Daikin WCT Series Operating & Maintenance Manual Download Page 15

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OMM WCT

Centrifugal Chillers

D-EOMWC01302-16EN - 15/84

Controller Description

Hardware Structure

The MicroTech III control system for WCT chillers consists of a main unit controller with a number of extension
input/output I/O modules, Operator touch screen, lubrication control, miscellaneous switches and field
connections terminals.

One of the optional BAS communication modules may be included.

The MicroTech III controllers used on WCT chillers are not interchangeable with previous MicroTech II
controllers.

BACnet/IP

BACnet/

MSTP

MODbus LON

Communication

Cards

AWM

MicroTech III unit controller

Extension I/O Modules

Touch Screen

Figure 7, Hardware layout

Summary of Contents for WCT Series

Page 1: ...ow Centrifugal Chillers with Two Stage Compressors 2200 to 3250 TONS 7750 to 11400 kW Series Counter Flow with Two Stage Compressors 4500 to 6400 TONS 15830 to 22500 kW Operating Maintenance Manual D EOMWC01302 16EN ...

Page 2: ...Cleaning and Preserving 69 Annual Startup 71 Repair of System 72 Charging the System 74 Maintenance Schedule 77 PERATING LOG SHEET 81 Service Programs 82 Operator Schools 82 Warranty Statement 82 Manufactured in an ISO Certified Facility 2013 Daikin International Illustrations and data cover the Daikin International product at the time of publication and we reserve the right to make changes in des...

Page 3: ...ervice personnel Cautions and Warnings At several points in the manual items of special interest or significant impact are highlighted by one of the following notices in the appropriate section of the manual DANGER Dangers indicate a hazardous situation which will result in death or serious injury if not avoided WARNING Warnings indicate potentially hazardous situations which can result in propert...

Page 4: ...tage K compressors and provide cooling capacity from 2200 to 3250 TONS 7750 to 11400 kW depending on operating conditions in each chiller which comes up 4500 to 6400 TONS 15830 to 22500 kW system capacity when chiller installs in series counter flow configuration In the WCT series each unit has two compressors and two economizers connected to a single condenser and an evaporator Each condenser and...

Page 5: ...peller P2 Motor Rating kW Z Voltage V and Frequency Hz EVAPORATOR E5426 Evaporator Diameter in and Length ft B Tube Count G Tube Type 1 Number of Passes L Water Inlet Nozzle Location R Right Inlet L Left Inlet L Nozzle Configuration CONDENSER C5426 Condenser Diameter in and Length ft B Tube Count R Tube Type 1 Number of Passes L Water Inlet Nozzle Location R Right Inlet L Left Inlet L Nozzle Confi...

Page 6: ... the two compressors and economizers on the chiller Each circuit is isolated from each other by a welded tube sheet in the middle of the vessel They are available in single pass only Single pass water flows in evaporator and condenser are counterflow to each other Each of the two separate refrigerant circuits use the vapor compression cycle as shown in Figure 3 Figure 2 Series Counterflow Flow Dia...

Page 7: ...e 3 phase squirrel cage induction semi hermetic motor Condenser Subcooler The condenser is a shell and water tube heat exchanger with the refrigerant in the shell side where gained heat from evaporator and compressor is rejected out of chiller system Starting at the inlet of the condenser the high pressure high temperature refrigerant vapor is forced into the condenser and as it passes through the...

Page 8: ...hiller operation than without economizer system which is one of the most advantage of 2 stage with economizer system The expanded liquid vapor mixture from the expansion valve enters the economizer where vapor and liquid separate from each other The liquid being denser than the vapor accumulates at the bottom of the economizer and the vapor bubbles through liquid refrigerant to the top of the econ...

Page 9: ...d level upwards until the entire bundle is just submerged in boiling refrigerant The increased boiling takes place where the tube depth is greater in the bundle at the center The greater the tube depth the greater the amount of heat transferred causing boiling The flow is then directed out of the evaporator shell and routed to the inlet of the compressor Any major entrained liquid in the vapor flo...

