AAON LF Series Installation Operation & Maintenance Download

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LF Series

Air-Cooled Chillers

Installation, Operation,

& Maintenance

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.

FOR YOUR SAFETY

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

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
Factory Trained Service Technician. A
copy of  this IOM should  be kept  with
the unit.

WARNING

Summary of Contents for LF Series

Page 1: ...SAFETY Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other appliance 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 Factory Trained Service Technician A copy of this IOM should be kept w...

Page 2: ...e Gauge and Thermometers 16 Pipe Insulation 16 Installation 16 Forklifting the Unit 4 17 22 and 24 ton 16 Lifting the Unit 17 Locating the Unit 18 Water Connection 18 Mounting Isolation 19 Access Doors 19 Low Ambient Operation 19 LAC Valve 20 Condenser Flooding 21 Electrical 21 Startup 23 Maintenance 24 General 24 Compressors 24 Refrigerant Filter Driers 24 Adjusting Refrigerant Charge 24 Lubricat...

Page 3: ...rvice Clearances 18 Table 2 8 10 13 ton Service Clearances 18 Table 3 14 17 22 24 ton Service Clearances 18 Table 4 21 26 55 ton Service Clearances 18 Table 5 Water Connection Sizes 19 Table 6 Condenser Flooding 21 Table 7 Nameplate Voltage Markings 21 Table 8 Max Filter Drier Pressure Drops 24 Table 9 Acceptable Refrigeration Circuit Values 25 Table 10 R 410A Refrigerant Temperature Pressure Char...

Page 4: ...n Single Point Non Fused Disconnect Power Switch Waterside Thermometer and Pressure Gauge Installation and Maintenance Double Wall Rigid Polyurethane Foam Injected Panel Construction Access Doors with Full Length Stainless Steel Piano Hinges Molded Lockable Handles Factory Installed Convenience Outlet Service Vestibule Heating Controls Diagnostics Touchscreen Computer Controls Interface Liquid Lin...

Page 5: ...ould result in dangerous operation serious injury death or property damage Improper servicing could result in dangerous operation serious injury death or property damage 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 FIRE EXPLOSION OR CARBON MONOXIDE POISONING HA...

Page 6: ...MUM ON TIME To maintain the proper oil level compressors must cycle on for a minimum of 2 minutes The cycle rate must not exceed 6 starts per hour 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 WARNING PVC Po...

Page 7: ...Capacity 017 17 ton Capacity 021 21 ton Capacity 022 22 ton Capacity 024 24 ton Capacity 026 26 ton Capacity 031 31 ton Capacity 042 42 ton Capacity 048 48 ton Capacity 055 55 ton Capacity SERIES A 4 7 and 9 ton units B 8 and 10 13 ton unit C 14 17 22 and 24 ton units D 21 and 26 55 ton units MINOR REVISION A VOLTAGE 2 230V 3Φ 60Hz 3 460V 3Φ 60Hz 4 575V 3Φ 60Hz 8 208V 3Φ 60Hz A1 COMPRESSOR STYLE A...

Page 8: ...g System Large Pipe Size J No Pumping Package Piping to Connections at Wall Cutouts 3A Building Pump Configuration 0 No Building Pumps A 1 Pump High Eff Motor B 1 Dual Pump High Eff Motors D 1 Pump VFD High Eff Motor E 1 Dual Pump 2 VFD s High Eff Motors 3B Building Pump Series and RPM 0 No Building Pumps A 4360 1 170 nominal rpm B 4360 1 760 nominal rpm C 4360 3 520 nominal rpm D 4380 1 170 nomin...

Page 9: ...d 4C Blank 0 Standard 4D Blank 0 Standard 5A Blank 0 Standard 5B Blank 0 Standard 5C Blank 0 Standard 5D Blank 0 Standard 6 Refrigeration Options 0 None A Hot Gas Bypass Non Variable Capacity Compressor Circuits B Hot Gas Bypass All Circuits 7 Refrigeration Accessories 0 Standard A Sight Glass B Compressor Isolation Valves C Option A B D Single Circuit 0 F Low Ambient E Option A D F Option B D G O...

