CL SERIES ROOFTOP CONDENSING UNITS INSTALLATION, SERVICE & OWNER’S INFORMATION MANUAL
TABLE OF CONTENTS SECTION Page GENERAL DESCRIPTION………………………………………………………………………………………………… 04 Unpacking………………………………………………………………………………………………………….. 04 OWNER’S INFORMATION………………………………………………………………………...................................... 04 Wiring Diagrams……………………………………………………………………................................................ 04 General Maintenance……………………………………………………………………………………………….. 05 INSTALLATION…………………………………………………………………………….…………………………….... 05 Lifting and Handling……………………………………….……………………………………………………….
It is the intent of AAON, Inc. to provide accurate and current specification information. However, in the interest of product improvement, AAON, Inc. reserves the right to change pricing, specifications, and/or design of its products without notice, obligation or liability © 2007 AAON, Inc., all rights reserved throughout the world. AAON & AAONAIRE are registered trademarks of AAON, Inc., Tulsa, OK. R10110 · Rev.
GENERAL DESCRIPTION All AAON 'CL Series' condensers are factory assembled, wired, and charged with 15 lbs. of refrigerant per system. Models are available for air-cooled and evaporative-cooled applications. Unpacking: 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.
OWNER'S INFORMATION cont. General Maintenance: When the initial startup is made and on a periodic schedule during operation, it is necessary to perform routine service checks on the performance of the condenser. This includes reading and recording suction pressures and checking for normal sub-cooling and superheat. See the evaporative-cooled condenser and aircooled condenser sections in this manual for specific details.
INSTALLATION cont. low, there will be insufficient pressure to operate the expansion valve properly. During low ambient temperatures, it is difficult to start a system because the refrigerant will migrate to the cold part of the system (condenser) and make it difficult for refrigerant to flow.
INSTALLATION cont. OROA Valve: This system uses a nonadjustable head pressure control valve that performs the function of limiting the flow of liquid refrigerant from the condenser and at the same time regulates the flow of the hot gas around the condenser to the receiver. The valve setpoint is 180 psig. This valve is called an OROA valve (Open on Rise of Outlet pressure). The following schematic shows an example system using the OROA valve. Piping Schematic of Example system using the OROA valve.
INSTALLATION cont. Piping Schematic of Example system using the ORI/ORD valve. The pressure setting of the ORI valve determines how well the system will operate. The proper setting is a function of the specific system in which is installed. Generally, the setting should be equivalent to a condensing temperature of 90°F to 100°F or a receiver pressure equivalent to a temperature of 80°F to 90°F.
INSTALLATION cont. During higher ambient temperatures the entire condenser is required to condense refrigerant. During these higher ambient temperatures, a receiver tank is used to contain the refrigerant that was required to flood the condenser during low ambient operation. The receiver must be sized to contain all of the flooded volume otherwise there will be high head pressures during higher ambient conditions.
Diagram of Evaporative-cooled condenser Section including field water connections and base cutout tap 10
STARTUP Pre-Startup: After the installation and immediately before the startup of the condenser be sure that these items have been checked. 1. Verify that electrical power is available to the unit. 2. Verify that any remote stop/start device is requesting the condenser to start. While performing the Startup, use the Condensing Startup Form at the back of this booklet to record motor amps and any other comments.
STARTUP cont. Step 2. Find Blade Pitch Angle: ( 20, 25, 27.5, 30, 32.5, 35, 37.5, 40, 45 or 50 ) • Carefully disassemble fan on flat surface and note in which groove the pin is located. Refer to groove number code diagram. • Using diagrams in step 5, determine if the pin was in the hub (HUB) or retainer side (RET) of fan. • Using table in step 4, find the possible blade pitch. • Using table in step 3, select your blade angle based on whether your pin was in the HUB or RET. Step 3.
STARTUP cont. Step 3. Determine blade rotation – on the concave side of the blade is a blade marking showing 6WR, 6WL, 7WL, 7WR, or 9WR. The “L” and “R” denote the rotation of the blade. Step 4. Replace the pitch insert in the blade root with an insert of the desired pitch. Compressors: The scroll compressors are fully hermetic and require no maintenance except keeping the shell clean. Refrigerant Filter Driers: Each refrigerant circuit contains a replaceable core filter drier.
