Bryant Air Conditioning Model 581A COMMERCIAL SINGLE PACKAGE ROOFTOP Sizes 155-240 GAS HEATING/ELECTRIC COOLING UNITS 13 to 20 Tons Model 581A155,180 Model 581A240 DESCRIPTION The 581A gas heating/electric cooling rooftop units are designed to deliver optimum performance and reliability in a commercial rooftop unit. The 13 to 20 ton units are one-piece gas heating, electric cooling units that are prewired and precharged with R-22 at the factory, making jobsite installation easy. Every unit is factory runtested prior to shipment to ensure reliable installation. The 581A units are designed to be field-convertible from vertical supply/return to horizontal supply/return (using an accessory horizontal supply curb or adapter), making them easily adaptable to a wide variety of new construction and replacement applications. For vertical supply/return jobs, ductwork can be connected directly to the roof curb, allowing ductwork to be completed before unit is available for installation. All units include easily replaceable internal filters. The 581A units are available in a range of heating sizes and voltage options to meet most job requirements. Low-voltage terminal blocks make wiring connections quick and simple. All units are listed with ETL (ETL Testing Laboratory) and ETL, Canada. All units are ARI (Air-Conditioning & Refrigeration Institute) approved and comply with ASHRAE Standard 62 (American Society of Heating, Refrigeration, and Air Conditioning Engineers). STANDARD FEATURES INDUSTRY-LEADING COOLING EERS (Energy Efficiency Ratios) assure minimum operating costs and will qualify for attractive utility rebates in many areas. SEMI-HERMETIC COMPRESSORS are fully serviceable. They are highly regarded and preferred by owners and users, and are offered exclusively on the high-efficiency 13 to 20 ton 581A units. Two 06D semi-hermetic compressors on independent refrigeration circuits are offered on the 180 and 240 units for 2 steps of capacity control and redundancy. A single 06D semi-hermetic compressor with unloading capability and TXV (thermostatic expansion valve) refrigerant control is offered on the 155 units. All compressors have service valves and a full complement of safety devices, including high- and low-pressure switches, overtemperature protection, an electronic compressor lockout device, and crankcase heaters. OVERSIZED FAN MOTORS AND VARIABLE-PITCH BELT DRIVES are supplied standard from the factory. A 5 hp motor is provided standard on the 581A180 (15-ton unit), and a 10 hp motor is standard on the 581A240 (20-ton unit). EASY INSTALLATION makes these units perfect for vertical supply and return roof curb mount applications on new construction, retrofit, and replacement applications. The unique industry-leading compact size and weight are favored by designers, contractors, owners, and users, and are significant advantages in terms of minimizing required roof structures on new construction and retrofit jobs. The new 581A units can be easily converted to horizontal supply and return with the new fan-performance-boosting horizontal high-static regain adapter (part no. 389210-201). These vertical-to-horizontal supply/return adapters are not only fully factory assembled with a built-in insulated transition duct, they improve fan performance by as much as 0.6 in. wg of static. THE FACTORY-ASSEMBLED PACKAGE is a compact, fully self-contained electric cooling/gas heating unit that is prewired, prepiped, and precharged for minimum installation expense. INTERNAL RETURN-AIR FILTERS are provided. Two-in. throwaway filters are provided standard on all units, and can be easily accessed. There is no need to field-fabricate filter racks or install external filter accessories. COMPRESSOR PROTECTION is assured. The 581A units have high- and low-pressure protection external to the compressor. These protections prohibit operation under abnormal unit conditions. DUAL COMPRESSORS AND DUAL REFRIGERATION CIR- CUITS (180,240 units) are provided. Two compressors, each on its own independent circuit, provide standby reliability and high operating efficiency. POWER, CONTROL, AND GAS CONNECTIONS are made on the same side of the unit to simplify installation. Form No. PDS 581A.155.3B
INDUCED-DRAFT COMBUSTION provides the exact amount of combustion air for the most efficient operation. Induced-draft combustion also eliminates the flue stack, giving the unit a low profile appearance. The draw-through design ensures safe operation under any conditions. TUBULAR U-SHAPED CELL design of the heat exchanger provides high-efficiency heating operation. The hot gases make 2 passes over the supply-air path to enhance efficiency. POSITIVE-PRESSURE MECHANICAL FLUE GAS VENTING is unaffected by adverse wind conditions. FURNACE SAFETY CONTROLS shut off gas if there is a pilot outage, combustion-air failure, overheating of heat exchangers, or flame rollout. TWO-STAGE HEATING WITH 2 INDEPENDENT GAS CON- TROL SYSTEMS (180,240 units) minimizes heating costs. These independent gas control systems make single-stage heating possible if one stage fails. ADVANCED DESIGN of evaporator and condenser coils provides optimum heat transfer and cooling efficiency. Coils are computer-designed with advanced heat transfer surfaces, and are fabricated of copper tubing with aluminum fins. COMMERCIAL STRENGTH BASE RAILS with built-in rigging capability allow easy rigging of unit. WEATHER-RESISTANT CABINET is built for durability in any climate. The cabinet is made of pre-painted, galvanized steel for long life and high-quality appearance. LOW-AMBIENT OPERATION is provided standard. The units operate in cooling down to 35 F as shipped from the factory. Low-ambient kits are not required for most applications. COMPRESSOR VIBRATION ISOLATION MOUNTING on all units eliminates noise-causing vibration transmission into the conditioned space. CRANKCASE HEATERS keep the oil free of refrigerant during the off cycle for added compressor life and reliability. STANDARD WARRANTIES include 1 year on parts (no labor), with an additional 4 years on compressors (155 units) and heat exchangers (all units). Additional extended warranties are available. BELT-DRIVEN EVAPORATOR-FAN MOTORS are standard on all units and allow adjustment of the available static pressure. INTEGRATED GAS UNIT CONTROLLER BOARD on the units makes the control of gas