Page 10: ...iagnostics M Modbus RTU with Diagnostics N LonTalk with Diagnostics 11 Blank 0 Standard 12 Vestibule Accessories 0 None C Vestibule Heating Electric 13 Maintenance Accessories 0 None A 115VAC Convenience Outlet Factory Wired B 115VAC Convenience Outlet Field Wired 14 Blank 0 Standard 15 Code Options 0 Standard ETL U S A Listing 16 Shipping Splits 0 One Piece Unit B Crating C Export Crating 17 Air ...

Page 11: ...23 24 25 26A 26B 26C 26D 26E 26F 27 28 29 30 31 32 33 34 35 11 26C Blank 0 Standard 26D Blank 0 Standard 26E Blank 0 Standard 26F Blank 0 Standard 27 Blank 0 Standard 28 Blank 0 Standard 29 Blank 0 Standard 30 Blank 0 Standard 31 Blank 0 Standard 32 Blank 0 Standard 33 Warranty 0 Standard Warranty D Compressor Warranty Years 2 5 34 Cabinet Material 0 Standard Double Wall R 13 Foam Insulation 35 Pa...

Page 12: ...d 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 AAON Technical Supp...

Page 13: ...heater time to clear any liquid accumulation out of the compressor before it is required to run COMPRESSOR CYCLING 5 MINUTE MINIMUM OFF TIME To prevent motor overheating compressors must cycle off for a minimum of 5 minutes 2 MINUTE MINIMUM ON TIME To maintain the proper oil level compressors must cycle on for a minimum of 2 minutes The cycle rate must not exceed 6 starts per hour WARNING CRANKCAS...

Page 14: ... and on a periodic schedule during operation it is necessary to perform routine service checks on the performance of the chiller This includes reading and recording suction pressures and checking for normal sub cooling and superheat Primary Pumping Package Primary pumping uses a single pump to move water or glycol through the evaporator and back to the building This pumping package provides the ne...

Page 15: ... diaphragm compression tank that is preset for 12 psig Pressure Relief Valve Required pressure relief valve is installed in the unit This valve is set at 125 psig Figure 1 shows inlet pressure versus capacity for this pressure relief valve See appendix for additional information Figure 1 Pressure Relief Valve Manual and Automatic Air Vent A manual air vent is supplied in chillers without pumping p...

Page 16: ... the LF Series chiller is factory insulated The water piping pumps and other components on units with pumping packages are not insulated at the factory Insulation should be installed on the water piping after the system has been checked for leaks Installation Forklifting the Unit 4 17 22 and 24 ton 4 17 22 and 24 ton units can be lifted using a forklift 8 10 17 22 and 24 ton units must have forks ...

Page 17: ... lifting points lugs provided on the unit Hoist unit to a point directly above the curb or concrete pad Be sure that the gasket material has been applied to curb Carefully lower and align the unit with utility and duct openings Lower the unit until the unit skirt fits around the curb Some units are designed to overhang the curb Take care that any recessed base rails fit around the curb Make sure t...

Page 18: ... Location Clearance Left 42 Right 36 Compressor End 30 Chiller HXC End 30 Top Open Table 2 8 10 13 ton Service Clearances Location Clearance Left 36 Right 36 Compressor End 30 Chiller HXC End 30 Top Open Table 3 14 17 22 24 ton Service Clearances Location Clearance Left 42 Right 36 Compressor End 36 Chiller HXC End 30 Top Open Table 4 21 26 55 ton Service Clearances Location Clearance Left 42 Righ...

Page 19: ...outside air temperature As the ambient temperature drops the condenser becomes more effective therefore lowering the head pressure The low ambient system maintains normal head pressure during periods of low ambient by restricting liquid flow from the condenser to the receiver and at the same time bypassing hot gas around the condenser to the inlet of the receiver This reduces liquid refrigerant fl...

Page 20: ...s below the valve setting 295 psig for R 410A the valve modulates to bypass discharge gas around the condenser The discharge gas warms the liquid in the receiver and raises the pressure to the valve setting The following schematic shows an example system using the LAC valve Figure 5 Piping Schematic of Example System using the LAC Valve ...

Page 21: ...e unit is supplied with its own power supply factory wired to the main power of the chiller Check the unit nameplate voltage to make sure it agrees with the power supply Connect power to the unit according to the wiring diagram provided with the unit Table 7 Nameplate Voltage Markings Voltage Feature Nameplate Voltage Marking Min Max VAC 2 230V 3Φ 60Hz 230 197 252 3 460V 3Φ 60Hz 460 456 504 4 575V...

Page 22: ...k voltage imbalance at the unit disconnect switch and at the compressor terminal Contact your local power company for line voltage corrections Note Startup technician must check motor amperage to ensure that the amperage listed on the motor nameplate is not exceeded CONVENIENCE OUTLETS AND SERVICE LIGHTS Convenience outlet and service light circuits are wired to the incoming power side of the disc...

Page 23: ...he compressors to confirm that all are operating within tolerance While performing the check use the startup form to record observations of amps and refrigerant pressures When all is running properly place the controller in the Run mode and observe the system until it reaches a steady state of operation Note For more information on programming the controller refer to the MCS Controller manual prov...

Page 24: ...ive of the charge than evaporator superheat but both measurements must be taken Before Charging Refer to the Unit Nameplate as a reference when determining the proper refrigerant charge Unit being charged must be at or near full load conditions before adjusting the charge After adding or removing charge the system must be allowed to stabilize typically 10 15 minutes before making any other adjustm...

Page 25: ...ompressors in a refrigeration system running Compare calculated superheat to Table 9 for the appropriate unit type and options Table 9 Acceptable Refrigeration Circuit Values Air Cooled Condenser Sub Cooling2 12 18 F Superheat1 10 15 F 1 One compressor running in tandem 2 Two compressors running in tandem Adjusting Sub cooling and Superheat Temperatures The system is overcharged if the sub cooling...

Page 26: ...35 107 1 62 175 4 89 269 4 116 395 2 143 560 9 36 109 2 63 178 4 90 273 5 117 400 5 144 567 9 37 111 4 64 181 5 91 277 6 118 405 9 145 575 1 38 113 6 65 184 5 92 281 7 119 411 4 146 582 3 39 115 8 66 187 6 93 285 9 120 416 9 147 589 6 40 118 1 67 190 7 94 290 1 121 422 5 148 596 9 41 120 3 68 193 9 95 294 4 122 428 2 149 604 4 42 122 7 69 197 1 96 298 7 123 433 9 150 611 9 43 125 0 70 200 4 97 303...

Page 27: ...o 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 Pump Fan Motor Maintenance Cleaning Remove oil dust water and chemicals from exterior of motor and pump Keep motor...

Page 28: ...ace loaded fibers or dirt should be removed with a vacuum cleaner If a vacuum cleaner is not available a soft non metallic bristle brush may be used In either case the tool should be applied in the direction of the fins Coil surfaces can be easily damaged fin edges bent over if the tool is applied across the fins Use of a water stream such as a garden hose against a surface loaded coil will drive ...

Page 29: ...ess to the coil s to be cleaned 4 Using a pump up sprayer fill to the appropriate level with potable water and add the correct amount of approved cleaner as per manufacture instructions leaving room for the pump plunger to be reinserted NOTE Coils should always be cleaned back flushed opposite of airflow to prevent impacting the dirt into the coil 5 If the coils have heavy dirt fibers grass leaves...

Page 30: ...able water 2 56 ounces of Chlor rid to 1 gal of water Using a pump up sprayer fill to the appropriate level with potable water and add the correct amount of CHLOR RID salt remover leaving room for the pump plunger to be reinserted 2 Apply CHLOR RID to all external coil surfaces using a pressurized pump up sprayer maintaining a good rate of pressure and at a medium size nozzle spray not a solid str...

Page 31: ...Green is available from AAON Parts and Supply Part T10701 and is biodegradable with a neutral 6 5 pH Recommendation is to use it at a 4 to 1 mix Use the following procedure 1 Rinse the coil completely with water Use a hard spray but be careful not to bend or damage the fins A spray that is too hard will bend the fins Spray from the fan side of the coil 2 With a pump sprayer filled with a mix of 4 ...

Page 32: ...rket for condenser coils Before using any cleaner that is not covered in this section you must get written approval from the AAON warranty and service department Use of unapproved chemicals will void the warranty AAON testing has determined that unless a chemical has a neutral pH 6 8 it should not be used Beware of any product that claims to be a foaming cleaner The foam that is generated is cause...

Page 33: ...ruction and is tested listed and certified by the National Board of Boiler and Pressure Vessel Inspectors ANSI Z21 22 Relief Valves for Hot Water Supply Systems DESIGN CERTIFIED and listed by C S A Automatic Air Vent Valves Automatic Air Vent Valves provide air venting for hot or cold water distribution systems These vents purge air that may be in the water system The vent valve utilizes an intern...

Page 34: ...is ready to connect to the piping Rotate the shaft periodically At least monthly to keep rotating element free and bearings fully functional For long term storage the pump must be placed in a vertical position in a dry environment Internal rusting can be prevented by removing the plugs at the top and bottom of the casing and drain or air blow out all water to prevent rust buildup or the possibilit...

Page 35: ...major source of concern in centrifugal pump applications Alignment Alignment is unnecessary on close coupled pumps as there is no shaft coupling Split coupled units are accurately aligned at the factory prior to being shipped and do not need re aligning when installed Operation Starting Pump Ensure that the pump turns freely by hand or with some mechanical help such as a strap and lever on larger ...

Page 36: ...p operating head by deducting the suction pressure gauge value from the discharge gauge reading Convert the result into the units of the pump head as stated on the pump nameplate and compare the values Should the actual pump operating head be significantly less than the nameplate head value it is typically permissible to throttle the discharge isolation valve until the actual operating head is equ...

Page 37: ...mp is flushed from the pump discharge because the mechanical seal chamber is isolated from the liquid in the pump by a throttle bushing Because the seal chamber is isolated seal environmental controls such as filters and separators when installed in the split coupled flush line are very effective as only the seal chamber needs cleansing and will prolong seal life in HVAC systems Do not run the pum...

Page 38: ... system clean 8 Is the area around the pump clean Warranty Does not cover any damages to the equipment resulting from failure to observe the above precautions Noise Levels Estimated Pumping Unit Sound Power Level Decibels A Weighted at 1 m 3 ft from unit Vibration Levels Vertical In Line pumps are designed to meet vibration levels set by Hydraulic Institute Standard HI Pump Vibration 9 6 4 Standar...

Page 39: ...s per instructions below 5 Unlock the suction valve as per instructions below NOTE Keep hands and tools away from locked suction valve arm as the differential pressure may cause the arm to rotate quickly with force when unlocked 6 Close the seal flush line interconnect valve and restart pump Valve Operation Refer to the valve illustrations on the following pages Discharge Valve This valve performs...

Page 40: ...11 Suction Valve Manual Operation The suction side valve is designed for use as a manually operated isolation valve This valve is not designed to automatically pivot as the discharge flappers do Locking 1 Loosen suction side set screw 11 to release the locking handle 3 2 Rotate the suction side locking handle 3 so that the handle points towards the pump to be serviced and secure in the horizontal ...

Page 41: ...ep hands and tools away from suction valve locking arm when freed by locking handle as differential pressure may cause arm to rotate quickly with force when unlocked 3 Rotate valve to center position so that the center pin of the locking arm 4 is located in the recess on the locking handle 3 4 Loosen set screw 11 and raise locking arm 3 to the vertical position locking the center pin in the lockin...

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Page 44: ... special attention need be paid to the Suction Guide at start up The fitting is stationary and will strain the pumped fluid and stabilize the flow into the pump automatically Temporary strainer must be removed following system clean up After all debris has been removed from the system or a maximum of 24 running hours stop the pump and close the pump isolation valves Drain the Suction Guide by remo...

Page 45: ... between the anti rotation lugs on the valve body as shown Insert two bolts of specified size Table A1 to secure the halves of the flange adapter to the valve body as shown Table A1 Armgrip Flange Adapter Details Valve Size 125 psi 150 psi 250 psi 300 psi Ductile Iron Bolt Ductile Iron Bolt No Size No Size 2 1 2 4 5 8 8 3 4 3 4 5 8 8 3 4 4 8 5 8 8 3 4 5 8 3 4 8 3 4 6 8 3 4 12 3 4 8 8 3 4 12 7 8 10...

Page 46: ... diameter 6 Flange gaskets are not interchangeable with other mechanical pipe couplings or flange gaskets Recommended Bolt Tightening Procedure Field Conversion Straight to Angle Pattern Valve 1 Open valve at least one complete turn 2 Remove the body bolts from valve body using Allen Key 3 Rotate one half of the valve body 180 making sure the lower valve seat and O ring stay in position Inspect th...

Page 47: ...tled position of the valve The quarter turn graduations on the sleeve with the scribed line on the stem provide an approximate flow measurement Note The valve is shipped in closed position The indicator on the plastic sleeve is aligned with the vertical scribed line on the stem Step 2 Record the size of the valve and stem position using the flow indicator scale Calculate the percentage of valve op...

Page 48: ...p a line vertically down to read the flow rate at the bottom of the chart Step 6 Calculate the flow rate of the valve in the throttled position by multiplying the flow rate Step 5 by the percentage of maximum flow rate Step 4 Example Valve size 4 in Differential pressure is 5 4 ft Number of open rings is 3 From the table the number of rings for the 4in valve fully open is 6 Divide open rings by to...

Page 49: ...metal to metal contact and minimal leakage Step 3 The valve bonnet may now be removed There may be a slight leakage as the metal to metal backseating does not provide a drip tight seal Step 4 Clean exposed portion of valve stem being careful not to leave scratches Step 5 Remove and replace the O ring gasket Step 6 Install the valve bonnet Step 7 Tightening the valve bonnet is necessary to stop any...

Page 50: ...Pressure Temperature Limits Flo Trex Cross Section ...

Page 51: ...tor should verify the following items 1 Is there any visible shipping damage Yes No 2 Is the unit level Yes No 3 Are the unit clearances adequate for service and operation Yes No 4 Do all access doors open freely and are the handles operational Yes No 5 Have all shipping braces been removed Yes No 6 Have all electrical connections been tested for tightness Yes No 7 Does the electrical service corr...

Page 52: ...the water piping been insulated Yes No 7 Is the glycol the proper type and concentration N A if water Yes No 8 What is the freeze point of the glycol N A if water ______________________________ Chiller Configuration Air Cooled Chiller Low Ambient Control Condenser Safety Check No Water Leaks Water Flow ________ gpm Chilled Water In Temperature ________ F Chilled Water Out Temperature ________ F Co...

Page 53: ...ction N A Liquid N A Refrigeration System 2 Cooling Mode Pressure Saturated Temperature Line Temperature Sub cooling Superheat Discharge N A N A Suction N A Liquid N A Condenser Fans Alignment Check Rotation Nameplate Amps________ Number hp L1 L2 L3 1 2 3 4 5 6 Pumping Package hp L1 L2 L3 Flow gpm Chiller Pump 1 Chiller Pump 2 ...

Page 54: ...ument 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 ...

Page 55: ...on sizes Added a phase imbalance example May 2018 Updated technical support contact information June 2018 Clarified piping insulation section Updated Flo Trex Combination Valve section Updated E coated coil cleaning procedure Minor Revision changed to A because LF is now AHRI certified March 2019 Added ECM Low Sound Condenser Fan Head Pressure Control option May 2019 Added the minimum maximum volt...

Page 56: ...e unit available Parts For replacement parts please contact your local AAON Representative It is the intent of AAON to provide accurate and current product information However in the interest of product improvement AAON reserves the right to change pricing specifications and or design of its product without notice obligation or liability Copyright AAON all rights reserved throughout the world AAON...

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