Page 10: ...rough a factory pre set pressure regulator valve It maintains above 22 psi as minimum and around 50psi 50Hz 36psi 60Hz as normal oil differential pressure the difference between the oil sump and oil supply pressure to gear bearings A plate type oil cooler maintains the proper oil temperature under normal operating conditions A TXV valve maintains less than max 140 F 60 C oil supply temperature by ...

Page 11: ...st of the case oil out of the compressor happens through vent line see Figure 4 and will primarily drain to bottom of IGV plenum and any oil out of the compressor eventually fall or drain to the evaporator The excess accumulation of oil in the evaporator will cause oil foaming which may entrain liquid refrigerant into compressor carry over and letting compressor performance lower Also it will caus...

Page 12: ...r filter drier when excessive amount of lubricant is noticeable in the refrigerant charge as viewed in the liquid line sight glass The filter drier PN is 735028828 Figure 5 Eductor Circuits and Scroll Drain Lines Note Connections are not necessarily in correct relative location and can vary depending upon specific model Standby Power It is essential that any centrifugal chiller connected to standb...

Page 13: ...Warning and fault diagnostics to inform operators of warning and fault conditions in plain language Al1 warnings problems and faults are time and date stamped so there is no guessing of when the fault condition occurred In addition the operating conditions that existed just prior to shutdown can be recalled to aid in isolating the cause of the problem Twenty five latest faults are displayed on the...

Page 14: ...ing conditions by using the screens on the OITS or screen located on the main controller In addition to providing all normal operating controls the MicroTech III control system will take corrective action if the chiller is operating outside of its normal design conditions If a fault condition develops the controller will shut a compressor or the entire unit down and activate an alarm output The sy...

Page 15: ...dules Operator touch screen lubrication control miscellaneous switches and field connections terminals One of the optional BAS communication modules may be included The MicroTech III controllers used on WCT chillers are not interchangeable with previous MicroTech II controllers BACnet IP BACnet MSTP MODbus LON Communication Cards AWM MicroTech III unit controller Extension I O Modules PC Touch Scr...

Page 16: ...communicate and have optimized series counter flow system capacity control by looking at common ELWT at lag chiller when providing Konex interface cable between controllers are provided and series chiller mode is chosen from MicroTech III controller Figure 8 System Architecture I O Extension Circuit 1 C C 1 I O Extension Circuit 1 V C 1 I O Extension Circuit 1 O P 1 I O Extension Tower Control BAS...

Page 17: ...OMM WCT Centrifugal Chillers D EOMWC01302 16EN 17 84 Field Wiring Diagram Figure 9 Field Wiring Diagram ...

Page 18: ...and condenser flow switches are required Factory mounted flow switches are standard on WCT units Field installed flow switches must be wired as shown If field supplied pressure differential switches are used then these must be installed across the vessel and not the pump Paddle flow switches may also be field installed if desired 7 Customer supplied 24 to 230 VAC 20 amp power for optional evaporat...

Page 19: ...ent position Figure 10 OTIS Screen Layout Hardware Structure The controller is fitted with a 32 bit microprocessor for running the control program There are terminals for connection to the controlled devices for example solenoid valves pumps The program and settings are saved permanently in FLASH memory preventing data loss in the event of power failure without requiring a back up battery The cont...

Page 20: ...ll shut down Signal Converter Board On medium voltage starters the AC current signal generated by the starter is converted by the signal converter board into a 0 5 VDC signal that is directly proportional to the compressor motor amp draw The amp draw signal is sent to the compressor controller Navigation The Main screen is shown Main screen on page 25 is usually left on Other of screens can be acc...

Page 21: ... 4 Fan Contactor Fan OFF Fan ON Table 4 Unit Controller Analog Outputs Description Output Signal Range OC X1 Cooling Tower Bypass Valve Position 0 to 10 VDC 0 to 100 Open OC X2 Cooling Tower VFD Speed 0 to 10 VDC 0 to 100 Circuit I O Inputs and outputs are as follows Table 5 Circuit I O Analog Inputs Description Signal Source Range CC AI1 Compressor Suction Temperature NTC Thermister 10k 25 C 58 t...

