M2 Series Modular Indoor Air Handling Units, Modular Outdoor Air Handling Units, Self Contained Units & Packaged Rooftop Units Installation, Operation & Maintenance WARNING 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.
Table of Contents Safety .............................................................................................................................................. 7 Model Number Nomenclature ...................................................................................................... 13 M2 Base Model Description ......................................................................................................... 14 Fan Module Description ....................................................
Gas Fired Duct Furnace............................................................................................................. 57 Duct Furnace Component Identification ................................................................................... 59 Furnace Maintenance ................................................................................................................ 66 Troubleshooting ....................................................................................................
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-) ......
Figures: Figure 1 - Typical Configurations................................................................................................. 24 Figure 2 - Unit Orientation ........................................................................................................... 25 Figure 3 - Lockable Handle .......................................................................................................... 28 Figure 4 - Service Access Clearance .........................................................
Safety Attention should be paid to the following statements: NOTE - Notes are intended to clarify the unit installation, operation and maintenance. CAUTION - Caution statements are given to prevent actions that may result in equipment damage, property damage, or personal injury. WARNING - Warning statements are given to prevent actions that could result in equipment damage, property damage, personal injury or death.
WARNING Electric shock hazard. Before servicing, shut off all electrical power to the unit, including remote disconnects, to avoid shock hazard or injury from rotating parts. Follow proper Lockout-Tagout procedures. WARNING 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.
CAUTION 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. WARNING CAUTION Failure to properly drain and vent coils when not in use during freezing temperature may result in coil and equipment damage.
CAUTION To prevent damage to the unit, do not use acidic chemical coil cleaners. Do not use alkaline chemical coil cleaners with a pH value greater than 8.5, after mixing, without first using an aluminum corrosion inhibitor in the cleaning solution. WARNING Some chemical coil cleaning compounds are caustic or toxic. Use these substances only in accordance with the manufacturer’s usage instructions. Failure to follow instructions may result in equipment damage, injury or death.
WARNING HOT PARTS 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. CAUTION PVC (Polyvinyl Chloride) and CPVC (Chlorinated Polyvinyl Chloride) are vulnerable to attack by certain chemicals.
conditions including input temperature rise and ESP. rate, 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 Identifies the main unit features and options. Individual Module Model Numbers Identifies module configurations, features and options.
M2 Base Model Description Model Number M2 Series and Generation - H Type - 011 Unit Size BASE MODEL SERIES AND GENERATION M2 = Modular 2nd Generation TYPE H = Horizontal V = Vertical UNIT SIZE 005 = 5 ft2 Coil 008 = 8 ft2 Coil 011 = 11 ft2 Coil 014 = 14 ft2 Coil 018 = 18 ft2 Coil 022 = 22 ft2 Coil 026 = 26 ft2 Coil 032 = 32 ft2 Coil 036 = 36 ft2 Coil 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/6
Fan Module Description Model Number SFA Module ID - 103 Position - F Motor Size - B Blower 0 Isolation - A 00 Motor Type Blank 0C Pulleys - 0 0000 Safety Control Blank - 0 - Blank 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 Drive
Filter Module Description Model Number FTA Module ID 102 - Position P - Filter Type A0 - Filters - 0 Safety Control 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.
Mixing Box Module Description Model Number MBH Module ID - 101 Position - A Position - 00 Filters - 0 Safety Control 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
Heat Module Description Model Number PHA Module ID - 101 Position - H Function - 00 Filters - 0 Rows 00 FPI 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.
Blank Module Description Model Number BBA Module ID 101 - Position 0 - Drain Pan Type AR - Airway Type 0 - Safety Control 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 0000 Blank 0 - Bypass Opening 0000 Blank 0 - Blank 0 - SAFETY CONTROL 0 = None 2 = Firestat BLANK 0000 = Standard BYPASS OPENING 0 = None A
Coil Module Description Model Number CBL Module ID - 101 Position - C Cooling Type - 0 kW 0 Stages - 0 Rows 00 FPI 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 kW A =
Control Panel Module Description Model Number TRA Module ID - 101 Position - 0 Blank - 00 Blank - 0 0000 Safety Options Blank 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 - 00000 Blank - 0 Blank - 0 Type SAFETY OPTIONS 0 = None 2 = Firestat BLANK 0000 = Standard BLANK 00000 = Standard BLANK 0 = Standard TYPE 0 = None X = Special Pricing Authorization 21
Energy Recovery Module Description Model Number HRA Module ID - 101 Position - A Wheel Size - 00 Blank - 00000 Blank - MODULE ID HRA = AAONAIRE Energy Recovery Wheel BLANK 00000 = Standard POSITION ### = Level and Position of Module in Air Handling Unit BLANK 00000 = Standard WHEEL SIZE A = Standard BLANK 00 = Standard 22 00000 Blank BLANK 0 = Standard TYPE 0 = None X = Special Pricing Authorization - 0 Blank - 0 Type
Condenser Module Description Model Number WCC Module ID 101 - Position A - Compressor Type 06 - Tonnage A - Heat Exchanger Type 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 Ca
M2 Series Typical Configurations M2 Series units have been designed as practical, high performance alternative to expensive custom air handling equipment.