heating rooftop units more reliable, safe, and efficient. The board provides timed control of evaporator-fan functions and ignites the burners. The board also simplifies troubleshooting through its built-in diagnostic function which provides system status and fault notification via a light-emitting diode (LED). In addition, the board provides anticycle protection for gas heat operation. FACTORY-INSTALLED OPTIONS DESCRIPTION AND USAGE Economizer The economizer will allow a fixed percentage (between 0 and 100%) outdoor ventilation air into the unit any time the evaporator fan is running. A dry-bulb thermostat placed outdoors will bring in 100% outdoor air whenever the temperature of the outdoor air alone will adequately provide cooling. If the economizer alone cannot provide enough cooling, then simultaneous economizer and compressor operation will provide the most economical operation. SUGGESTED USE: To allow a fixed percentage of outdoor air any time the evaporator fan is on, or operates in economizer mode if outdoor air can provide cooling, but closes when the evaporator fan is off to prevent cold backdrafts and wasted energy. To reduce energy usage. Use whenever the number of hours of operation at below 55 F is significant. The damper may be used on either vertical or horizontal applications. Manual Outdoor-Air Dampers Package consists of a damper which can be set at 25% outdoor air. The package includes a rainhood and birdscreen. SUGGESTED USE To allow a fixed percentage of outdoor air for ventilation under all conditions. The damper may be used on either vertical or horizontal applications. NOTE: The 25% manual outdoor-air damper will be factory installed whenever the factory-installed economizer is not chosen. FIELD-INSTALLED ACCESSORY DESCRIPTION AND USAGE Roof Curbs (Horizontal and Vertical) Full-perimeter galvanized steel support frame in 14- and 24-in. high designs provides wood nailer to attach roof counter flashing. Insulated basepans in curb are provided to prevent condensation. Ductwork attaches to rails provided in the roof curb. A gasket is provided to form an air- and watertight seal between unit and curb. The gasket meets the standards of the NRCA (National Roofing Contractors Association). SUGGESTED USE: Rooftop application for vertical or horizontal discharge. Slab-mounted applications when elevation of the unit is necessary. Horizontal Adapter The adapter is prefabricated, factoryassembled with built-in insulated duct, and permits full perimeter mounting. SUGGESTED USE: Rooftop applications for horizontal discharge where high air delivery cfms are required. Two-Position Damper Package consists of a low-leak damper assembly for easy installation. The damper will allow either 0 or 25% outdoor air into the unit any time the evaporator fan is running. When the evaporator fan is off or when there is a loss of power, the damper will be closed. SUGGESTED USE: Allows a fixed percentage of outdoor air any time the evaporator fan is on, but closes when the evaporator fan is off to prevent cold backdrafts and wasted energy. The damper may be used on either vertical or horizontal airflow applications. Economizer See description listed under Factory-Installed Options Description and Usage section above. CONTENTS Page Model Description...3 Heating Capacities and Efficiencies...4 Capacity Ratings...4 Dimensional Drawings...5-8 Specifications...9,10 Selection Procedure...11 Gross Cooling Capacities...12-14 Air Delivery...15-17 Electrical Data...19 Operating Sequence...20 Typical Wiring Schematic...21-23 Typical Installation...24 Application Data...25,26 Engineers Specification Guide... 27 2
FIELD-INSTALLED ACCESSORY DESCRIPTION AND USAGE (cont) Thermostats and Subbases Provide staged cooling and heating, automatic (or manual) changeover, fan control, and indicator light. SUGGESTED USE: To control unit operations. Enthalpy Control Sensor Package consists of a solid-state sensor to be paired with a second enthalpy sensor for differential enthalpy control. This sensor is mounted on the economizer assembly so that it can sense building return-air temperature. The 2 sensors will determine which combination of outdoor and return air will provide the greatest energy savings. SUGGESTED USE: To enhance economizer operation for maximum energy savings. NOTE: A single sensor may be used for single-sensor, outdoorair, enthalpy control if desired. Time Guard II Device Package consists of a control to be field wired into the unit controls, and provides a 5-minute delay in compressor operation between cooling cycles. SUGGESTED USE: Prevents compressor short cycling when rapid compressor cycles may be a problem. Head Pressure Control Device Kit consists of an outdoorair thermostat that permits adequate head pressure control during cooling operation at low outdoor-ambient temperatures. Refer to Trade Prices for more details or contact your local representative. SUGGESTED USE: When cooling at low-ambient outdoor temperatures is desired. Low-Ambient Kit Kit consists of a solid-state control and condenser coil temperature sensor to modulate the condenserfan motors in order to maintain condenser-coil head pressure for proper cooling operation. Refer to Trade Prices for more details or contact your local representative. SUGGESTED USE: Whenever cooling is required at low outdoor ambient temperatures (as low as 20 F). Low-ambient kit is not usually required when economizer is used. Barometric Relief Package This package is useful when it is necessary to remove excess pressure from the conditioned space. NOTE: Optional economizer is required. SUGGESTED USE: When the job requires the ability to relieve internal building pressure. Power Exhaust Package This package is useful when it is necessary to remove excess pressure from the conditioned space. NOTE: Optional economizer is required. SUGGESTED USE: When the job requires the ability to relieve internal building pressure and pressure losses through the return-air ductwork are greater than 0.20 in. wg. When the job requires the ability to move large quantities of air to relieve pressure in the conditioned space. Winter Start Time Delay Relay Used in conjunction with accessory low-ambient kit or head pressure control device, permits operation in cooling at lower outdoor ambient temperatures. See Trade Prices for more details or contact your local representative. SUGGESTED USE: When job requires the ability to operate in cooling at low outdoor-ambient temperatures. LP Conversion Kit The natural gas to LP gas conversion kit contains burner orifaces, hardware, and labels necessary to convert unit for LP gas. SUGGESTED USE: When natural gas cannot be obtained. MODEL DESCRIPTION (ODS Model Number) LEGEND ODS Order Distribution System 3