Page 22: ...tput OFF Output ON CC DO1 Latch Relay Relay CC DO2 Open CC DO3 Hot Gas Bypass Solenoid No Bypass Bypass CC DO4 Economizer Bypass Solenoid No Bypass Bypass CC DO5 Open CC DO6 Open CC DO7 Open CC DO8 Open CC DO9 Open CC DO10 Open CC X7 Open CC X8 Open VC DO1 EXV Init Relay VC DO2 Open VC DO3 Open VC DO4 Open VC DO5 Hot Gas Bypass Open Relay Null Actuator Drive Open VC DO6 Hot Gas Bypass Close Relay ...

Page 23: ...Press Trend Trend Any Screen TREND Alarm History Press Main Main Any Screen MAIN Detail Press Compressor Compressor Any Screen COMPRESSOR Summary Motor Lubrication IGV DDC Hot Gas Press Evaporator Evaporator Any Screen EVAPORATOR Press Condenser Condenser Any Screen CONDENSER Press Economizer Economizer Any Screen ECONOMIZER Press Expansion Expansion Any Screen EXPANSION Press Tower Tower Any Scre...

Page 24: ...ion of the chiller and is the screen that is normally left on Superimposed on a chiller schematic is Information Active chilled water setpoint Entering and leaving chilled water temperatures Entering and leaving condenser water temperatures Percent motor amps UNIT STATUS is MODE followed by STATE followed by the SOURCE that is the device or signal that created the STATE The possible combinations a...

Page 25: ... or signal that created the STATE The possible combinations are in the following table Table 10 COMPRESSOR STATUS Possibilities Status Text in priority sequence Off Ready Off Cycle Timer xxx Off Max Comp Starts Off Manual Switch Off Oil Temperature Off DDC Calibrating Off IGV Calibrating Off Alarm Test Mode Prelube Timer xxx Unload Timer xxx Postlube Timer xxx Run Normal Off Exv Calibrating Oil Pu...

Page 26: ...cally when it is under control of a remote signal such as a BAS Trend takes you to the Trend history screen Settings take to you to Set points screens Alarms Warnings take you to the Alarms screens Returning Pressing the Main button from any screen will return to the Main screen Figure 13 Detail View Screen Pressing the Detail button on the bottom of the Main screen Figure on page 25 24 accesses t...

Page 27: ...OMM WCT Centrifugal Chillers D EOMWC01302 16EN 27 84 Table 14 Compressor Screen Pressing the Compressor button will give detailed information on the compressor State Inputs and Outputs ...

Page 28: ... 28 84 Figure 15 Evaporator Screen Pressing the Evaporator or Condenser button will give detailed information on the evaporator or condenser Figure 16 Economizer Screen Pressing the Economizer button will give detailed information on the Economizer ...

Page 29: ...s involving pumps and tower operation are field set Pressing the SET button found on almost every screen accesses the last SET screen used or the SERVICE screen whichever of the two was used last When in any SET screen pressing the SET button again will toggle to the SERVICE screen shown on page 43 The next figure shows the Settings screen with WATER setpoints selected The various setpoint groups ...

Page 30: ...rsonnel T Technician level password is reserved for authorized technicians 4 Press the appropriate numbers in the numeric keyboard to enter the password There is a small delay between pressing the keypad and recording the entry Be sure that an asterisk appears in the window before pressing the next number Press Green Check button to return to the Settings screen The password will remain open for 1...

Page 31: ...c 2 ALARMS for setting the limit and shutdown alarms 3 VALVE sets the parameters for operation of an optional field installed tower bypass valve 4 TOWER selects the method of controlling the cooling tower and sets the parameters for fan staging VFD 5 MOTOR selects motor related setpoints such as amp limits VFD settings etc Also has maximum and minimum rate of change of chilled water temperature 6 ...

Page 32: ...0 to 10 0 F M Degrees above setpoint for compressor to start Stage Delta T 1ºF 0 5 to 5 F M Sets the temperature the leaving water must be below setpoint for next compressor to start LWT Reset Type NONE NONE RETURN 4 20mA M Select reset type NONE for none RETURN for reseting chilled water based on the entering water or 4 20 mA for external analog signal Start Reset Delta T 10 0 F 0 0 to 20 0 F M S...

