series modules on the second tier. Module 101 will always be located on the end of the bottom tier - the bottom left as you face the access side of a right hand unit, or the bottom right as you face the access side of a left hand unit. Module 201 will always be located on the end of the top tier - the top left as you face the access side of a right hand unit, or the top right as you face the access side of a left hand unit. Therefore, it is possible to identify the exact module arrangement even without knowing the module type, and without a configuration schematic.

If, for any reason, you are unable to identify a module or its position in the final assembly, then consult the project engineer or AAON sales representative.

After identifying modules and determining module arrangement you can prepare the modules for assembly.

CONFIGURATION: M2-H-011-R-2-A-A-0-C-0 FTF-101-P-A0-00000-00000-0-0 HRA-102-A-00-00000-00000-0-0 CLF-103-C-00-210F0-610F0-S-0 SFA-104-K-C0-A0000-00000-0-0 PEC-201-K-BI-A0000-00000-0-0 FTE-203-P-B0-00000-00000-0-0

Module

configuration

numbers

Table provides required

service access clearances

for applicable modules

201

Note: Energy recovery wheel module will have a 100 series number, but will span both tiers, also utilizing a 200 series space.

101

Figure 8 - Module Assembly Schematic

Base model

number

PEC FTE

Configuration Schematic can

be found in unit literature packet

Arrows

indicate

airflow

203

HRA

CLF FTF SFA

104

102

103

2. Apply Bulb Gasket

The bulb gasket material creates an airtight seal between adjacent modules after connection. The adhesive backing is initially low tack so the gasket can be easily repositioned during installation. The adhesive backing will cure to full bond strength after 72 hours and will then no longer be easily removable.

Figure 9 - Bulb Gasket

Apply bulb gasketing

around entire perimeter

of airway opening

Figure 10 - Applying Bulb Gasket

Each joint in the unit body should have gasket applied to one side

of the opening separation. That is, only one airway opening of two adjacent modules should have a gasket applied.

Apply bulb gasket to one side of the opening between adjacent modules

Figure 11 - Gasket Application

3. Connect Modules

Modules are to be connected with nuts and bolts through the base rail and with metal strapping over module joints. Metal straps have adhesive backs and are to be additionally fastened to the unit case with sheet metal screws. All connection hardware is shipped with the unit.

Align modules, and insert bolts through the bolt holes in the base rails of two adjacent modules. Secure with nuts to pull the bases of the two modules together tightly.

Figure 12 - Bolted Base Rail

Use bar clamps or other non-destructive winching device to pull the tops of the modules together tightly.

You should now have a fully gasketed, airtight joint that needs to be permanently secured into position.

Figure 13 - Bar Clamp

You should now have a fully gasketed, airtight joint that needs to be permanently secured into position.

4. Secure Module Joints

The metal straps are to be used to secure module joints in order to maintain the airtight seal. Straps are provided with predrilled holes and adhesive backing already affixed. Self-tapping sheet metal screws are provided to attach the straps to the unit cabinet.

Leave bar clamps in place until strap is secure.

Peel away backing from adhesive side of a strap.

Place the strap over a module joint with the adhesive side of the strap against the unit case.

Ensure that strap completely covers the joint and that it is square with the unit casing.

Apply pressure to the strap to affix the adhesive and to hold strap in place.

Insert self-tapping screws through predrilled holes in strap and secure screws into unit casing using a power drill. For best results, use the lowest effective power drill torque setting. Be careful not to over tighten the screws.

Remove bar clamps and repeat for all remaining module joints.

5/16” Hex Head

Self-Tapping Screws

Provided with Unit

1”

Figure 14 - Self-Tapping Screw

Top

Strap

Side

Strap

Angle

Strap

Figure 15 - Strap Types

Top

Strap

Side

Strap

ngle

Strap

Figure 16 - Strap Locations

ngle

Strap

Put straps in position,

hold in place and attach

with self-tapping sheet

metal screws.

Figure 17 - Strap Installation

5. Run Power and Control Wiring

M2 Series units are equipped with an internal wiring chase, located along the inside top of each module. Wire is provided for power and control wiring inside the unit. Wire from the unit to external controls and power sources must be provided in the field.

A color-coded wiring diagram is laminated and affixed to the inside of the control compartment access door. M2 Series units are equipped with a single point power connection.

6. Final Sealing

It is very important to keep air from infiltrating the unit cabinet. Seal all piping penetrations with Armaflex, Permagum or other suitable sealant. Also seal around drain connections, electrical connections and all other inlets where air may enter the cabinet. This is especially important when the unit is installed in an unconditioned area.

Refrigerant Piping

(See back of the manual for refrigerant piping diagrams and connection sizes.)

Piping from the condensing unit to the air handling unit is the responsibility of the installing contractor.

The Split System Configurator

or Refrigerant Piping Calculator in AAONEcat32 should be used to determine acceptable refrigerant line sizes.

The pipe sizes must be selected to meet the actual installation conditions and not simply based on the connection sizes at the evaporator or condensing unit.

CAUTIO

This section is for information only and is not intended to provide all details required by the designer or installer of the refrigerant piping between the condenser or condensing unit and the air handling unit. AAON is not responsible for interconnecting refrigerant piping. Consult ASHRAE Handbook – Refrigeration and ASME Standards.

Only clean ACR tubing should be used. Piping should conform to generally accepted practices and codes.

The air handling unit coils are pressurized. The copper caps must be punctured to permit a gradual escape of the pressure prior to un-sweating those caps. Immediately couple the tubing to the indoor unit to avoid exposing the coils to moisture. A properly sized filter drier is furnished in the condenser. When making solder connections, make sure dry nitrogen flows through the lines, when heating the copper, to prevent oxidization inside of the copper.

When piping is completed interconnecting piping and air handling unit must be evacuated to 500 microns or less and leak checked. Condenser shutoff

valves can then be opened to allow refrigerant to flow to the air handling unit.

Thermal expansion valve bulbs should be mounted with good thermal contact on a horizontal section of the suction line close to the evaporator, but outside the cabinet, and well insulated.

Refrigerant lines should be fastened and supported according to local codes.

Unit should be charged based on determination of sub-cooling and superheat. See Adjusting Refrigerant Charge section for more information.

Refrigerant reheat coil for the modulating hot gas reheat option is factory installed. Liquid line receiver should be installed at the condensing unit. Care must be taken not to cross circuits in reheat systems.

Modulating Hot Gas Reheat Piping:

1. Run a hot gas reheat line from the condensing unit and connect it to the inlet of the stub-out on the reheat coil. The inlet connection is the top (or highest) stub-out of the reheat coil. Connect the hot gas line from the outdoor unit to the upper stub-out connection of the reheat coil.

2. Run a liquid line from the discharge of the reheat coil through a tee connection. Run a liquid line from the condenser, through a check valve to the other side of the tee. Run a liquid line from the tee to the liquid line stub-out of the evaporator coil.

3. Run a suction line from the evaporator coil outlet stub-out to the condensing unit.

Determining Refrigerant Line Size

Line sizes must be selected to meet actual installation conditions, not simply based on the connection sizes at the condensing unit or air handling unit.

The piping between the condenser and low side must ensure:

1. Minimum pressure drop, and

2. Continuous oil return, and

3. Prevention of liquid refrigerant slugging, or carryover

Minimizing the refrigerant line size is favorable from an economic perspective, reducing installation costs, and reducing the potential for leakage. However, as pipe diameters narrow, pressure-reducing frictional forces increase.

Excessive suction line pressure drop causes loss of compressor capacity and increased power usage resulting in reduced system efficiency. Excessive pressure drops in the liquid line can cause the liquid refrigerant to flash, resulting in faulty TXV operation and improper system performance. In order to operate efficiently and cost effectively, while avoiding malfunction, refrigeration systems must be designed to minimize both cost and pressure loss.

Equivalent Line Length

All line lengths discussed in this manual, unless specifically stated otherwise, are Equivalent Line Lengths. The frictional pressure drop through valves, fittings, and accessories is determined by establishing the equivalent length of straight pipe of the same diameter. Always use equivalent line lengths when calculating pressure drop. Special piping provisions must be taken when lines are run underground, up vertical risers, or in excessively long line runs.

Liquid Line Sizing

When sizing the liquid line, it is important to minimize the refrigerant charge to reduce installation costs and improve system reliability. This can be achieved by minimizing the liquid line diameter. However, reducing the pipe diameter will increase the velocity of the liquid refrigerant which increases the frictional pressure drop in the liquid line, and causes other undesirable effects such as noise.

Maintaining the pressure in the liquid line is critical to ensuring sufficient saturation

temperature, avoiding flashing upstream of the TXV, and maintaining system efficiency. Pressure losses through the liquid line due to frictional contact, installed accessories, and vertical risers are inevitable. Maintaining adequate subcooling at the condenser to overcome these losses is the only method to ensure that liquid refrigerant reaches the TXV.

Liquid refrigerant traveling upwards in a riser loses head pressure. If the evaporator is below the condenser, and the liquid line does not include risers, the gravitational force will increase the pressure of the liquid refrigerant. This will allow the refrigerant to withstand greater frictional losses without the occurrence of flashing prior to the TXV.

A moisture-indicating sight glass may be field installed in the liquid line to indicate the occurrence of premature flashing or moisture in the line. The sight glass should not be used to determine if the system is properly charged. Use temperature and

pressure measurements to determine liquid sub-cooling, not the sight glass.

Liquid Line Routing

Care should be taken with vertical risers. When the system is shut down, gravity will pull liquid down the vertical column, and back to the condenser when it is below the evaporator. This could potentially result in compressor flooding. A check valve can be installed in the liquid line where the liquid column rises above the condenser to prevent this. The liquid line is typically pitched along with the suction line, or hot gas line, to minimize the complexity of the configuration.

Liquid Line Insulation

When the liquid line is routed through regions where temperature losses are expected, no insulation is required, as this

may provide additional sub-cooling to the refrigerant. When routing the liquid line through high temperature areas, insulation of the line is appropriate to avoid loss of subcooling through heat gain.

Liquid Line Guidelines

In order to ensure liquid at the TXV, frictional losses must not exceed available sub-cooling. A commonly used guideline to consider is a system design with pressure losses due to friction through the line not to exceed a corresponding 1-2°F change in saturation temperature.

If the velocity of refrigerant in the liquid line is too great, it could cause excessive noise or piping erosion. The recommended maximum velocities for liquid lines are 100 fpm from the condenser to a receiver tank to discourage fluid backup, and 300 fpm from receiver tank to the evaporator to minimize valve induced liquid hammer.

Liquid Line Accessories

Liquid line shut off valves and filter driers are factory provided. Filter driers must be field installed on 2-6 ton units. The total length equivalent of pressure losses through valves, elbows and fittings must be considered when adding additional components in the field. It is a good practice to utilize the fewest elbows that will allow the mating units to be successfully joined.

Suction Line Sizing The suction line is more critical than the liquid line from a design and construction standpoint. More care must be taken to ensure that adequate velocity is achieved to return oil to the compressor at minimum loading conditions. However, reducing the piping diameter to increase the velocity at minimal load can result in excessive pressure losses, capacity reduction, and noise at full load.

Suction Line Routing

Pitch the suction line in the direction of flow (about 1 foot per 100 feet of length) to maintain oil flow towards the compressor, and keep it from flooding back into the evaporator. Crankcase heaters are provided to keep any condensed refrigerant that collects in the compressor from causing damage or wear. Make sure to provide support to maintain suction line positioning, and insulate completely between the evaporator and condensing unit.

