GAS FIRED SINGLE-EFFECT ABSORPTION CHILLER
Contents
1. gt YAZAKI OPERATING INSTRUCTIONS WFC SC5 Aroace GAS FIRED SINGLE EFFECT ABSORPTION CHILLER This product is a water fired absorption unit which provides chilled water for cooling in central plant type air conditioning systems The unit has a nominal capacity of 5 tons and is complete with operating and safety controls The unit is energized by heat medium hot water from a process cogeneration solar or other waste heat applications that can supply the heat medium fluid within the operating range of 158 203 F 70 950 When this equipment is correctly applied installed in accordance with Yazaki INSTALLATION INSTRUCTIONS and properly maintained it can provide many years of trouble free operation CONTENTS GENERAL Page MAINTENANCE Page e ABSORPTION PRINCIPLE 2 GENERAL INFORMATION e COOLING OPERATION 2 ROUTINE MAINTENANGE MAINTENANCE INTERVALS CONTROLS EVACUATION OVERVIEW e GENERAL INFORMATION 3 CHEMICAL MAINTENANCE OOO O ON N N N e CONTROL ADJUSTMENTS 4 WINTER SHUTDOWN e CONTROL SEQUENCE 4 TROUBLESHOOTING WATER QUALITY 1 OPERATION ERROR CODES 1 e COOLING 5 e REMOTE CONTROL 5 WARRANTY e SAFETY CONTROLS 6 e YAZAKI LIMITED EXPRESS e PRECAUTIONS 6 WARRANTY 11 GENERAL These instructions are intended to acquaint the Owner End User with the operation and general maintenance requirements of Yazaki WFC SC5 Water Fired Single Effect Absorption Chiller units Please read ALL instructions carefully and obs2. return to the root screen PRECAUTIONS Ensure that all AUTO OFF HAND switches for external pumps and the cooling tower fan are set in the AUTO position during normal operation The chiller is designed to automatically control the chilled water pump cooling water pump heat medium pump and or heat medium bypass valve 1 At the beginning of the cooling season clean and refill the cooling tower with fresh water 2 During the winter season the cooling tower and cooling water circuits should be drained to avoid freezing 3 When two or more absorption chiller modules are installed in parallel set all units for the same operating mode MAINTENANCE GENERAL INFORMATION ALL MAINTENANCE SHOULD BE PERFORMED BY TRAINED AND EXPERIENCED PERSONNEL Your Yazaki Authorized Service Provider ASP can help you establish a standard maintenance procedure For your safety keep the area around the equipment clear and free of combustible materials gasoline and other flammable substances DO NOT obstruct service access to the equipment ROUTINE MAINTENANCE Routine maintenance should be provided throughout the life of the equipment to ensure Satisfactory performance and operation During the warranty period an ASP must be engaged to provide routine maintenance on chillers at the beginning of each cooling season When the chiller is used for process cooling or heavy load operation it may be necessary to schedule additional ser
3. the gt button three times to get to the PARAMETER SET screen Then simply use the A and Y buttons to change the set point to the desired value Once set to the desired value use the A button to return to the root menu A PARANETER SET SET POINT FOR CHILLED TC U s The set point itself can be set as low as 41 9 F 5 5 C and as high as 59 9 F 15 5 C but the dead band will always be 7 2 F 4 C The dead band cannot be adjusted CONTROL SEQUENCE A built in microprocessor in the chiller controls the external pumps in response to the cooling load The operating sequence of each pump and the cooling tower fan after Startup during normal operation and after a normal stop is shown below in a series of flow charts It is important that the chiller has control over the pumps to allow for controlled shutdown under normal and abnormal circumstances Standby Mode Unit Enabled i P1 P2 P3 CTF SP Disengaged RBV Engaged FS1 Open Error Code 27 longer Generated than 10 minutes P1 Engaged CTF Disengaged Cooling Operation WTO gt Setpoint gt NO P1 P2 P3 CTF SP Disengaged RBV Engaged Standby Mode Error Code 27 Reset Cleared WTO gt Setpoint 7 2 F 4 c Cooling Operation Cooling Operation Post Dilution Cycle Post Dilution Cycle P3 Disengaged RBV Engaged P2 CTF