Page 33: ...cted in SP 2 Evap Pump Pump 1 Only Pump 1 Only Pump 2 Only Auto Lead 1 Primary 2 Primary M Pump 1 Only Pump 2 Only use only these pumps AUTO balance hours between 1 and 2 1 Primary 2 Primary if primary fails use other Cond Pump Pump 1 Only Pump 1 Only Pump 2 Only Auto Lead 1 Primary 2 Primary M Pump 1 Only Pump 2 Only use only these pumps AUTO balance hours between 1 and 2 1 Primary 2 Primary if p...

Page 34: ... of RLA Soft Load Ramp 5 min 1 to 60 min M Time period to go from initial load point RLA set in SP 5 to 100 RLA Minimum Rate 0 1 F min 0 0 to 5 0 F min M Additional compressor can start if LWT change is below setpoint Maximum Rate 0 5 F min 0 1 to 5 0 F min M Inhibits loading if LWT change exceed the setpoint value Nominal Capacity 0 to 9999 Tons Determines when to shut off a compressor Oil No Sta...

Page 35: ...etween stage up down event and next stage down Stage Differential Lift 6 0 psi 1 0 to 20 0 psi M Fan staging deadband with Setpoint 1 Lift Stage 1 On Lift 35 psi 10 to 130 psi M Lift pressure for fan stage 1 on Stage 2 On Lift 45 psi 10 to 130 psi M Lift pressure for fan stage 2 on Stage 3 On Lift 55 psi 10 to 130 psi M Lift pressure for fan stage 3 on Stage 4 On Lift 65 psi 10 to 130 psi M Lift p...

Page 36: ...control with VFD plus bypass valve control Tower Fan Staging Only NONE The following settings are used for the Tower Fan Staging Only mode SP setpoint 1 TOWER SETPOINT Screen i Tower Control Select TEMP if control is based on condenser EWT or LIFT if based on compressor lift expressed in psi ii Valve VFD Control Select NONE for no bypass valve or fan VFD control iii Tower Stages Select one to four...

Page 37: ...e i Stage Diff Select STAGE DIFFERENTIAL in PSI Start with default of 6 PSI ii Stage 1 On Lift Start with default setpoints The number of STAGE ON setpoints used must be the same as Tower Stages 2 VALVE SETPOINT Screen a Valve Type Select NC or NO depending if valve is closed to tower with no control power or open to tower with no control power b If TEMP was selected for fan control above use i Va...

Page 38: ...vii Error Gain Set the control gain for error Default is 25 viii Slope Gain Set the control gain for slope Default is 25 NOTE Setpoints Error Gain and Slope Gain are site specific dealing with system fluid mass component size and other factors affecting the reaction of the system to control inputs These setpoints should be set by personnel experienced with setting up this type of control Figure 23...

Page 39: ...se to an error between the tower target and feedback signal Slope Gain The slope signal is used to correct the current tower setting based on the direction and rate of change in the tower feedback signal The Slope Gain setpoint is used to increase or decrease the control logic sensitivity to this input The default setting is 25 with an adjustment range from 10 to 99 Increasing this setting will in...

Page 40: ... Tower Setpoint 1 Lift Stage Up 80 0 to 100 M Valve position above which the fans can stage up Tower Setpoint 2 Valve Stage Down VFD speed above which the next fan speed can turn on Tower Setpoint 2 valve VFD Stage Down 20 0 to 100 M Valve position below which the fans can stage down Tower Setpoint 2 Valve Stage Down VFD speed below which the next fan speed can turn off Tower Setpoint 2 valve VFD ...

Page 41: ...ax discharge gas temp load comp High Discharge Temp Shutdown 190 F 120 to 240 F T Max discharge gas temp stop compressor Surge Temperature Limit 6 2 25 F T See screen above Surge Slope Limit 20 1 99 F min T Surge slope temp that triggers alarm Motor Current Threshold 10 3 to 99 T Min RLA to consider motor off Evaporator Freeze 34 0 F 9 0 to 45 0 F T Minimum evap sat temp to start pump Condenser Fr...

