AIRSTACK - Multistack
Contents
1. _ OE compo _ __ Compro o __ OE TESTI oP IS ES ES Es __ pL Ent Chw tvyChw __ Demand Capacity System O ES o O OE Pct tosa Upset VSP Load Limit Tdiff __ COMMENTS2. 14 0 recommended the compressor be replaced as removing all the moisture from the oil is very difficult Replacement of the condenser the expansion valve and installation of a liquid line filter drier with a water core cartridge is also recommended Evacuate the circuit to a maximum of 500 microns and let stand for 20 minutes Charge the circuit and run 2 3 weeks with the high water core cartridge and then replace with a standard core The condensers on the ASP module are all copper coil with aluminum fin type Period cleaning of the fin s should be done to keep air born debris from plugging up the fins and causing high pressure conditions A coil cleaner suitable for copper and aluminum can be used for this Troubleshooting Air Cooled Packaged Modules ASP modules use the Carel PCO2 master control The user manual for the PCO2 controller is located in section 6 of the O amp M package The user manual details the different status screens and explanations of system or module faults The following guide is for troubleshooting ASP modules and the PC02 FAULT SOLUTION No Display on Master Module Check main disconnect for power Check circuit breakers in module Check transformer in modules Check for 24V at J1 on board EX 1 2 Interlock Check appropriate interlock component Check jumpers on TS2 in master module EX 4 Interlock Check for proper rotation phasing Check PPM device Waiting For Chilled Water Flow Check CHW pump Check flo
3. AIRSTACK ASP30 ASP20 ASP15 ASP13 ASP10 ASP OOP ASP OOF Air Cooled Packaged Modules OPERATION amp MAINTENANCE Airstack 1065 Maple Ave PO Box 510 Sparta WI 54656 608 366 2400 phone 608 366 2450 fax www airstack com 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 10 0 11 0 12 0 13 0 14 0 15 0 Table of Contents Chiller Identification oa 3 1 1 Air Cooled Packaged Model Number LL 3 1 22 Serial Numbers ra boni 3 Theory of Operation Aa 3 Daily Log Sheet zie ra si tees eres a 4 Pressure Readings ves esa noir ess rata ced cas ececusey sens eve rr 4 Strainer CIN NA 4 Ol Ec ento au ARESE 5 Refrigerant Charge Evacuation di oe 5 Filtet DAS Aa it 6 superheat Subcooling si rese 6 Pressure Relief Valve coria TI tenuis isis sb sn au ene 6 Annual Maintenance a a da lisi 6 COMPresSOLS A AAA AA AAA AAA eas 7 Heat Exchanpers A A 8 Troubleshooting Air Cooled Packaged Modules L 20 9 Daily Lo SS e ad A A AAA eee 11 1 0 Chiller Identification The module information data plate is located inside the electrical box compartment of each module When ordering service parts or inquiring for technical assistance it is important to provide the model and serial number 1 1 ASP Model Number ASPI5HV ASP Airstack Packaged 15 tons 10 13 20 30 tons OOF free cool OOP pump module HV 460V AV 208V LV 230V CV 575V V special 12 Serial Number Identi
4. fication JC 06 25 J 0 decade built I 1990 s J 2000 s C 3 year built A 01 BS 0 fasano 06 June month built 01 Jan 02 Febo Lila 25 25 module built 01 1 A AN 2 0 Theory of Operation The Airstack ASP chiller provides chilled water to an external load based off of the return water temperature to the ASP master control When the Entering Chilled Water sensor sends the signal to the master control that cooling is needed compressors will begin to start and produce chilled water The point at which the ECHW temperature calls for compressors to start is determined by the Upset point and the Variable Set point setting in the system variables menu of the master control When the ECHW sensor senses that the chilled water temperature has dropped below the set point compressors will begin to cycle off 3 0 Daily Log Sheet On the back page of this manual is a chiller information log sheet The log sheet can be used daily weekly or as desired to record operation characteristics of the chiller The information recorded on the log sheet can also be very helpful for diagnosing potential problems in the system 4 0 Pressure Readings The operating suction and discharge pressures in the system are directly related to water flow condenser temperatures chilled water set points and the cleanliness of the system All ASP modules have a high pressure cut out safety device Each circuit will cut out on HP when the pr
