H3/V3 Series. Installation, Operation & Maintenance. Horizontal and Vertical Indoor Air Handling Units WARNING WARNING WARNING

Transcription

1 H3/V3 Series Horizontal and Vertical Indoor Air Handling Units Installation, Operation & Maintenance WARNING WARNING QUALIFIED INSTALLER Improper installation, adjustment, alteration, service or maintenance can cause property damage, personal injury or loss of life. Installation and service must be performed by a trained, qualified installer. A copy of this IOM should be kept with the unit. If the information in this manual is not followed exactly, a fire or explosion may result causing property damage, personal injury or loss of life. WARNING FOR YOUR SAFETY Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other appliance.

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3 Table of Contents Safety... 6 H3/V3 Base Model Description General Information Codes and Ordinances Receiving Unit Storage Direct Expansion (DX) Systems Wiring Diagrams Condensate Drain Pans Installation Locating the Unit Lifting and Handling the Unit Electrical Cutting Electrical Openings Thermostat Control Wiring Duct Connection Condensate Drain Piping Heating Coils Chilled Water Coil Refrigerant Piping Determining Refrigerant Line Size Startup Supply Fans Fan Air Flow Adjustment Filters Adjusting Refrigerant Charge Operation Electric Heating Operation Steam or Hot Water Preheating Operation Chilled Water or Non-Compressorized DX Cooling Operation Maintenance DX Cooling Condensate Drain Pans E-Coated Coil Cleaning Recommended Coil Cleaner Recommended Chloride Remover Supply Fans Filter Replacement Replacement Parts AAON-Longview Customer Service Department Filter Information

4 Refrigerant Piping Diagrams Maintenance Log Literature Change History R94200 Rev. A (ACP 30584) 4

5 Index of Tables and Figures Tables: Table 1 - H3 and V3 Series Clearances Table 2 - Control Wiring Table 3 - Drain Trap Dimensions Table 4 - Acceptable Air-Cooled Refrigeration Circuit Values Table 5 - Acceptable Water-Cooled Refrigeration Circuit Values Table 6 - R-410A Refrigerant Temperature-Pressure Chart Table 7 - H3 Series A Cabinet Pre Filters Table 8 - V3 Series A Cabinet Pre Filters Table 9 - H3 Series B Cabinet Pre Filters Table 10 - V3 Series B Cabinet Pre Filters Table 11 - H3 Series C Cabinet Pre Filters Table 12 - V3 Series C Cabinet Pre Filters Table 13 - H3 Series D Cabinet Pre Filters Table 14 - V3 Series D Cabinet Pre Filters Table 15 - H3 Series E Cabinet Pre Filters Table 16 - V3 Series E Cabinet Pre Filters Table 17 - H3 Series A Cabinet Unit Filters Table 18 - V3 Series A Cabinet Unit Filters Table 19 - H3 Series B Cabinet Unit Filters Table 20 - V3 Series B Cabinet Unit Filters Table 21 - H3 Series A Cabinet Final Filters Table 22 - V3 Series A Cabinet Final Filters Table 23 - H3 Series B Cabinet Final Filters Table 24 - V3 Series B Cabinet Final Filters Table 25 - H3 Series C Cabinet Final Filters Table 26 - V3 Series C Cabinet Final Filters Table 27 - H3 Series D Cabinet Final Filters Table 28 - V3 Series D Cabinet Final Filters Table 29 - H3 Series E Cabinet Final Filters Table 30 - V3 Series E Cabinet Final Filters Figures: Figure 1 - Lockable Handle Figure 2 - H3 Series Unit Orientation Figure 3 - V3 Series Unit Orientation Figure 4 - Drain Trap Figure 5 - Supply Fan Banding Figure 6 - Standard Split System Piping Figure 7 - Modulating Hot Gas Reheat with Hot Gas Bypass Split System Piping Figure 8 - Hot Gas Bypass Split System Piping Figure 9 - Modulating Hot Gas Reheat Split System Piping Figure 10 - Heat Pump Split System Piping Figure 11 - Heat Pump with Factory Installed Modulating Hot Gas Reheat Split System Piping 56 Figure 12 - Heat Pump with Field Installed Modulating Hot Gas Reheat Split System Piping