Page 42: ...to 60 min M Time from when compressor starts to when it can start again Stop Start 3 min 3 to 20 min M Time from when compressor stops to when it can restart Prelube Timer 30 sec 10 to 240 sec T Time compressor must prelube before starting Full Load Timer 30 sec 5 to 60 sec T Time compressor must load for full open vanes Unload Timer 30 sec 10 to 240 sec T Time compressor will unload before going ...

Page 43: ...le information for the operator The touch screen software version number shown in the upper right corner The Operating Manual button will access the operating and maintenance manual for the unit Pressing these buttons will display the manual on the screen where it can be manipulated as an Adobe Acrobat file Language allows toggling between the available languages Date Time in the lower right corne...

Page 44: ...our 2 hour or 20 minute periods by pressing 8 hour 2 hour or 20 min respectively from the default 1 hour Display for the current time beginning on the left of the screen with history flowing to the right To download trend data or trend image connect a USB portable storage device to the USB port located in the unit control box adjacent to the OITS press the copy trend data button or the copy trend ...

Page 45: ... on top with date stamp action taken and the cause of the alarm This screen is also used to download the Alarm History shown above To download alarm history connect a USB portable storage device to the USB port located in the unit control box adjacent to the OITS press the copy alarm data button then select location to save the file ...

Page 46: ...ive alarm connect a USB portable storage device to the USB port located in the unit control box adjacent to the OITS press the copy alarm data button then select location to save the file Clearing Alarms After eliminating the cause of the alarm clear the alarm by pressing the clear alarm button This will clear the alarm from the register and allow the unit to restart after going through the start ...

Page 47: ...art Compressor State START for 30 sec Rapid Stop No Evaporator Water Flow Chilled Water Flow Switch Open Rapid Stop No Condenser Water Flow Condenser Water Flow Switch Open Rapid Stop Leaving Evaporator Water Temperature Sensor Fault Sensor shorted or open Rapid Stop Evaporator Pressure Sensor Fault Sensor shorted or open Rapid Stop Condenser Pressure Sensor Fault Sensor shorted or open Rapid Stop...

Page 48: ...SP Start condenser pump Temp Condenser Freeze SP 2 F High Discharge Temperature Temperature High Discharge Temperature Load SP AND Suction superheat 15 F Load Temp High Dsch Temp Load SP 3 F OR Superheat 18 F A warning is annunciated whenever an abnormal condition exists which does not affect chiller operation Table 19 Warning Alarm Description WARNING CONDITION Liquid Line Refrigerant Temperature...

Page 49: ...ne visible on each display includes the menu title and the line number to which the cursor is currently pointing in the above case 3 Temperature The left most position of the title line includes an up arrow to indicate there are lines parameters above the currently displayed line and or a down arrow to indicate there are lines parameters below the currently displayed items or an up down arrow to i...

Page 50: ...e screen so pressing the wheel goes to the edit mode where the password 5321 can be entered The first will be highlighted rotate the wheel clockwise to the first number and set it by pressing the wheel Repeat for the remaining three numbers The password will time out after 10 minutes and is cancelled if a new password is entered or the control powers down Not entering a password allows access to a...

Page 51: ...ition An R W indicates a read and or write opportunity a value can be read or changed providing the proper password has been entered Example 1 Check Status for example is the unit being controlled locally or by an external network We are looking for the Unit Control Source since this is a unit status parameter start at Main Menu and select View Set Unit and press the wheel to jump to the next set ...

Page 52: ...ntrifugal Chillers D EOMWC01302 16EN 52 84 to jump to the next screen With the first line highlighted press the wheel to enter edit mode Rotate wheel until AlmClr is set to On then press wheel to clear the alarms ...

Page 53: ...me Until Restart Compressor 1 Cycle Time Remaining Compressor 2 Cycle Time Remaining Alarms Alarm Active Active Alarm 1 Active Alarm n Clear Alarms Alarm Log Alarm Entry 1 Alarm Entry 25 Clear Log Scheduled Maintenance Next Maintenance Month Year Service Support Reference About This Chiller Model Number G O Number Unit Serial Number Starter Model Number s Starter Serial Number s BSP Version Applic...