UNIT 581A HEATING INPUT (Btuh) Stage 2/Stage 1 HEATING CAPACITIES AND EFFICIENCIES OUTPUT CAPACITY (Btuh) TEMPERATURE RISE (F) STEADY-STATE EFFICIENCY (%) MINIMUM HEATING CFM 155 230 230,000/172,000 186,300 15-45 81 3800 155 300 300,000/225,000 243,000 30-60 81 3800 180 275, 240 275 275,000/206,000 222,750 15-45 81 4750 180 360, 240 360 360,000/270,000 291,600 20-50 81 5450 NOTE: Minimum allowable temperature of mixed-air entering the heat exchanger during first-stage heating is 45 F. There is no minimum mixed-air temperature limitation during second-stage heating. CAPACITY RATINGS UNIT 581A NOMINAL NET COOLING TOTAL TONS CAPACITY (Btuh) kw EER IPLV 155 13 146,000 13.91 10.5 12.8 180 15 186,000 18.05 10.3 10.5 240 20 234,000 25.29 9.3 9.3 LEGEND ARI Air Conditioning and Refrigeration Institute db Dry Bulb EER Energy Efficiency Ratio IPLV Integrated Part-Load Values wb Wet Bulb NOTE: Rated in accordance with ARI Standards 360-96. Ratings are net values, reflecting the effects of circulating fan heat. Ratings are based on: Cooling Standard: 80 F db, 67 F wb indoor entering-air temperature and 95 F db air entering outdoor unit. IPLV Standard: 80 F db, 67 F wb indoor entering-air temperature and 80 F db outdoor entering-air temperature. 4
DIMENSIONAL DRAWING 581A155,180 UNIT MAXIMUM SHIPPING WEIGHT 581A Lb Kg 155 1800 816 180 2200 998 DIMENSIONS UNIT 581A X Y Ft-in. mm Ft-in. mm 155 3-2 965 4-0 1219 180 3-7 3 8 1102 3-6 5 8 1083 WEIGHT OF CORNER* UNIT 581A A B C D Lb Kg Lb Kg Lb Kg Lb Kg 155 384 174 370 168 358 162 538 244 180 519 235 516 234 485 220 529 240 *Weights are for unit only and do not include options or crating. NOTES: 1. Dimensions in ( ) are in millimeters. 2. Center of gravity. 3. Direction of airflow. 4. Ductwork to be attached to accessory roof curb only. 5. Minimum clearance: a. Rear: 7-0 (2134) for coil removal. This dimension can be reduced to 4-0 (1219) if conditions permit coil removal from the top. b. Left side: 4-0 (1219) for proper condenser coil airflow. c. Front: 4-0 (1219) for control box access. d. Right side: 4-0 (1219) for proper operation of damper and power exhaust (if so equipped). e. Top: 6-0 (1829) to assure proper condenser fan operation. f. Local codes or jurisdiction may prevail. 6. With the exception of clearance for the condenser coil and the damper/power exhaust as stated in Note No. 5, a removable fence or barricade requires no clearance. 7. Dimensions are from outside of corner post. Allow 0-5 16 (8) on each side for top cover drip edge. 8. Do not locate adjacent unit with flue discharge facing economizer inlet. 5
DIMENSIONAL DRAWING 581A240 MAXIMUM SHIPPING WEIGHT Lb Kg 2400 1089 NOTES: 1. Dimensions in ( ) are in millimeters. 2. Center of gravity. 3. Direction of airflow. 4. Ductwork to be attached to accessory roof curb only. 5. Minimum clearance: a. Rear: 7 0 (2134) for coil removal. This dimension can be reduced to 4 0 (1219) if conditions permit coil removal from the top. b. 4 0 (1219) to combustible surfaces, all four sides (includes between units). c. Left side: 4 0 (1219) for proper condenser coil airflow. d. Front: 4 0 (1219) for control box access. e. Right side: 4 0 (1219) for proper operation of damper and power exhaust (if so equipped). f. Top: 6 0 (1829) to assure proper condenser fan operation. g. Bottom: 14 (356) to combustible surfaces (when not using curb). h. Control box side: 3 0 (914) to ungrounded surfaces (non-combustible). i. Control box side: 3 6 (1067) to block or concrete walls, or other grounded surfaces. j. Local codes or jurisdiction may prevail. 6. With the exception of clearance for the condenser coil and the damper/power exhaust as stated in Note No. 5, a removable fence or barricade requires no clearance. 7. Dimensions are from outside of corner post. Allow 0-5 16 (8) on each side for top cover drip edge. 8. Do not locate adjacent units with flue discharge facing economizer inlet. CORNER WEIGHT* A B C D Lb Kg Lb Kg Lb Kg Lb Kg 527 239 545 247 578 262 600 272 *Weights are for unit only and do not include options or crating. 6
DIMENSIONAL DRAWING HORIZONTAL AND VERTICAL ROOF CURBS AND HORIZONTAL ADAPTER NOTE: To prevent the hazard of stagnant water build-up in the drain pan of the indoor-air section, unit can only be pitched as shown. LEGEND COMPR SECT. Compressor Section NOTES: 1. Roof curb accessory is shipped unassembled. 2. Insulated panels, 1 2-in. thick neoprene-coated, 2 lb density. 3. Dimensions in ( ) are in millimeters. 4. Direction of airflow. 5. Roof curb: 16 gage steel. 6. Attach all ductwork to roof curb. 7. Field installation of sidewall insulation is mandatory. ACCESSORY PACKAGE NO. 308450-201 308450-202 308450-203 389210-201 CURB HEIGHT DESCRIPTION A B C D E 1-2 Standard Curb 5-7 1 16 1-7 13 16 (355) 14 High (1703) (503) 2-0 Standard Curb for Units Requiring 5-7 1 16 1-7 13 16 (610) High Installation (1703) (503) 2-0 (610) 1-11 (584) Horizontal Supply and Return Curb Pre-Assembled, High-Static, Horizontal Adapter 5-7 1 16 (1703) 5-7 1 16 (1703) 1-7 13 16 (503) 1-7 13 16 (503) 5-6 (1676) 6-2 (1880) 0-2 1 2 (64) 0-6 1 4 (159) 1-6 (457) 1-2 5 8 (371) 7
DIMENSIONAL DRAWING HORIZONTAL ADAPTER INSTALLATION NOTES: 1. The 389210-201 is a fully factory-preassembled horizontal adapter which include an insulated high-static regain transition duct to substantially improve fan static performance. 2. Power exhaust and barometric relief accessories cannot be used with factory pre-assembled, high-static, horizontal adapters. 8