6 Safety Attention should be paid to the following statements: NOTE - Notes are intended to clarify the unit installation, operation and maintenance. CAUTION - Caution statements are given to prevent actions that may result in equipment damage, property damage, or personal injury. WARNING - Warning statements are given to prevent actions that could result in equipment damage, property damage, personal injury or death. DANGER - Danger statements are given to prevent actions that will result in equipment damage, property damage, severe personal injury or death. WARNING ELECTRIC SHOCK, FIRE OR EXPLOSION HAZARD Failure to follow safety warnings exactly could result in dangerous operation, serious injury, death or property damage. Improper servicing could result in dangerous operation, serious injury, death or property damage. Before servicing, disconnect all electrical power to the unit. More than one disconnect may be provided. When servicing controls, label all wires prior to disconnecting. Reconnect wires correctly. Verify proper operation after servicing. Secure all doors with key-lock or nut and bolt. WARNING Electric shock hazard. Before servicing, disconnect all electrical power to the unit, including remote disconnects, to avoid shock hazard or injury from rotating parts. Follow proper Lockout-Tagout procedures. WARNING FIRE, EXPLOSION OR CARBON MONOXIDE POISONING HAZARD Failure to replace proper controls could result in fire, explosion or carbon monoxide poisoning. Failure to follow safety warnings exactly could result in serious injury, death or property damage. Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this appliance. 6

7 WARNING During installation, testing, servicing and troubleshooting of the equipment it may be necessary to work with live electrical components. Only a qualified licensed electrician or individual properly trained in handling live electrical components shall perform these tasks. Standard NFPA-70E, an OSHA regulation requiring an Arc Flash Boundary to be field established and marked for identification of where appropriate Personal Protective Equipment (PPE) be worn, should be followed. WARNING GROUNDING REQUIRED All field installed wiring must be completed by qualified personnel. Field installed wiring must comply with NEC/CEC, local and state electrical code requirements. Failure to follow code requirements could result in serious injury or death. Provide proper unit ground in accordance with these code requirements. WARNING 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. 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 UNIT HANDLING To prevent injury or death lifting equipment capacity shall exceed unit weight by an adequate safety factor. Always test-lift unit not more than 24 inches high to verify proper center of gravity lift point to avoid unit damage, injury or death. WARNING 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 Failure to properly drain and vent coils when not in use during freezing temperature may result in coil and equipment damage. 7

8 CAUTION Rotation must be checked on all MOTORS AND COMPRESSORS of 3 phase units at startup by a qualified service technician. Scroll compressors are directional and can be damaged if rotated in the wrong direction. Compressor rotation must be checked using suction and discharge gauges. Fan motor rotation should be checked for proper operation. Alterations should only be made at the unit power connection WARNING WATER PRESSURE Prior to connection of condensing water supply, verify water pressure is less than maximum pressure shown on unit nameplate. To prevent injury or death due to instantaneous release of high pressure water, relief valves should be field supplied on system water piping. WARNING 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. 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. CAUTION 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. WARNING 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. 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. 8

9 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. CAUTION 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. 1. The unit is for indoor use only. See General Information section for more unit information. 2. 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. 3. READ THE ENTIRE INSTALLATION, OPERATION AND MAINTENANCE MANUAL. OTHER IMPORTANT SAFETY PRECAUTIONS ARE PROVIDED THROUGHOUT THIS MANUAL. 4. Keep this manual and all literature safeguarded near or on the unit. CAUTION PVC (Polyvinyl Chloride) and CPVC (Chlorinated Polyvinyl Chloride) are vulnerable to attack by certain chemicals. Polyolester (POE) oils used with R-410A and other refrigerants, even in trace amounts, in a PVC or CPVC piping system will result in stress cracking of the piping and fittings and complete piping system failure. 9