Page 54: ...t Up Temperatures Date Time Schedules Power Conservation Alarm Limits Ctrlr IP Setup Design Conditions Menu Password View Set Circuit Circuit 1 Circuit 2 Data Compressor 1 Data Motor Oil Sump Exv Unit Status Active Setpoint Evap Leaving Water Temp Unit Mode Time Until Restart Alarms Alarm Active Alarm Log Event Log Unit Power Restore Circuit 1 Circuit 2 Scheduled Maintenance About This Chiller ...

Page 55: ... Alarm Limits Calibrate Sensors Configuration Ctrlr IP Setup Design Conditions Evap Approach Design Cond Approach Design Menu Password View Set Circuit Circuit 1 Circuit 2 Data Compressor 1 Data Motor Oil Sump IGV DDC VFD Setup Exv Calibrate Sensors Unit Status Active Setpoint Evap Leaving Water Temp Unit Mode Time Until Restart Alarms Alarm Active Alarm Log Event Log Unit Power Restore Circuit 1 ...

Page 56: ...l Control Unit Circuit 1 Compressor 1 Circuit 2 Compressor 1 Commission Unit About Chiller Configure Unit Set Up Date Time Schedules Power Conservation Alarm Limits Calibrate Unit Sensors Calibrate Circuit Sensors Ctrlr IP Setup Alarm Active Alarm Log Scheduled Maintenance Save Parameters Unit Manual Control C1 Manual Control C2 Manual Control About This Chiller ...

Page 57: ...135 0 F 100 0 to 150 0 F O Startup Delta T 3 0 F 0 0 to 10 0 F O Shutdown Delta T 3 0 F 0 0 to 3 0 F O LWT Reset Type NONE NONE RETURN 4 20mA M Max Reset Delta T 0 0 F 0 0 to 20 0 F M Start Reset Delta T 10 0 F 0 0 to 20 0 F M Evap Recirculate 30 sec 0 2 to 5 min M Evap Pump Control Pump 1 Only Pump 1 Only Pump 2 Only Auto Lead 1 Primary 2 Primary M Cond Pump Control Pump 1 Only Pump 1 Only Pump 2...

Page 58: ...inimum Amps 40 5 to 80 T Demand Limit Maximum Amps 100 10 to 100 T Soft Load Enable OFF OFF ON M Begin Amp Limit 40 10 to 100 M Nameplate RLA 0 0 Amps 0 0 to 2000 Amps Soft Load Ramp Time 5 min 1 to 60 min M Stage Down RLA 60 0 0 to 99 0 Db Adjustment 0 0 0 0 to 0 3 C Capacity Balance 10 0 2 to 18 Lead Unload Rate 6 0 2 to 18 Balance Mode Local Unit Local Unit Network Unit Alternative Motor RLA In...

Page 59: ...rature 158 F 0 to 212 F T Vanes Calibration Time 8 hrs 0 3 to 24 hrs VFD VFD Enable No No Yes T VFD Minimum Speed 70 70 to 100 T Speed 0 Lift 50 0 to 100 T Lift 100 Speed 22 2 C 16 7 to 33 3 C T VFD Update 4 sec 1 to 20 sec VFD Output Type 4 20mA 4 20mA 0 10Vdc Circuit Exv Gain 1 0 25 to 4 0 Exv Offset 700 0 100 0 to 2000 0 Exv SC Ratio 110 0 80 0 to 250 0 Exv Offset Target 0 0 9 0 to 9 0 Exv Supe...

Page 60: ...d Default DDC_Y1 0 0 T DDC_Y2 16 0 T DDC_Y3 22 0 DDC_Y4 25 0 M DDC_Y5 39 0 M DDC_Y6 45 0 DDC_Y7 100 0 T IGV_X1 5 0 T IGV_X2 8 0 IGV_X3 12 0 T IGV_X4 15 0 IGV_X5 20 0 T IGV_X6 25 0 IGV_X7 32 0 T SavedDDC_Y1 0 0 T SavedDDC_Y2 16 0 T SavedDDC_Y3 22 0 SavedDDC_Y4 25 0 M SavedDDC_Y5 39 0 M SavedDDC_Y6 45 0 SavedDDC_Y7 100 0 T SavedIGV_X1 5 0 T SavedIGV_X2 8 0 SavedIGV_X3 12 0 T SavedIGV_X4 15 0 SavedIG...