It is important to consider part load operation when sizing suction lines. At minimum capacity, refrigerant velocity may not be adequate to return oil up the vertical riser. Decreasing the diameter of the vertical riser will increase the velocity, but also the frictional loss.

Circuits with variable capacity scroll compressors require suction riser traps every 10 feet.

A double suction riser can be applied to the situation of part load operation with a suction riser. A double suction riser is designed to return oil at minimum load while not incurring excessive frictional losses at full load. A double suction riser consists of a small diameter riser in parallel with a larger diameter riser, and a trap at the base of the large riser. At minimum capacity, refrigerant velocity is not sufficient to carry oil up both risers, and it collects in the trap, effectively closing off the larger diameter riser, and diverting refrigerant up the small riser where velocity of the refrigerant is sufficient to maintain oil flow.

At full load, the mass flow clears the trap of oil, and refrigerant is carried through both

risers. The smaller diameter pipe should be sized to return oil at minimum load, while the larger diameter pipe should be sized so that flow through both pipes provides acceptable pressure drop at full load.

Suction Line Insulation

The entire suction line should be insulated. This prevents condensation from forming on the line, and reduces any potential loss in capacity associated with heat gain.

Suction Line Guidelines

For proper performance, suction line velocities less than a 4,000 fpm maximum are recommended. The minimum velocity required to return oil is dependent on the pipe diameter, however, a general guideline of 1,000 fpm minimum may be applied.

In a fashion similar to the liquid line, a common guideline to consider is a system design with pressure losses due to friction through the line not to exceed a corresponding 1-2°F change in saturation temperature.

At points where small pipe size can be used to provide sufficient velocity to return oil in vertical risers at part loads, greater pressure losses are incurred at full loads. This can be compensated for by over sizing the horizontal runs and vertical drop sections. This will however require additional refrigerant charge.

Circuits with variable capacity scroll compressors require suction riser traps every 15 feet.

Suction Line Accessories

If the job requirements specify suction accumulators, they must be separately purchased and field installed.

Hot Gas Bypass Line

Hot Gas Bypass is available for use with DX systems that may experience low suction pressure during the operating cycle. This may be due to varying load conditions associated with VAV applications or units supplying a large percentage of outside air. The system is designed to divert refrigerant from the compressor discharge to the low pressure side of the system in order to keep the evaporator from freezing and to maintain adequate refrigerant velocity for oil return at minimum load.

Hot discharge gas is redirected to the evaporator inlet via an auxiliary side connector (ASC) to false load the evaporator when reduced suction pressure is sensed.

Field piping between the condensing unit and the evaporator is required.

Hot Gas Bypass Piping Considerations for Evaporator above Condensing Unit

Pitch the hot gas bypass (HGB) line downward in the direction of refrigerant flow, toward the evaporator.

When installing hot gas bypass risers, a drain leg must be provided at the lowest point in the system. The drain leg must be vertical, its diameter should be the same as the diameter of the riser, and it should be 1 foot long. Install a sight glass in the drain leg for observation. Run an oil return line, using 1/8 inch capillary tube, 10 feet in length, from the drain leg to the suction line. Connect the oil return line below the sight glass and 1 inch above the bottom of the drain leg.

HGB valves are adjustable. Factory HGB valve settings will be sufficient for most applications, but may require slight adjustments for some applications, including some make up air applications.

Insulate the entire length of the HGB line with a minimum 1 inch thick Armaflex insulation.

Hot Gas Bypass Piping Considerations for Evaporator below Condensing Unit

The line must slope downward from the HGB valve toward the evaporator.

Hot Gas Bypass Line Guidelines

Choose a small size line to ensure oil return, and minimize refrigerant charge.

Maintain velocities below a maximum of 4,000 fpm. A general minimum velocity guideline to use is approximately 1,000 fpm.

Hot Gas Reheat

The AAON modulating hot gas reheat system diverts hot discharge gas from the condenser to the air handling unit through the hot gas line. Field piping between the

condensing unit and the air handler is required.

The line delivers the hot discharge gas to the reheat coil and/or the hot gas bypass valve, so it is sized as a discharge line.

Discharge lines should be sized to ensure adequate velocity of refrigerant to ensure oil return, avoid excessive noise associated with velocities that are too high, and to minimize efficiency losses associated with friction.

Pitch the hot gas line in the direction of flow for oil return.

When installing hot gas reheat risers, a drip leg must be provided at the lowest point in the system. The drip leg must be vertical, its diameter should be the same as the diameter of the riser, and it should be 1 foot long. Run a drip line, using 1/8 inch capillary tube, 10 feet in length, from the drip leg to the suction line. Connect the drip line a

minimum of 1-inch above the bottom of the drain leg.

Insulate the entire length of the hot gas line with a minimum 1 inch thick Armaflex insulation.

Hot Gas Reheat Guidelines

Maintain velocities below a maximum of 3,500 fpm. A general minimum velocity guideline is 2,000 fpm.

Water-Cooled Condenser

Condenser water pump, condenser water piping, cooling tower, pressure gauges, strainers and all components of the waterside piping must be field installed.

Open Loop Applications

This product contains one or more refrigerant-to-water heat exchangers made of 316 Stainless Steel. 316 Stainless Steel is subject to severe corrosion and failure when exposed to chlorides.

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.

Do not allow water containing any form of chlorides to enter this heat exchanger.

Common forms of chlorides include:

1. Sea water mist entering an open cooling tower system.

2. Contaminated make-up water containing salt water.

3. Disinfection the water loop with solutions containing sodium hypochlorite.

Chlorides will result in a premature failure of the condenser.

Failure of the condenser as a result of chemical corrosion is excluded from coverage under AAON warranties and the heat exchanger manufacturer warranties.

Failure of the condenser 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 condenser failure from chemical corrosion due the fluid in the condenser is excluded from coverage under AAON warranties and the heat exchanger manufacturer warranties.

OPEN LOOP APPLICATIONS

SMO 254 brazed plated refrigerantto-water heat exchangers are recommended with all open loop applications. Failure to use a SMO 254 heat exchanger may result in premature failure of your system and possible voiding of the warranty.

Cleaning the cooling tower or condenser water loop with harsh chemicals such as hydrochloric acid (muriatic acid), chlorine or other chlorides, can damage the refrigerant-to-water heat exchanger. Care should be taken to avoid allowing chemicals to enter the refrigerant-to-water heat exchanger. See Appendix A - Heat Exchanger Corrosion Resistance for more information.

Freezing Water in the Heat Exchanger

This product contains one or more refrigerant-to-water heat exchangers. A refrigerant-to-water heat exchanger contains refrigerant in one passage and water in another passage. Water is subject to freezing at 32°F. When water freezes in a heat exchanger significant forces are exerted on the components of the heat exchanger where the water is confined.

WATER FREEZING

Unit is capable of operating with Entering Water Temperatures (EWT) as low as 50°F during heat pump heating mode without the

need for head pressure control. If the EWT is expected to be lower than 50°F or more stable operation is desired, a field provided water regulating valve may be used.

Glycol solution should be used if ambient temperatures are expected to fall below freezing or if the loop water temperature is below 50°F while operating in the heating mode (heat pump units only). Adding glycol to condenser water causes an increase in pressure drop resulting in a decrease in unit performance. A minimum concentration of 20% glycol solution is recommended.

Table 2 - Glycol Freezing Points

% Glycol Ethylene

Glycol

Propylene

Glycol 20 18°F 19°F 30 7°F 9°F 40 -7°F -6°F 50 -28°F -27°F

Water loop piping runs through unheated areas or outside the building should be insulated.

Water Piping

Installing contractor must ensure a differential pressure switch is installed between the condenser water supply and return connections. This sensor provides a signal to the unit controller that water flow is present in the heat exchanger and the unit can operate without damaging unit components.

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 water piping. Supply water connection may require a backflow preventer to prevent supply makeup water from backing up into the public water system.

WATER PRESSURE

Condenser water connections range in size from 1-18”-4” OD copper or black pipe. Only use approved water pipe material. Avoid using galvanized material for water lines/fittings as the material is corrosive and may cause fouling of the water system.

Condenser water pump must be field sized and installed between the cooling tower and self contained unit. System should be sized in accordance with the ASHRAE Handbook. Use engineering guidelines to maintain equal distances for supply and return piping and limit bend radiuses to maintain balance in the system. Balancing valves, permanent thermometers and gauges may be required.

CAUTIO

Follow national and local codes when installing water piping. Connections to the unit should incorporate vibration eliminators to reduce noise and vibration and shutoff valves to facilitate servicing. Supply and return water piping must be at least as large as the unit connections and larger depending on length of runs, rise and bends.

WATER PIPING

Before connection to the unit the condenser water system should be flushed to remove foreign material that could cause condenser fouling. Install a screen strainer with a minimum of 20 Mesh ahead of the condenser inlet to prevent condenser fouling and internal tube damage.

Mineral content of the condenser water must be controlled. All make-up water has minerals in it and as the water is evaporated in the cooling tower, these minerals remain. As the mineral content of the water increases, the conductivity of the water increases.

Field provided and installed water treatment program must be compatible with stainless steel, copper, aluminum, ABS plastic, and PVC. Batch feed processes should never be used as concentrated chemicals can cause corrosion. Never use hydrochloric acid (muriatic acid) or chlorine as it will corrode stainless steel.

Each heat exchanger is equipped with a refrigerant pressure relief device to relieve pressure should excessive condensing pressures (>675 psig) occur. Codes may require installing contractor to connect and route relief piping outdoors. The relief valve has a 5/8” male flare outlet connection.

Unit is capable of operating with Entering Water Temperatures (EWT) as low as 50°F without the need for head pressure control. If the EWT is expected to be lower than 50°F or more stable operation is desired, a field provided water regulating valve may be used.

Table 3 - Freezing Points

CAUTIO

% Glycol Ethylene

Glycol

Propylene

Glycol 20 18°F 19°F 30 7°F 9°F 40 -7°F -6°F 50 -28°F -27°F

Do not exceed recommended condenser fluid flow rates shown in above table. Serious damage to or erosion of the heat exchanger tubes could occur.

Piping systems should not exceed 10 ft/sec velocity to ensure tube wall integrity and reduce noise.

Table 4 - Coaxial Heat Exchanger Pressure Drops (WCC- & WHP-)

-002 -003 -004 -005

gpm psi gpm psi gpm psi gpm psi

3 1.9 6 2.3 8 3.3 7 1.6 5 4.3 8 3.7 10 4.8 11 2.8 7 7.4 10 5.3 12 6.7 15 4.6

-006 -008 -010 -013

gpm psi gpm psi gpm psi gpm psi

11 2.6 16 3.8 14 2 20 3.4 16 4.2 20 5.5 22 3.5 28 5.8 20 6.0 24 7.6 30 5.6 36 8.8

-016 -020 -025 -030

gpm psi gpm psi gpm psi gpm psi

28 3.6 28 2.3 40 3.9 56 4.1 36 5.3 44 3.9 56 6.6 72 6 44 7.8 60 6.1 72 10 88 8.9

-040 -050 -060

gpm psi gpm psi gpm psi

56 2.6 80 4.2 112 4.33 88 4.4 112 7.1 144 6.5

120 6.9 144 10.4 176 9.6

Table 5 - Brazed Plate Heat Exchanger Pressure Drops (WCC- & WHP-)

-003 -004 -005 -006

gpm psi gpm psi gpm psi gpm psi

7.9 2.89 10.0 4.41 12.5 5.46 15 2.37

9.5 4.03 12.1 6.21 15.1 7.69 18.1 3.39

-006 -008 -010 -013

gpm psi gpm psi gpm psi gpm psi

17.5 3.17 20.0 2.91 25.0 3.34 32.5 4.3

21.1 4.55 24.1 4.71 30.2 4.79 39.2 6.17

-016 -020 -025 -030

gpm psi gpm psi gpm psi gpm psi

40.0 4.26 50.0 4.72 62.5 4.92 75.0 4.75

48.3 6.11 60.4 6.77 75.4 7.06 90.5 6.82

-040 -050 -060

gpm psi gpm psi gpm psi

100.0 6.6 125.0 10.1 150.0 9.46

120.7 9.5 150.9 14.4 181.0 13.6

Water-Cooled Condenser Safeties

Electronic freeze protection and water flow safeties should be field installed or factory provided. If the leaving water temperature drops below 38°F or water flow has ceased the 24VAC control circuit will be broken to disable the cooling system.