10 H3/V3 Base Model Description Model Number H3 Series and Generation - A R A Unit Unit Revision Size Orientation - 3 Voltage - 0 Corrosion Protection C A1 A2 A3 A4 - BASE MODEL SERIES AND GENERATION H3 = Horizontal - Back Intake, Front Discharge V3 = Vertical - Back Intake, Top Discharge UNIT SIZE A = Up to 1,200 cfm B = Up to 2,000 cfm C = Up to 4,000 cfm D = Up to 6,000 cfm E = Up to 10,000 cfm UNIT ORIENTATION R = Right Hand Connections L = Left Hand Connections REVISION A = First Revision VOLTAGE 1 = 230V/1Φ/60Hz 2 = 230V/3Φ/60Hz 3 = 460V/3Φ/60Hz 4 = 575V/3Φ/60Hz 8 = 208V/3Φ/60Hz 9 = 208V/1Φ/60Hz Model Option A: COOLING A1: COOLING TYPE 0 = No Cooling 1 = R-410A DX Cooling 2 = Chilled Water Cooling A2: COOILNG ROWS 0 = No Cooling 4 = 4 Row Coil 6 = 6 Row Coil 8 = 8 Row Coil A3: COOLING STAGES 0 = No Cooling 1 = Single Circuit 2 = Two Circuits - Interlaced Coil D = Double Serpentine F = Single Serpentine H = Half Serpentine Q = Quarter Serpentine A4: COOLING FPI 0 = No Cooling A = 10 fpi B = 8 fpi C = 12 fpi CORROSION PROTECTION 0 = None A = Interior Corrosion Protection 10

11 H3/V3 Base Model and Features Description Model/Feature Number 1 2 F A A B B : B1 B2 B3 1A 1B 1C 1D - Model Option B: HEATING B1: HEATING TYPE 0 = No Heating 1 = Hot Water 3 = Electric Heating 4 = Steam Distributing B2: HEATING DESIGNATION 0 = No Heating 1 = 1 Row Coil 2 = 2 Row Coil A = 7 kw ( V) B = 14 kw ( V) C = 21 kw ( V) D = 28 kw ( V) E = 35 kw ( V) F = 42 kw ( V) G = 49 kw ( V) H = 56 kw ( V) J = 63 kw ( V) K = 70 kw ( V) L = 77 kw ( V) M = 84 kw ( V) B3: HEATING STAGES 0 = No Heating 1 = 1 Stage 2 = 2 Stage 3 = 3 Stage 4 = 4 Stage S = Modulating/SCR Electric F = Single Serpentine 10 fpi H = Half Serpentine 10 fpi Q = Quarter Serpentine 10 fpi Feature 1: SUPPLY FAN 1A: SUPPLY AIR BLOWER CONFIGURATION 0 = 1 Blower + Premium Eff. Motor 1 = 1 Blower + Premium Eff. Motor + 1 VFD A = 1 Blower + 1 High Efficiency EC Motor B = 2 Blowers + 2 High Efficiency EC Motors 1B: SUPPLY AIR BLOWER 1 = 15 Backward Curved Plenum Fan 2 = 15 BC Plenum, 50% Width with Banding 3 = 18.5 Backward Curved Plenum Fan 4 = 18.5 BC Plenum Fan, 70% Width with Banding 5 = 22 Backward Curved Plenum Fan 6 = 24 Backward Curved Plenum Fan 7 = 27 Backward Curved Plenum Fan 8 = 27 BC Plenum Fan, 70% Width with Banding A = 310 mm Direct Drive BC Plenum Fan B = 355 mm Direct Drive BC Plenum Fan C = 450 mm Direct Drive BC Plenum Fan 1C: SUPPLY AIR BLOWER MOTOR 1 = 1 hp rpm 2 = 2 hp rpm 3 = 3 hp rpm 4 = 5 hp rpm 5 = 7.5 hp rpm 6 = 10 hp rpm A = 500 W (0.67 hp) B = 1.0 kw (1.34 hp) C = 1.7 kw (2.28 hp) D = 3.0 kw (2.90 hp or 4.02 hp) 1D: SUPPLY BLOWER CONTROL/CONTROL VENDORS 0 = Standard - Terminal Block A = Potentiometer Supply Fan Control B = WattMaster Orion Controls System C = Field Installed Controls by Others 11