Page 61: ...Press 6 0 psi 1 0 to 20 0 psi M Tower Stage On Lift 1 35 psi 10 to 130 psi M Tower Stage On Lift 2 45 psi 10 to 130 psi M Tower Stage On Lift 3 55 psi 10 to 130 psi M Tower Stage On Lift 4 65 psi 10 to 130 psi M Tower Valve Setpoint Lift 207 0 69 0 to 897 0 kPa Tower Valve Db Lift 14 0 7 0 to 138 0 kPa Tower Valve VFD Control None None Valve Setpoint Valve Stage VFD Stage Valve SP VFD Stage M Towe...

Page 62: ...w as calculated by the following equation and shown in the chart following Note Provisions or modifications need to be made in the event of inverted starts condenser water colder than chilled water For example 3 way bypass valve controlled by the chiller or tower controls Min ECWT 10 973 LCHWT 0 17 CHWDTFL PLD 100 8 PLD 100 2 ECWT Entering condenser water temperature LCHWT Leaving chilled water te...

Page 63: ...erations the minimum allowable entering condenser water temperature must be maintained Depending on local climatic conditions using the lowest possible entering condenser water temperature may be more costly in total system power consumed than the expected savings in chiller power would suggest due to the excessive fan power required Even with tower fan control some form of water flow control such...

Page 64: ... Charging CAUTION Improper servicing of the oil system including the addition of excessive or incorrect oil substitute quality oil filter or any mishandling can damage the equipment Only authorized and trained service personnel should attempt this service For qualified assistance contact your local Daikin service location Failure to do so can cause severe compressor damage After the system is once...

Page 65: ...rk color or cloudy oil rather than clear is an indication of contamination and should be further investigated An annual oil check by a qualified laboratory is essential for maintaining a high level of maintenance It is useful to have an oil analysis at initial startup to provide a benchmark from which to compare future tests Oil analysis has long been recognized as a useful tool for indicating the...

Page 66: ...N above 0 19 change lubricant lubricant filter and filter drier and resample at normal interval In general Daikin International does not recommend changing oil and filters on a periodic basis The need should be based on a careful consideration of oil analysis vibration analysis and knowledge of the operating history of the equipment A single oil sample is not sufficient to estimate the condition o...

Page 67: ...o handling or contamination of the oil sample It should be noted that air and moisture can penetrate plastic containers Metal or glass containers with gasket in the top will slow moisture entry In conclusion a single element of an oil analysis should not be used as the basis to estimate the overall internal condition of a Daikin chiller The characteristics of the oil and refrigerant and knowledge ...

Page 68: ... Also check all pump and motor amperages and compare with nameplate ratings 2 Inspection must verify that the lubricant heaters are operative The heaters are insert cartridge type and can be checked by ammeter reading They should be energized whenever power is available to the control circuit when the lubricant temperature sensor calls for heat and when the compressor is inoperative When the compr...

Page 69: ...witch in the unit control panel to the OFF position 4 Check for corrosion and clean and paint rusted surfaces 5 Clean and flush the water tower Make sure tower blowdown or bleed off is operating Set up and use a good maintenance program to prevent scaling of both tower and condenser It should be recognized that atmospheric air contains many contaminants that increase the need for proper water trea...

Page 70: ...es and the process is often referred to as scaling Warmer the surface less soluble Deposits on cold surfaces if bulk solubilities are exceeded In precipitation fouling which may occur simultaneously with particulate fouling chemicals dissolved solids that are contained in the cooling water will deposit on the inner surface of the tube if the concentration of the chemicals is higher than the solubi...

Page 71: ...lly through the sight glasses or poor chiller capacity Eddy current testing is recommended based on site conditions to determine any defective tubes Annual Startup A dangerous condition can exist if power is applied to a faulty compressor motor starter that has been burned out This condition can exist without the knowledge of the person starting the equipment This is a good time to check all the m...

Page 72: ...t down until the MicroTech III controller cuts out at approximately 26 psig It is possible that the unit might experience a mild surge condition prior to cutout If this should occur immediately shut off the compressor Then close the following lines only after the compressor stops 1 Oil cooling supply line 2 Motor cooling supply line 3 Eductor gas supply line 4 First stage scroll drain line Use a p...