4. to the generator where the cycle is repeated Dilute Solution Concentrated Solution Refrigerant Vapor Refrigerant Liquid Heat Medium A U Wah A Chilled Water Cooling Water Sir 5055 Figure 1 SINGLE EFFECT ABSORPTION CYCLE COOLING CONTROLS GENERAL INFORMATION The control panel of the WFC SC5 is located behind the front panel of the unit A non fused breaker is present on the control panel for disconnect purposes It does not substitute for any other NEC required disconnects external of the unit Also on the front of the control panel is a small window which allows observation of three LEDs on the control boards These LEDs are labeled CHD CHE and PL The CHD LED illuminates when the unit is Enabled The CHE LED illuminates when the unit is in alarm condition The PL LED illuminates any time there is power to the unit and the on board disconnect is turned on All control of the WFC SC5 unit is done through a touch screen device which is included with the chiller The root screen of the GTO1R device allows for status monitoring I O monitoring changes to the operation of the unit and data history Full operating details are available in the WFC SC5 Service Manual CONTROL ADJUSTMENTS A HEC _MENTENANCE TOOL STATUS Fii MOH TOR OHI TOR MANUAL DATA OPERAT OH HI STORY In order to set the desired leaving chilled water temperature press MANUAL OPERATION then press
5. where it drains down and flows through a heat exchanger before flowing to the absorber Condenser In the condenser refrigerant vapor is condensed on the surface of the condenser tubing bundle and latent heat removed by the cooling water is rejected to a cooling tower Refrigerant liquid accumulates in the condenser and then passes through an orifice into the evaporator Evaporator In the evaporator refrigerant liquid is exposed to a substantially deeper vacuum than in the condenser due to the influence of the absorber As refrigerant liquid flows over the surface of the evaporator tubing bundle it boils and removes from the chilled water circuit an amount of heat equivalent to the latent heat of the refrigerant The recirculating chilled water is cooled to 44 6 F 7 C while the refrigerant vapor is attracted to the concentrated solution dripping over the absorber tubing bundle Absorber A deep vacuum in the absorber is maintained by the affinity of the concentrated solution from the generator with the refrigerant vapor formed in the evaporator Refrigerant vapor is absorbed by concentrated lithium bromide solution flowing across the surface of the absorber coil and being cooled by the cooling water The heat of condensation and dilution are removed by the cooling water and rejected to a cooling tower The resulting dilute solution is kT e preheated in a heat exchanger before the solution pump returns it
6. P3 ERROR P3D circuit is open co High Evaporator LT sensor reads above 68 F 20 c while HWT sensor reads COOLING Temperature above 140 F 60 c for 20 consecutive minutes E72 LT Sensor Error LT SENSOR LT sensor reads below 14 F 10 c or above 194 F 90 C Table 2 ERROR CODES 10 WARRANTY YAZAKI LIMITED EXPRESS WARRANTY 1 Scope of Coverage The Limited Express Warranty of Yazaki Energy Systems Inc Company applies to the initial retail purchaser and assigns Customer of Yazaki water fired chillers and chillers Product installed in the U S A Canada and Mexico 2 General Express Warranties a The Company warrants to the Customer that the Product shall be free from defects in materials and workmanship within a period of one 1 year Original Warranty Period from the time when the Product is initially placed in operation Start Up Date or two 2 years from the date of manufacture whichever expires first and subject to the disclaimers and limitations of this Limited Express Warranty b For liability under this Limited Express Warranty the Customer must arrange at its own cost for annual and seasonal routine maintenance of the Product prior to cooling operation and prior to heating operating of the Product by a Service Provider authorized by the Company in accordance with the Yazaki Operating and Maintenance Instructions 3 Disclaimer and Limitation of Express Wa
7. RBV Engaged for 5 minutes Standby Mode YES P1 Engaged Unit Enabled CTF Disengaged Error Code 27 Set Displayed than 10 minutes YES Error Code 27 Reset Cleared P2 P3 SP Engaged RBV Disengaged NO 84 2 F CTF CTF Control s Pontoled cond co by CTI 80 6 F 27 Sensor WTO lt Setpoint YES Post Dilution Cycle OPERATION COOLING To turn on the chiller simply turn on the disconnect switch on the Control Panel The unit will engage immediately The unit will be Enabled so long as the circuit is made at the terminals on the I O Board at TB1 labeled terminals 10 This is jumped from the factory so that the unit will always be in Local control REMOTE CONTROL To Enable and Disable the chiller by remote control locate TB1 on the I O board There are two terminals identified as terminal 10 on this terminal block These terminals have a jumper in place between them provided by the factory Remove this jumper and use these terminals for remote control of the Enable Disable function for the chiller These terminals are NOT a dry set of contacts Voltage is provided by the Yazaki circuit board on one of the two terminal 10 screws The completion of this circuit would be controlled by a field supplied set of dry contacts So long as that voltage returns to the other terminal 10 the chiller is Enabled lf that voltage is missing the chiller is Disabled SAFETY CONTROLS S