Unit Orientation Determine left hand or right hand orientation/connections: M2 Series Top View Right Hand Side Supply Air Return Air AIRFLOW Supply Fan Connections & service access on left side for left hand orientation Coil Filter Left Hand Side Consider the airflow to be hitting the back of your head.
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.
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.
all doors with locks or nuts and bolts to prevent unauthorized access. CAUTION CRANKCASE HEATER OPERATION 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. 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.
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.
Installation WARNING AAON equipment has been designed for quick and easy installation. 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 or service agency. A copy of this IOM should be kept with the unit. Locating Units Verify rooftop, foundation or mounting frame can support the total unit weight, including accessory weights.
Local codes may supersede or further place restrictions on vent termination locations. Energy Recovery Wheel Module Energy Recovery Wheel Coil Module 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.
Figure 5 - M2 Series Unit Four Point Lifting 32
Figure 6 - M2 Series Unit Eight Point Lifting 33
Indoor Floor Mounted Units Indoor M2 Series units can be floor mounted. Cross members perpendicular to airflow Supports positioned under base rails parallel to airflow 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.
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.
Base model number 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 Configuration Schematic can be found in unit literature packet Module configuration numbers Arrows indicate airflow Table provides required service access clearances for applicable modules 201 PEC FTE 203 HRA Note: Energy recovery wheel module will have a 100 series number,
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. Apply bulb gasket to one side of the opening between adjacent modules Figure 11 - Gasket Application 3.
Remove bar clamps and repeat for all remaining module joints. 1” Figure 13 - Bar Clamp You should now have a fully gasketed, airtight joint that needs to be permanently secured into position. 5/16” Hex Head Self-Tapping Screws Provided with Unit Figure 14 - Self-Tapping Screw 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.
6. Final Sealing Put straps in position, hold in place and attach with self-tapping sheet metal screws. 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.
CAUTION 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.
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.
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.
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.
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.
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.
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.
CAUTION WATER PIPING 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. CAUTION PVC (Polyvinyl Chloride) and CPVC (Chlorinated Polyvinyl Chloride) are vulnerable to attack by certain chemicals.
Table 3 - Freezing Points % Glycol Ethylene Propylene Glycol Glycol 20 18°F 19°F 30 7°F 9°F 40 -7°F -6°F 50 -28°F -27°F CAUTION 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.
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 gpm 17.5 21.1 -008 psi 3.17 4.55 gpm 20.0 24.1 psi 4.26 6.11 gpm 50.0 60.4 -016 gpm 40.0 48.3 gpm 25.0 30.2 psi 4.72 6.77 gpm 62.5 75.4 -020 -040 gpm 100.0 120.7 -010 psi 2.91 4.71 gpm 125.0 150.9 gpm 32.5 39.2 psi 4.92 7.06 gpm 75.0 90.5 -025 -050 psi 6.6 9.5 -013 psi 3.34 4.79 psi 4.3 6.
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. WARNING 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. Note: Locations for field cut electrical entries are marked on the unit.
voltages from the average divided by the 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.
All external devices must be powered via a separate external power supply. Note: The drain pan connection is a 1” MPT fitting. 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.
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.
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.
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. 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.
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.
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 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.
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.
Duct Furnace Component Identification attachment of condensate drain line to remove condensate from heat exchanger. Figure 23 - Vertical Configuration 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.
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. 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. Operating and Safety Instructions 1. This duct furnace does not have a pilot.
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.
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.
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.
Table 9 - Gas Heater Troubleshooting LED Code System Description Actions None No Power to T1 On call for heat nothing happens Open Limit Switch Thermostat call for heat. No power across terminals V1 / V2 control. 1. Check for open fuse or circuit breaker. 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.