SPECIFICATIONS UNIT SIZE 581A 155 180 240 NOMINAL CAPACITY (tons) 13 15 20 OPERATING WEIGHT (lb) Unit Al/Al* 1650 2050 2250 Al/Cu* 1800 2200 2400 Cu/Cu* 1930 2330 2530 Economizer 110 110 110 Roof Curb 200 200 200 COMPRESSOR Semi-Hermetic Type 06D328 06D818 06D824 Quantity 1 2 2 Cylinders 6 4 6 REFRIGERANT TYPE R-22 Expansion Device TXV Acutrol Feed Device Quantity (lb) System 1 22.50 14.25 17.50 System 2 15.00 17.00 CONDENSER COIL 3 8-in. Enhanced Copper Tubes, Aluminum Lanced or Copper Plate Fins Rows...Fins/in. 3...15 4...15 4...15 Total Face Area (sq ft) 22.2 22.2 22.2 CONDENSER FAN Propeller Type Nominal Cfm 10,500 14,200 Quantity...Diameter (in.) 3...22 2...30 Motor Hp...Rpm 1 2...1075 1...1075 Watts Input (Total) 1090 3400 EVAPORATOR COIL 3 8-in. Enhanced Copper Tubes, Aluminum or Copper Plate Fins Rows...Fins/in. 2...17 3...15 4...15 Total Face Area (sq ft) 17.9 17.9 17.9 EVAPORATOR FAN Centrifugal Type Quantity...Size (in.) 2...10 x 10 2...12 x 12 2...12 x 12 Type Drive Belt Belt Belt Nominal Cfm 5000 6000 8000 Motor Hp 3.7 5 10 Maximum Continuous Bhp 4.25 5.90 10.2 [208/230 v] 11.8 [460 v] Motor Frame Size 56H 184T 215T Fan Rpm Range 862-1132 737-885 983-1180 Motor Bearing Type Ball Ball Ball Maximum Allowable Rpm 1550 1550 1550 Motor Pulley Pitch Diameter Min/Max (in.) 3.1/4.1 3.7/4.7 4.9/5.9 Nominal Motor Shaft Diameter (in.) 7 8 1 1 8 1 3 8 Fan Pulley Pitch Diameter (in.) 6.0 9.4 8.6 Nominal Fan Shaft Diameter (in.) 1 3 16 1 7 16 1 7 16 Belt, Quantity...Type...Length (in.) 1...BX...42 1...BX...48 2...BX...50 Pulley Center Line Distance (in.) 13.5-15.5 13.3-14.8 14.6-15.4 Speed Change per Full Turn of 54 36 39 Movable Pulley Flange (rpm) Movable Pulley Maximum Full Turns From Closed Position 6 6 6 Factory Setting 3 3 3 Factory Speed Setting (rpm) 1024 826 1101 Fan Shaft Diameter at Pulley (in.) 1 3 16 1 7 16 1 7 16 LEGEND Al Aluminum Bhp Brake Horsepower Cu Copper TXV Thermostatic Expansion Valve (Table continued on next page.) *Evaporator coil fin material/condenser coil fin material. Weight of 14-in. roof curb. **Rollout switch is manual reset. NOTE: The 581A units have a low-pressure switch (standard) located on the suction side. 9
SPECIFICATIONS (cont) UNIT SIZE 581A 155 180 240 FURNACE SECTION Low Heat High Heat Low Heat High Heat Low Heat High Heat Rollout Switch Cutout Temp (F)** 190 190 190 190 190 190 Burner Orifice Diameter (in....drill size) Natural Gas 0.1405...28 0.136...29 0.1405...28 0.136...29 0.1405...28 0.136...29 Thermostat Heat Anticipator Setting (amps) 208/230 v Stage 1 0.98 0.98 0.98 0.98 0.98 0.98 Stage 2 0.44 0.44 0.44 0.44 0.44 0.44 460 v Stage 1 0.80 0.80 0.80 0.80 0.80 0.80 Stage 2 0.44 0.44 0.44 0.44 0.44 0.44 Gas Input (Btuh) Stage 1 172,000 225,000 206,000 270,000 206,000 270,000 Stage 2 230,000 300,000 275,000 360,000 275,000 360,000 Efficiency (Steady State) (%) 81 81 81 81 81 81 Temperature Rise Range 15-45 30-60 15-45 20-50 15-45 20-50 Manifold Pressure (in. wg) Natural Gas 3.3 3.3 3.3 3.3 3.3 3.3 Gas Valve Quantity 1 1 1 1 1 1 Field Gas Connection Size (in.) 3 4 3 4 3 4 3 4 3 4 3 4 HIGH-PRESSURE SWITCH (psig) Standard Compressor Internal Relief Cutout 426 Reset (Auto.) 320 LOW-PRESSURE SWITCH (psig) Cutout 7 Reset (Auto.) 22 FREEZE PROTECTION THERMOSTAT (F) Opens 30±5 Closes 45±5 OUTDOOR-AIR INLET SCREENS Cleanable Quantity...Size (in.) 2...20 x 25 x 1 1...20 x 20 x 1 RETURN-AIR FILTERS Throwaway Quantity...Size (in.) 4...20 x 20 x 2 4...16 x 20 x 2 LEGEND Al Aluminum Bhp Brake Horsepower Cu Copper *Evaporator coil fin material/condenser coil fin material. Weight of 14-in. roof curb. **Rollout switch is manual reset. NOTE: The 581A units have a low-pressure switch (standard) located on the suction side. 10
SELECTION PROCEDURE (with 581A240 275 example) I DETERMINE COOLING AND HEATING REQUIRE- MENTS AT DESIGN CONDITIONS: Given: Total Cooling Capacity Required...205,000 Btuh Sensible Heat Capacity...162,000 Btuh Required Heating Capacity...190,000 Btuh Condenser Entering Air Temperature...95F Evaporator Entering Air Temperature...80FEdb/ 67 F Ewb Evaporator Air Quantity...8000 cfm External Static Pressure... 1.30 in. wg Power Supply (V-Ph-Hz)...460-3-60 edb Entering dry bulb ewb Entering wet bulb II DETERMINE UNIT SIZE: Select unit based on cooling requirements. Enter Gross Cooling Capacities tables on pages 12-14 at condenser entering temperature of 95 F, evaporator air entering at 8000 cfm and 80 F db and 67 F wb. The 581A240 275 unit will provide a gross cooling capacity of 254,000 Btuh and a sensible heat capacity of 193,800 Btuh. For evaporator air temperatures other than 80 F, calculate sensible heat capacity correction, using the formula found in Note 3 following the Gross Cooling Capacities tables. NOTE: Unit ratings are gross capacities and do not include the effect of evaporator-fan motor heat. To calculate net capacities, see Step V. III SELECT HEATING CAPACITY OF UNIT TO PROVIDE DESIGN CONDITION REQUIREMENTS: In the Heating Capacities table on page 4, note that unit 581A240 275 will provide output capacity of 222,750 Btuh, which is adequate for the given application. IV DETERMINE FAN SPEED AND POWER REQUIRE- MENTS AT DESIGN CONDITIONS: Before entering the Air Delivery tables on pages 15-17, calculate the total static pressure required based on unit components. From the given and the Pressure Drop table on page 18, find: External static pressure 1.30 in. wg Economizer 0.10 in. wg Total Static Pressure 1.40 in. wg Enter the Air Delivery table for standard 581A240 275 460-v unit at 8000 cfm and 1.40 in. wg external static pressure. Find that the rpm is 1409 and the bhp is 6.84. See the Air Delivery table on page 17. A field-supplied drive is required. V DETERMINE NET COOLING CAPACITY: Cooling capacities are gross capacities and do not include indoor (evaporator) fan motor (IFM) heat. Use the watts input power to the motor from the Air Delivery table. IFM Watts = 6297 Determine net capacity using the following formula: Net capacity = gross capacity IFM heat Btuh = 254,000 Btuh 6297 Watts (3.412 ) Watt = 254,000 Btuh 21,485 Btuh Net capacity = 232,515 Btuh Net sensible capacity = 193,800 21,485 Btuh Net sensible capacity = 172,315 Btuh The 581A240 275 is the correct selection for the given conditions. 11