Electrical

Verify the unit name plate agrees with power supply. M2 Series units are provided with single point power wiring connections. Connection terminations are made to the main terminal block. A complete set of unit specific wiring diagrams, showing factory and field wiring are laminated in plastic and located inside the controls compartment door.

Disconnect all electrical power sources before servicing the unit. More than one power source may be

All units require a field supplied electrical

provided. Failure to do so may result

overcurrent and short circuit protection.

in injury or death from electrical

Device must not be sized larger than the

shock or entanglement in moving

Maximum Overcurrent Protection (MOP)

parts.

shown on the unit nameplate.

Codes may require a disconnect switch be within sight of the unit.

Note: Do not install the required field installed overcurrent protection or disconnect switch on the unit!

Electrical supply can enter through the bottom or side of the controls compartment. Entry must be field cut into panels of the unit.

A single point connection to a terminal block is provided. Split units may require connection between the units. High voltage conductors should enter the control panel in a separate opening and separate conduit than 24V low voltage conductors.

The foam insulation releases dangerous fumes when it is burnt. Do not cut a foam part with a cutting torch or plasma cutter. Do not weld to a foam filled part.

WARNING

Note: Locations for field cut electrical entries are marked on the unit. Field cut openings must be a minimum of 6 inches away from all components and wiring to prevent damage due to drilling or cutting.

To pass wires through the wall or roof of the unit, a hole should be cut and conduit passed through it. Use the following procedure to cut a round hole in a foam panel.

Cutting Electrical Openings

1. Locate the placement of the hole. Be sure that the conduit will not interfere with the operation of any component or prevent access of any door or removable panel.

2. Drill a pilot hole all the way through the foam panel.

3. Using a hole saw cut the hole through the metal on both sides of the foam part.

4. With a knife cut the foam out of the hole.

5. After the conduit is installed in the hole caulk the entire perimeter of the hole on both sides with an industrial grade silicone sealant or a duct seal compound.

If a larger cut-out is needed for additional duct connections not provided by the factory, or for any other reason, it is very

important that the foam be completely sealed. Insulation covers should be fabricated from sheet metal to cover the foam at the cut. The edges and corners that are not covered should be sealed using silicone caulking. If a reciprocating saw is used to make the cut out, take care that the metal skins of the foamed part do not separate from the foam, this would result in reduced structural integrity of the part.

Size supply conductors based on the unit Minimum Current Ampacity (MCA) rating. Supply conductors must be rated a minimum of 75°C.

Protect the branch circuit in accordance with code requirements. The unit 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.

Wire power leads to the unit’s terminal block or main disconnect. All wiring beyond this point has completed at the factory.

Three phase voltage imbalance will cause motor overheating and premature failure.

Supply voltage must be within the min/max range shown on the unit nameplate. Available short circuit current should not exceed the SCCR rating shown on the unit nameplate.

Three phase voltage imbalance will cause motor overheating and premature failure. The maximum allowable imbalance is 2.0%.

Voltage imbalance is defined as 100 times the sum of the deviation of the three

voltages from the average divided by the

CAUTIO

average voltage.

Example: (221V+230V+227V)/3 = 226V, then 100*(226V-221V)/226V = 2.2%, which exceeds the allowable imbalance.

Check voltage imbalance at the unit disconnect switch and at the compressor terminal. Contact your local power company for line voltage corrections.

Installing contractor must check for proper motor rotation and check blower motor amperage listed on the motor nameplate is not exceeded. Motor overload protection may be a function of the variable frequency drive (VFD) and must not be bypassed.

Note: All units are factory wired for 208/230V, 460V, or 575V. If unit is to be connected to a 208V supply, the transformer must be rewired to 208V service. For 208V service interchange the yellow and red conductor on the low voltage control transformer. Red-Black for 208V Yellow-Black for 230V

Rotation must be checked on all MOTORS AND COMPRESSORS 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

Wire control signals to the unit’s low voltage terminal block located in the controls compartment.

If any factory installed wiring must be replaced, use a minimum 105°C type AWM insulated conductors.

Thermostat Control Wiring

If a thermostat is used for unit control, thermostat should be located on an inside wall 4-5 feet above the floor where it will not be subjected to drafts, sun exposure, or heat from electrical fixtures of appliances. Control wiring must deliver adequate voltage to components to assure proper operation. Control voltage returning from controller circuit must be a minimum of 21 VAC. To assure proper wiring use the following chart to determine the allowable wiring distances.

Table 6 - Control Wiring

Wire Size (Stranded)

- Copper Conductors Only 20 AWG 200 ft 18 AWG 350 ft 16 AWG 500 ft 14 AWG 750 ft 12 AWG 1250 ft

Total Wire Distance Allowable = (Quantity of Control Wires) x (Control Wire Distance)

Take the total wire distance allowable and divide by the number of wires to be connected. This indicates the distance allowable for that size wire. The wiring to the unit must not exceed the total wire distance allowable. If the voltage at the connectors is less than 21 VAC, isolation relays must be installed. If under external control 21 VAC must be field verified.

Total Wire Distance Allowable

All external devices must be powered via a separate external power supply.

Example: A total of 8 wires must be pulled 75ft to a control the unit. What size wire should be used?

According to the Table 2, 16 AWG allows for 63ft (500 ft/8 wires) and 14 AWG allows for 94ft (750 ft/8 wires). Thus, 14 AWG should be used.

Condensate Drain Piping

Unit may be equipped with more than one condensate drain pan connection. A p-trap and drain line must be installed on every drain connection, with the p-trap not to exceed 6” from the drain connection. The lines should be the same pipe size or larger than the drain connection, include a p-trap, and pitch downward toward drain. An air break should be used with long runs of condensate lines.

Unit should not be operated without p-traps. Failure to install a p-traps may result in overflow of condensate water.

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. Blow-through coils will have a positive static pressure in the drain pan. The condensate piping on these drain pans must be trapped to prevent pressure loss through the drain.

Condensate drain trapping and piping should conform to all applicable governing codes.

Note: The drain pan connection is a 1” MPT fitting.

Figure 18 - Draw-Through Drain Trap

The X dimension on the draw-through trap should be at least equal to the absolute value of the negative static pressure in the drain pan plus one inch. To calculate the static pressure at the drain pan add the pressure drops of all components upstream of the drain pan, including the cooling coil, and add the return duct static pressure. Include the dirt allowance pressure drop for the filters to account for the worst-case scenario.

The height from top of the bottom bend of the trap to the bottom of the leaving pipe must be at least equal to one half of the X dimension. This ensures that enough water is stored in the trap to prevent losing the drain seal during unit startup

Note: The absolute value of the fan inlet pressure will always be greater than or equal to the absolute value of the static pressure in the drain pan on draw-through units, so the fan inlet pressure is a safe value to use for the drain pan static pressure.

Table 7 - Drain Trap Dimensions

Draw-Through

Drain Pan Pressure Trap Dimensions

Negative Static X X/2

(inches of water) (inch) (inch)

-0.50 1.50 0.75

-1.00 2.00 1.00

-1.50 2.50 1.25

-2.00 3.00 1.50

-2.50 3.50 1.75

-3.00 4.00 2.00

-3.50 4.50 2.25

-4.00 5.00 2.50

-4.50 5.50 2.75

-5.00 6.00 3.00

-5.50 6.50 3.25

-6.00 7.00 3.50

-6.50 7.50 3.75

-7.00 8.00 4.00

-7.50 8.50 4.25

-8.00 9.00 4.50

Figure 19 - Blow-Through Drain Trap

The Y dimension of blow-through traps should be at least equal to the value of the positive pressure in the drain pan plus one inch. This ensures that there will be enough water stored in the trap to counter the static pressure in the drain pan. To find the pressure subtract any pressure drops between the drain pan and the supply blower from the blower discharge pressure. The worst-case scenario for blow-through coils

is the minimum pressure drop, so do not include dirt allowance pressure drops for filters.

The bottom of the leaving pipe should be at least one half inch lower than the bottom of the drain pan connection. This ensures proper drainage when the unit is not running.

Note: It may be necessary to fill the trap manually, or the trap can be filled automatically by operating the unit until enough condensate collects to fill the trap. The trap will then be filled when the unit is turned off.

Table 8 - Blow-Through Drain Trap

Dimensions

Blow-Through

Drain Pan Pressure Trap Dimension

Positive Static Y

(inches of water) (inch)

0.5 1.5

1.0 2.0

1.5 2.5

2.0 3.0

2.5 3.5

3.0 4.0

3.5 4.5

4.0 5.0

4.5 5.5

5.0 6.0

5.5 6.5

6.0 7.0

6.5 7.5

7.0 8.0

7.5 8.5

8.0 9.0

Blower Wheels

AAON units are equipped with a backward curved blower wheels that is set to deliver the air volume specified according to unit size and/or job requirements.

Air Adjustment

In the event that reduced air volume is required, an air volume band can be installed within the blower wheel to reduce the amount of air delivery. If the unit is factory equipped with the air band but additional air delivery is needed, the band can be removed from the wheel.

The air band is sized according to the air delivery specifications and can be ordered from the factory for field installation.

The related photos of the wheel are provided for practical guidelines only in order to identify the air band location in the wheel. Actual field installation of the air band into the wheel will require access into and through the blower wheel venturi.

The band is made of aluminum, sized and equipped with easy bend tabs that are to be inserted into pre-punched slots provided on the wheel. Once the band has been inserted into the slots, it MUST BE secured by bending the tabs over from the back side of the wheel and also MUST BE secured from the inside by connecting the ends together with a pop-rivet in the holes provided on the ends of the band. If the band is to be field installed, a hand held pop-rivet tool is recommended for connecting the band ends together. Caution must be taken to assure that the band is tightly installed and no damage, denting, or alteration to the wheel or blades occurs during the installation.

Figure 20 - Supply Fan Banding

Waterside Economizer

Pre-cooling waterside economizer coil is supplied without water piping. A kit to pipe the coil in series with the condenser water circuit along with a valve which diverts condenser water to the coil or around the coil is optional.

During economizer mode cool water passes through the economizer and condenser in series. During standard cooling mode water bypasses the economizer coil and passes through the condenser.

A p-trap must be installed on the coil drain outlet, not to exceed 6” from the drain connection. See the previous section on condensate drain piping for additional p-trap and drain information.