Table 10 - Gas Heater Troubleshooting Continued LED Code System Description Actions 2 Flash Flame Fault (No Call for Heat) Flame sense failure / flame present with no call for heat. 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. 3 Flash Ignition Lockout Failure to light and or carryover.
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 WARNING Improper installation, adjustment, alteration, service or maintenance can cause property damage, personal injury or loss of life.
2. Check for proper start-up and ignition as outlined in Start-Up section. 5. Return thermostat or heat controller to normal setting. 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.
Startup (See back of the manual for startup form) 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. 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.
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.
Air Balancing 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. continued efficient and reliable operation for the owner.
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.
temperature range as shown in the table above (high superheat results in increased sub-cooling). Correct an undercharged system by adding refrigerant to the system to reduce superheat and raise sub-cooling. Correct an overcharged system by reducing the amount of refrigerant in the system to lower the sub-cooling. If the sub-cooling is correct and the superheat is too high, the TXV may need adjustment to correct the superheat.
Table 14 - R-410A Refrigerant Temperature-Pressure Chart °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 °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.
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.
Table 15 - Bearing Setscrew Torque Recommendations Setscrew Locking Shaft Size Torque (inches) Thread (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 Skewzloc Locking Shaft Size Torque (inch) Thread (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.
Indoor Coils 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.
CAUTION 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.
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.
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.
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 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.
Table 19 - M2-018 and M2-022 Filters (Quantity) Size Filter Type M2-018 M2-022 2” Pleated - 30% Eff, MERV 8 4” Pleated - 30% Eff (MERV 8), 65% Eff (MERV 11), 85% Eff (MERV 13), (8) 20” x 20” 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 (Quantity) Size M2-026 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
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.
Water Containing Total Hardness (°dH) Nitrate (NO3) Iron (Fe) Aluminum (Al) Manganese (Mn) Chloride Content = 10 ppm = 25 ppm = 50 ppm = 80 ppm = 150 ppm = 300 ppm > 300 ppm Concentration (mg/l or ppm) Time Limits Analyze Before AISI 316 SMO 254 Copper Alloy Nickel Alloy 4.0-8.5 No Limit + + + + + + + + + + + + + + + + + + + + + 0 + 0 + 0 + 0 + + + + + + + + < 100 > 100 < 0.2 > 0.2 < 0.2 > 0.2 < 0.1 > 0.
Refrigerant Piping Diagrams Figure 32 - Standard Split System Piping 84
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 87
Figure 36 - Heat Pump Split System Piping 88
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:___
Supply Fan Assembly Alignment Number Check Rotation hp L1 Nameplate Amps________ L2 L3 1 2 Band Size_____________________ VAV Controls_________________ VFD Frequency________________ Springs Operating Correctly Energy Recovery Wheel Assembly Wheels Spin Freely Number Check Rotation hp L1 FLA ________ L2 L3 1 2 Power Exhaust Fan Assembly Alignment Number Check Rotation hp L1 Nameplate Amps________ L2 L3 1 2 Band Size_____________________ VFD Frequency________________ Springs Operating Corr
Outside Air/Economizer Dampers OA Operation Check Damper Wiring Check Gears Check RA Operation Check Damper Wiring Check Gears Check EA Operation Check Damper Wiring Check Gears Check Damper Actuator Type:__________________________________________________________ Economizer Changeover Type and Operation:_______________________________________ Unit Configuration Water-Cooled Condenser Air-Cooled Condenser No Water Leaks Condenser Safety Check Water Flow ________ gpm Water Inlet Temperature _____
Refrigeration System 2 - Cooling Mode Saturated Pressure Temperature Discharge Suction Liquid Refrigeration System 3 - Cooling Mode Saturated Pressure Temperature Discharge Suction Liquid Refrigeration System 4 - Cooling Mode Saturated Pressure Temperature Discharge Suction Liquid Line Temperature Superheat N/A N/A N/A N/A Line Temperature Sub-cooling Superheat N/A N/A N/A N/A Line Temperature Refrigeration System 1 - Heating Mode (Heat Pump Only) Saturated Line Pressure Temperature Temperature D
Refrigeration System 4 - Heating Mode (Heat Pump Only) Saturated Line Pressure Temperature Temperature Discharge Suction Liquid Sub-cooling Superheat N/A N/A N/A N/A Air-Cooled Condenser Alignment Number Check Rotation hp L1 Nameplate Amps________ L2 L3 1 2 3 4 5 6 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.
Electric Heating Stages__________ Stage 1 2 3 4 96 Limit Lockout Amps Aux.
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.
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. Copyright © AAON, all rights reserved throughout the world.