SERVICING AND MAINTENANCE cont. Charging Refrigerant: • Charging a system in the field must be based on determination of liquid sub-cooling and evaporator superheat. On a system with a thermostatic expansion valve liquid sub-cooling is more representative of the charge than evaporator superheat but both measurements must be taken. Before Charging: • Refer to the Unit Nameplate to determine the proper refrigerant to charge the system with.
SERVICING AND MAINTENANCE cont. Adjusting Sub-cooling and Superheat Temperatures: The system is overcharged if: 1. the sub-cooling temperature is too high and 2. the evaporator is fully loaded (low loads on the evaporator result in increased sub-cooling) and 3. the evaporator superheat is within the temperature range as shown in TABLE 1 (high superheat results in increased sub-cooling) Correct an overcharged system by reducing the amount of refrigerant in the system to lower the sub-cooling.
AAON, Inc. www.aaon.com Customer Service Department 2425 South Yukon Ave • Tulsa, OK 74107 Phone: 918-583-2266 • Fax: 918-382-6364 ALWAYS USE AAON SPECIFIED PARTS To order parts from the AAON Parts store online go to www.aaonparts.com. EVAPORATIVE-COOLED CONDENSER • Evaporative cooling equipment rejects heat by evaporating a portion of the recirculated water spray and discharging it from the unit with the hot, saturated air.
EVAPORATIVE-COOLED CONDENSER cont. Recirculating Water System: Electric sump heaters are available to keep the sump water from freezing when the refrigeration system is not operating. An electric resistance heater is supplied in the vestibule when sump heaters are selected. Note: The condenser should not be operated with the fan on and the pump cycled on and off to maintain head pressure control under any conditions.
EVAPORATIVE-COOLED CONDENSER cont. 4. Turn rotating element by hand to assure that it rotates freely. Running: Periodically inspect pump while running, but especially after initial start-up and after repairs. 1. Check pump and piping for leaks. Repair immediately. 2. Record pressure gauge readings for future reference. 3. Record voltage, amperage per phase, and kW.
EVAPORATIVE-COOLED CONDENSER cont. Water Treatment System: • All AAON evaporative-cooled condensers come equipped with a water treatment system that should be maintained by a local water treatment professional trained in the water treatment of evaporative condensers. This system consists of a controller, three chemical pumps and storage tanks, a conductivity sensor, a motorized ball valve for water bleed, and a water meter.
EVAPORATIVE-COOLED CONDENSER cont. MAINTENANCE RECOMMENDATIONS Pump Maintenance: • Cleaning - Remove oil, dust, water, and chemicals from exterior of motor and pump. Keep motor air inlet and outlet open. Blow out interior of open motors with clean compressed air at low pressure.
EVAPORATIVE-COOLED CONDENSER cont. WATER QUALITY Recirculating Water Quality Guidelines: • Cycles of concentration (the ratio of dissolved solids in recirculated water to dissolved solids in make-up), should be determined and monitored frequently by a competent water treatment expert. • To limit cycles of concentration to maintain the above guideline, it is necessary to “bleed” a certain portion of the recirculated water.
REFRIGERANT PIPING cont. • 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 expansion valve 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.
REFRIGERANT PIPING cont. • 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 accessories including sight glasses and filter driers are available and factory installed.
REFRIGERANT PIPING cont. 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.
REFRIGERANT PIPING cont. (ASHRAE Handbook 2006 - Refrigeration p. 2.19). Hot gas bypass pipe diameters are selected to maintain velocity below a maximum 4000 fpm, while a minimum criteria guarantees oil return up vertical rise sections, as with the suction line (ASHRAE Handbook 2006 – Refrigeration p. 2.20). • Acceptable pressure loss criteria are applied to each of the lines: The total equivalent length of the liquid line available is determined such that 3°F of liquid sub-cooling remain at the TXV.
REFRIGERANT PIPING cont. TABLE RP-1 Predetermined Line sizes for Dual Circuit CL units with R-410A R-410A Tons System 45 60 70 75 95 100 110 125 134 135 155 170 190 210 230 26 1 2 1 2 1 2 1 2 1 2 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 4 1 2 3 4 1 2 3 4 Connection Size Suction Line Liquid Line Hot Gas Bypass Reheat Predetermined Line Size Suction Line Liquid Line Hot Gas Bypass Reheat 1-3/8 in. 7/8 in. 7/8 in. 7/8 in. 1-5/8 in. 7/8 in. 3/4 in. 1-1/8 in. 1-5/8 in. 7/8 in.
REFRIGERANT PIPING cont. TABLE RP-2 Predetermined Line sizes for Dual Circuit CL units with R-22 R-22 Tons 45 60 70 75 95 100 110 125 134 135 155 170 190 210 230 System 1 2 1 2 1 2 1 2 1 2 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 4 1 2 3 4 1 2 3 4 Connection Size Suction Line Liquid Line Hot Gas Bypass Predetermined Line Size Reheat Suction Line Liquid Line Hot Gas Bypass Reheat 1-3/8 in. 5/8 in. 7/8 in. 7/8 in. 2-1/8 in. 7/8 in. 7/8 in. 1-1/8 in. 2-1/8 in. 7/8 in. 7/8 in.
REFRIGERANT PIPING cont. TABLE RP-3 Predetermined Line sizes for Single Circuit CL units with R-410A Tons 45 60 70 75 95 System 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 R-410A Connection Size Predetermined Line Size Suction Line Liquid Line Hot Gas Bypass Reheat Suction Line Liquid Line Hot Gas Bypass Reheat 1-1/8 in. 5/8 in. 7/8 in. 7/8 in. 1-3/8 in. 5/8 in. 5/8 in. 3/4 in. 1-3/8 in. 5/8 in. 7/8 in. 7/8 in. 1-3/8 in. 3/4 in. 3/4 in. 7/8 in. 3/4 in. 7/8 in. 3/4 in. 7/8 in. 3/4 in.
REFRIGERANT PIPING cont. Acceptable Region FIGURE RP-1. Riser height versus total equivalent line length for R-410A split system applications with dual circuited CL-045 through CL-230 units. The region of acceptable riser height is the lighter area. Select the corresponding predetermined line size from TABLE RP-1 on page 26. Acceptable Region FIGURE RP-2. Riser height versus total equivalent line length for R22 split system applications with dual circuited CL-045 through CL-230 units.
REFRIGERANT PIPING cont. Acceptable Region FIGURE RP-3. Riser height versus total equivalent line length for R-410A split system applications with single circuited CL-045 through CL-230 units. The region of acceptable riser height is the lighter area. Select the corresponding predetermined line size from TABLE RP-3 on page 28. Acceptable Region FIGURE RP-4. Riser height versus total equivalent line length for R22 split system applications with single circuited CL-045 through CL-230 units.
Note: Components shown within air handler and condensing unit are factory installed; all other components are field installed. FIGURE RP-2. Hot Gas Bypass Piping Diagram with air handler above condenser.
Note: Components shown within air handler and condensing unit are factory installed; all other components are field installed. FIGURE RP-3. Hot Gas Bypass Piping Diagram with air handler below condenser.
Note: Components shown within air handler and condensing unit are factory installed; all other components are field installed. FIGURE RP-4. Hot Gas Reheat Piping Diagram with air handler above condenser.
Note: Components shown within air handler and condensing unit are factory installed; all other components are field installed. FIGURE RP-5. Hot Gas Reheat Piping Diagram with air handler below condenser.
TO BE INSTALLED IN FIELD Note: Components shown within air handler and condensing unit are factory installed; all other components are field installed. FIGURE RP-6. Hot Gas Reheat Piping Diagram with air handler above condenser and field installed suction line accumulator.
TO BE INSTALLED IN FIELD Note: Components shown within air handler and condensing unit are factory installed; all other components are field installed. FIGURE RP-7. Hot Gas Reheat Piping Diagram with air handler above condenser and field installed suction line accumulator.
Note: Components shown within air handler and condensing unit are factory installed; all other components are field installed. FIGURE RP-8. Reheat/Hot Gas Bypass Piping Diagram with air handler above condenser.
Note: Components shown within air handler and condensing unit are factory installed; all other components are field installed. FIGURE RP-9. Reheat/Hot Gas Bypass Piping Diagram with air handler below condenser.
TO BE INSTALLED IN FIELD Note: Components shown within air handler and condensing unit are factory installed; all other components are field installed. FIGURE RP-10. Reheat/Hot Gas Bypass Piping Diagram with air handler evaporator above condenser and field installed suction line accumulator.
TO BE INSTALLED IN FIELD Note: Components shown within air handler and condensing unit are factory installed; all other components are field installed. FIGURE RP-11. Reheat/Hot Gas Bypass Piping Diagram with air handler below condenser and field installed suction line accumulator.
Note: Components shown within air handler and condensing unit are factory installed; all other components are field installed. FIGURE RP-5. Hot Gas Bypass Piping Diagram with air handler above condenser.
Note: Components shown within air handler and condensing unit are factory installed; all other components are field installed. FIGURE RP-6. Hot Gas Bypass Piping Diagram with air handler below condenser.
Note: Components shown within air handler and condensing unit are factory installed; all other components are field installed. FIGURE RP-7. Hot Gas Reheat Piping Diagram with air handler above condenser.
Note: Components shown within air handler and condensing unit are factory installed; all other components are field installed. FIGURE RP-8. Hot Gas Reheat Piping Diagram with air handler below condenser.
TO BE INSTALLED IN FIELD Note: Components shown within air handler and condensing unit are factory installed; all other components are field installed. FIGURE RP-9. Hot Gas Reheat Piping Diagram with air handler above condenser and field installed suction line accumulator.
TO BE INSTALLED IN FIELD Note: Components shown within air handler and condensing unit are factory installed; all other components are field installed. FIGURE RP-10. Hot Gas Reheat Piping Diagram with air handler above condenser and field installed suction line accumulator.
Note: Components shown within air handler and condensing unit are factory installed; all other components are field installed. FIGURE RP-11. Reheat/Hot Gas Bypass Piping Diagram with air handler above condenser.
Note: Components shown within air handler and condensing unit are factory installed; all other components are field installed. FIGURE RP-12. Reheat/Hot Gas Bypass Piping Diagram with air handler below condenser.
TO BE INSTALLED IN FIELD Note: Components shown within air handler and condensing unit are factory installed; all other components are field installed. FIGURE RP-13. Reheat/Hot Gas Bypass Piping Diagram with air handler evaporator above condenser and field installed suction line accumulator.
TO BE INSTALLED IN FIELD Note: Components shown within air handler and condensing unit are factory installed; all other components are field installed. FIGURE RP-14. Reheat/Hot Gas Bypass Piping Diagram with air handler below condenser and field installed suction line accumulator.
Condenser and Condenser Unit Startup Form Date:______________ Job Name:_____________________________________________________________________ Address:______________________________________________________________________ Model Number:_________________________________________________________________ ______________________________________________________________________________ Serial Number:_____________________________________________ Tag:_______________ Startup Contractor:___________________________________
Refrigeration System 1 Pressure Saturated Temperature Line Temperature Sub-cooling Superheat N/A N/A N/A Discharge Suction Liquid Refrigeration System 2 N/A Pressure Saturated Temperature Line Temperature Sub-cooling Superheat N/A N/A N/A Discharge Suction Liquid Refrigeration System 3 N/A Pressure Saturated Temperature Line Temperature Sub-cooling Superheat N/A N/A N/A Discharge Suction Liquid Refrigeration System 4 N/A Pressure Saturated Temperature Line Temperature Sub-cooli
Maintenance Log This log must be kept with the unit. It is the responsibility of the owner and/or maintenance/service contractor to document any service, repair or adjustments. AAON Service and Warranty Departments are available to advise and provide phone help for proper operation and replacement parts. The responsibility for proper start-up, maintenance and servicing of the equipment falls to the owner and qualified licensed technician. Entry Date Action Taken Name/Tel.
CL SERIES CONDENSING UNIT • INSTALLATION, SERVICE & OWNERS INFORMATION MANUAL AAON, Inc. 2425 South Yukon Tulsa, Oklahoma 74107 Phone: (918) 583-2266 • Fax: (918) 583-6094 R10110 · Rev.