DRAIN PAN CONNECTION

With a waterside economizer coil a separate drain connection is included. Failure to use this separate drain connection may result in water backup and overflow of drain pan.

An aquastat is included with the field installed water piping kit and is used to modulate water flow through the economizer coil. The controller is mounted in the controls compartment. Electrical connections must be field wired. The temperature bulb requires field mounting. Care should be taken to firmly mount the bulb on the supply water piping, but not to dent the bulb when installing. The aquastat has a temperature calibration range adjustment of -10°F to 100°F and must be field set.

Hot Water and Steam Coils

Factory installed one or two row hot water heating coils can be factory mounted. These coils are supplied from a hot water source through separate piping from the condenser water source. All controls for heating operation are field supplied and field installed.

Always connect the supply to the top of the coil and the return to the bottom. Water coils should not be subjected to entering air temperatures below 38°F to prevent coil freeze-up. If air temperature across the coil

is going to be below this value, use a glycol solution to match the coldest air expected.

Water supply lines must be insulated, properly fastened, drained, and supported according to local code requirements.

Air handling units with steam heating coils MUST BE installed high enough to allow for a minimum of 1 foot condensate drop leg off of the steam coil, or as recommended by the steam trap manufacturer. Lines should be insulated with approved insulation and be properly fastened, sloped, and supported according to local code requirements.

Chilled Water Coils

Factory installed four or six row chilled water cooling coils can be factory mounted. These coils are supplied from a chilled water source through separate piping from the condenser water source. All controls for the cooling coil are field supplied and field installed.

Water supply lines must be insulated with closed cell type pipe insulation or insulation that includes a vapor barrier. Lines should be properly fastened, drained and supported according to local code requirements, and job specifications.

Piping shall be in accordance with national and local codes. Pressure limiting devices, backflow preventers and all other safety requirements are the sole responsibility of the installing contractor.

Electric Heating

Heating is accomplished by passing electrical current through a specified amount of resistance heaters which will produce the

required heat. The indoor fan motor will energize at the same time as the heaters. Wiring to the air handling unit must be done in accordance with local electrical codes and standards. Check specified electrical rating and install with proper wire size.

Gas Fired Duct Furnace

WARNING

Inspection on Arrival

1. Inspect unit upon arrival for any damage that may have occurred during shipping.

2. Prior to installation locate rating plate and verify that furnace is equipped for the available fuel supply and power supply at point of installation.

Unit Location and Clearances

1. Be sure unit is located with respect to building construction and other equipment to provide ready access and clearance to access panels or doors that must be opened to permit adjustment and servicing of the heating module.

2. The heating unit provided is listed for installation on the positive side of the circulating air blower only.

3. Do not install unit where it may exposed to potentially explosive or flammable vapors.

4. Do not locate unit in areas where corrosive vapors (such as chlorinated, halogenated, or acidic) are present in the atmosphere or can be mixed with combustion air entering heater.

Outdoor Units

1. Provide at least 6 feet clearance to roof/side of the unit, where the combustion air inlet or vent (flue) gas discharge is located, from walls, parapets or adjacent buildings or equipment. If equipment is for replacement and required clearances are not available, contact unit manufacturer for recommendations.

2. Unit must be installed with combustion air openings located at least one (1) foot above the average snow depth for the location.

3. Do not locate unit near building ventilators or exhausts, or areas where corrosive chemical vapors can be drawn into combustion air supply.

4. Do not install units in locations where flue products can be drawn in the adjacent building openings such as windows, fresh air intakes, etc.

5. Be sure that vent discharge for flue gases is directed away from combustion air inlet and located to prevent flue products from being drawn into combustion air supply. Burner performance can be adversely affected by recirculation of flue products.

Indoor Units

1. Locate unit to insure an adequate supply of fresh air to replace air used in the combustion and ventilation process.

2. When locating units, it is important to consider the exhaust vent piping connected to the outside atmosphere. Location should

minimize the number of elbows or turns in

vent pipe.

Gas Supply, Piping and Connections

Gas piping must be installed in accordance with local codes, or in the absence of local code, installation must conform to the current (United States) National Fuel Gas Code ANSI-Z223.1/NFPA 54 or the current (Canada) National Fuel & Propane Installation Code CSA B149.1 or B149.2.

1. Gas piping must be sized for the total Btu input of all units (heaters) serviced by a single supply.

2. Be sure that gas regulators servicing more than one heater have the proper pipe and internal orifice size for the total input of all heaters serviced by the regulator.

3. Duct furnaces require a minimum inlet gas pressure of 5.0 “w.c and limited to a maximum inlet gas pressure of 13.5” w.c., with the furnace operating.

4. A 1/8” NPT tap is provided on the inlet side of the gas valve to the heater. A fitting suitable for connection to a pressure gauge capable of measuring gas pressure should be connected to each heater serviced by a single regulator so that gas pressure at each heater can be measured with all heaters in operation.

5. A drip leg (sediment trap) and a manual shut off valve must be provided immediately upstream of the gas control on the heating unit. To facilitate servicing of unit, installation of a union is recommended.

Figure 21 - Sediment Trap

1. All field gas piping must be pressure / leak tested prior to operation. NEVER use an open flame to check for leaks. Use a soap solution or other leak detecting solution for testing.

2. Gas pressure to appliance controls must never exceed 13.5” w.c. (1/2 psi)

WARNIN

1. When pressure testing at 1/2 psi or less, close the manual shutoff valve on the appliance before testing.

2. When pressure testing gas supply line at 1/2 psi or higher, close manual gas valve and disconnect heater from supply line to be tested. Cap or plug the supply line.

Duct Furnace Component Identification

Figure 22 - Horizontal Configuration

Horizontal Airflow Configuration

1. Airflow may be from either right or left for heater as shown, without any difference in system performance.

2. Typically no condensate drain attachment is necessary in “Heat” only applications. Condensation should not occur during heating cycle. However, in applications operating at low temperature rise or with 50% or more outside air, condensation may occur early in the heating cycle. In these applications connection of a condensate drain line is recommended, to avoid condensate buildup and possible heat exchanger damage.

3. If heating section is located downstream of a refrigeration system or cooling coil, condensation can occur during operation of the air conditioning, resulting in condensation from warm, moist air in the heat exchanger tubes and flue collector. This condensate is not harmful to the heat exchanger provided it is drained continuously. For these applications a 1/4 inch NPT connection is provided for

attachment of condensate drain line to remove condensate from heat exchanger.

Figure 23 - Vertical Configuration

Vertical Airflow Configuration

1. Airflow may be either upflow or downflow for heater as shown, without any difference in system performance.

2. In this configuration, condensate due to operation of air conditioning system would drain through the open heat exchanger tubes near base of heater. An optional condensate drain pan is available for these applications, if none is incorporated integral to the unit.

3. Some condensation may occur in the flue collector box, and it is recommended that a drain tube be connected to the lower condensate drain fitting as well.

Gas Valve

Figure 24 - Gas Valve

Input

The correct heat capacity of the furnace is controlled by the burner orifices and the gas manifold pressure. The manifold pressure is factory set, but should be checked at the time of start-up.

Operating and Safety Instructions

1. This duct furnace does not have a pilot. It is equipped with a direct spark ignition device that automatically lights the gas burner. DO NOT try to light burners by hand.

2. BEFORE OPERATING, leak test all gas piping up to heater gas valve. Smell around the unit area for gas. DO NOT attempt to place heater in operation until source of gas leak is identified and corrected.

3. Use only hand force to push and turn the gas control knob to the “ON” position. NEVER use tools. If knob does not operate by hand, replace gas valve prior to staring the unit. Forcing or attempting to repair the gas valve may result in fire or explosion.

4. Do not attempt to operate unit, if there is indication that any part or control has been under water. Any control or component that has been under water must be replaced prior to trying to start the unit.

Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other appliance.

Startup

1. Turn thermostat or temperature controller to its lowest setting.

2. Turn off gas supply at the manual shut-off valve (supplied by others).

3. Turn off power to the unit at the disconnect switch.

4. Open door to unit module housing the gas heater.

5. Move gas control knob to “Off” position.

6. Install a tapped fitting for attachment to a manometer, or other gauge suitable for 14.0” w.c., in the inlet pressure tap, and for 10.0” w.c., in the manifold pressure tap.

7. Wait 5 minutes for any gas to clear out. If you smell gas, turn off gas supply at the manual shut-off valve (field installed). If you don’t smell gas or have corrected any leaks, go to the next step.

8. Turn gas control knob to “On” position.

9. Open all manual gas valves (supplied by others).

10. Turn power on at disconnect switch.

11. Set thermostat or controller to its highest position to initiate call for heat and maintain operation of unit.

12. Draft inducer will run for a 15 to 30 second pre-purge period.

13. At the end of the pre-purge the direct spark will be energized and gas valve will open.

Check and Adjust Manifold Pressure

For 2 stage (TS) and modulating control (MD) systems manifold pressure should be

1.2” w.c. Adjust Lo Regulator on 2 stage gas valve, if necessary. The controls are design to hold operation at this pressure for 2 minutes. After that time manifold pressure should increase to 3.5” w.c. within 30 to 45 seconds.

For On-Off units the manifold pressure should be 3.5” w.c.

Failure to Ignite

1. For the initial start-up, or after unit has been off long periods of time, the first ignition trial may be unsuccessful due to need to purge air from manifold at start-up.

2. If ignition does not occur on the first trial, the gas and spark are shut-off by the ignition control and the control enters an inter-purge period of 15 to 90 seconds, during which the draft inducer continues to run.

3. At the end of the inter-purge period, another trial for ignition will be initiated.

4. Control will initiate up to three ignition trials on a call for heat before lockout of control occurs.

5. Control can be brought out of lockout by turning thermostat or controller to its lowest position and waiting 5 seconds and then turning back up to call for heat. Some controls provided will automatically reset after one hour and initiate a call for heat.

Burner Flames

Prior to completing the start-up, check the appearance of the main burner flame. See Figure 34a and Figure 34b for flame characteristics of properly adjusted natural gas systems.

Figure 25 - 1.2” w.c. Manifold

Figure 26 - 3.5” w.c. Manifold

1. The burner flame should be predominately blue in color and well defined and centered at the tube entry as shown in Figure 34a and Figure 34b. Distorted flame or yellow tipping of natural gas flame, or a long yellow flame on propane, may be caused by lint and dirt accumulation inside burner or at burner ports, at air inlet between

burner and manifold pipe, or debris in the main burner orifice. Soft brush or vacuum clean affected areas after performing Shutdown procedure.

2. Poorly defined, substantially yellow flames, or flames that appear lazy, indicate poor air supply to burners or excessive burner input. Verify gas supply type and manifold pressure with rating plate.

3. Poor air supply can be caused by obstructions or blockage in heat exchanger tubes or vent discharge pipe. Inspect and clean as necessary by to eliminate blockage. Vacuum any dirt or loose debris found in the tubes or vents. Clean heat exchanger tubes with stiff brush after performing Shutdown procedure. Poor flame characteristics can also be caused by undersized combustion air openings or flue gas recirculation into combustion air supply. Increase air opening size or re-direct flue products to prevent recirculation.

4. Reduced air delivery can also be the result of fan blade slippage, dirt accumulation the fan blade or low voltage to draft inducer motor. Inspect draft fan assembly and be sure fan blade is secure to motor shaft. Check line voltage to heater.

Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other appliance.