581A155 (13 TON) Air Entering Evaporator Cfm BF 3750 0.06 4375 0.07 5000 0.08 5625 0.09 6250 0.10 GROSS COOLING CAPACITIES Air Entering Condenser (F) 75 85 95 Ewb Capacity MBtuh Compressor Capacity MBtuh Compressor Capacity MBtuh (F) Total Sensible kw Total Sensible kw Total Sensible 72 177.0 85.0 9.84 172.0 83.2 10.90 165.0 81.0 12.00 67 164.0 106.0 9.64 157.0 104.0 10.70 150.0 101.0 11.60 62 150.0 126.0 9.42 143.0 123.0 10.40 135.0 119.0 11.30 Compressor kw 72 181.0 88.0 9.91 175.0 87.0 11.00 168.0 85.0 12.10 67 167.0 113.0 9.69 161.0 111.0 10.70 154.0 108.0 11.80 62 154.0 136.0 9.51 147.0 132.0 10.50 139.0 129.0 11.40 72 184.0 92.2 10.00 177.0 89.8 11.00 170.0 89.4 12.10 67 169.0 123.0 9.74 165.0 118.0 10.80 157.0 115.0 11.80 62 157.0 145.0 9.56 150.0 142.0 10.50 142.0 139.0 11.60 72 185.0 94.3 10.00 180.0 95.5 11.10 172.0 93.2 12.20 67 172.0 125.0 9.81 166.0 125.0 10.90 159.0 122.0 11.90 62 160.0 152.0 9.63 153.0 150.0 10.60 146.0 146.0 11.60 72 186.0 96.1 10.00 180.0 97.4 11.10 175.0 97.0 12.30 67 173.0 134.0 9.84 167.0 133.0 10.90 160.0 128.0 12.00 62 162.0 159.0 9.66 155. 0 155.0 10.70 149.0 149.0 11.70 581A155 (13 TON) (cont) Air Entering Air Entering Condenser (F) Evaporator 105 115 125 Cfm BF Ewb Capacity MBtuh Compressor Capacity MBtuh Compressor Capacity MBtuh Compressor (F) Total Sensible kw Total Sensible kw Total Sensible kw 72 158.0 78.4 13.00 149.0 75.5 14.00 141.0 72.8 15.10 3750 0.06 67 143.0 98.2 12.70 134.0 94.8 13.60 123.0 90.6 14.60 62 126.0 115.0 12.20 113.0 109.0 13.20 102.0 102.0 14.20 72 160.0 82.2 13.10 153.0 79.7 14.20 144.0 77.3 15.20 4375 0.07 67 146.0 106.0 12.80 138.0 103.0 13.80 127.0 98.3 14.70 62 129.0 125.0 12.40 119.0 119.0 13.30 109.0 109.0 14.40 72 164.0 86.9 13.20 155.0 83.9 14.20 146.0 81.2 15.30 5000 0.08 67 149.0 113.0 12.90 140.0 110.0 13.80 131.0 106.0 14.80 62 134.0 134.0 12.50 125.0 125.0 13.50 116.0 116.0 14.60 72 164.0 90.9 13.30 155.0 87.9 14.20 148.0 85.6 15.40 5625 0.09 67 151.0 120.0 13.00 142.0 116.0 13.90 133.0 113.0 14.90 62 140.0 139.0 12.70 132.0 132.0 13.70 122.0 122.0 14.70 72 165.0 94.0 13.30 157.0 91.9 14.30 148.0 88.8 15.30 6250 0.10 67 152.0 125.0 13.00 143.0 121.0 13.90 134.0 118.0 14.90 62 143.0 143.0 12.80 136.0 136.0 13.80 129.0 129.0 14.80 LEGEND BF Bypass Factor Edb Entering Dry Bulb Ewb Entering Wet Bulb kw Compressor Motor Power Input MBtuh Btuh in thousands NOTES: 1. Direct interpolation is permissible. Do not extrapolate. 2. The following formulas may be used: t ldb = t edb sensible capacity (1000 x MBtuh) 1.10 x cfm t lwb = Wet-bulb temperature corresponding to enthalpy of air leaving evaporator coil (h lwb) total capacity (1000 x MBtuh) h lwb = h ewb 4.5 x cfm Where: hewb = Enthalpy of air entering evaporator coil. 3. The sensible heat capacity is based on 80 F entering dry-bulb (edb) temperature of air entering evaporator coil. Below 80 F edb, subtract (corr factor x cfm) from the sensible heat capacity. Above 80 F edb, add (corr factor x cfm) to the sensible heat capacity. Correction Factor = 1.10 x (1 BF) x (edb 80). 12
581A180 (15 TON) Air Entering Evaporator Cfm BF 4500 0.03 5250 0.03 6000 0.04 6750 0.05 7500 0.05 GROSS COOLING CAPACITIES (cont) Air Entering Condenser (F) 75 85 95 Ewb Capacity MBtuh Compressor Capacity MBtuh Compressor Capacity MBtuh (F) Total Sensible kw Total Sensible kw Total Sensible 72 224.0 108.0 12.94 216.0 105.0 14.34 206.0 101.2 15.64 67 206.0 133.2 12.62 196.2 129.6 13.94 186.4 125.6 15.16 62 186.2 156.2 12.26 177.0 153.0 13.48 167.6 148.8 14.70 Compressor kw 72 230.0 113.2 13.06 220.0 109.4 14.42 210.0 107.0 15.82 67 212.0 143.0 12.74 202.0 139.6 14.08 191.6 135.6 15.34 62 191.8 171.4 12.38 182.6 166.4 13.66 172.6 162.0 14.90 72 234.0 117.8 13.16 224.0 114.8 14.52 214.0 112.4 15.96 67 216.0 152.0 12.84 206.0 148.8 14.20 195.6 144.8 15.46 62 196.4 182.8 12.50 186.8 179.2 13.80 177.0 174.0 15.02 72 236.0 122.8 13.22 226.0 119.6 14.60 216.0 115.8 15.94 67 218.0 160.8 12.92 210.0 157.4 14.28 198.4 153.4 15.56 62 200.0 194.2 12.60 190.6 190.2 13.92 182.6 182.2 15.20 72 238.0 127.8 13.28 228.0 124.0 14.66 216.0 120.4 16.02 67 220.0 168.4 12.96 212.0 165.6 14.34 200.0 161.6 15.62 62 204.0 204.0 12.70 196.2 196.0 14.04 187.6 187.6 15.34 581A180 (15 TON) (cont) Air Entering Air Entering Condenser (F) Evaporator 105 115 125 Cfm BF Ewb Capacity MBtuh Compressor Capacity MBtuh Compressor Capacity MBtuh Compressor (F) Total Sensible kw Total Sensible kw Total Sensible kw 72 194.6 97.4 16.92 183.0 92.6 18.02 171.2 88.6 19.08 4500 0.03 67 176.4 121.8 16.38 166.4 117.6 17.48 155.8 113.0 18.42 62 156.8 143.6 15.84 149.0 140.0 16.86 139.4 135.4 17.84 72 198.4 102.0 17.02 186.4 97.6 18.18 172.6 92.2 19.16 5250 0.03 67 181.4 131.0 16.54 170.8 127.0 17.66 159.0 121.6 18.60 62 163.0 157.6 16.02 154.0 152.4 17.04 145.4 145.2 18.12 72 200.0 106.8 17.12 188.6 102.6 18.30 176.2 98.0 19.38 6000 0.04 67 184.8 140.6 16.70 173.4 136.0 17.80 161.4 129.8 18.74 62 168.2 168.2 16.22 160.0 160.0 17.34 151.4 151.2 18.40 72 202.0 111.8 17.22 190.8 107.6 18.40 178.2 103.0 19.50 6750 0.05 67 187.2 149.0 16.80 175.4 144.2 17.88 163.4 138.0 18.90 62 174.0 174.0 16.44 165.4 165.2 17.58 156.2 155.8 18.64 72 204.0 116.4 17.28 192.2 112.4 18.48 178.8 106.8 19.54 7500 0.05 67 188.8 157.2 16.86 177.0 151.8 17.98 164.8 145.4 18.98 62 179.0 178.8 16.60 169.6 169.4 17.74 159.6 159.6 18.82 LEGEND BF Bypass Factor Edb Entering Dry Bulb Ewb Entering Wet Bulb kw Compressor Motor Power Input MBtuh Btuh in thousands NOTES: 1. Direct interpolation is permissible. Do not extrapolate. 2. The following formulas may be used: t ldb = t edb sensible capacity (1000 x MBtuh) 1.10 x cfm t lwb = Wet-bulb temperature corresponding to enthalpy of air leaving evaporator coil (h lwb) total capacity (1000 x MBtuh) h lwb = h ewb 4.5 x cfm Where: hewb = Enthalpy of air entering evaporator coil. 3. The sensible heat capacity is based on 80 F entering dry-bulb (edb) temperature of air entering evaporator coil. Below 80 F edb, subtract (corr factor x cfm) from the sensible heat capacity. Above 80 F edb, add (corr factor x cfm) to the sensible heat capacity. Correction Factor = 1.10 x (1 BF) x (edb 80). 13