12 H3/V3 Features Description Feature Number 0 C 0 F T B A 5B 5C - Feature 2: REFRIGERATION OPTIONS 0 = Standard - None A = Single Circuit External Hot Gas Bypass B = Dual Circuit External Hot Gas Bypass C = Heat Pump D = Option B + H E = Options B + J F = Options C + H G = Options C + J H = Modulating Hot Gas Reheat J = Factory Installed Modulating Hot Gas Reheat K = Dual Circuit Modulating Hot Gas Reheat + Option B L =Factory Installed Dual Circuit Modulating Hot Gas Reheat + Option B M = Dual Circuit Modulating Hot Gas Reheat + Option C N = Factory Installed Dual Circuit Modulating Hot Gas Reheat + Option C P = Option H (Circuit 1) + Option A (Circuit 2) Q = Option J (Circuit 1) + Option A (Circuit 2) Feature 3: SPECIAL CONTROLS 0 = Standard - None A = Constant Volume Controller - CV Cool + CV Heat B = Constant Volume Controller with Modulating Hot Gas Reheat - CV Cool + CV Heat C = VAV Controller - VAV Cool + CV Heat D = VAV Controller with MHGR - VAV Cool + CV Heat E = Make Up Air Controller - CV Cool + CV Heat F = Make Up Air Controller with Modulating Hot Gas Reheat - CV Cool + CV Heat G = WattMaster Modulating Hot Gas Reheat Controller Feature 4: ADDITIONAL CONTROLS 0 = Standard - None A = Phase and Brownout Protection B = Return and Supply Air Firestat C = Return Air Smoke Detector D = Options A + B E = Options A + C F = Options B + C G = Options A + B + C Feature 5: MIXING BOX 5A: RETURN AIR DAMPER POSITION 0 = Standard - None F = Front L = Left Hand (Front OA Damper Required) R = Right Hand (Front OA Damper Required) T = Top (Front OA Damper Required) 5B: OUTSIDE AIR DAMPER POSITION 0 = Standard - None F = Front L = Left Hand (Front RA Damper Required) R = Right Hand (Front RA Damper Required) T = Top (Front RA Damper Required) 5C: MIXING BOX DAMPER CONTROL 0 = Standard - None A = 2 Position Actuators B = Fully Modulating Actuators C = Fixed Position Dampers 12

13 H3/V3 Features Description Feature Number 0 G A A A - 6A 6B 6C Feature 6: FILTER BOX 6A: PRE FILTER BOX 0 = Standard - None A = 2 Pleated - 30% Eff. - MERV 8 B = 4 Pleated - 30% Eff. - MERV 8 C = 4 Pleated - 65% Eff. - MERV 11 D = 4 Pleated - 85% Eff. - MERV 13 E = 4 Pleated - 95% Eff. - MERV 14 F = 2 Pleated - 30% Eff. - MERV Pleated - 30% Eff. - MERV 8 G = 2 Pleated - 30% Eff. - MERV Pleated - 65% Eff. - MERV 11 H = 2 Pleated - 30% Eff. - MERV Pleated - 85% Eff. - MERV 13 J = 2 Pleated - 30% Eff. - MERV Pleated - 95% Eff. - MERV 14 6B: UNIT FILTER 0 = Standard - None A = 2 Pleated - 30% Eff. - MERV 8 B = 4 Pleated - 30% Eff. - MERV 8 C = 4 Pleated - 65% Eff. - MERV 11 D = 4 Pleated - 85% Eff. - MERV 13 E = 4 Pleated - 95% Eff. - MERV 14 F = 2 Pleated - 30% Eff. - MERV Pleated - 30% Eff. - MERV 8 G = 2 Pleated - 30% Eff. - MERV Pleated - 65% Eff. - MERV 11 H = 2 Pleated - 30% Eff. - MERV Pleated - 85% Eff. - MERV 13 J = 2 Pleated - 30% Eff. - MERV Pleated - 95% Eff. - MERV 14 Feature 7: FILTER OPTIONS 0 = Standard - None A = Magnehelic Gauge B = Clogged Filter Switch C = Options A + B Feature 8: COIL COATING 0 = Standard - None A = E-coated Cooling and Heating Coils Feature 9: EXPANSION VALVE 0 = None A = Thermal Expansion Valves Feature 10: EXPANSION VALVE CONTROLS 0 = None A = Standard Control Feature 11: EXTERNAL PAINT 0 = Standard - None A = AAON Gray Paint B = Special Paint 6C: FINAL FILTER BOX 0 = Standard - None A = 2 Pleated - 30% Eff. - MERV 8 B = 12 Cartridge - 65% Eff. - MERV 11 C = 12 Cartridge - 85% Eff. - MERV 13 D = 12 Cartridge - 95% Eff. - MERV 14 E = 2 Pleated - 30% Eff. - MERV Cartridge - 65% Eff. - MERV 11 F = 2 Pleated - 30% Eff. - MERV Cartridge - 85% Eff. - MERV 13 G = 2 Pleated - 30% Eff. - MERV Cartridge - 95% Eff. - MERV 14 13

14 H3/V3 Features Description Feature Number C A A 14B Feature 12: TONNAGE 0 = Standard - None A = 2 ton Capacity B = 3 ton Capacity C = 4 ton Capacity D = 5 ton Capacity E = 6 ton Capacity F = 7 ton Capacity G = 8 ton Capacity H = 10 ton Capacity J = 14 ton Capacity K = 17 ton Capacity L = 22 ton Capacity M = 25 ton Capacity N = 30 ton Capacity P = 31 ton Capacity Q = 34 ton Capacity R = 45 ton Capacity S = 55 ton Capacity T = 63 ton Capacity Feature 13: ADDED OR MODIFIED SYSTEMS 0 = Standard - None Feature 14: GPM 14A: GPM COOLING COIL 0 = Standard - None A = gpm B = gpm C = gpm D = gpm E = gpm F = gpm G = gpm H = gpm 14B: GPM HEATING COIL 0 = Standard - None A = gpm B = gpm C = gpm D = gpm E = gpm F = gpm G = gpm H = gpm Feature 15: CONTROL PANEL 0 = None A = Small Control Panel - 12 x 12 B = Medium Control Panel - 25 x 22 C = Large Control Panel - 48 x 22 Feature 16: BLANK 0 = Standard - None Feature 17: BLANK 0 = Standard - None Feature 18: BLANK 0 = Standard - None Feature 19: BLANK Digit 41: 0 = Standard - None Feature 20: BLANK 0 = Standard - None Feature 21: BLANK 0 = Standard - None Feature 22: WARRANTY 0 = Standard - 1 Year Parts Feature 23: TYPE 0 = Standard X = Special Pricing Authorization 14

15 General Information H3 and V3 Series indoor air handling units have been designed for indoor installation only. Units are assembled, wired, charged and run-tested at the factory. H3 and V3 Series units are not intended for residential use. 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 qualified installer. A copy of this IOM should be kept with the unit. CAUTION 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. Certification of Steam or Hot Water Heat Models a. Certified as a forced air heating system with or without cooling. b. Certified for indoor installation only. Certification of Electric Heat Models a. Certified as an electric warm air furnace with or without cooling. b. Certified for indoor installation only. Certification of Cooling Models a. Certified as a commercial central air conditioner with or without electrically operated compressors. b. Certified for indoor installation only. c. Certified with refrigerant R-410A coils or with chilled water cooling coils. Codes and Ordinances H3 and V3 Series units have been tested and certified, by ETL, in accordance with UL Safety Standard 1995/CSA C22.2 No System should be sized in accordance with the American Society of Heating, Refrigeration and Air Conditioning Engineers Handbook. Installation of H3 and V3 Series units must conform to the ICC standards of the International Mechanical Code, the International Building Code, Installation of Air Conditioning and Ventilating Systems Standard, NFPA 90A, and local building, plumbing and waste water codes. All appliances must be electrically grounded in accordance with local codes, or in the absence of local codes, the current National Electric Code, ANSI/NFPA 70 or the current Canadian Electrical Code CSA C22.1. CAUTION The Clean Air Act of 1990 bans the intentional venting of refrigerant as of July 1, Approved methods of recovery, recycling, or reclaiming must be followed. WARNING Coils and sheet metal surfaces present sharp edges and care must be taken when working with equipment. 15

16 WARNING 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 Warranty Department for assistance with handling damaged goods, repairs, and freight claims: (903) 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. The warranty card must be completed in full and returned to AAON not more than 3 months after unit is delivered. Figure 1 - Lockable Handle Storage This equipment is not suitable for outdoor use of storage. If installation will not occur immediately following delivery, store equipment in a dry protected area away from construction traffic and in the proper orientation as marked on the packaging with all internal packaging in place. Secure all loose-shipped items. Direct Expansion (DX) Systems All DX systems include evaporator coils and thermal expansion valves (TXV). Never turn 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 condensing unit compressors. This means the compressor may 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. 16

17 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. 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 emergency or complete shutdown of the unit. During the cooling season, if the airflow is reduced due to dirty air filters or any other reason, the cooling coils can get too cold which 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 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. Wiring Diagrams Unit specific wiring diagrams are laminated and affixed inside the controls compartment door. Condensate Drain Pans Units require drain p-traps and lines to be connected to the condensate drain pans of the unit. 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. Installation CAUTION Unit should not be operated without a p-trap. Failure to install a p-trap may result in overflow of condensate water. AAON equipment has been designed for quick and easy installation. Locating the Unit Placement of the unit relative to ductwork, electrical and plumbing must be carefully considered. Return air plenum or duct can be mounted directly to the return air flanges. Use flexible gasket material to seal the duct to the unit. Verify floor, foundation or suspension support can support the total unit weight, including accessory weights. Unit must be level in both horizontal axes to support the 17

18 unit and reduce noise and vibration from the unit. Allow adequate service clearances as shown on the unit nameplate and unit drawing. Consult your local building codes for additional service clearance requirements. Allow adequate space for piping access and panel removal. Condenser water piping and condensate drain connections are located on either side of the unit. Table 1 - H3 and V3 Series Clearances Access Door Side Minimum Unit Size Clearance Required V3-A V3-B V3-C 36 inches V3-D V3-E H3-A H3-B 36 inches H3-C H3-D 45 inches* H3-E 60 inches* *Additional clearance is required to allow for coil removal. CAUTION Emergency drain pan is recommended for all applications where a risk of water damage to surrounding structure or furnishings. Refer to local codes. Floor Mounted Units Make sure the unit is level and mounted on a field supplied platform with a minimum height to allow for proper depth of the condensate line p-trap. Other installation provisions may be necessary according to job specifications. V3 Series vertical air handling units are designed for upflow applications only. Suspended Units H3 Series horizontal air handling units are equipped for suspended installations. The unit should be lifted into position by supporting the unit with the skid used for shipping. The air handling unit must be installed level and care should be taken to prevent damage to the cabinet. Other installation provisions may be necessary according to job specifications. 18

19 H3 Series Left Hand Side Top View Return Air Air Flow Supply Air Connections and service access on right side for right hand orientation Right Hand Side Figure 2 - H3 Series Unit Orientation Consider the air flow to be hitting the back of your head. V3 Series Top View Left Hand Side Right Hand Side Supply Air Return Air Connections and service access on right side for right hand orientation Consider the air flow to be Air Flow hitting the back of your head. Figure 3 - V3 Series Unit Orientation 19

20 Lifting and Handling the Unit H3 and V3 Series air handling units have channels underneath the base which provide lifting access to the underside of the equipment and allow moving and placement without physical damage. Before lifting unit, be sure that all shipping material has been removed from unit. Care should be taken if using spreader bars, blocking or other lifting devices to prevent damage to the cabinet, coil or fans. WARNING UNIT HANDLING Incorrect lifting can cause damage to the unit, injury or death. Lifting equipment capacity should exceed unit weight by an adequate safety factor. Always test lift unit not more than 24 inches high to verify proper center of gravity lift point. Electrical Verify the unit name plate agrees with power supply. H3 and V3 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 control compartment door. Route power and control wiring, separately, through the utility entry in the unit. Do not run power and control signal wires in the same conduit. WARNING Electric shock hazard. Before attempting to perform any installation, service, or maintenance, shut off all electrical power to the unit at the disconnect switches. Unit may have multiple power supplies. Failure to disconnect power could result in dangerous operation, serious injury, death, or property damage. All units require field supplied electrical overcurrent and short circuit protection. Device must not be sized larger than the Maximum Overcurrent Protection (MOP) shown on the unit nameplate. Codes may require a disconnect switch be within sight of the unit. It is recommended that the field installed overcurrent protection or disconnect switch not be installed 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. 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. 20

21 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 then be sealed using silicone caulking or a duct seal compound. If a reciprocating saw is used to make the cut-out take care that the metal skins of the foam 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. Note: Units are factory wired for 208V, 230V, 460V or 575V. In some units, the 208V and 230V options may also be provided in single or three phase configurations. The transformer configuration must be checked by a qualified technician prior to startup. Wire power leads to the unit s terminal block or main disconnect. All wiring beyond this point has been completed by AAON and cannot be modified without effecting the unit s agency/safety certification. Supply voltage must be within the min/max range shown on the unit nameplate. Available short circuit current should not exceed the short circuit current rating (SCCR) shown on the unit nameplate. CAUTION Three phase voltage imbalance will cause motor overheating and premature failure. 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 maximum deviation from the average voltage divided by the average voltage. 21

22 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. CAUTION Rotation must be checked on all MOTORS AND COMPRESSORS of three phase units. Supply fan motors should all be checked by a qualified service technician at startup and any wiring alteration should only be made at the unit power connection. CAUTION Scroll compressors are directional and will be damaged by operation in the wrong direction. Low pressure switches on compressors have been disconnected after factory testing. Rotation should be checked by a qualified service technician at startup using suction and discharge pressure gauges and any wiring alteration should only be made at the unit power connection. 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 2 - 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) Total Wire Distance Allowable 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. All external devices must be powered via a separate external power supply. 22

23 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. Duct Connection Remove shipping covers and attach duct to flanges provided on the unit. The installer is responsible for sealing ducts to the flanges to prevent water leaks. Return air enters either the left or right side of the V3 unit, or the left or right end of the H3 unit, where the air filters are located. Ductwork should be sized in accordance with the ASHRAE Handbook. Ductwork should be installed in accordance with NFPA Standard 90A. CAUTION 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. Condensate drain trapping and piping should conform to all applicable governing codes. Note: The drain pan connection(s) is a 1 MPT fitting. When attaching duct to the unit, use a flexible/compressible material rated for duct connections. A three inch flexible connector for both return and supply duct connections is recommended. 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 at least one section s 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. Figure 4 - 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. 23

24 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. 24 Table 3 - Drain Trap Dimensions Draw-Through Drain Pan Pressure Trap Dimensions Negative Static X X/2 (inches of water) (inch) (inch) Heating Coils One or two row hot water and steam heating and preheating coils can be factory installed. All valve controls for heating operation are field supplied and field installed. 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. Chilled Water Coil Factory installed four or six row chilled water cooling coils can be factory mounted. All controls for the cooling coil are field supplied and field installed. WARNING 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. 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. 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.

25 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. 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 CAUTION 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 25

26 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 26

27 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. CAUTION 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 27

28 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 10 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. 28

29 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. 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 qualified installer. A copy of this IOM should be kept with the unit. WARNING Electric shock hazard. Shut off all electrical power to the unit to avoid shock hazard or injury from rotating parts. 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 and refrigerant charge. Supply Fans H3 and V3 Series units are equipped with direct drive backward curved plenum supply fan assemblies or belt driven backward curved plenum supply fans that deliver the 29

30 air volume specified according to unit size and job requirements. Fan Air Flow Adjustment A specific air volume is delivered by the fans with air volume bands in the blower wheels, Electronically Commutated Motors (ECM), or Variable Frequency Drives (VFD). Field air flow adjustment may be required at startup. Air volume bands for the wheels are sized according to the unit s air delivery specifications and can also be ordered from the factory for field installation. 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 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. Air Flow Adjustment If reduced air volume is required an air volume band or larger air volume band can be installed within the blower wheel to reduce the amount of air delivered by the wheel. If the unit is factory equipped with the air volume band and additional air volume is required, the band can be removed from the wheel. Use fan program in AAONEcat32 to determine the new band size for the required cfm and static pressure. The following photos of a 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 venture, which may require removal of the blower motor and wheel. Air volume bands are 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 30

31 Figure 5 - Supply Fan Banding Filters Do not operate the unit without filters in place. Unit should be checked for correct filter placement during startup. Operation of the equipment without filters will result in a clogged evaporator coil. CAUTION Before completing startup and leaving the unit a complete operating cycle should be observed to verify that all components are functioning properly. 31