Shutdown

1. Set thermostat or controller to lowest setting.

2. Turn off electrical supply to unit at disconnect switch.

3. Turn off manual gas supply (supplied by others).

4. Disconnect manifold and inlet pressure taps and re-install pipe plugs.

5. Close module door.

Normal Operation

1. Turn on electrical supply to unit at disconnect switch.

2. Turn on manual gas supply (supplied by others).

3. Set Thermostat or Temperature controller to desired temperature.

Figure 27 - Flame Sensor Current Check

Service Checks

Flame current is the current which passes through the flame from the sensor to ground. The minimum flame current necessary to keep the system from lockout is 0.7 microamps. To measure flame current, connect an analog DC microammeter to the FC- and FC+ terminals per figure. Meter should read 0.7 uA or higher. If the meter reads below “0” on scale, meter leads are reversed. Disconnect power and reconnect meter leads for proper polarity.

Air Pressure Switch

An air pressure switch is provided as part of the control system to verify airflow through draft inducer by monitoring the difference in pressure between the draft inducer and the atmosphere. If sufficient negative pressure is not present, indicating lack of proper air movement through heat exchanger, the switch opens shutting off gas supply though the ignition control module. On units with two speed draft inducer operation, a dual air pressure switch is used, monitoring high and low speed pressures. The air pressure switches have fixed settings and are not adjustable.

Rollout Switch (Manual Reset)

The duct furnace is equipped with manual reset rollout switches in the event of burner flame rollout. The switch will open on temperature rise and shut-off gas supply through the ignition control module. Flame rollout can be caused by insufficient airflow for the burner firing rate (high gas pressure), blockage of the vent system or in the heat exchanger. The duct furnace should not be

placed back in operation until the cause of rollout condition is identified. The rollout switch can be reset by pressing the button on the top of the switch.

High Limit Switch

The duct furnace is equipped with a fixed temperature high limit switch mounted on the vestibule panel that shuts off gas to the heater through the ignition control module in the event of reduced circulating airflow over the heat exchanger. Reduced airflow can be caused by motor failure of the circulating air blower, dirty or blocked filters or restriction of the air inlet or outlet to the unit. The high limit switch will automatically reset when the temperature drops to 15ºF below the set point. Determine the cause of the reduced air flow and correct.

Ignition Control Diagnostics and Service Guide (Fenwal 35-61 Series). LED flashes on for ¼ second, and off for ¼ second during fault condition. Pause between fault codes is 3 seconds.

Table 9 - Gas Heater Troubleshooting

LED

System Description Actions

Code

None No Power to

Open Limit

Switch

Steady

Flash

Internal

Control Fault

(No Operation)

Combustion

Air Flow Fault

On call for heat nothing happens 1. Check for open fuse or circuit breaker.

Thermostat call for heat. No power

across terminals V1 / V2 control.

24VAC across Terminal 24VAC /

V2-Gnd when Thermostat calling for

heat

Pressure switch contacts in closed

position for 30 seconds with no

output to Combustion blower.

Remains in this mode with

combustion blower off.

Open pressure switch or flame

rollout switch when inducer (IND

terminal) is energized. If switch remains open for more than 30

seconds after combustion blower is

energized, control will remain in this

mode with IND terminal (blower)

energized.

2. Check for poor wiring connection.

3. Check for failed 24V transformer.

1. Check for proper operation of circulating air supply system and for air filter blockage.

2. Check manifold pressure when limit cools and closes. Natural gas 3.5” w.c / LP gas 10.0” w.c.

3. Low combustion blower air output. Flue gas temp exceeds 550ºF. Inspect for debris accumulation, proper wheel attachment, and proper voltage to blower.

Control fault – Replace ignition control.

1. Check for short in wiring to pressure switch.

2. Check pressure switch for closed contacts (with leads disconnected).

3. Replace pressure switch

1. Failed Combustion blower.

2. Check connections and air tube from draft inducer to air switch for leaks.

3. Check rollout switch manual reset - depress reset.

4. Check supply tube from draft inducer housing to pressure switches for condensate - drain line and re-connect.

5. Check pressure switch for condensate accumulation

6. Replace pressure switch

Table 10 - Gas Heater Troubleshooting Continued

LED

Code

Flash

System Description Actions

Flame Fault

(No Call for

Heat)

Ignition

Lockout

Flame sense failure / flame present

with no call for heat.

Failure to light and or carryover.

Loss of flame or flame signal during

ignition or operation cycle.

Control will initiate up to 3 ignition

re-trials before lockout.

1. Check for voltage to gas valve with thermostat in off position. Valve should not be powered.

2. If valve is not energized, check for gas flow (manifold pressure reading greater than 0). If gas flow, turn off main shut-off valve and replace gas valve.

1. Verify gas supply available and operation of gas valve - manifold pressure at start of ignition cycle. Check for power to valve terminals LO & COM while spark is energized.

2. Is spark present? - If not check igniter for debris between electrodes, cracked ceramic and check ignition wire for short to ground.

3. Check flame sensor wiring connections to electrode and control and for any abrasions.

4. Check for cracked ceramic on flame sensor or grounded sensor rod.

5. Verify that ample air supply and proper venting of flue gases occurs during operating cycle.

6. Check for circulating air leaks into burner compartment during operation.

7. Check for re-circulation of flue gases into combustion air supply.

8. If all conditions satisfactory – replace ignition control.

Operating Control Systems

Two Stage (TN) - Low / High Fire / High Speed Inducer Only

Modulating (MD) - Modulating (25 to 100%) / 2 Speed Draft Inducer - Mid-Fire Start (55%)

Modulating (MH) - Modulating (25 to 100%) / 2 Speed Draft Inducer - High Fire Start (100%)

Refer to unit wiring diagrams located in unit door.

Furnace Maintenance

Disconnect all electrical power sources before servicing the unit. More than one power source may be provided. Failure to do so may result in injury or death from electrical shock or entanglement in moving parts.

If any original wiring needs to be replaced it must be replaced with wiring materials suitable for 105ºC.

Label all wires prior to disconnection when servicing unit. Wiring errors can cause improper or dangerous operation. Verify proper operation after servicing.

Duct Furnace Inspection

1. The duct furnace should be inspected annually by a qualified service agency. The condition of the burners, heat exchanger, draft inducer, vent system, operating controls and wiring should be determined. Check for obvious signs of deterioration, accumulation of dirt and debris and any heat or water related damage. Any damaged or deteriorated parts should be replaced before the unit is put back into service.

2. Clean burners, heat exchanger, draft inducer and vent ducts with a soft brush or vacuum.

3. Check Heat Exchanger for cracks. If any are present, replace heat exchanger before putting unit back into service.

4. Check the attachment point of the duct furnace to the cabinet or ducts to verify that they are air tight.

5. Check the automatic gas valve to insure that the gas valve seat is not leaking.

Duct Furnace Operation Check

1. Turn on power to the unit and set thermostat or heat controller to call for heat, allowing duct furnace to operate.

2. Check for proper start-up and ignition as outlined in Start-Up section.

3. Check the appearance of the burner flame.

4. Check that the circulating air fan is operating and verify the proper airflow through duct furnace.

5. Return thermostat or heat controller to normal setting.

Troubleshooting

Table 11 - Problems, Causes and Solutions

Problem Possible Cause Solutions

Frosted evaporator coil, low suction pressure

Unit runs, but supplies warm air Loss of refrigerant

Compressor starts, but opens high pressure control

High suction pressure, but low superheat

Unit operates continuously Low refrigerant charge

Restricted air flow Low fan speed Reversed blower rotation Low refrigerant charge

Faulty expansion valve element Plugged filter-drier

Refrigerant over-charged Air in condenser coil Condenser fan faulty Condenser coil dirty

Oversized expansion valve Poor sensing bulb location Low superheat adjustment

Unit undersized

Clean, or replace filters Check fan drives Correct wiring Add refrigerant

Check leaks, add refrigerant Replace valve element Replace filter-drier

Remove some refrigerant Evacuate and recharge refrigerant Replace fan motor Clean condenser coil

Replace with correct expansion valve Relocate sensing bulb, secure to suction line Adjust expansion valve

Check and recharge to nameplate Decrease load or resize unit Thermostat set too low, increase temperature setting

Startup

(See back of the manual for startup form)

During startup, it is necessary to perform routine checks on the performance of the unit. This includes checking of the air flow, the air filters, condenser water flow and refrigerant charge.

Filters

Units are shipped with the selected filters installed. If filters have been removed during installation, open the filter access door and re-install the correct filters with the airflow indicator arrows pointing in the direction of airflow.

Filters should be checked after a few days of operation after the unit has been started up as dust and debris from construction may cause premature filter loading. Replace the filters if necessary.

Check Out

Equipment should be thoroughly checked for loose wiring, a free spinning blower wheel, and well fitting access panels. Air handlers should not be operated without proper ductwork and access panels installed, except as required during start-up and air balancing.

1. Check all electrical connections to be

sure they are tight.

2. Open all access panels, and remove

all shipping screws, or restraints.

3. Clean out any debris that may have

been left.

4. Check belt alignment and tightness

of fan drives.

5. Check bearing locking collars and

fan wheel set screws for tightness.

6. Turn fan wheels to assure free

rotation.

7. Ensure electrical supply matches the

unit nameplate.

8. Ensure condensate lines are

connected, glued, and sloped toward building drain.

9. Check local codes for any special

provisions.

10. Attach or close all access doors and

panels.

11. Ensure that all ductwork dampers are

open.

12. Check electrical phasing to ensure

that fan rotate in the proper direction.

Electric Heating Section Procedures

1. Perform final visual inspection.

Check all equipment, ductwork, and piping to verify that all work is complete and equipment is properly installed and mounted. Improperly installed equipment or ductwork can affect readings.

2. Ensure there is no construction

debris in the unit.

3. Check the unit for external damage.

4. Note all accessories installed.

5. Install new filters of the proper size

and type.

6. Check all terminal blocks, fuses, fuse

blocks, and contactors for correctness.

7. Check all high and low voltage

wiring connections for correctness and tightness.

8. Check unit for correct incoming

voltage per the data plate.

9. Check the security of the locking

system on all blower bearings

10. Turn the unit power on.

11. Turn the unit blower on and check

for correct rotation.

12. If correct, take blower amp readings

and compare to see if the amp draw is within the safety factor area of the motor. Once correct, turn blower off.

13. Turn on the first stage of heating

− Check amp draw of each

element of each stage

− Ensure blower started w/

electric heat

− Check for temperature rise

across heating section while all stages are on

− If temperature rise is within

range, turn all heating calls off

− Check to see that blower

stops

Refrigerant (DX) Cooling Section Procedures:

1. Perform final visual inspection.

Check all equipment, ductwork, and piping to verify that all work is complete, and equipment is properly installed and mounted. Improperly installed equipment, or ductwork can affect readings.

2. Perform condenser start-up checks in

addition to these air handler checks according to the condenser manufacturer’s instructions.

3. Ensure there is no construction

debris in the unit.

4. Check the unit for external damage.

5. Note all accessories installed.

6. Ensure that drain P-trap is properly

installed.

7. Check all terminal blocks, fuses, fuse

blocks, and contactors for correctness.

8. Check all high and low voltage

wiring connections for tightness. Check unit for correct incoming voltage per the data plate.

9. Check the security of the locking

system on all blower bearings

10. Turn the unit power on.

11. Turn the unit blower on and check

for correct rotation.

12. If correct, take blower amp readings

and compare to see if the amp draw is within the safety factor area of the motor.

13.