Page 73: ...down on low evaporator pressure 2 Continue taking liquid charge out after shutdown while circulating warm condenser water in the unit to keep the condenser pressure higher than the cylinder pressure 3 Once the pressures between the cylinder and unit equalizes connect a recovery unit with a capacity that will reduce the vacuum to the acceptable EPA standards 4 An electronic or other type of micron ...

Page 74: ...rator and at the bottom of economizer as well as sight glasses on the evaporator economizer and condenser If there are any leaks found then first repair the leaks If the system is evacuated due to service and is still under a vacuum then in order to put charge back into the system follow these steps which are applicable for both circuits 1 Make up a suitable charging connection from new copper tub...

Page 75: ...f freezing liquid within the evaporator tubes If the liquid is water then the system pressure corresponding to the freezing point would be 28 psig 0 19 MPaG for R 134a at sea level Therefore keep charging with refrigerant vapor until the chiller pressure is well above 28 psig 8 After the chiller pressure is above 28 psig by gas charging the rest of the charge could be put into the system by refrig...

Page 76: ...d through the main control console in order to manage the process If charge needs to be taken out during trimming for optimum performance then repeat Step 8 with connection to the bottom of the condenser during running at high load high head condition or at full load with high condenser water inlet temperature The refrigerant charge level and capacity should be monitored as explained above in orde...

Page 77: ...p X B Lubrication System Lubricant Appearance clear color quantity O Lubricant Filter Pressure Drop O Lubricant Analysis Note 6 X Lubricant change if indicated by lubricant analysis X III Controls A Operating Controls Calibrate Temperature Transducers X Calibrate Pressure Transducers X Check Vane Control Setting and Operation X Verify Motor Load Limit Control X Verify Load Balance Operation X Chec...

Page 78: ...r reading Failure to do so will produce a low reading In handling electrical components only fully qualified technicians must attempt service 3 Approach temperature the difference between the leaving water temperature and the saturated refrigerant temperature of either the condenser or evaporator is a good indication of tube fouling particularly in the condenser where constant flow usually prevail...

Page 79: ...t give enough load due to linkage slippage etc High Evaporator pressure Low Evaporator water leaving Temperature IGV failed to open Check the IGV motor positioning circuit System Overload Be sure the vanes are wide open without overloading the motor until the load decreases Low discharge superheat Overall reduced performance due to refrigerant accumulation in Evaporator Economizer float valves are...

Page 80: ...is displayed on control center when the oil pump is running Defective oil pressure transducer or oil pressure regulator valve is not adjusted Adjust oil pressure regulator valve to maintain proper oil pressure differential and or check oil pressure transducer Oil pump vibrates or is noisy Oil pump vibrates or is extremely noisy with some oil pressure Oil not reaching pump suction inlet in sufficie...

Page 81: ...ER TEMPERATURE VIEW 2 14 DELTA TEMPERATURE LINE 13 12 Calculate 15 COMPRESSOR DISCHARGE PRESSURE VIEW 2 16 COMPRESSOR DISCHARGE TEMPERATURE VIEW 2 17 COND SATURATION TEMPERATURE FROM 15 R 134a Chart 18 APPROACH TEMPERATURE LINE 17 13 Calculate 19 DISCHARGE SUPERHEAT LINE 16 17 Calculate 20 LIQUID LINE TEMPERATURE VIEW 2 21 SUBCOOLING LINE 17 20 Calculate 22 CONDENSER G P M Note 1 23 Economizer Pre...

Page 82: ...times a year These sessions are structured to provide basic classroom instruction and include hands on operating and troubleshooting exercises For further information contact your Daikin representative Training courses for Centrifugal Maintenance and Operation are held through the year at the Daikin Training Center The school duration is three and one half days and includes instruction on basic re...

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Page 85: ...ent and the products and services presented therein Specification are subject to change without prior notice Refer to the data communicated at the time of the order Daikin Applied Europe S p A explicitly rejects any liability for any direct or indirect damage in the broadest sense arising from or related to the use and or interpretation of this publication All content is copyrighted by Daikin Appl...

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