5. n valve ASP condensers are sized so that subcooling of the liquid refrigerant will take place with no separate subcooler being needed The general range of subcooling seen is 7 15 degrees 10 0 Pressure Relief Valve Each module has a 450 psig pressure relief valve The relief valve is installed on the receiver of the module and has a 3 8 flare connection 11 0 Annual Maintenance Most of the annual maintenance requirements for ASP Chillers involve proper shut down of the machine and if needed cleaning of the heat exchangers Preventative Maintenace bulletin 021594PM and Heat Exchanger Cleaning Procedures bulletin 091594CP describe the recommended procedures for both processes Airstack has available the 151A Cleaning Kit to assist with this process Please see the 5 A Cleaning Kit bulletin 090195CK for more details All of these bulletins are part of the standard O amp M manual package Annual Maintenance Checks Electrical Components a check all external interlocks b inspect compressor terminals c check compressor crankcase heater operation d tighten all contactor relay and circuit breaker terminals e check and calibrate all compressor safety controls f check and record voltages and amperages for compressors g check and record amperages for pumps and condenser fans h check and calibrate low ambient fan cycling controls 1 inspect relay contacts for damage or pitting Refrigeration Circuits a analyze refrigerant
6. ogrammed setting limit in the master control is met In addition a back up HP cut out switch is installed on each module The HP cut out is 365 psig for both R 22 and R 407C Each ASP module also has a low pressure safety cut out The LP cut out is controlled by a setting in the program chip of the module The LP cut out for modules with R 22 or R 407C is 15 psig If circuits are faulting on HP fault you should first check to see that the fans are operating If both fans are working check the cleanliness of the condenser coil A LP fault is an indication of low refrigerant charge in the system If a circuit is going out on a LP fault check the static pressure of the system while the circuit is in the off mode If pressures are low check the circuit for possible leaks The circuit can be pressurized to 15 psig with refrigerant and topped to 160 psig with dry Nitrogen 5 0 Strainer Cleaning All ASP modules have a 30 mesh filter cartridge in the chilled water inlet header The purpose for the filter cartridge is to keep debris from entering the heat exchanger An external Y or basket type system strainer should also be installed as a pre filter to the factory supplied strainers There is no set time for cleaning the filter cartridges The frequency of this process is dependant on the water quality in the evaporator loop Normally debris in a water loop is going to take the path of least resistance and build up on the last modules to recei
7. ome factory charged with the recommended refrigerant volume Prior to charging each circuit is evacuated to a maximum of 150 microns and held 15 minutes The proper refrigerant charge for each module can be found on the module data plate On air cooled machines the proper charging procedure is by a calculated weigh in method Charging to a full sight glass on air cooled machines will likely result in over charging as the elbows in the liquid line as well as the liquid line solenoid valve still produce some flashing even with the correct charge As fans are cycling the sight glass will also display some bubbling 8 0 Filter Driers ASP modules have short refrigerant pipe runs but a higher refrigerant charge due to the copper fin condenser and exposure to lower ambient conditions These modules are built with a factory installed liquid line filter drier The filter driers are a solid core sweat fitting replaceable type In the case of a compressor failure heat exchanger failure or water contamination in the system it is always recommended to replace the drier 9 0 Superheat Subcooling ASP modules use a mechanical type expansion valve on all modules By turning the valve adjustment clockwise superheat is increased On each module superheat is set at the factory during the run test Superheat is set for 10 12 degrees during the test run Subcooling is necessary in the system to prevent flash gas as the refrigerant enters the expansio
8. the discharge side See refrigerant charge on nameplate data of unit 6 Run the system 2 3 weeks with burnout filter core Replace with standard core drier 13 0 Heat Exchangers Airstack uses brazed plate stainless steel heat exchangers for all evaporators Without proper water treatment or due to abuse heat exchangers can corrode over time and eventually develop an internal leak In such an event it would become necessary to replace the heat exchanger Following are the step s for field replacement of a failed evaporator heat exchanger 1 If the refrigerant has not been lost on the failed circuit you should first do a standard refrigerant recovery 2 Begin by isolating the chiller and draining the water glycol from the loop 3 Remove the 4 round header pipes that attach to the evaporator if you have a front module If rear module remove the crossover pipes from the front module 4 Cut the refrigerant lines below the elbows and sweat off remaining pipe Remove old evaporator and replace with new one 6 Fit in copper connections and braze Purge with Nitrogen while brazing 7 After brazing leak check and evacuate to a maximum of 500 microns Charge the circuit according to the name plate charge A If the evaporator heat exchanger failure has caused water to enter into the refrigerant side the compressor and condenser should also be checked for possible contamination If water has entered into the compressor it is
9. ve water If circuits are faulting on Low Suction Temperature or Low Chilled Water Temperature the chilled water inlet filter cartridge should be checked The strainers are located in the top header on the CHW side If the strainers are clean the fault is most likely being caused by a low flow condition or too low of set points in the master control If these possibilities are eliminated the evaporator heat exchangers may need cleaning Steps to remove the strainers for cleaning 1 Stop CHW pump and shut down chiller 2 Close inlet and outlet water valves to the chiller 3 Drain the water glycol from the top header in the end module so the strainers can be removed 4 Remove the 4 Victaulic end cap on last module 5 Remove strainers and clean You may need to make a tool to hook the other strainers for removal Re install clean strainers 7 Open the bottom water isolation valve and fill unit from the bottom up to prevent air from being trapped 8 Restart CHW pump bleed any air and start chiller A 6 0 Compressor Oil Level Compressors used on ASP modules are oil charged by the compressor manufacturer These compressors do not have an oil level sight glass indicator To ensure no liquid is present in the oil the crankcase heaters should be on 24 hrs before starting of the compressors Factory oil charge volume for each compressor can be found in the Product Data Catalog 7 0 Refrigerant Charge Evacuation All ASP modules c
10. w switch operation Check filter strainers Check TS2 inputs 3 5 Low Chilled Water Temp Check LCHW sensor Check setpoints in system variables Check for flow restriction No Demand Check entering CHW sensor Check setpoints in system variables 100 Demand all the time 100 Demand chiller won t load Excessive Cycling High Discharge Pressure HP Low Suction Pressure LP Low Suction Temperature Communication Error Circuit Fault P Lan Error Check sensor location Check entering CHW sensor Check setpoints in system variables Turn chiller on Check sensors Check load limit setting in system variables Check VSP setting is system variables Check entering CHW sensor location Check fan operation Check coil condition Check fan settings in system variables Check refrigerant charge leaks Check expansion valve Check suction sensor Check setpoints in system variables Check for flow restriction Check settings in system variables Check cables at J11 comm ports Check dip switch settings Check components in control circuit Check wire crimps in control circuit Check for possible airwave interference Ill AIRSTACK CHILLER DAILY LOG SHEET Status Suct Press_ Head Press Suct Temp LoChw Temp Fault if any Compt __ __ comp 2 O OE Compt3 __ __ Comptg 1 o O _ OE compo ES IS ES __ comp 6 ES E ESOS E E compia ISS eS nil Comp 6
11. with tube type moisture acid analyzer b check and record refrigerant subcooling and superheat c check liquid solenoid valves d check expansion valve and sensing bulb connections Chilled Water System a clean pump strainers and system strainers b remove header caps and clean the ECHW strainers in accordance with the Multistack Annual Cleaning Procedure detailed in Section 5 of this manual c check glycol inhibitor content in system chilled water Cabinet and Related Hardware a dry clean electrical panels remove debris b apply protective coatings or wax if required Update Your Maintenance Log Book 12 0 Compressors With any chiller system there is always the chance of a compressor failure In the event of a failure proper steps should be taken to determine the cause of the failure A motor burn due to a fault in the motor insulation is quite rare Most burnouts are actually caused by a mechanical condition or lubrication problems In the event of a burnout proper clean up procedures should be followed 1 Check all electrical components of the circuit contactors fuses wires etc 2 Ifnecessary do a system clean up Nu Calgon RX 11 flush or Sporlan System Cleaner work well 3 Replace the liquid line filter drier with burnout core See section 7 on filter driers 4 Evacuate the system to a minimum of 500 microns and hold for 20 minutes 5 Charge the circuit with virgin refrigerant Charge with liquid into
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