Check and record ambient temperature.

14. Check for Guaranteed Off Timers

(GOT) and Time Delay Relays (TDR).

15. Start the first stage cooling circuit

and blower circuit.

16. After all stages of cooling have been

on for at least five minutes, record the return air temperature and supply air temperature.

17. Check the temperature difference

across the evaporator coil.

Commissioning

The commissioning of an air conditioning system is the process of achieving, verifying, and documenting the performance of that system to meet the operational needs of the building. This may not be a formal process in smaller structures, but some form of owner acceptance will occur. Adjustments made during the commissioning phase may include air or water balancing, or configuration of controls and operational sequences.

Air Balancing

CAUTIO

High performance systems commonly have complex air distribution and fan systems. Unqualified personnel should not attempt to adjust fan operation or air circulation, as all systems have unique operating characteristics. Professional air balance specialists should be employed to establish actual operating conditions and to configure the air delivery system for optimal performance.

Water Balancing

A hydronic specialist with a complete working knowledge of water systems, controls, and operation must be employed to properly balance the entire system. Unqualified personnel should not attempt to manipulate temperatures, pressures, or flow rates, as all systems have unique operating characteristics and improper balancing can result in undesirable noises and operation.

Controls

A variety of controls and electrical accessories may be provided with the equipment.

Identify the controls on each unit by consulting appropriate submittal and order documents, and operate according to the control manufacturer’s instructions. If you cannot locate installation, operation, or maintenance information for the specific controls, then contact your sales representative, or the control manufacturer, for assistance.

Operation

Immediately following building occupancy, the air conditioning system requires a maintenance schedule to assure continued successful operation. A maintenance program similar to the example given below should be scheduled for routine maintenance of this equipment in order to provide

continued efficient and reliable operation for the owner.

Adjusting Refrigerant Charge

Adjusting the charge of a system in the field must be based on determination of liquid sub-cooling and evaporator superheat. On a system with a TXV liquid sub-cooling is more representative of the charge than evaporator superheat but both measurements must be taken.

Before Charging

Unit being charged must be at or near full load conditions before adjusting the charge.

The Clean Air Act of 1990 bans the intentional venting of refrigerant (CFC’s and HCFC’s) as of July 1,

1992. Approved methods of recovery, recycling or reclaiming must be followed. Fines and/or incarceration may be levied for non-compliance.

Units equipped with hot gas reheat must be charged with the hot gas reheat valves closed while the unit is in cooling mode to get the proper charge. After charging, unit should be operated in reheat (dehumidification) mode to check for correct operation.

After adding or removing charge the system must be allowed to stabilize, typically 10-15 minutes, before making any other adjustments.

The type of unit and options determine the ranges for liquid sub-cooling and evaporator superheat. Refer to the tables below when determining the proper sub-cooling.

Checking Liquid Sub-Cooling

Measure the temperature of the liquid line as it leaves the condenser.

Read the gauge pressure at the liquid line close to the point where the temperature was taken. Use liquid line pressure as it will vary from discharge pressure due to condenser pressure drop.

Convert the pressure obtained to a saturated temperature using the appropriate refrigerant temperature-pressure chart.

Subtract the measured liquid line temperature from the saturated temperature to determine the liquid sub-cooling.

Compare calculated sub-cooling to the table below for the appropriate unit type and options.

Checking Evaporator Superheat

Measure the temperature of the suction line close to the compressor.

Read gauge pressure at the suction line close to the compressor.

Convert the pressure obtained to a saturated temperature using the appropriate refrigerant temperature-pressure chart.

Subtract the saturated temperature from the measured suction line temperature to determine the evaporator superheat.

Compare calculated superheat to the table below for the appropriate unit type and options.

DO NOT OVERCHARGE!

Refrigerant overcharging leads to excess refrigerant in the condenser coils resulting in elevated compressor discharge pressure.

Table 12 - Acceptable Air-Cooled

Refrigeration Circuit Values

Air-Cooled

Condenser

Sub-Cooling 12-18°F

Sub-Cooling with

Hot Gas Reheat

15-22°F

Superheat 8-15°F

Table 13 - Acceptable Water-Cooled

Refrigeration Circuit Values

Water-Cooled

Condenser

Sub-Cooling 6-10°F

Sub-Cooling with

Hot Gas Reheat

8-12°F

Superheat 8-15°F

Thermal expansion valve must be adjust to approximately 8-15°F of suction superheat. Failure to have sufficient superheat will damage the compressor and void the warranty.

Adjusting Sub-Cooling and Superheat Temperatures

The system is overcharged if the sub-cooling temperature is too high and the evaporator is fully loaded (low loads on the evaporator result in increased sub-cooling) and the evaporator superheat is within the

temperature range as shown in the table above (high superheat results in increased sub-cooling).

Correct an overcharged system by reducing the amount of refrigerant in the system to lower the sub-cooling.

Refrigerant overcharging leads to

The system is undercharged if the superheat

excess refrigerant in the condenser

is too high and the sub-cooling is too low

coils resulting in elevated compressor discharge pressure.

DO NOT OVERCHARGE!

Correct an undercharged system by adding refrigerant to the system to reduce superheat and raise sub-cooling.

If the sub-cooling is correct and the superheat is too high, the TXV may need adjustment to correct the superheat.

°F 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46

PSIG

78.3

80.0

81.8

83.6

85.4

87.2

89.1

91.0

92.9

94.9

96.8

98.8

100.9

102.9

105.0

107.1

109.2

111.4

113.6

115.8

118.1

120.3

122.7

125.0

127.4

129.8

132.2

Table 14 - R-410A Refrigerant Temperature-Pressure Chart

°F 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73

PSIG

134.7

137.2

139.7

142.2

144.8

147.4

150.1

152.8

155.5

158.2

161.0

163.8

166.7

169.6

172.5

175.4

178.4

181.5

184.5

187.6

190.7

193.9

197.1

200.4

203.6

207.0

210.3

°F 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99

100

PSIG

213.7

217.1

220.6

224.1

227.7

231.3

234.9

238.6

242.3

246.0

249.8

253.7

257.5

261.4

265.4

269.4

273.5

277.6

281.7

285.9

290.1

294.4

298.7

303.0

307.5

311.9

316.4

°F 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127

PSIG

321.0

325.6

330.2

334.9

339.6

344.4

349.3

354.2

359.1

364.1

369.1

374.2

379.4

384.6

389.9

395.2

400.5

405.9

411.4

416.9

422.5

428.2

433.9

439.6

445.4

451.3

457.3

°F 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150

PSIG

463.2

469.3

475.4

481.6

487.8

494.1

500.5

506.9

513.4

520.0

526.6

533.3

540.1

547.0

553.9

560.9

567.9

575.1

582.3

589.6

596.9

604.4

611.9

Maintenance

(See back of the manual for maintenance log.)

One week after start-up:

− Check operating pressures.

− Adjust belt tension on all fan drives.

− Check filters for cleanliness. Measure

pressure loss if applicable. Replace if necessary.

− Check cycling of compressors, fans, and

valves. Correct unusual cycling.

Monthly:

− Lubricate bearings if operating

continuously at 1500 rpm, or higher, or in other extreme conditions.

− Check cleanliness of filters and replace

if necessary.

− Check cooling coil drain pan to assure

proper drainage.

− Inspect all coils. Clean if dirty or

obstructed in any way.

Quarterly:

− Lubricate bearings if operating at 1000

rpm, or less, and in temperatures less than 150°F, or other extreme conditions.

− Check damper operation for freedom of

movement. Correct any binding that may occur.

− Check belts and pulleys on fan drives for

tension and unusual wear.

− Check operation of heating and cooling

sections.

− Check inlet and outlet air temperatures.

Annually:

− Clean the coils with steam or non-

corrosive coil cleaner.

− Clean the drain line, “P” trap, and

condensate pan.

− Check refrigerant pressures and

temperatures every Spring.

− Check heating section every Fall. Check

all electrical connections for tightness and check heater elements for indications of overheating.

Fan Assembly

M2 Series units use backward curved fan wheels which are non-overloading, energy efficient and easy to clean. Cleaning the wheels is necessary to reduce electrical use, maintain capacity, and reduce stress on the unit. The wheel and fan section need to be inspected periodically and cleaned of dust or debris.

To inspect and clean the blower, set thermostat to the “OFF” position. Turn the electrical power to the unit to the “OFF” position at the disconnect switch. Clean the assembly. Check the bearings. Inspect the belt condition and tightness. Check screws for tightness. Rotate blower wheels while listening closely to each bearing to check for noise or roughness in the bearing, which can indicate a failing bearing.

Bearings

AAON uses pre-lubricated bearings, and bearings that have been sized for an average failure rate of 50% after 200,000 hours, or

22.8 years, of operation (see heading “Lubrication” in this section for more information). The bearing sizing tables below are based on rotational speeds and radial loading. However, the alignment of the bearing to the shaft and the security of the bearing inner race to the shaft will greatly affect bearing life. Even though the manufacturer is responsible for bearing tolerances and mounting design, the

servicer is advised to regularly check the security of the bearing locking system.

Table 15 - Bearing Setscrew Torque

Recommendations

Shaft Size

(inches)

Setscrew Locking

Thread

Torque

(in-lbs.)

1 1/4 - 28 66 - 85 1 3/16 1/4 - 28 66 - 85 1 7/16 5/16 - 24 126 - 164

1 7/8 3/8 - 24 228 - 296

Shaft Size

(inch)

Skewzloc Locking

Thread

Torque

(in-lbs.)

1 8 - 32 63 - 70 1 3/16 8 - 32 63 - 70 1 7/16 10 - 24 81 - 90

1 7/8 1/4 - 20 162 - 180

Belts

Belt drive misalignment is one of the most common causes of premature belt failure. A belt can be destroyed in a matter of days if the drives have been aligned incorrectly.

The most common tool for measuring misalignment is a straightedge. Hold the straightedge flush across one pulley to gauge the degree of misalignment of the two sheaves. The maximum allowed misalignment is one half degree of angular misalignment, and 1/10th of an inch per foot between sheave centers for parallel misalignment.

Pulley Pulley

Straightedge

Belt

Figure 28 - Angular Misalignment

Correct by moving the position of the motor.

Pulley

Straightedge

Pulley

Belt

Figure 29 - Parallel Misalignment

Correct by adjusting sheaves on one, or both shafts.

Frequent belt tensioning is highly recommended. Most belt manufacturers would suggest a re-tensioning after as little as 8 hours of operation. A simplified method of adjusting tension is to gauge the amount of force required to deflect the belt by 1/64th of an inch per inch of distance between sheave centers. For example, if the sheaves are 20 inches apart, then the amount of deflection with the forces listed below is 20/64th (5/16th) of an inch.

Deflection required for “A” belts: 4-6 lbs. “B” belts: 6-10 lbs. “C” belts: 10-18 lbs.

Sheave Centers

Force

Deflection = 1/64th in. per inch of length

Figure 30 - Belt Deflection

Indoor Coils

CAUTIO

Indoor cooling/evaporator coils must be cleaned regularly to maintain unit efficiency and operation. Dirty evaporator coils will eventually freeze up and often result in a time consuming and expensive service call. Clean filters will help to prevent dirt from accumulating on cooling coils, however cooling coils should be cleaned at least annually by an HVAC professional.