8. afety and limit controls monitor critical operating conditions in the chiller and may shutdown the unit when abnormal conditions occur An Error Code will be displayed on the touch screen control To view the code from the root screen press STATUS MONITOR The following screen should then be displayed A STATUS MONOTOR MODE STAGE STOP ERROR HOH Refer to Table 2 in this manual or to the Service Manual for explanation of the ERROR displayed Many errors automatically clear themselves when the abnormal condition no longer exists However some errors do require a manual reset of the unit To reset the unit turn off the breaker on the control panel wait 10 seconds then turn the breaker back on When errors are cleared they are recorded in the Error History screen The last 6 errors are kept in memory even after the unit has had power to it disconnected To access this error history from the root screen press DATA HISTORY Press the gt button located at the top right corner of the screen until the screen shown below is reached DATA HISTORY S ERROR HISTORY i E 4 Etg 2 y 5 EX 3 Ex g Egg CLP This screen displays the last 6 error codes Pressing the CLR button will clear these codes from memory For an explanation of code numbers found on this screen refer to Table 2 in this manual or to the Service Manual Press the A button located at the top left of the screen to
9. aki chiller Permanent damage could result from even _ a small amount of oil being introduced into the vacuum section e Never leave a vacuum pump running unattended Power loss could allow the chiller vacuum section to suck oil out of the pump in a matter of seconds e Never have the Service Valve open unless the vacuum pump is running and the integrity of the vacuum lines between the valve and the pump has been verified as tight e Never have the vacuum pump discharge tube in the water bucket unless the vacuum pump is running The vacuum pump could suck water from the bucket and contaminate the oil charge e Never pull an extended vacuum exceeding a few hours If such seems to be necessary there is likely to be something wrong with the vacuum pump or the oil has been contaminated with moisture inherently found inside the chiller vacuum section e Always start with a fresh oil charge in the vacuum pump e Always use a liquid trap or collection flask e Always use a vacuum gauge to verify the level of vacuum achieved Run time has almost nothing to do with the level of vacuum achieved Use only dual stage deep vacuum pumps Typical refrigeration vacuum pumps may not perform well on a vessel as large as the chillers vacuum section Just because the vacuum pump has stopped producing bubbles in the water bucket does NOT mean the vacuum level is adequate A digital vacuum gauge MUST be used in order to dete
10. anty and Limitation of Remedy Customer s remedies shall be limited even in the event of the Company s default of its warranty obligations or the failure of the essential purposes of this Warranty exclusively to those provided in Section 6 UNDER NO CIRCUMSTANCES SHALL THE COMPANY BE LIABLE FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES If the limitation of liability fails the essential purpose the Company s liability shall be 11 expanded to the minimum extent to avoid failure of the essential purpose Customer waives any cause of action or theory of liability including but not limited to those arising under contract tort strict liability product liability statutes or otherwise except as specifically provided by the Uniform Commercial Code as modified and limited herein The warranty periods of all replacement parts and Products shall be deemed to commence on the Start Up Date of the original component or Product not the installation date of the replacement part or Product and the Company s warranty obligation hereunder shall not be extended because of such replacement 8 Disclaimer of Implied Warranties The Company DISCLAIMS ALL IMPLIED WARRANTIES OTHER THAN GOOD TITLE INCLUDING BUT NOT LIMITED TO THOSE OF FITNESS FOR A PARTICULAR PURPOSE MERCHANTABILITY AND NON INFRINGEMENT There are no warranties which extend beyond those express warranties contained in this Limited Express Warranty Customer affirms that it has not rel