581A240 (20 TON) Air Entering Evaporator Cfm BF 6000 0.03 7000 0.04 8000 0.05 9000 0.05 10000 0.06 GROSS COOLING CAPACITIES (cont) Air Entering Condenser (F) 75 85 95 Ewb Capacity MBtuh Compressor Capacity MBtuh Compressor Capacity MBtuh (F) Total Sensible kw Total Sensible kw Total Sensible 72 290.0 142.6 17.12 280.0 139.2 18.78 268.0 135.0 20.40 67 264.0 176.2 16.56 254.0 172.0 18.16 242.0 167.2 19.68 62 242.0 208.0 16.08 228.0 202.0 17.52 214.0 196.0 18.96 Compressor kw 72 300.0 151.4 17.36 286.0 147.0 18.98 274.0 142.8 20.60 67 272.0 189.4 16.76 262.0 185.8 18.38 250.0 180.8 19.94 62 250.0 228.0 16.28 236.0 222.0 17.76 222.0 214.0 19.24 72 304.0 159.0 17.46 292.0 154.8 19.12 280.0 150.8 20.80 67 278.0 202.0 16.90 266.0 198.0 18.50 254.0 193.8 20.20 62 256.0 244.0 16.46 244.0 238.0 17.98 230.0 228.0 19.48 72 306.0 166.4 17.52 296.0 162.2 19.26 284.0 158.6 21.00 67 284.0 214.0 17.08 272.0 212.0 18.70 258.0 206.0 20.40 62 260.0 258.0 16.58 250.0 250.0 18.16 240.0 240.0 19.72 72 308.0 176.2 17.54 302.0 170.6 19.42 286.0 165.2 21.00 67 286.0 228.0 17.14 274.0 224.0 18.80 262.0 218.0 20.40 62 266.0 266.0 16.68 258.0 258.0 18.34 246.0 246.0 19.94 581A240 (20 TON) (cont) Air Entering Evaporator Cfm BF 6000 0.03 7000 0.04 8000 0.05 9000 0.05 10000 0.06 Air Entering Condenser (F) 105 115 125 Ewb Capacity MBtuh Compressor Capacity MBtuh Compressor Capacity MBtuh (F) Total Sensible kw Total Sensible kw Total Sensible 72 256.0 130.2 22.00 240.0 125.6 23.60 224.0 119.8 25.00 67 226.0 161.2 21.20 210.0 154.6 22.60 193.8 148.2 24.20 62 199.6 189.0 20.40 185.0 181.2 21.80 170.4 170.4 23.40 Compressor kw 72 260.0 139.6 22.20 246.0 133.8 23.80 230.0 128.4 25.40 67 234.0 174.8 21.40 218.0 168.6 23.00 199.2 161.8 24.40 62 208.0 206.0 20.80 194.8 194.6 22.20 181.0 181.0 23.80 72 264.0 146.4 22.40 252.0 141.8 24.00 236.0 136.8 25.60 67 238.0 188.0 21.60 222.0 181.6 23.20 204.0 174.8 24.60 62 218.0 218.0 21.00 206.0 206.0 22.60 192.4 192.4 24.20 72 268.0 154.2 22.60 256.0 149.8 24.20 238.0 144.4 25.80 67 242.0 200.0 21.80 226.0 194.4 23.40 210.0 188.0 24.80 62 228.0 228.0 21.20 214.0 214.0 22.80 200.0 200.0 24.40 72 272.0 161.4 22.60 256.0 157.0 24.20 240.0 152.0 25.80 67 246.0 212.0 22.00 230.0 206.0 23.40 214.0 199.4 24.80 62 236.0 234.0 21.60 222.0 222.0 23.00 208.0 208.0 24.80 LEGEND BF Bypass Factor Edb Entering Dry Bulb Ewb Entering Wet Bulb kw Compressor Motor Power Input MBtuh Btuh in thousands NOTES: 1. Direct interpolation is permissible. Do not extrapolate. 2. The following formulas may be used: t ldb = t edb sensible capacity (1000 x MBtuh) 1.10 x cfm t lwb = Wet-bulb temperature corresponding to enthalpy of air leaving evaporator coil (h lwb) total capacity (1000 x MBtuh) h lwb = h ewb 4.5 x cfm Where: hewb = Enthalpy of air entering evaporator coil. 3. The sensible heat capacity is based on 80 F entering dry-bulb (edb) temperature of air entering evaporator coil. Below 80 F edb, subtract (corr factor x cfm) from the sensible heat capacity. Above 80 F edb, add (corr factor x cfm) to the sensible heat capacity. Correction Factor = 1.10 x (1 BF) x (edb 80). 14
581A155 (13 TON) Airflow (Cfm) AIR DELIVERY Standard Belt-Drive Motor External Static Pressure (in. wg) 0.2 0.4 0.6 0.8 1.0 Rpm Watts Bhp Rpm Watts Bhp Rpm Watts Bhp Rpm Watts Bhp Rpm Watts Bhp 3750 741 510 0.58 854 715 0.82 952 921 1.05 1041 1130 1.29 1124 1344 1.53 4000 773 647 0.74 882 859 0.98 978 1071 1.22 1064 1285 1.46 1145 1502 1.71 4250 806 796 0.91 912 1015 1.16 1004 1233 1.40 1089 1452 1.65 1167 1674 1.91 4500 839 958 1.09 942 1183 1.35 1032 1407 1.60 1114 1632 1.86 1191 1859 2.12 4750 873 1134 1.29 972 1365 1.56 1060 1595 1.82 1140 1825 2.08 1215 2056 2.34 5000 908 1323 1.51 1003 1560 1.78 1089 1796 2.05 1167 2032 2.32 1241 2268 2.58 5250 942 1527 1.74 1035 1769 2.02 1118 2011 2.29 1195 2252 2.57 1267 2494 2.84 5500 978 1745 1.99 1067 1992 2.27 1148 2240 2.55 1223 2487 2.83 1293 2733 3.11 5750 1013 1978 2.25 1099 2230 2.54 1179 2484 2.83 1252 2736 3.12 1321 2988 3.40 6000 1049 2227 2.54 1132 2483 2.83 1210 2742 3.12 1282 2999 3.42 1349 3257 3.71 6250 1085 2491 2.84 1166 2751 3.13 1241 3015 3.44 1312 3279 3.74 1378 3541 4.03 581A155 (13 TON) (cont) Airflow (Cfm) Standard Belt-Drive Motor External Static Pressure (in. wg) 1.2 1.4 1.6 1.8 2.0 Rpm Watts Bhp Rpm Watts Bhp Rpm Watts Bhp Rpm Watts Bhp Rpm Watts Bhp 3750 1203 1562 1.78 1277 1784 2.03 1349 2010 2.29 1417 2240 2.55 1483 2473 2.82 4000 1222 1724 1.96 1294 1950 2.22 1364 2180 2.48 1431 2413 2.75 1495 2650 3.02 4250 1242 1900 2.16 1313 2129 2.43 1381 2362 2.69 1446 2599 2.96 1509 2839 3.23 4500 1264 2089 2.38 1333 2322 2.65 1399 2558 2.91 1463 2799 3.19 1525 3042 3.47 4750 1286 2290 2.61 1354 2528 2.88 1419 2769 3.15 1482 3012 3.43 1542 3259 3.71 5000 1310 2507 2.86 1376 2748 3.13 1440 2992 3.41 1501 3240 3.69 1560 3489 3.98 5250 1335 2737 3.12 1399 2983 3.40 1461 3230 3.68 1522 3481 3.97 5500 1360 2981 3.40 1423 3231 3.68 1484 3483 3.97 1543 3737 4.26 5750 1386 3241 3.69 1448 3495 3.98 1508 3750 4.27 6000 1413 3514 4.00 1474 3773 4.30 1532 4032 4.59 6250 1440 3803 4.33 1500 4066 4.63 1558 4330 4.93 LEGEND Bhp Brake Horsepower Input to Fan FIOP Factory-Installed Option Watts Input Watts to Motor NOTES: 1. Boldface indicates field-supplied drive required. 2. Indicates field-supplied motor and drive required. 3. indicates maximum bhp/watts of standard motor and drive. 4. Factory shipped motor drive range is 862 to 1132 rpm. Other rpms require a field-supplied drive. 5. Static pressure losses (i.e., economizer) must be added to external static pressure before entering Air Delivery table. See page 18 for accessory/fiop static pressure information. 6. Interpolation is permissible. Do not extrapolate. 7. Maximum continuous bhp is 4.25 and the maximum continuous watts are 3775. Extensive motor and drive testing on these units ensures that the full horsepower range of the motor can be utilized with confidence. Using your fan motors up to the wattage ratings shown will not result in nuisance tripping or premature motor failure. Unit warranty will not be affected. 15
581A180 (15 TON) Airflow (Cfm) AIR DELIVERY (cont) Standard Belt-Drive Motor External Static Pressure (in. wg) 0.2 0.4 0.6 0.8 1.0 Rpm Watts Bhp Rpm Watts Bhp Rpm Watts Bhp Rpm Watts Bhp Rpm Watts Bhp 4500 630 805 0.9 741 1059 1.2 846 1341 1.5 945 1653 1.9 1039 1993 2.2 4800 659 943 1.1 765 1208 1.4 865 1497 1.7 961 1816 2.0 1052 2163 2.4 5100 688 1094 1.2 789 1371 1.5 885 1668 1.9 977 1993 2.2 1064 2345 2.6 5400 717 1262 1.4 814 1550 1.7 907 1856 2.1 994 2187 2.4 1079 2546 2.8 5700 748 1450 1.6 842 1752 2.0 930 2067 2.3 1015 2406 2.7 1096 2770 3.1 6000 776 1648 1.8 867 1963 2.2 952 2289 2.6 1034 2635 2.9 1112 3004 3.4 6300 804 1861 2.1 892 2190 2.5 975 2526 2.8 1053 2880 3.2 1129 3256 3.6 6600 835 2103 2.4 919 2445 2.7 1000 2793 3.1 1076 3156 3.5 1149 3540 4.0 6900 863 2356 2.6 946 2712 3.0 1024 3072 3.4 1098 3445 3.9 1169 3835 4.3 7200 892 2628 2.9 972 2998 3.4 1049 3371 3.8 1120 3754 4.2 1189 4152 4.6 7500 923 2933 3.3 1001 3318 3.7 1076 3704 4.1 1146 4098 4.6 1213 4506 5.0 581A180 (15 TON) (cont) Airflow (Cfm) Standard Belt-Drive Motor External Static Pressure (in. wg) 1.2 1.4 1.6 1.8 2.0 Rpm Watts Bhp Rpm Watts Bhp Rpm Watts Bhp Rpm Watts Bhp Rpm Watts Bhp 4500 1128 2355 2.6 1211 2734 3.1 1289 3127 3.5 1363 3531 4.0 1433 3944 4.4 4800 1138 2533 2.8 1219 2921 3.3 1297 3325 3.7 1370 3742 4.2 1440 4170 4.7 5100 1148 2722 3.0 1228 3119 3.5 1305 3532 4.0 1377 3961 4.4 1447 4400 4.9 5400 1160 2928 3.3 1238 3332 3.7 1313 3755 4.2 1385 4192 4.7 1454 4643 5.2 5700 1175 3158 3.5 1251 3569 4.0 1324 3999 4.5 1395 4445 5.0 1462 4906 5.5 6000 1188 3398 3.8 1262 3814 4.3 1334 4250 4.8 1403 4704 5.3 1470 5173 5.8 6300 1203 3654 4.1 1275 4075 4.6 1344 4517 5.1 1412 4976 5.6 1478 5453 6.1 6400 1221 3944 4.4 1290 4370 4.9 1358 4817 5.4 1424 5283 5.9 1489 5765 6.5 6900 1238 4245 4.8 1305 4676 5.2 1371 5128 5.7 1436 5598 6.3 1499 6087 6.8 7200 1256 4569 5.1 1322 5006 5.6 1386 5463 6.1 1449 5938 6.6 1509 6420 7.2 7500 1278 4930 5.5 1341 5373 6.0 1403 5835 6.5 1465 6316 7.1 1515 6733 7.5 LEGEND Bhp Brake Horsepower Input to Fan FIOP Factory-Installed Option Watts Input Watts to Motor NOTES: 1. Boldface indicates field-supplied drive required. 2. Indicates field-supplied motor and drive required. 3. indicates maximum bhp/watts of standard motor and drive. 4. Factory shipped motor drive range is 737 to 885 rpm. Other rpms require a field-supplied drive. 5. Static pressure losses (i.e., economizer) must be added to external static pressure before entering Air Delivery table. See page 18 for accessory/fiop static pressure information. 6. Interpolation is permissible. Do not extrapolate. 7. Maximum continuous bhp is 5.9, and the maximum continuous watts are 5180. Extensive motor and drive testing on these units ensures that the full horsepower range of the motor can be utilized with confidence. Using your fan motors up to the wattage ratings shown will not result in nuisance tripping or premature motor failure. Unit warranty will not be affected. 16
AIR DELIVERY (cont) 581A240 (20 TON) Standard Belt-Drive Motor Airflow External Static Pressure (in. wg) (Cfm) 0.2 0.4 0.6 0.8 1.0 Rpm Watts Bhp Rpm Watts Bhp Rpm Watts Bhp Rpm Watts Bhp Rpm Watts Bhp 6000 800 1732 1.88 891 2047 2.22 975 2376 2.58 1055 2728 2.96 1133 3104 3.37 6500 853 2134 2.32 939 2471 2.68 1018 2819 3.06 1094 3185 3.46 1167 3573 3.88 7000 907 2596 2.82 989 2957 3.21 1064 3324 3.61 1136 3707 4.02 1205 4107 4.46 7500 962 3123 3.39 1039 3507 3.81 1111 3895 4.23 1179 4295 4.66 1245 4710 5.11 8000 1017 3717 4.04 1091 4126 4.48 1160 4536 4.93 1225 4954 5.38 1287 5386 5.85 8500 1072 4385 4.76 1143 4818 5.23 1209 5250 5.70 1271 5688 6.18 1332 6137 6.66 9000 1128 5129 5.57 1196 5587 6.07 1260 6042 6.56 1323 6501 7.06 1377 6968 7.57 9500 1185 5955 6.47 1250 6437 6.99 1311 6915 7.51 1369 7395 8.03 1424 7881 8.56 10000 1241 6865 7.45 1304 7372 8.00 1363 7873 8.65 1419 8376 9.09 1472 8882 9.64 581A240 (20 TON) (cont) Standard Belt-Drive Motor Airflow External Static Pressure (in. wg) (Cfm) 1.2 1.4 1.6 1.8 2.0 Rpm Watts Bhp Rpm Watts Bhp Rpm Watts Bhp Rpm Watts Bhp Rpm Watts Bhp 6000 1208 3504 3.80 1282 3926 4.26 1353 4368 4.74 1421 4826 5.24 1488 5299 5.75 6500 1239 3983 4.32 1308 4415 4.79 1376 4866 5.28 1442 5337 5.79 1507 5823 6.32 7000 1273 4529 4.92 1339 4970 5.40 1403 5432 5.90 1467 5911 6.42 1520 6339 6.88 7500 1309 5143 5.58 1372 5597 6.08 1434 6067 6.59 1494 6558 7.12 1548 7014 7.62 8000 1349 5833 6.33 1409 6297 6.84 1467 6779 7.36 1529 7313 7.94 8500 1390 6600 7.17 1447 7077 7.68 1504 7571 8.22 9000 1433 7446 8.08 1488 7938 8.62 9500 1478 8378 9.10 10000 1524 9396 10.20 LEGEND Bhp Brake Horsepower Input to Fan FIOP Factory-Installed Option Watts Input Watts to Motor NOTES: 1. Boldface indicates field-supplied drive required. 2. indicates maximum bhp/watts of standard motor and drive. 3. Factory shipped motor drive range is 983 to 1180 rpm. Other rpms require a field-supplied drive. 4. Static pressure losses (i.e., economizer) must be added to external static pressure before entering Air Delivery table. See page 18 for accessory/fiop static pressure information. 5. Interpolation is permissible. Do not extrapolate. 6. Maximum continuous bhp is 10.2 for 208/230-v units and 11.8 for 460-v units. The maximum continuous watts are 9510 for the 208/ 230-v units and 11,000 for the 460-v unit. Extensive motor and drive testing on these units ensures that the full horsepower range of the motor can be utilized with confidence. Using your fan motors up to the wattage ratings shown will not result in nuisance tripping or premature motor failure. Unit warranty will not be affected. NOTE: The 389210-201 high static regain adapter accessory may be used to provide horizontal supply/return. NOTE: The 389210-201 horizontal supply/return adapter accessory improves 581A fan performance by increasing external static pressure by amount shown above. Horizontal Supply/Return Fan Performance With 389210-201 High Static Regain Adapter 17
Fan Performance Using Accessory Power Exhaust UNIT 581A SOUND RATING-BELS (60 Hz) A-WEIGHTED (db) SOUND POWER (Total Unit) OCTAVE BANDS 63 125 250 500 1000 2000 4000 8000 155 8.8 87.3 87.1 89.9 86.4 84.0 82.7 79.0 73.9 68.6 180 8.9 88.0 95.7 88.9 87.2 85.2 91.9 79.5 72.7 66.0 240 9.5 94.1 90.6 87.2 89.9 86.2 85.8 81.0 75.6 69.6 BELS Sound Levels (1 bel = 10 decibels) NOTE: All values are in db unless otherwise noted. AIR QUANTITY LIMITS UNIT 581A MINIMUM CFM MAXIMUM CFM 155 3800 6,250 180 4750 7,500 240 5450 10,000 ACCESSORY/FIOP ECONOMIZER STATIC PRESSURE (in. wg) UNIT 581A UNIT VOLTAGE 155,180 All 240 All CFM ECONOMIZER PRESSURE DROP 3,750.03 4,000.03 5,000.05 6,000.07 7,500.10 6,000.07 7,200.09 9,000.11 10,000.12 LEGEND FIOP Factory-Installed Option NOTES: 1. The factory-assembled horizontal adapter substantially improves fan performance. See graph on page 17. 2. The static pressure must be added to external static pressure. The sum and the evaporator entering-air cfm should then be used in conjunction with the Air Delivery table to determine blower rpm, bhp, and watts. 18
UNIT 581A FAN RPM AT MOTOR PULLEY SETTINGS* (FACTORY-SUPPLIED DRIVES) MOTOR PULLEY TURNS OPEN 0 1 2 1 1 1 2 2 2 1 2 3 3 1 2 4 4 1 2 5 5 1 2 6 155 1132 1105 1078 1051 1024 997 970 943 916 889 862 180 885 870 855 840 826 811 796 781 766 751 737 240 1180 1160 1141 1121 1101 1082 1062 1043 1023 1003 983 *Approximate fan rpm shown. Due to belt and pulley size, pulley cannot be set to this number of turns open. NOTE: To run units at speeds not listed, field-supplied drives are required. UNIT 581A 155 180 240 NOMINAL VOLTAGE (3 Ph, 60 Hz) VOLTAGE COMPRESSOR RANGE OFM No. 1 No. 2 Min Max RLA LRA RLA LRA Qty FLA (ea) ELECTRICAL DATA LRA (ea) 208/230 187 254 39.7 228 3 1.7 3.8 3.7 10.5/10.5 84.5/84.5 460 414 508 19.9 114 3 0.8 1.9 3.7 4.8 42.3 208/230 187 254 28.2 160 28.2 160 3 1.7 24.8 5 15.8/15.8 105/91 460 414 508 14.1 80 14.1 80 3 0.8 10.8 5 7.9 46 208/230 187 254 35.6 198 35.6 198 2 5.5 24.8 10 28.0/28.0 193/168 460 414 508 17.8 99 17.8 99 2 2.8 10.8 10 14.6 84 IFM POWER EXHAUST COMBUSTION FAN MOTOR POWER SUPPLY DISCONNECT SIZE Hp FLA LRA FLA LRA FLA MCA MOCP* FLA LRA 0.57 65/65 100/100 64/64 324/324 4.6 18.8 0.57 70/70 100/100 70/70 343/343 0.30 32 50 32 162 2.3 6.0 0.30 34 50 34 168 0.57 84/84 110/100 90/90 499/485 4.6 18.8 0.57 89/89 110/110 95/95 518/504 0.30 42 50 45 238 2.3 6.0 0.30 44 50 47 244 0.57 119/119 150/150 127/127 639/614 4.6 18.8 0.57 124/124 150/150 133/133 657/632 0.30 60 70 65 304 2.3 6.0 0.30 63 80 67 310 LEGEND FLA Full Load Amps HACR Heating, Air Conditioning and Refrigeration IFM Indoor (Evaporator) Fan Motor LRA Locked Rotor Amps MCA Minimum Circuit Amps MOCP Maximum Overcurrent Protection NEC National Electrical Code OFM Outdoor (Condenser) Fan Motor RLA Rated Load Amps *This is the maximum size permissible; smaller fuse size may be used where conditions permit. NOTES: In compliance with NEC requirements for multimotor and combination load equipment (refer to NEC Articles 430 and 440), the overcurrent protective device for the unit shall be fuse or HACR breaker. The Canadian units may be fuse or circuit breaker. 19
OPERATING SEQUENCE Cooling, Units Without Economizer When thermostat calls for cooling, terminals G and Y1 are energized. The indoor (evaporator) fan contactor (IFC) and compressor contactor no. 1 (C1) are energized and evaporator-fan motor (IFM), compressor no. 1 (180,240) or unloaded compressor (155), and condenser fan start. The condenser-fan motors run continuously while unit is cooling. If the thermostat calls for a second stage of cooling by energizing Y2, compressor contactor no. 2 (C2) is energized and compressor no. 2 starts (180,240), or compressor no. 1 runs fully loaded (155). A freeze protection thermostat (FPT) is located on the evaporator coil. It detects frost build-up and locks out the compressors, allowing the coil to clear. Once frost has melted, the compressors can be reenergized by resetting the thermostat. Heating, Units Without Economizer NOTE: The 581A units have 2 stages of heat. When the thermostat calls for heating, power is sent to W on the IGC (integrated gas unit controller) board. An LED (lightemitting diode) on the IGC board will be on during normal operation. A check is made to ensure that the rollout switch and limit switch are closed. The induced-draft motor is then energized, and when speed is proven with the hall effect sensor on the motor, the ignition activation period begins. The burners will ignite within 5 seconds. If the burners do not light, there is a 22-second delay before another 5-second attempt. If the burners still do not light, this sequence is repeated for 15 minutes. After the 15 minutes have elapsed, if the burners still have not lighted, heating is locked out. To reset the control, break 24-v power to the thermostat. When ignition occurs the IGC board will continue to monitor the condition of the rollout and limit switches, the hall effect sensor, as well as the flame sensor. If the unit is controlled through a room thermostat set for fan auto., 45 seconds after ignition occurs, the indoor-fan motor will be energized. If for some reason the overtemperature limit opens prior to the start of the indoor fan blower, on the next attempt, the 45-second delay will be shortened to 5 seconds less than the time from initiation of heat to when the limit tripped. Gas will not be interrupted to the burners and heating will continue. Once modified, the fan on delay will not change back to 45 seconds unless power is reset to the control. When additional heat is required, W2 closes and initiates power to the second stage of the main gas valve. When the thermostat is satisfied, W1 and W2 open and the gas valve closes, interrupting the flow of gas to the main burners. If the call for W1 lasted less than 1 minute, the heating cycle will not terminate until 1 minute after W1 became active. If the unit is controlled through a room thermostat set for fan auto., the indoor-fan motor will continue to operate for an additional 45 seconds then stop. If the overtemperature limit opens after the indoor motor is stopped within 10 minutes of W1 becoming inactive, on the next cycle the time will be extended by 15 seconds. The maximum delay is 3 minutes. Once modified, the fan off delay will not change back to 45 seconds unless power is reset to the control. A LED indicator is provided on the IGC to monitor operation. The IGC is located by removing the side panel and viewing the IGC through the view port located in the control box access panel. During normal operation, the LED is continuously on. The LED on the IGC board can be viewed without removing the control box cover. The IGC board is located to the left of the view port. Cooling, Units With Economizer Upon a call for cooling, when outdoor ambient is above the changeover control setting, the economizer damper moves to VENT position. The compressors and evaporator and condenser fans energize and operate as per Cooling, Units Without Economizer section. Upon a first call for cooling, when outdoor ambient is below the changeover control setting, the evaporator fan starts and the economizer is fully open. The compressors remain off. Upon a second-stage call for cooling, compressor no. 1 (180,240) or unloaded compressor (155) is energized and mechanical cooling is integrated with economizer cooling. If the outdoor-air temperature drops below 50 F, a cooling lockout switch prevents the compressors from running. When supply-air temperature drops below a fixed set point, the economizer damper modulates to maintain the temperature at the fixed set point. Heating, Units With Economizer Outdoor-air damper stays at VENT position while evaporator fan is operating. Refer to Heating, Units Without Economizer section for heating sequence of operation. 20