Refrigeration Cycle

Satisfactory performance of the refrigeration cycle can be determined by measuring suction line superheat. In order to determine if refrigerant flowing from the evaporator is dry, ensure that the system has enough refrigerant to produce liquid line subcooling, but not so much to cause abnormally high condensing temperatures (and pressures). Refrigerant cycle analysis is best performed in conditions that approach the conditions where the air conditioner will be expected to operate.

E-Coated Coil Cleaning

Documented routine cleaning of e-coated coils is required to maintain coating warranty coverage.

Electric shock hazard. Shut off all electrical power to the unit to avoid shock hazard or injury from rotating parts.

Surface loaded fibers or dirt should be removed prior to water rinse to prevent restriction of airflow. If unable to back wash the side of the coil opposite of the coils entering air side, then surface loaded fibers or dirt should be removed with a vacuum cleaner. If a vacuum cleaner is not available, a soft non-metallic bristle brush may be

used. In either case, the tool should be applied in the direction of the fins. Coil surfaces can be easily damaged (fin edges bent over) if the tool is applied across the fins.

Use of a water stream, such as a garden hose, against a surface loaded coil will drive the fibers and dirt into the coil. This will make cleaning efforts more difficult. Surface loaded fibers must be completely removed prior to using low velocity clean water rinse.

A monthly clean water rinse is recommended for coils that are applied in coastal or industrial environments to help to remove chlorides, dirt, and debris. It is very important when rinsing, that water temperature is less than 130°F and pressure is than 900 psig to avoid damaging the fin edges. An elevated water temperature (not to exceed 130°F) will reduce surface tension, increasing the ability to remove chlorides and dirt.

High velocity water from a pressure washer or compressed air should only be used at a very low pressure to prevent fin and/or coil damages. The force of the water or air jet may bend the fin edges and increase airside pressure drop. Reduced unit performance or nuisance unit shutdowns may occur.

Quarterly cleaning is essential to extend the life of an e-coated coil and is required to maintain coating warranty coverage.

Coil cleaning shall be part of the unit’s regularly scheduled maintenance procedures. Failure to clean an e-coated coil will void the warranty and may result in reduced efficiency and durability.

CAUTIO

Harsh chemicals, household bleach, or acid cleaners should not be used to clean outdoor or indoor e-coated coils. These cleaners can be very difficult to rinse out of the coil and can accelerate corrosion and attack the e-coating. If there is dirt below the surface of the coil, use the recommended coil cleaners.

For routine quarterly cleaning, first clean the coil with the below approved coil cleaner. After cleaning the coils with the approved cleaning agent, use the approved chloride remover to remove soluble salts and revitalize the unit.

Recommended Coil Cleaner

The following cleaning agent, assuming it is used in accordance with the manufacturer’s directions on the container for proper mixing and cleaning, has been approved for use on e-coated coils to remove mold, mildew, dust, soot, greasy residue, lint and other particulate:

Enviro-Coil Concentrate, Part Number HEC01.

Recommended Chloride Remover

CHLOR*RID DTS™ should be used to remove soluble salts from the e-coated coil, but the directions must be followed closely. This product is not intended for use as a degreaser. Any grease or oil film should first be removed with the approved cleaning agent.

Remove Barrier - Soluble salts adhere themselves to the substrate. For the effective use of this product, the product must be able to come in contact with the salts. These salts may be beneath any soils, grease or dirt;

therefore, these barriers must be removed prior to application of this product. As in all surface preparation, the best work yields the best results.

Apply CHLOR*RID DTS - Apply directly onto the substrate. Sufficient product must be applied uniformly across the substrate to thoroughly wet out surface, with no areas missed. This may be accomplished by use of a pump-up sprayer or conventional spray gun. The method does not matter, as long as the entire area to be cleaned is wetted. After the substrate has been thoroughly wetted, the salts will be soluble and is now only necessary to rinse them off.

Rinse - It is highly recommended that a hose be used, as a pressure washer will damage the fins. The water to be used for the rinse is recommended to be of potable quality, though a lesser quality of water may be used if a small amount of CHLOR*RID DTS is added. Check with CHLOR*RID International, Inc. for recommendations on lesser quality rinse water.

Energy Recovery Wheel

The AAONAIRE® Energy Recovery Wheel is a total energy recovery wheel and is a disc composed of spirally wound desiccant matrix material. The wheel is divided across the center when installed, and rotated by an electric motor at up to 60 rpm so that one half of the matrix material is exposed at one moment to the exhaust air stream, and at the next moment to the ventilation supply air stream. With a heat wheel, efficiencies of 70 to 85% are achievable for both sensible and latent energy transfer.

The figure below shows the basics of an energy recovery wheel.

Cleaning

The need for cleaning of the wheel will be determined by the operating schedule, climate and regular contaminants of the conditioned space. The AAONAIRE Wheel is “self-cleaning” in that the smallest particles will pass through and larger particles will land on the wheel surface and will then be blown clear as the wheel rotates into the opposite direction of laminar flow.

The primary cleaning need will be to remove oil based aerosols that have condensed on energy transfer surfaces. These oily films can clog micron sized pores in the desiccant material reducing the wheel’s efficiency. It can take several years in a reasonably clean environment such as a school or an office building, for measurable efficiency loss to occur. Dirtier air, such as that from a kitchen, industrial or machine shop or a smoke filled room, will reduce efficiency in a much shorter period of time.

Motor Side Pulley Side

Outdoor Air Fresh Air Supply

Indoor Air Exhaust Air

Capacitor

P.C.S. Motor

Pulley Drive Belts

Figure 31 - Energy Recovery Wheel

Heat

To clean the wheel, remove the segments from the wheel frame, and brush foreign material from the face. Soak the segments in a non-acid based coil cleaner, or another alkaline detergent, and warm water. Massaging the matrix with your hands will increase the cleaning action. Rinse well, and shake excess water away before reinstalling. For applications where frequent cleaning is required, it is advisable to keep a second set of wheel segments on hand. While a set is soaking, or being cleaned, the spare set can be replaced in the wheel.

“Pulley Side” View

Rim Diameter Seal

Rotation

Bearing Access Cover

Energy Recovery

Wheel with 8

Removable Segments

Electric Heating

Set thermostat in the heat mode; call for heat to engage all electric heat strips. Check blower for proper rotation and voltage. Measure the amperage and voltage. Compare them to the nameplate data.

If applicable, check remote heat pump condenser as per the manufacturer’s recommendations.

Steam or Hot Water Heating

Set thermostat in the heat mode. Observe supply blower for proper rotation and voltage. Check boiler or hot water operation according to the manufacturer’s instructions. Check control flow valves for correct operation and settings per the manufacturer’s instructions.

Cleaning

Inspect and clean unit interior at the beginning of each heating and cooling season and as operating conditions require.

Chilled Water

Check remote chiller operations as per the manufacturer’s instructions. Check coolant flow valves for correct operation and settings.

Lubrication

Most motors and bearings are permanently lubricated. Some applications may require that bearings be re-lubricated periodically. The schedule will depend on the operating duty, temperature variations, and other atmospheric conditions.

For bearings equipped with lubrication fittings, the lubrication schedule is dependent on operating temperatures and rotational speeds as shown in the table below. Lithium based grease conforming to an NLGI grade No. 2 consistency is

recommended. This medium viscosity, low torque grease is rust inhibiting and waterresistant. It is satisfactory for operating temperatures in the range of –10°F to 250°F.

Bearings should only be re-lubricated when at normal operating temperatures and not running. Rotate the fan shaft by hand, adding only enough grease to purge the seals. A one-inch bearing has a total grease capacity of only .25 ounces. Added grease should be limited to .09 ounces.

Do Not Over Lubricate!

Recommended greases are: SHELL OIL - DOLIUM R CHEVRON OIL - SRI No. 2 TEXACO INC. - PREMIUM RB

Table 16 - Fan Bearing Lubrication

Schedule

Fan

Speed

500

rpm

1000

rpm

1500

rpm Any

Speed

Any

Speed

In the event the unit is not functioning correctly and a service company is required, only a company with service technicians qualified and experienced in both commercial heating and air conditioning should be permitted to service the systems in order to keep warranties in effect. The service tech may call the factory if assistance is required.

Temp. Environ.

Up to

150 °F

Up to

210 °F

Up to

210 °F

Up to

150 °F

210 -

250 °F

Clean

Clean Monthly

Dirty

Dirty Weekly

Greasing

Interval

2 to 6

months

2 weeks to

2 months

1 week to

1 month

Replacement Parts

Parts for AAON equipment may be obtained from AAON at www.aaonparts.com. When ordering parts, reference the unit serial number and part number.

AAON-Longview Customer Service Department

203 Gum Springs Road Longview, TX 75602 Ph: 903-236-4403 Fax: 903-236-4463 www.aaon.com

Note: Before calling, technician should have model and serial number of the unit available for the service department to help answer questions regarding the unit.

Filter Replacement

Monthly air filter inspection is required to maintain optimum unit efficiency. It is

Table 17 - M2-005 and M2-008 Filters

Filter Type

2” Pleated - 30% Eff, MERV 8

4” Pleated - 30% Eff (MERV 8), 65% Eff

(MERV 11), 85% Eff (MERV 13),

or 95% Eff (MERV 14)

12” Cartridge - 65% Eff (MERV 11),

85% Eff (MERV 13),

or 95% Eff (MERV 14)

Table 18 - M2-011 and M2-014 Filters

Filter Type

2” Pleated - 30% Eff, MERV 8

4” Pleated - 30% Eff (MERV 8), 65% Eff

(MERV 11), 85% Eff (MERV 13),

or 95% Eff (MERV 14)

12” Cartridge - 65% Eff (MERV 11),

85% Eff (MERV 13),

or 95% Eff (MERV 14)

strongly recommended that filter media be replaced monthly. Open access panel and pull filters straight out to inspect all of the filters. Replace filters with the size indicated on each filter. Arrow on the replacement filters must point towards the blower.

Electric shock hazard. Shut off all electrical power to the unit to avoid shock hazard or injury from rotating parts.

(Quantity) Size

M2-005 M2-008

(2) 20” x 20” (4) 16” x 20”

(Quantity) Size

M2-011 M2-014

(2) 16” x 20” and

(4) 20” x 20”

Table 19 - M2-018 and M2-022 Filters

Filter Type

2” Pleated - 30% Eff, MERV 8

4” Pleated - 30% Eff (MERV 8), 65% Eff

(MERV 11), 85% Eff (MERV 13),

or 95% Eff (MERV 14)

12” Cartridge - 65% Eff (MERV 11),

85% Eff (MERV 13),

or 95% Eff (MERV 14)

Table 20 - M2-026 Filters

Filter Type

2” Pleated - 30% Eff, MERV 8

4” Pleated - 30% Eff (MERV 8), 65% Eff

(MERV 11), 85% Eff (MERV 13),

or 95% Eff (MERV 14)

12” Cartridge - 65% Eff (MERV 11),

85% Eff (MERV 13),

or 95% Eff (MERV 14)

Table 21 - M2-032 and M2-036 Filters

Filter Type

2” Pleated - 30% Eff, MERV 8

4” Pleated - 30% Eff (MERV 8), 65% Eff

(MERV 11), 85% Eff (MERV 13),

or 95% Eff (MERV 14)

12” Cartridge - 65% Eff (MERV 11),

85% Eff (MERV 13),

or 95% Eff (MERV 14)

(Quantity) Size

M2-018 M2-022

(8) 20” x 20”

(Quantity) Size

M2-026

(4) 16” x 20” (8) 20” x 20”

(Quantity) Size

M2-032 M2-036

(6) 16” x 20” and

(9) 20” x 20”

(8) 16” x 20” and

(12) 20” x 20”

Appendix A - Heat Exchanger Corrosion Resistance

Corrosion Resistance of Copper and Stainless Steel in Brazed Plate Heat Exchangers

- Points to Measure and Check in a Water Analysis

The resistance guide provides the corrosion resistance of stainless steel type AISI 316 and pure Copper (99.9%) in water, to a number of important chemical factors. The actual corrosion is a very complex process influenced by many different factors in combination.