11. bitor charge is typically needed every eight years in Yazaki water fired chillers Graduated Figure 4 Capturing Gases WINTER SHUTDOWN The fluids contained within the chiller itself need no preparation for freezing conditions Only the fluid in the chilled water cooling water and heat medium fluid circuits needs to be addressed during potentially freezing conditions lf a chiller is to be shut down for the winter but no fluid circuits are to be drained then simply Disable the chiller and allow the unit to complete its Post Dilution Cycle Once completed it is safe to leave the unit as it sits for the off season Make certain that appropriate measures are taken to ensure the fluids in all fluid circuits are protected from freezing glycol heat tape etc lf a chiller is to be shut down and fluid circuits are to be drained Disable the chiller and allow the unit to complete its Post Dilution Cycle Once completed turn off the breaker on the unit control panel Then drain each fluid circuit Once drained make sure to blow in both directions through each circuit with compressed air or similar to make sure no significant amount of liquid remains inside them When the equipment is located outdoors in climates subject to freezing cooling water should be drained from the chiller fluid circuit piping and cooling tower at the end of the cooling season Use glycol of adequate concentration in the chilled water an
12. d heat medium circuits to prevent freeze damage The glycol will reduce the cooling and heating capacity but this may be offset somewhat by increasing the circuit flow If in doubt about potential freeze damage in your area discuss it with your ASP Remember damage to the chiller due to freezing is not covered by the product warranty TROUBLESHOOTING SYMPTOM Chiller does not operate Possible Cause REMEDY No High Voltage Check the LED for the Power indication on the Control Panel If it is not illuminated check the main power disconnect fuses and breakers Solution Pump Not Check for illumination of the CHE LED on the Control Panel If lit check the touch Running screen to determine the current error code Nothing may be wrong If the system chilled water loop has satisfied by reaching Chiller is not running but WTO temperature is above set point is above the set point SYMPTOM Poor cooling capacity the desired set point the unit will shut down until the WTO sensor reads a temperature 7 2 F 4 C above the set point temperature no matter how long that may take To force operation turn power off to the chiller leave power off for 10 seconds then restore power The chiller should start up if the WTO sensor reading Possible Cause REMEDY Evacuate the machine per normal maintenance procedure High Inlet Cooling Water amp 8 Check the cooling tower fan Check the cooling tower fluid level Tempe
13. erve precautions Failure to operate and maintain this equipment in accordance with the OPERATING INSTRUCTIONS may affect the equipment performance and product Warranty lf the equipment does not operate as expected check the Troubleshooting Guide in these instructions BEFORE calling your Yazaki Authorized Service Provider ASP This approach will not only save cost but also avoid any unnecessary downtime ABSORPTION PRINCIPLE Yazaki absorption chillers use a solution of lithium bromide and water under a vacuum as the working fluid Water is the refrigerant and lithium bromide is the absorbent During cooling operation refrigerant liquid boils under the influence of a deep vacuum in the evaporator and creates a refrigeration effect which removes heat from the chilled water circuit The single etfect absorption cycle has one generator heated by an external source of hot water a condenser an evaporator and an absorber The absorber and condenser are water cooled and heat is normally rejected to a cooling tower COOLING OPERATION Generator When the heat medium inlet temperature exceeds 154 4 F 68 C with a maximum of 203 F 95 C the solution pump forces dilute solution into the generator The solution is dripped over the generator tubing bundle where it boils under vacuum releasing refrigerant vapor The hot refrigerant vapor flows into the condenser and concentrated solution drips into the generator sump
14. ied upon the Company s skill nor judgement to select or furnish Product for any particular purpose The Company does not warrant that the Product complies with the requirements of any safety or environmental code or regulation of any federal state municipality or other jurisdiction beyond the specific express warranties in this Limited Express Warranty 9 Specific Exclusions In addition to all other exclusions contained in this Limited Express Warranty the Company s warranty shall also not apply under the following circumstances a Damage to the Product unauthorized Service Provider b Defect in any part which is not supplied by the Company c Installation or operation of the Product in any way not described in the applicable Yazaki Installation and Operating Instructions d Applications for single effect absorption chillers e Failure to provide routine maintenance of the Product by a Company authorized Service Provider in accordance with the applicable Yazaki Operating and Maintenance Instructions f Failure to maintain the quality flow and supply temperature of cooling water in accordance with Yazaki standards and limitations g Damage caused to the Product from freezing overpressure and corrosion in any water circuit h Misuse abuse negligence accident natural disaster alteration misapplication or experimental use of the Product caused by an process cooling except i Normal fading and mi
15. nor deterioration of the cabinet surface caused by exposure to the elements j Removal of the Product from its original installation site unless the relocation is approved in writing by the Company and performed by a Company authorized Service Provider k Materials such as inhibitor and batteries if required that are consumed during normal operation of the Product Damage to other products outside the Product not supplied by the Company caused by use of materials that are not compatible with the operating temperatures of the Product regardless of the absence of specific instructions in Yazaki Installation and Operating Instructions YAZAKI AUTHORIZED SERVICE PROVIDER For information concerning service operation or technical assistance please contact your Yazaki Authorized Service Provider or the following YAZAKI ENERGY SYSTEMS INC 701 E PLANO PKWY SUITE 305 PLANO TEXAS 75074 6700 Phone 469 229 5443 Fax 469 229 5448 Email yazaki yazakienergy com Web http www yazakienergy com UL us This symbol on the product s name plate means it is listed by UNDERWRITERS LABORATORIES INC Yazaki reserves the right to discontinue or change at any time specifications or designs without notice and without incurring obligations WFC5UL OI 1A1 061 1 12
16. rature Low Cooling Water Flow a ee 6 Check the cooling tower sump and cooling water circuit strainers Condenser Absorber Fouling Scale Buildup Check the cooling water circuit strainers It may be necessary to drain the cooling water circuit and open the inspection doors on the chiller condenser and absorber for a visual confirmation Nothing may be wrong If the load of the chilled water circuit exceeds the capacity Everything appears normal but the leaving chilled water temperature approximately 8 12 F 4 6 C then the chiller is actually giving its full capacity and it is too high of the chiller the system will find equilibrium at a higher leaving chilled water temperature Ifthe temperature drop through the chilled water loop is simply may not be enough Check for reasons that the load may have artificially increased open doors new equipment leaking valves etc WATER QUALITY It is the End User s responsibility to have the limits specified in Table 1 The water quality in cooling water analyzed and chemically treated as the chilled water cooling water and heat medium often as necessary so that it conforms to the circuits shall not exceed the following limits pH at 77 F 6 8 8 0 Ghiordeion CF ppm Sulfate ion SO ppm Makiy CaCOspom Total hardness GaCOsppm 70 Calcium hardness CaGOsppm BO OO O aaa Sows pO ND NH ppm wo Residual chlorine CI ppm P08 Free ca
17. rbon dioxide CO2 ppm p40 Ryzner stability index E NOTES 1 ND Not Detectable 2 Total hardness of make up water shall not exceed 70 ppm when bleed off is the only method used to control water quality Table 1 WATER QUALITY REQUIREMENTS i i 00 50 50 50 70 50 30 1 0 1 0 ND 1 0 0 3 4 0 O Las xe Cc _ a S im tj am ERROR CODES P1D circuit is open P2D circuit is open TF Error TF ERR FD circuit is open E08 Solution Pump Error SP ERR Solution Pump VFD controller reports alarm condition WTO Sensor Error WT SENSOR WTO sensor reads below 14 F 10 C or above 194 F 90 C 27 Flow Switch 1 Open FS1 ERR On board chilled water flow switch is open E33 CTI Sensor Error CTI SENSOR CTI sensor reads below 14 F 10 c or above 194 F 90 C High Cooling Water CTI sensor reads above 95 F 35 C for 5 continous E37 CTI HIGH i Temperature Error seconds Ignored for first 3 minutes of a cycle HWT sensor reads above 204 8 F 96 c for 5 consecutive Heat Medium HWT HIGH seconds Reset only allowed once HWT sensor reading Overtemp Error falls below 190 4 F 88 C Low Cooling Water CTI LOW consecutive minutes Reset only allowed once CTI sensor Temperature Error reads above 48 2 F 9 C HWT Sensor Error HWT SENSOR HWT sensor reads above 212 F 100 C co CTI sensor reads below 46 4 F 8 c for more than 2 E48 P3Error
18. rmine the true level of vacuum achieved The desired level of vacuum on a machine that is not running would be less than 1500 microns lt 1 5mmHg with less than 1000 microns lt immHg preferred On a machine actively running in Cool mode attempting to satisfy chilled water loop load the desired level of vacuum is 4 5000 microns 4 5mmHg no less Any lower than that on a running machine can cause the vacuum pump to remove an extraordinary amount of refrigerant vapor water A step by step detailed evacuation method is provided in the Service Manual The general evacuation assembly setup is displayed in Figure 3 Service Vaive A Digital Vacuum Gauge Latex Chiller Fiare Adapter pm Vacuum Hose Vinyl Tubing Bucket Service Valve B Latex Vacuum Hose Liquid Trap Vacuum Pump Figure 3 General Evacuation Assembly Setup CHEMICAL MAINTENANCE It is not necessary to perform regular chemical maintenance on the Yazaki Chiller itself The chemical balance has been established in the factory during run testing Normally the only chemical that must be maintained is the inhibitor charge By capturing non condensable gases as shown in Figure 4 comparisons can be made to determine if the normal hydrogen byproduct is being produced at anticipated rates If more hydrogen is being produced than anticipated a maintenance inhibitor charge may need to be introduced into the machine by the ASP An inhi
19. rranties There are no express warranties other than those contained in this Limited Express Warranty 4 Warranty Registration Card Every new Product is accompanied by a Warranty Registration Card which must be completed signed by an authorized representative of the Customer and returned to the Company This Limited Express Warranty shall not apply unless the Warranty Registration Card is fully completed and returned to the Company within thirty 30 days of the Start Up date of the Product 5 Warranty Service All routine maintenance parts replacement and vacuum section repairs of the Product during the Original Warranty Period must be performed by a Service Provider authorized by the Company 6 Remedy During Original Warranty Period The Company shall at its sole discretion repair or replace the covered Product or parts thereof which the Company shall determine upon examination to be defective or not in conformity with the Original Warranty contained herein Defective Part subject to the terms hereof The Company shall supply by standard ground transportation all parts required to repair or replace any Defective Part and shall pay to the Service Provider the necessary labor charges as fixed in the Company s warranty service payment schedule in effect from time to time Fixed Labor Charges The Customer shall be solely responsible for all labor costs or charges in excess of the Fixed Labor Charges 7 Limitation of Warr
20. vice visits to evacuate non condensable gases from the vacuum section MAINTENANCE INTERVALS Every 4 months 1 Evacuate non condensable gases from the vacuum section Evacuation can be skipped during the off season 2 Inspect the condition of the cooling tower and cooling water circuit Every 12 months 1 Check function of the flow switch 2 Measure the absorption cycle temperatures to verify they remain in normal ranges 3 Visual inspection of all controls and of the physical condition of the unit 4 Verify the unit remains level EVACUATION OVERVIEW Arguably the most important aspect of maintenance for the chiller is maintaining a proper level of vacuum Evacuation is performed at the front of the machine The evacuation service valves are referred to as Service Valve A upper and Service Valve B lower The evacuation service valves are back seating access valves similar to those used throughout the refrigeration industry The stem has a 10mm square head The stem secures a copper seal to a steel seat inside the valve Do not over torque this valve or else the seal can become damaged and compromise vacuum integrity The proper torque is 14 75 ft lbs 20 Nm Yazaki offers a torque wrench P N N7510 specifically for use with this service valve A number of precautions should be observed at all times during evacuation Key points are Great care must be taken to ensure that no oil enters the Yaz
Download Pdf Manuals
Related Search