Explanations: + Good resistance under normal conditions 0 Corrosion problems may occur especially when more factors are valued 0

- Use is not recommended

Water

Containing

Alkalinity

/ SO

)

(HCO

Sulfate (SO

HCO

Electrical

Conductivity

Ammonium

(NH

)

Chlorides (Cl-)*

Free Chlorine

(Cl2)

Hydrogen

Sulfide (H2S)

Free (aggressive)

Carbon Dioxide

(CO

*See Chloride Content Table

Concentration (mg/l or ppm)

< 70

70-300 + + + +

Time Limits -

Analyze Before

Within 24 Hours

AISI

316

SMO

254

Copper

Alloy

Nickel

Alloy

+ + 0 +

> 300 + + 0/+ +

< 70

70-300 + + 0/- +

No Limit

+ + + +

> 300 0 0 - +

> 1.0 < 1.0 + + 0/- +

No Limit

< 10µS/cm

10-500 µS/cm + + + +

No Limit

+ + + +

+ + 0 +

> 500 µS/cm + + 0 +

< 6.0

6.0-7.5 0/+ + 0 +

7.5-9.0 + + + +

Within 24 Hours

0 0 0 +

> 9.0 + + 0 +

< 2

2-20 + + 0 +

Within 24 Hours

+ + + +

> 20 + + - + < 300 > 300 0 + 0/+ +

No Limit

< 1 1-5 + + 0 +

Within 5 Hours

+ + + +

> 5 0/+ + 0/- + < 0.05 > 0.05 + + 0/- +

No Limit

< 5

5-20 + + 0 +

No Limit

+ + + +

> 20 + + - +

Water

Containing

Total Hardness

(°dH)

Nitrate (NO3)

Iron (Fe)

Aluminum (Al)

Manganese (Mn)

Chloride Content

= 10 ppm SS 304 SS 304 SS 304 SS 316 = 25 ppm SS 304 SS 304 SS 316 SS 316 = 50 ppm SS 304 SS 316 SS 316 Ti / SMO 254

= 80 ppm SS 316 SS 316 SS 316 Ti / SMO 254 = 150 ppm SS 316 SS 316 Ti / SMO 254 Ti / SMO 254 = 300 ppm SS 316 Ti / SMO 254 Ti / SMO 254 Ti / SMO 254 > 300 ppm Ti / SMO 254 Ti / SMO 254 Ti / SMO 254 Ti / SMO 254

Concentration (mg/l or ppm)

4.0-8.5 No Limit + + + +

< 100 > 100 + + 0 +

< 0.2 > 0.2 + + 0 + < 0.2 > 0.2 + + 0 + < 0.1 > 0.1 + + 0 +

60°C (140°F) 80°C (176°F) 120°C (248°F) 130°C (266°F)

Time Limits -

Analyze Before

No Limit

Chloride Content

Maximum Temperature

AISI

316

+ + + +

SMO

254

Copper

Alloy

Nickel

Alloy

Refrigerant Piping Diagrams

Figure 32 - Standard Split System Piping

Figure 33 - Modulating Hot Gas Reheat with Hot Gas Bypass Split System Piping

Note: When installing hog gas bypass risers, an oil drip line must be provided at the lowest point in the system (See Detail A).

Figure 34 - Hot Gas Bypass Split System Piping

Note: When installing hog gas bypass risers, an oil drip line must be provided at the lowest point in the system (See Detail A).

Figure 35 - Modulating Hot Gas Reheat Split System Piping

Figure 36 - Heat Pump Split System Piping

Figure 37 - Heat Pump with Factory Installed Modulating Hot Gas Reheat Split System Piping

Note: When installing hog gas bypass risers, an oil drip line must be provided at the lowest point in the system (See Detail A).

Figure 38 - Heat Pump with Field Installed Modulating Hot Gas Reheat Split System Piping

Note: When installing hog gas bypass risers, an oil drip line must be provided at the lowest point in the system (See Detail A).

M2 Series Startup Form

Job Name:_______________________________________________

Date:______________

Address:______________________________________________________________________

______________________________________________________________________________

Model Number:_________________________________________________________________

Serial Number:_____________________________________________ Tag:_______________

Startup Contractor:______________________________________________________________

Address:______________________________________________________________________

_______________________________________________________ Phone:______________

Pre Startup Checklist

Installing contractor should verify the following items.

1. Is there any visible shipping damage? Yes No

2. Is the unit level? Yes No

3. Are the unit clearances adequate for service and operation? Yes No

4. Do all access doors open freely and are the handles operational? Yes No

5. Have all shipping braces been removed? Yes No

6. Have all electrical connections been tested for tightness? Yes No

7. Does the electrical service correspond to the unit nameplate? Yes No

8. On 208/230V units, has transformer tap been checked? Yes No

9. Has overcurrent protection been installed to match the unit nameplate

requirement? Yes No

10. Have all set screws on the fans been tightened? Yes No

11. Do all fans rotate freely? Yes No

12. Does the field water piping to the unit appear to be correct per design

parameters? Yes No

13. Is all copper tubing isolated so that it does not rub? Yes No

14. Have the damper assemblies been inspected? Yes No

15. Are air filters installed with proper orientation? Yes No

16. Have condensate drain and p-trap been connected? Yes No

Ambient Temperature

Ambient Dry Bulb Temperature ________°F

Ambient Wet Bulb Temperature ________°F

Supply Fan Assembly

Alignment

Check Rotation

Nameplate Amps________

Number hp L1 L2 L3

1 2

Band Size_____________________

VAV Controls_________________

VFD Frequency________________ Springs Operating Correctly

Energy Recovery Wheel Assembly

Wheels Spin Freely

Check Rotation

FLA ________

Number hp L1 L2 L3

1 2

Power Exhaust Fan Assembly

Alignment

Check Rotation

Nameplate Amps________

Number hp L1 L2 L3

1 2

Band Size_____________________

VFD Frequency________________ Springs Operating Correctly

Power Return Fan Assembly

Alignment

Check Rotation

Nameplate Amps________

Number hp L1 L2 L3

1 2

Band Size_____________________

VFD Frequency________________ Springs Operating Correctly

Outside Air/Economizer Dampers

OA Operation Check

RA Operation Check

EA Operation Check

Damper Actuator Type:__________________________________________________________

Economizer Changeover Type and Operation:_______________________________________

Damper Wiring Check

Gears Check

Unit Configuration

Water-Cooled Condenser Air-Cooled Condenser

No Water Leaks Condenser Safety Check

Water Flow ________ gpm

Water Inlet Temperature ________°F

Water Outlet Temperature ________°F

Compressors/DX Cooling

Check Rotation

Number L1 L2 L3

Pressure

Head

PSIG

Suction

Pressure

PSIG

Crankcase

Heater

Amps 1 2 3 4

Refrigeration System 1 - Cooling Mode

Pressure

Saturated

Temperature

Line

Temperature

Sub-cooling Superheat

Discharge N/A N/A

Suction N/A

Liquid N/A

Refrigeration System 2 - Cooling Mode

Discharge N/A N/A

Suction N/A

Liquid N/A

Refrigeration System 3 - Cooling Mode

Discharge N/A N/A

Suction N/A

Liquid N/A

Refrigeration System 4 - Cooling Mode

Discharge N/A N/A

Suction N/A

Liquid N/A

Refrigeration System 1 - Heating Mode (Heat Pump Only)

Discharge N/A N/A

Suction N/A

Liquid N/A

Refrigeration System 2 - Heating Mode (Heat Pump Only)

Discharge N/A N/A

Suction N/A

Liquid N/A

Refrigeration System 3 - Heating Mode (Heat Pump Only)

Discharge N/A N/A

Suction N/A

Liquid N/A

Pressure

Saturated

Temperature

Saturated

Temperature

Saturated

Temperature

Saturated

Temperature

Saturated

Temperature

Saturated

Temperature

Line

Temperature

Line

Temperature

Line

Temperature

Line

Temperature

Line

Temperature

Line

Temperature

Sub-cooling Superheat

Refrigeration System 4 - Heating Mode (Heat Pump Only)

Pressure

Saturated

Temperature

Line

Temperature

Sub-cooling Superheat

Discharge N/A N/A

Suction N/A

Liquid N/A

Air-Cooled Condenser

Alignment

Check Rotation

Nameplate Amps________

Number hp L1 L2 L3

Water/Glycol System

1. Has the entire system been flushed and pressure checked? Yes No

2. Has the entire system been filled with fluid? Yes No

3. Has air been bled from the heat exchangers and piping? Yes No

4. Is the glycol the proper type and concentration (N/A if water)? Yes No

5. Is there a minimum load of 50% of the design load? Yes No

6. Has the water piping been insulated? Yes No

7. What is the freeze point of the glycol (N/A if water)? ______________________________

Gas Heating

Natural Gas Propane Purge Air from Lines Verify Pilot Spark

Stage Manifold Pressure (w.c.) Stage Manifold Pressure (w.c.)

1 3

2 4

Electric Heating

Stages__________ Limit Lockout Aux. Limit Lockout

Stage Amps Stage Amps

1 5 2 6 3 7 4 8

Maintenance Log

This log must be kept with the unit. It is the responsibility of the owner and/or maintenance/service contractor to document any service, repair or adjustments. AAON Service and Warranty Departments are available to advise and provide phone help for proper operation and replacement parts. The responsibility for proper startup, maintenance and servicing of the equipment falls to the owner and qualified licensed technician.

Entry Date Action Taken Name/Tel.

Literature Change History

March 2010

Update of IOM adding gas heater, self contained unit and packaged rooftop unit information.

July 2010

Update of IOM adding PVC and CPVC piping Caution and split system piping information.

November 2010

Update of IOM adding control wiring information, correcting M2-022 and M2-026 filter sizes and adding modulating hot gas reheat only piping diagram.

June 2011

Update of the IOM adding additional electric heat capacity options to the heat module, correcting the condensate drain connection to 1” MPT, and adding the electronic startup form.

April 2012

Update of the IOM, changing the suction trap requirement for variable capacity scroll compressor circuits to every 10 feet, correcting the Modulating Hot Gas Reheat and Modulating

Hot Gas Reheat with Hot Gas Bypass piping diagrams to show the liquid line tee connection factory installed, adding the Heat Pump with Field Installed Modulating Hot Gas Reheat Split System Piping Diagram,

and updating the table of contents.

AAON

2425 South Yukon Ave.

Tulsa, OK 74107-2728

Phone: 918-583-2266

Fax: 918-583-6094

www.aaon.com

M2 Series

Installation, Operation &

Maintenance

R40681 · Rev. B · 120509

(ACP 30752)

It is the intent of AAON to provide accurate and current product information. However, in the interest of product improvement, AAON reserves the right to change pricing, specifications, and/or design of its product without notice, obligation, or liability.

AAON® and AAONAIRE® are registered trademarks of AAON, Inc., Tulsa, OK.

AAON M2-036 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual