MODEL YK (STYLE G) R-134a WITH OPTIVIEW TM CONTROL CENTER FOR ELECTRO-MECHANICAL STARTER, SOLID STATE STARTER AND VARIABLE SPEED DRIVE

Transcription

1 CENTRIFUGAL LIQUID CHILLERS OPERATIONS AND MAINTENANCE Supersedes: O1 (508) Form O1 (211) MODEL YK (STYLE G) R-134a WITH OPTIVIEW TM CONTROL CENTER FOR ELECTRO-MECHANICAL STARTER, SOLID STATE STARTER AND VARIABLE SPEED DRIVE LD15222

2 IMPORTANT! READ BEFORE PROCEEDING! GENERAL SAFETY GUIDELINES This equipment is a relatively complicated apparatus. During installation, operation maintenance or service, individuals may be exposed to certain components or conditions including, but not limited to: refrigerants, materials under pressure, rotating components, and both high and low voltage. Each of these items has the potential, if misused or handled improperly, to cause bodily injury or death. It is the obligation and responsibility of operating/service personnel to identify and recognize these inherent hazards, protect themselves, and proceed safely in completing their tasks. Failure to comply with any of these requirements could result in serious damage to the equipment and the property in which it is situated, as well as severe personal injury or death to themselves and people at the site. This document is intended for use by owner-authorized operating/service personnel. It is expected that this individual posseses independent training that will enable them to perform their assigned tasks properly and safely. It is essential that, prior to performing any task on this equipment, this individual shall have read and understood this document and any referenced materials. This individual shall also be familiar with and comply with all applicable governmental standards and regulations pertaining to the task in question. SAFETY SYMBOLS The following symbols are used in this document to alert the reader to specific situations: Indicates a possible hazardous situation which will result in death or serious injury if proper care is not taken. Identifies a hazard which could lead to damage to the machine, damage to other equipment and/or environmental pollution if proper care is not taken or instructions and are not followed. Indicates a potentially hazardous situation which will result in possible injuries or damage to equipment if proper care is not taken. Highlights additional information useful to the technician in completing the work being performed properly. External wiring, unless specified as an optional connection in the manufacturer s product line, is not to be connected inside the OptiView cabinet. Devices such as relays, switches, transducers and controls and any external wiring must not be installed inside the micro panel. All wiring must be in accordance with Johnson Controls published specifications and must be performed only by a qualified electrician. Johnson Controls will NOT be responsible for damage/problems resulting from improper connections to the controls or application of improper control signals. Failure to follow this warning will void the manufacturer s warranty and cause serious damage to property or personal injury. 2 JOHNSON CONTROLS

3 CHANGEABILITY OF THIS DOCUMENT In complying with Johnson Controls policy for continuous product improvement, the information contained in this document is subject to change without notice. While Johnson Controls makes no commitment to update or provide current information automatically to the manual owner, that information, if applicable, can be obtained by contacting the nearest Johnson Controls Service office. Operating/service personnel maintains the responsibility of the applicability of these documents to the competitive equipment the kit is installed on. If there is any question regarding the applicability of these documents, the technician should verify whether the equipment has been modified and if current literature is available with the owner of the equipment prior to performing any work on the chiller. ASSOCIATED LITERATURE Variable Speed Drive Operation Solid State Starter Operation and Maintenance Floor Mounted MV SSS Operation Unit Mounted MV SSS Operation Installation Unit MANUAL DESCRIPTION Optiview Control Center Operation and Maintenance Wiring Diagram Field Connections for YK Chiller (Style G) OptiView Control Center with Remote Low or Medium Voltage EMS or Unit Mounted Low or Medium Voltage SSS Wiring Diagram Field Connections for YK Chiller (Style G) OptiView Control Center with Remote Medium Voltage SSS Wiring Diagram Field Connections for YK Chiller (Style G) OptiView Control Center with Remote Medium Voltage VSD Wiring Diagram Field Control Modifications for YK Chiller (Style G) Wiring Diagram YK Chiller (Style G) OptiView Control Center with Remote Low or Medium Voltage EMS Wiring Diagram YK Chiller (Style G) OptiView Control Center with Unit Mounted Low or Medium Voltage SSS, Unit Mounted Low Voltage VSD with Modbus, or Remote Medium Voltage VSD Wiring Diagram YK Chiller (Style G) OptiView Control Center with LTC I/O Board with Remote Low or Medium Voltage EMS Wiring Diagram YK Chiller (Style G) OptiView Control Center w/ LTC I/O Board with Unit Mounted Low or Medium Voltage SSS, Unit Mounted Low Voltage VSD with Modbus or Remote Medium Voltage VSD Renewal Parts Unit Renewal Parts OptiView Control Center FORM NUMBER O O O O N O PW PW PW PW PW PW PW PW RP RP1 JOHNSON CONTROLS 3

4 NOMENCLATURE YK KC K4 H9 CY G STYLE (Design Level) POWER SUPPLY for 60 Hz 5 for 50 Hz MOTOR CODE COMPRESSOR CODE* CONDENSER CODE* MODEL* EVAPORATOR CODE* * Refer to YK Engineering Guide for (Form EG1) Shell/Motor/Compressor combinations. 4 JOHNSON CONTROLS

5 TABLE OF CONTENTS SECTION 1 - DESCRIPTION OF SYSTEM AND FUNDAMENTALS OF OPERATION...7 System Operation Description...7 Capacity Control...8 SECTION 2 - SYSTEM OPERATING PROCEDURES Oil Heaters Oil Heater Operation Checking The Oil Level In The Oil Reservoir Start-Up Procedure Start-Up Chiller Operation...13 Condenser Water Temperature Control...13 Operating Log Sheet...13 Operating Inspections...13 Need For Maintenance Or Service...15 Stopping The System...15 Prolonged Shutdown...15 SECTION 3 - SYSTEM COMPONENTS DESCRIPTION...17 General...17 Compressor...17 Capacity Control...17 Compressor Lubrication System...17 Oil Pump...17 Oil Heater...21 Motor Driveline...21 Heat Exchangers...21 Refrigerant Flow Control...22 Optional Service Isolation Valves...22 Optional Hot Gas Bypass...22 OptiView Control Center...22 Solid State Starter (Optional)...22 Variable Speed Drive (Optional)...22 SECTION 4 - OPERATIONAL MAINTENANCE...23 Oil Return System...23 Changing The Dehydrator...23 The Oil Charge...24 Oil Charging Procedure...24 SECTION 5 - TROUBLESHOOTING...25 SECTION 6 - MAINTENANCE...27 Renewal Parts...27 Checking System For Leaks...27 Conducting R-22 Pressure Test...27 Vacuum Testing...28 Vacuum Dehydration...29 Operation...29 Refrigerant Charging...29 Checking The Refrigerant Charge During Unit Shutdown...30 Handling Refrigerant For Dismantling And Repairs...30 JOHNSON CONTROLS 5

6 TABLE OF CONTENTS (CONT'D) Megging The Motor...30 Compressor...33 Electrical Controls...34 SECTION 7 - PREVENTIVE MAINTENANCE...35 Compressor...35 Compressor Motor...35 Greased Bearings...35 Leak Testing...36 Evaporator And Condenser...36 Oil Return System...36 Electrical Controls...36 LIST OF FIGURES FIGURE 1 - Model YK Chiller...7 FIGURE 2 - Compressor Prerotation Vanes...8 FIGURE 3 - Refrigerant Flow-Thru Chiller (Falling Film Evaporator)...9 FIGURE 4 - Refrigerant Flow-Thru Chiller (Flooded Evaporator)...10 FIGURE 5 - Oil Level Indicator FIGURE 6 - Chiller Starting Sequence And Shutdown Sequence (Em Starter And Solid State Starter) FIGURE 7 - Chiller Starting Sequence And Shutdown Sequence (Variable Speed Drive)...12 FIGURE 8 - Liquid Chiller Log Sheets...14 FIGURE 9 - System Components Front View...18 FIGURE 10 - System Components Rear View...19 FIGURE 11 - Schematic Drawing (YK) Compressor Lubrication System...20 FIGURE 12 - Oil Return System...23 FIGURE 13 - Charging Oil Reservoir With Oil...24 FIGURE 14 - Evacuation Of Chiller...27 FIGURE 15 - Saturation Curve...29 FIGURE 16 - Diagram, Megging Motor Windings...30 FIGURE 17 - Motor Starter Temperature And Insulation Resistances...31 LIST OF TABLES TABLE 1 - Operation Analysis Chart...25 TABLE 2 - System Pressures...28 TABLE 3 - Bearing Lubrication JOHNSON CONTROLS

7 SECTION 1 - DESCRIPTION OF SYSTEM AND FUNDAMENTALS OF OPERATION SYSTEM OPERATION DESCRIPTION The YORK Model YK Chiller is commonly applied to large air conditioning systems, but may be used on other applications. The chiller consists of an open motor mounted to a compressor (with integral speed increasing gears), condenser, evaporator and variable flow control. The chiller is controlled by a modern state of the art Microcomputer Control Center that monitors its operation. The Control Center is programmed by the operator to suit job specifications. Automatic timed start-ups and shutdowns are also programmable to suit nighttime, weekends, and holidays. The operating status, temperatures, pressures, and other information perti- nent to operation of the chiller are automatically displayed and read on a graphic display. Other displays can be observed by pressing the keys as labeled on the Control Center. The chiller with the OptiView Control Center is compatible with an electro-mechanical starter, YORK Solid State Starter (optional), or Variable Speed Drive (optional). In operation, a liquid (water or brine to be chilled) flows through the evaporator, where boiling refrigerant absorbs heat from the liquid. The chilled liquid is then piped to fan coil units or other air conditioning terminal units, where it flows through finned coils, absorbing heat from the air. The warmed liquid is then returned to the chiller to complete the chilled liquid circuit. 1 CONTROL CENTER COMPRESSOR CONDENSER MOTOR LD15222 EVAPORATOR Figure 1 - MODEL YK CHILLER JOHNSON CONTROLS 7

8 SECTION 1 - DESCRIPTION OF SYSTEM AND FUNDAMENTALS OF OPERATION FORM O1 (211) from the refrigerant vapor, causing it to condense. The condenser water is supplied to the chiller from an external source, usually a cooling tower. The condensed refrigerant drains from the condenser into the liquid return line, where the variable orifice meters the flow of liquid refrigerant to the evaporator to complete the refrigerant circuit. The major components of a chiller are selected to handle the refrigerant, which would be evaporated at full load design conditions. However, most systems will be called upon to deliver full load capacity for only a relatively small part of the time the unit is in operation. 7619A(D) Figure 2 - COMPRESSOR PREROTATION VANES The refrigerant vapor, which is produced by the boiling action in the evaporator, flows to the compressor where the rotating impeller increases its pressure and temperature and discharges it into the condenser. Water flowing through the condenser tubes absorbs heat CAPACITY CONTROL The major components of a chiller are selected for full load capacities, therefore capacity must be controlled to maintain a constant chilled liquid temperature leaving the evaporator. Prerotation vanes (PRV), located at the entrance to the compressor impeller, compensate for variation in load (Refer to Figure 2 on Page 8). The position of these vanes is automatically controlled through a lever arm attached to an electric motor located outside the compressor housing. The automatic adjustment of the vane position in effect provides the performance of many different compressors to match various load conditions from full load with vanes wide open to minimum load with vanes completely closed. 8 JOHNSON CONTROLS

9 SECTION 1 - DESCRIPTION OF SYSTEM AND FUNDAMENTALS OF OPERATION Refrigerant Flow-Thru Chiller YK Mod G (Falling Film Evaporator) Refrigerant Flow-Thru Cross-Section Diagram (Falling-Film Evaporator) 1 COMPRESSOR HOT GAS BYPASS VALVE PRE-ROTATION VANES SUCTION DISCHARGE OPTIONAL HOT GAS BYPASS LINE OPTIONAL ISOLATION VALVE LIQUID LEVEL VALVE CONDENSER EVAPORATOR SUCTION BAFFLE LIQUID LEVEL LIQUID LEVEL SUB-COOLER OPTIONAL ISOLATION VALVE LD00924A Figure 3 - REFRIGERANT FLOW-THRU CHILLER (FALLING FILM EVAPORATOR) Rev. 2 ( ) Dan Sowers dan.sowers-ext@jci.com (717) JOHNSON CONTROLS 9

10 SECTION 1 - DESCRIPTION OF SYSTEM AND FUNDAMENTALS OF OPERATION FORM O1 (211) Refrigerant Flow-Thru Chiller (Flooded Evaporator) YK Mod G Refrigerant Flow-Thru Cross-Section Diagram (Flooded Evaporator) COMPRESSOR HOT GAS BYPASS VALVE PRE-ROTATION VANES SUCTION DISCHARGE OPTIONAL HOT GAS BYPASS LINE OPTIONAL ISOLATION VALVE MESH ELIMINATORS or SUCTION BAFFLE CONDENSER EVAPORATOR LIQUID LEVEL LIQUID LEVEL SUB-COOLER OPTIONAL ISOLATION VALVE LIQUID LEVEL VALVE LD00924B Figure 4 - REFRIGERANT FLOW-THRU CHILLER (FLOODED EVAPORATOR) Rev. 2 ( ) Dan Sowers dan.sowers-ext@jci.com (717) JOHNSON CONTROLS

11 SECTION 2 - SYSTEM OPERATING PROCEDURES OIL HEATERS If the oil heater is de-energized during a shutdown period, it must be energized for 12 hours prior to starting compressor, or remove all oil and recharge compressor with new oil. (Refer to Oil Charging Procedure on Page 24.) OIL HEATER OPERATION The oil heater operation is controlled by the OptiView Control Center. The heater is turned on and off to maintain the oil temperature differential to a value 50 F (27.8 C) above the condenser saturation temperature. This target value is maintained by the control panel. If the target value is greater than 160 F (71 C), the target defaults to 160 F (71 C). If the target value is less than 110 F (43.3 C), it defaults to 110 F (43.3 C). To prevent overheating of the oil in the event of a control center component failure, the oil heater thermostat (1HTR) is set to open at 180 F (82 C). CHECKING THE OIL LEVEL IN THE OIL RESERVOIR Proper operating oil level During operation, the oil level should fall to the OPERATING RANGE identified on the vertical oil level indicator label (Refer to Figure 5 on Page 11). If the oil level during operation is in the OVER FULL region of the oil level indicator, oil should be removed from the oil reservoir, This reduces the oil level to the OPERATING RANGE. If the oil level during operation is in the LOW OIL region of the oil level indicator, oil should be added to the oil reservoir. (Refer to Oil Charging Procedure on Page 24.) Comply with EPA and local regulations when removing or disposing of refrigeration system oil! START-UP PROCEDURE Pre-Starting Prior to starting the chiller, observe the Optiview Control Center Operation and Maintenance (Form O1). Make sure the display reads SYSTEM READY TO START. Vent any air from the chiller waterboxes prior to starting the water pumps. Failure to do so will result in pass baffle damage. 2 Figure 5 - OIL LEVEL INDICATOR LD08647 START-UP 1. If the chilled water pump is manually operated, start the pump. The Control Center will not allow the chiller to start unless chilled liquid flow is established through the unit. If the chilled liquid pump is wired to the Microcomputer Control Center the pump will automatically start, therefore, this step is not necessary. 2. To start the chiller, press the COMPRESSOR START switch. This switch will automatically spring return to the RUN position. (If the unit was previously started, press the STOP/RESET side of the COMPRESSOR switch and then press the START side of the switch to start the chiller.) When the start switch is energized, the Control Center is placed in an operating mode and any malfunction will be noted by messages on a graphic display. JOHNSON CONTROLS 11

12 SECTION 2 - SYSTEM OPERATING PROCEDURES FORM O1 (211) ** Not for all shutdowns. Refer to Display Messages in manual Optiview Control Center Operation and Maintenance (Form O1). LD15609 Figure 6 - CHILLER STARTING SEQUENCE AND SHUTDOWN SEQUENCE (EM STARTER AND SOLID STATE STARTER) LD15610 ** Not for all shutdowns. Refer to Display Messages in manual Optiview Control Center Operation and Maintenance (Form O1). Figure 7 - CHILLER STARTING SEQUENCE AND SHUTDOWN SEQUENCE (VARIABLE SPEED DRIVE) 12 JOHNSON CONTROLS

13 SECTION 2 - SYSTEM OPERATING PROCEDURES For display messages and information pertaining to the operation refer to Optiview Control Center Operation and Maintenance (Form O1). Any malfunctions which occur during STOP/RESET are also displayed. CHILLER OPERATION The unit capacity will vary to maintain the leaving CHILLED LIQUID TEMPERATURE setpoint by the Pre-rotation Vanes which are modulated by an actuator under the control of the Microprocessor Board. The vane control routine employs proportional plus derivative (rate) control action. A drop in chilled liquid temperature will cause the actuator to close the Prerotation Vanes to decrease chiller capacity. When the chilled liquid temperature rises, the actuator will open the Prerotation Vanes to increase the capacity of the chiller. However, the current draw (amperes) by the compressor motor is also limited to FLA setpoint by the microprocessor. If the load continues to decrease, after the Prerotation Vanes are entirely closed, the chiller will be shut down by the Leaving Chilled Liquid Low Temperature Control. CONDENSER WATER TEMPERATURE CONTROL The YORK chiller is designed to use less power by taking advantage of lower than design temperatures that are naturally produced by cooling towers throughout the operating year. Exact control of condenser water such as a cooling tower bypass, is not necessary for most installations. The minimum entering condenser water temperature for full and part load conditions is specified in the chiller engineering guide. where: Min. ECWT = LCWT C RANGE + 5ºF + 12 ( ) Min. ECWT = LCWT C RANGE + 2.8ºC ( ) ECWT = Entering Condensing Water Temperature LCWT = Leaving Chilled Water Temperature % Load 100 % Load 100 C Range = Condensing water temperature range at the given load condition. At start-up, the entering condenser water temperature may be as much as 25 F (14 C) colder than the standby return chilled water temperature. Cooling tower fan cycling will normally provide adequate control of the entering condenser water temperature on most installations. Heat recovery chillers and chillers using optional head pressure control would use a signal provided by the microprocessor to control main condenser bundle heat rejection or pressure, respectively. OPERATING LOG SHEET A permanent daily record of system operating conditions (temperatures and pressures) recorded at regular intervals throughout each 24 hour operating period should be kept. An optional status printer is available for this purpose or Figure 8 on Page 14 shows a log sheet used by Johnson Controls Personnel for recording test data on chiller systems. It is available from the factory in pads of 50 sheets each under Form F7 and may be obtained through the nearest Johnson Controls office. Automatic data logging is possible by connecting the optional printer and programming the DATA LOG- GER function. An accurate record of readings serves as a valuable reference for operating the system. Readings taken when a system is newly installed will establish normal conditions with which to compare later readings. For example, an increase in condenser approach temperature (condenser temperature minus leaving condenser water temperature) may be an indication of dirty condenser tubes. OPERATING INSPECTIONS By following a regular inspection using the display readings of the Microcomputer Control Center, and maintenance procedure, the operator will avoid serious operating difficulty. The following list of inspections and procedures should be used as a guide. Daily 1. Check OptiView Control Center displays. 2. If the compressor is in operation, check the bearing oil pressure on the SYSTEM Screen. Also check the oil level in the oil reservoir. Operating oil level should be operating range of oil indicator. Drain or add oil if necessary. 2 JOHNSON CONTROLS 13

14 SECTION 2 - SYSTEM OPERATING PROCEDURES FORM O1 (211) 3. Check entering and leaving condenser water pressure and temperatures for comparison with job design conditions. Condenser water temperatures can be checked on the SYSTEM Screen. 4. Check the entering and leaving chilled liquid temperatures and evaporator pressure for comparison with job design conditions on the SYSTEM Screen. 5. Check the condenser saturation temperature (based upon condenser pressure sensed by the condenser transducer) on the SYSTEM Screen. 6. Check the compressor discharge temperature on the SYSTEM Screen. During normal operation discharge temperature should not exceed 220 F (104 C). 7. Check the compressor motor current on the SYSTEM Screen. 8. Check for any signs of dirty or fouled condenser tubes. (The temperature difference between water leaving condenser and saturated condensing temperature should not exceed the difference recorded for a new unit by more than 4 F (2.2 C)). Weekly 1. Check the refrigerant charge. (Refer to Checking The Refrigerant Charge During Unit Shutdown on Page 30.) Monthly 1. Leak check the entire chiller. Quarterly 1. Perform chemical analysis of oil. Semi-Annually (or more often as required) 1. Change and inspect compressor oil filter element. 2. Oil return system. A. Change dehydrator. B. Check nozzle of eductor for foreign particles. 3. Check controls and safety cutouts. LD00467 *NOTE: These items can be printed by an electronic printer connected to the Microboard and pressing the PRINT key on the Keypad, or automatically using the Data Logger feature A Figure 8 - LIQUID CHILLER LOG SHEETS 14 JOHNSON CONTROLS

15 SECTION 2 - SYSTEM OPERATING PROCEDURES Annually (more often if necessary) 1. Drain and replace the oil in the compressor oil sump. (Refer to Oil Charging Procedure on Page 24.) 2. Evaporator and Condenser. A. Inspect and clean water strainers. B. Inspect and clean tubes as required. C. Inspect end sheets. 3. Compressor Drive Motor (See motor manufacturers maintenance and service instruction supplied with unit) A. Clean air passages and windings per manufacturers instructions. B. Meg motor windings Refer to Figure 16 on Page 30 for details. C. Lubricate per motor manufacturer recommendations. 4. Inspect and service electrical components as necessary. 5. Perform refrigerant analysis. If quarterly inspection indicates oil is fine, replacing the oil is not necessary NEED FOR MAINTENANCE OR SERVICE If the system is malfunctioning in any manner or the unit is stopped by one of the safety controls, consult the Operation Analysis Chart, Table 1 on Page 25 of this manual. After consulting this chart, if you are unable to make the proper repairs or adjustments to start the compressor or the particular trouble continues to hinder the performance of the unit, please call the nearest Johnson Controls District Office. Failure to report constant troubles could damage the unit and increase the cost of repairs. STOPPING THE SYSTEM The Optiview Control Center can be programmed to start and stop automatically (maximum, once each day) whenever desired. Refer to the Optiview Control Center Operation and Maintenance (Form O1). To stop the chiller, proceed as follows: 1. Push the soft shutdown key on the homescreen on the OptiView panel or rapid stop with the COM- PRESSOR STOP/RESET switch. The compressor will stop automatically. The oil pump will continue to run for coastdown period. The oil pump will then stop automatically. 2. Stop the chilled water pump (if not wired into the Microcomputer Control Center, in which case it will shut off automatically simultaneously with the oil pump.) (The actual water pump contact operation is dependent upon the position of Microboard jumper J54.) 3. Open the switch to the cooling tower fan motors, if used. 4. The compressor sump oil heater is energized when the unit is stopped. PROLONGED SHUTDOWN If the chiller is to be shut down for an extended period of time (for example, over the winter season), the following paragraphs outline the procedure to be followed. 1. Test all system joints for refrigerant leaks with a leak detector. If any leaks are found, they should be repaired before allowing the system to stand for a long period of time. During long idle periods, the tightness of the system should be checked periodically. 2. If freezing temperatures are encountered while the system is idle, carefully drain the cooling water from the cooling tower, condenser, condenser pump, and the chilled water system-chilled water pump and coils. Open the drains on the evaporator and condenser liquid heads to assure complete drainage. (If a Variable Speed Drive, drain its cooling system. If Solid State Starter equipped drain liquid from starter cooling loop.) 3. If freezing temperatures are encountered for periods longer than a few days, the refrigerant should be recovered to containers to prevent leakage from O-ring joints. 4. On the SETUP Screen, disable the clock. This conserves the battery. 5. Open the main disconnect switches to the compressor motor, condenser water pump and the chilled water pump. Open the 115 volt circuit to the Control Center. 2 JOHNSON CONTROLS 15

16 SECTION 2 - SYSTEM OPERATING PROCEDURES FORM O1 (211) THIS PAGE INTENTIONALLY LEFT BLANK 16 JOHNSON CONTROLS

17 SECTION 3 - SYSTEM COMPONENTS DESCRIPTION GENERAL The YORK Model YK Centrifugal Liquid Chiller is completely factory-packaged including evaporator, condenser, compressor, motor, lubrication system, OptiView Control Center, and all interconnecting unit piping and wiring. COMPRESSOR The compressor is a single-stage centrifugal type powered by an open-drive electric motor. The rotor assembly consists of a heat-treated alloy steel drive shaft and impeller shaft with a cast aluminum, fully shrouded impeller. The impeller is designed for balanced thrust and is dynamically balanced and overspeed tested. The inserted type journal and thrust bearings are fabricated of aluminum alloy. Single helical gears with crowned teeth are designed so that more than one tooth is in contact at all times. Gears are integrally assembled in the compressor rotor support and are film lubricated. Each gear is individually mounted in its own journal and thrust bearings. The open-drive compressor shaft seal is a double bellows cartridge style with ceramic internal and atmospheric seal faces. The seal is oil-flooded at all times and is pressure-lubricated during operation. CAPACITY CONTROL Prerotation vanes (PRV) modulate chiller capacity from 100% to as low as 15% of design for normal air conditioning applications. Operation is by an external, electric PRV actuator which automatically controls the vane position to maintain a constant leaving chilled liquid temperature. COMPRESSOR LUBRICATION SYSTEM The chiller lubrication system consists of the oil pump, oil filter, oil cooler and all interconnecting oil piping and passages. There are main points within the compressor which must be supplied with forced lubrication as follows: 1. Compressor Drive Shaft (Low Speed) A. Shaft seal. B. Front and rear journal bearings one on each side of driving gear. C. Low speed thrust bearing (forward and reverse). 2. Compressor Driven Shaft (High Speed) A. Forward and reverse high speed thrust bearing. B. Two journal bearings. 3. Speed Increasing Gears A. Meshing surfaces of drive and pinion gear teeth. To provide the required amount of oil under the necessary pressure to properly lubricate these parts, a motor driven submersible oil pump is located in a remote oil sump. Upon pressing of the COMPRESSOR START switch on the Control Center, the oil pump is immediately energized. After a 50 second pre-lube period, the compressor motor will start. The oil pump will continue to run during the entire operation of the compressor, and for 150 seconds during compressor coastdown. The submerged oil pump takes suction from the surrounding oil and discharges it to the oil cooler where heat is rejected. The oil flows from the oil cooler to the oil filter. The oil leaves the filter and flows to the emergency oil reservoir where it is distributed to the compressor bearings. The oil lubricates the compressor rotating components and is returned to the oil sump. There is an emergency oil reservoir located at the highest point in the lubrication system internally in the compressor. It provides an oil supply to the various bearings and gears in the event of a system shutdown due to power failure. The reservoir, located on the top of the compressor, allows the oil to be distributed through the passages by gravity flow, thus providing necessary lubrication during the compressor coastdown. OIL PUMP For normal operation, the oil pump should operate at all times during chiller operation. On shutdown of the system for any reason, the oil pump operates and continues to run for 150 seconds. The system cannot restart during that time interval. 3 JOHNSON CONTROLS 17

18 SECTION 3 - SYSTEM COMPONENTS DESCRIPTION FORM O1 (211) OPTIVIEW CONTROL CENTER COMPRESSOR SUCTION RELIEF VALVES VARIABLE SPEED DRIVE EVAPORATOR LD15222 SIGHT GLASS VARIABLE SPEED OIL PUMP CONTROL BOX FRONT VIEW Figure 9 - SYSTEM COMPONENTS FRONT VIEW 18 JOHNSON CONTROLS

19 SECTION 3 - SYSTEM COMPONENTS DESCRIPTION MOTOR COMPRESSOR DISCHARGE LINE 3 LD15223 CONDENSER OIL PUMP HOUSING LIQUID LINE REAR VIEW Figure 10 - SYSTEM COMPONENTS REAR VIEW JOHNSON CONTROLS 19

20 SECTION 3 - SYSTEM COMPONENTS DESCRIPTION FORM O1 (211) COMPRESSOR ROTOR SUPPORT SECTION EMERGENCY OIL RESERVE H.S. SHAFT SEAL HIGH PRESSURE TRANSDUCER MAIN JOURNAL AND THRUST BEARING IMPELLER THRUST COLLAR HIGH SPEED THRUST COVER DOUBLE BELLOWS SHAFT SEAL BEARING (PINION GEAR SHAFT) (PRV) INLET VALVES LOW SPEED- GEAR REAR BEARING LOW SPEED GEAR THRUST COLLAR BEARING LOW SPEED THRUST COVER REFRIG. HOT THERMISTOR SIGHT GLASSES OIL HEATER ANGLE DRAIN VALVE LOW OIL PRESSURE TRANSDUCER OIL COOLER OIL FILTER OIL SUMP OIL PUMP SUCTION SUBMERSIBLE OIL PUMP WITH 3-PHASE MOTOR OIL TEMP. CONTROL OIL Figure 11 - SCHEMATIC DRAWING (YK) COMPRESSOR LUBRICATION SYSTEM LD JOHNSON CONTROLS

21 SECTION 3 - SYSTEM COMPONENTS DESCRIPTION OIL HEATER During long idle periods, the oil in the compressor oil reservoir tends to absorb as much refrigerant as it can hold, depending upon the temperature of the oil and the pressure in the reservoir. As the oil temperature is lowered, the amount of refrigerant absorbed will be increased. If the quantity of refrigerant in the oil becomes excessive, violent oil foaming will result as the pressure within the system is lowered on starting. This foaming is caused by refrigerant boiling out of the oil as the pressure is lowered. If this foam reaches the oil pump suction, the bearing oil pressure will fluctuate with possible temporary loss of lubrication, causing the oil pressure safety cutout to actuate and stop the system. Refer to Optiview Control Center Operation and Maintenance (Form O1). MOTOR DRIVELINE The compressor motor is an open-drip-proof, squirrel cage, induction type constructed to YORK design specifications. 60 hertz motors operate at 3570 rpm. 50 hertz motors operate at 2975 rpm. The open motor is provided with a D-flange, cast iron adapter mounted to the compressor and supported by a motor support. Motor drive shaft is directly connected to the compressor shaft with a flexible disc coupling. This coupling has all metal construction with no wearing parts to assure long life, and no lubrication requirements to provide low maintenance. For units utilizing remote Electro-Mechanical starters, a terminal box is provided for field connected conduit. Motor terminals are brought through the motor casing into the terminal box. Jumpers are furnished for three-lead type of starting. Motor terminal lugs are not furnished. Overload/over current transformers are furnished with all units. HEAT EXCHANGERS Evaporator and condenser shells are fabricated from rolled carbon steel plates with fusion welded seams. Heat exchanger tubes are internally enhanced type. The evaporator is a shell and tube type with customer process fluid flowing inside the tubes and refrigerant removing heat on the shell side via evaporation. Evaporator codes A* to K* utilize a hybrid falling film design. It contains a balance of flooded and falling film technology to optimize efficiency, minimize refrigerant charge, and maintain reliable control. A specifically designed spray distributor provides uniform distribution of refrigerant over the entire length to yield optimum heat transfer. The hybrid falling film evaporator design has suction baffles around the sides and above the falling film section to prevent liquid refrigerant carryover into the compressor. Evaporators codes M* thru Z* are flooded type, with a liquid inlet distributor trough underneath the tube bundle which provides uniform distribution of refrigerant over the entire shell length to yield optimum heat transfer. Flooded evaporator designs have a suction baffle on M* shells with H9 compressors and an aluminum mesh eliminator on K* - Z* shells with K compressors located above the tube bundle to prevent liquid refrigerant carryover into the compressor. A 1-1/2" (38 mm) liquid level sight glass is conveniently located on the side of the shell to aid in determining proper refrigerant charge. The evaporator shell contains a dual refrigerant relief valve arrangement set at 180 psig (12.4 barg) on H and K compressor models; 235 psig (16.2 barg) on P and Q compressor models; or single-relief valve arrangement, if the chiller is supplied with optional refrigerant isolation valves. A 1" (25.4 mm) refrigerant charging valve is provided. The condenser is a shell and tube type, with a discharge gas baffle to prevent direct high velocity impingement on the tubes. The baffle is also used to distribute the refrigerant gas flow properly for most efficient heat transfer. An optional cast steel condenser inlet diffuser may be offered, on "M" and larger condensers, in lieu of the baffle, to provide dynamic pressure recovery and enhanced chiller efficiency. An integral sub cooler is located at the bottom of the condenser shell providing highly effective liquid refrigerant subcooling to provide the highest cycle efficiency. The condenser contains dual refrigerant relief valves set at 235 psig (16.2 barg). The removable waterboxes are fabricated of steel. The design working pressure is 150 psig (10.3 barg) and the boxes are tested at 225 psig (15.5 barg). Integral steel water baffles are located and welded within the waterbox to provide the required pass arrangements. Stub out water nozzle connections with ANSI/AWWA C-606 grooves are welded to the waterboxes. These nozzle connections are suitable for ANSI/AWWA C-606 couplings, welding or flanges, and are capped for shipment. Plugged 3/4" (19 mm) drain and vent connections are provided in each waterbox. 3 JOHNSON CONTROLS 21

22 SECTION 3 - SYSTEM COMPONENTS DESCRIPTION FORM O1 (211) REFRIGERANT FLOW CONTROL Refrigerant flow to the evaporator is controlled by a variable orifice. A level sensor senses the refrigerant level in the condenser and outputs an analog voltage to the Microboard that represents this level (0% = empty; 100% = full). Under program control, the Microboard modulates a variable orifice to control the condenser refrigerant level to a programmed setpoint. Other setpoints affect the control sensitivity and response. These setpoints must be entered at chiller commissioning by a qualified service technician. Only a qualified service technician may modify these settings. While the chiller is shut down, the orifice will be in the fully open position causing the sensed level to be approximately 0%. When the chiller is started, after the vane motor end switch (VMS) opens when entering SYSTEM RUN, if actual level is less than the level setpoint, a linearly increasing ramp is applied to the level setpoint. This ramp causes the setpoint to go from the initial refrigerant level (approximately 0%) to the programmed setpoint over a programmable period of time. If the actual level is greater than the setpoint when the VMS opens, there is no pulldown period, it immediately begins to control to the programmed setpoint. While the chiller is running, the refrigerant level is normally controlled to the level setpoint. However, anytime the vanes fully close (VMS closes), normal level control is terminated, any refrigerant level setpoint in effect is cancelled and the outputs to the level control will be constant open. OPTIONAL SERVICE ISOLATION VALVES If your chiller is equipped with optional service isolation valves on the discharge and liquid line, these valves must remain open during operation. These valves are used for isolating the refrigerant charge in either the evaporator or condenser to allow service access to the system. A refrigerant pump-out unit will be required to isolate the refrigerant. Isolation of the refrigerant in this system must be performed by a qualified service technician. OPTIONAL HOT GAS BYPASS Hot gas bypass is optional and is used to eliminate compressor surge during light load or high head operation. The OptiView control panel will automatically modulate the hot gas valve open and closed as required. Adjustment of the hot gas control valve must be performed by a qualified service technician following the Hot Gas Set-up procedure. Changes in chilled water flow will require re-adjustment of the hot gas control to insure proper operation. OPTIVIEW CONTROL CENTER The OptiView Control Center is factory-mounted, wired and tested. The electronic panel automatically controls the operation of the unit in meeting system cooling requirements while minimizing energy usage. For detailed information on the Control Center, refer to SECTION 2 - SYSTEM OPERATING PROCEDURES of this manual. SOLID STATE STARTER (OPTIONAL) The Solid State Starter is a reduced voltage starter that controls and maintains a constant current flow to the motor during start-up. It is mounted on the chiller. Power and control wiring between the starter and chiller are factory installed. The starter enclosure is NEMA-1 with a hinged access door with lock and key. Electrical lugs for incoming power wiring are provided. VARIABLE SPEED DRIVE (OPTIONAL) A Variable Speed Drive can be factory packaged with the chiller. It is designed to vary the compressor motor speed and prerotation vane position by controlling the frequency and voltage of the electrical power to the motor. Operational information is contained in the Variable Speed Drive Operation (Form O1). The control logic automatically adjusts motor speed and compressor prerotation vane position for maximum part load efficiency by analyzing information fed to it by sensors located throughout the chiller. 22 JOHNSON CONTROLS

23 SECTION 4 - OPERATIONAL MAINTENANCE OIL RETURN SYSTEM The oil return system continuously maintains the proper oil level in the compressor oil sump (Refer to Figure 12 on Page 23). High pressure condenser gas flows continuously through the eductor inducing the low pressure, oil rich liquid to flow from the evaporator, through the dehydrator to the compressor sump. CHANGING THE DEHYDRATOR To change the dehydrator, use the following procedure: 1. Isolate the dehydrator at the stop valves. 2. Remove the dehydrator (Refer to Figure 12 on Page 23). 3. Assemble the new filter-drier. 4. Open evaporator stop valve and check dehydrator connections for refrigerant leaks. 5. Open all the dehydrator stop valves. COMPRESSOR SOLENOID VALVE 4 CHECK VALVE OIL EDUCTOR BLOCK SOLENOID VALVE STOP VALVE DEHYDRATOR STOP VALVE Figure 12 - OIL RETURN SYSTEM LD08578 JOHNSON CONTROLS 23

24 SECTION 4 - OPERATIONAL MAINTENANCE FORM O1 (211) THE OIL CHARGE The nominal oil charge for all H, K, and P8-P9 YK compressors is 20 gallons, and for Q3-Q7 YK compressors is 10 gallons of type YORK K or YORK H oil. New YORK Refrigeration oil must be used in the centrifugal compressor. Since oil absorbs moisture when exposed to the atmosphere, it should be kept tightly capped until used. OIL CHARGING PROCEDURE During operation the compressor oil level must be maintained in the OPERATING RANGE identified on the vertical oil level indicator. If the oil level falls into the lower sight glass, it is necessary to add oil to the compressor oil reservoir. The oil should be charged into the oil reservoir using the YORK Oil Charging Pump YORK Part No To charge oil into the oil reservoir, proceed as follows: 1. The unit must be shut down. 2. Immerse the suction connection of the oil charging pump in a clean container of new oil and connect the pump discharge connection to the oil charging valve (A) located on the remote oil reservoir cover plate. (Refer to Figure 13 on Page 24) Do not tighten the connection at the charging valve until after the air is forced out by pumping a few strokes of the oil pump. This fills the lines with oil and prevents air from being pumped into the system. 3. Open the oil charging valve and pump oil into the system until oil level in the compressor oil reservoir is in the OVER FULL region of the oil level indicator label. Close the charging valve and disconnect the hand oil pump. 4. As soon as oil charging is complete, close the power supply to the starter to energize the oil heater. This will keep the concentration of refrigerant in the oil to a minimum. When the oil reservoir is initially charged with oil, the oil pump should be started manually to fill the lines, passages, oil cooler and oil filter. This will lower the oil level in the reservoir. It may then be necessary to add oil to bring the level back into the OPERATING RANGE of the oil level indicator label. OIL CHARGING VALVE LD08648 LD08579 Figure 13 - CHARGING OIL RESERVOIR WITH OIL 24 JOHNSON CONTROLS

25 SECTION 5 - TROUBLESHOOTING Table 1 - OPERATION ANALYSIS CHART RESULTS POSSIBLE CAUSE REMEDY 1. SYMPTOM: ABNORMALLY HIGH DISCHARGE PRESSURE Temperature difference between condensing temperature and water off condenser higher than normal. High discharge pressure. Temperature difference between condenser water on and water off higher than normal, with normal evaporator pressure. Air in condenser. Condenser tubes dirty or scaled. High condenser water temperature. Insufficient condensing water flow. 2. SYMPTOM: ABNORMALLY LOW SUCTION PRESSURE Temperature difference between leaving chilled water and refrigerant in evaporator greater than normal with high discharge temperature. Temperature difference between leaving chilled water and refrigerant in the evaporator greater than normal with normal discharge temperature. Temperature of chilled water too low with with low motor amperes. 3. SYMPTOM: HIGH EVAPORATOR PRESSURE High chilled water temperature. Insufficient charge of refrigerant. Variable orifice problem. Evaporator tubes dirty or restricted. Insufficient load for system capacity. Prerotation vanes fail to open. System overload. 4. SYMPTOM: NO OIL PRESSURE WHEN SYSTEM START BUTTON PUSHED Low oil pressure displayed on control center; compressor will not start. Oil pump running in wrong direction. Oil pump not running. 5. SYMPTOM: UNUSUALLY HIGH OIL PRESSURE DEVELOPS WHEN OIL PUMP RUNS Unusually high oil pressure is displayed when the oil pressure display key is pressed when the oil pump is running. High oil pressure. Transducer defective. Clean condenser tubes. Check water conditioning. Reduce condenser water inlet temperature. (Check cooling tower and water circulation.) Increase the quantity of water through the condenser to proper value. Check for leaks and charge refrigerant into system. Remove obstruction. Clean evaporator tubes. Check prerotation vane motor operation and setting of low water temperature cutout. Check the prerotation vane motor positioning circuit. Be sure the vanes are wide open (without overloading the motor) until the load decreases. Check rotation of oil pump (Electrical Connections). Troubleshoot electrical problem with oil pump VSD. Replace low or high oil pressure transducer. 5 JOHNSON CONTROLS 25

26 SECTION 5 - TROUBLESHOOTING FORM O1 (211) TABLE 1 - OPERATION ANALYSIS CHART (CONT'D) RESULTS POSSIBLE REMEDY 6. SYMPTOM: OIL PUMP VIBRATES OR IS NOISY Oil pump vibrates or is extremely noisy with some oil pressure when pressing OIL PRESSURE display key. When oil pump is run without an oil supply it will vibrate and become extremely noisy. Oil not reaching pump suction inlet in sufficient quantity. Worn or failed oil pump. Check oil level. Repair/Replace oil pump. 7. SYMPTOM: REDUCED OIL PUMP CAPACITY Oil pump pumping capacity. Excessive end clearance pump. Other worn pump parts. Partially blocked oil supply inlet. Inspect and replace worn parts. Check oil inlet for blockage. 8. SYMPTOM: OIL PRESSURE GRADUALLY DECREASES (Noted by Observation of Daily Log Sheets) When oil pump VSD frequency increases to 55 + hz to maintain target oil pressure. Oil filter is dirty. Change oil filter. 9. SYMPTOM: OIL PRESSURE SYSTEM CEASES TO RETURN AN OIL/REFRIGERANT SAMPLE Oil refrigerant return not functioning. Filter-drier in oil return system dirty. Jet or orifice of oil return jet clogged. 10. SYMPTOM: OIL PUMP FAILS TO DELIVER OIL PRESSURE No oil pressure registers when pressing OIL PRESSURE display key when oil pump runs. Faulty oil pressure transducer. Faulty wiring/connectors. Replace old filter-drier with new. Remove jet, inspect for dirt. Remove dirt using solvent and replace. Replace oil pressure transducer. 26 JOHNSON CONTROLS

27 SECTION 6 - MAINTENANCE RENEWAL PARTS For any required Renewal Parts, refer to the Renewal Parts Unit (Form RP1). CHECKING SYSTEM FOR LEAKS Leak Testing During Operation The refrigerant side of the system is carefully pressure tested and evacuated at the factory. After the system has been charged, the system should be carefully leak tested with a R-134a compatible leak detector to be sure all joints are tight. If any leaks are indicated, they must be repaired immediately. Usually, leaks can be stopped by tightening flare nuts or flange bolts. However, for any major repair, the refrigerant charge must be removed. (Refer to Handling Refrigerant For Dismantling And Repairs on Page 30) CONDUCTING R-22 PRESSURE TEST With the R-134a charge removed and all known leaks repaired, the system should be charged with a small amount of R-22 mixed with dry nitrogen so that a halide torch or electronic leak detector can be used to detect any leaks too small to be found by the soap test. To test with R-22, proceed as follows: 1. With no pressure in the system, charge R-22 gas into the system through the charging valve to a pressure of 2 PSIG (14 kpa). 2. Build up the system pressure with dry nitrogen to approximately 75 to 100 PSIG (517 to 690 kpa). To be sure that the concentration of refrigerant has reached all part of the system, slightly open the oil charging valve and test for the presence of refrigerant with a leak detector. 3. Test around each joint and factory weld. It is important that this test be thoroughly and carefully done, spending as much time as necessary and using a good leak detector. 4. To check for refrigerant leaks in the evaporator and condenser, open the vents in the evaporator and condenser heads and test for the presence of refrigerant. If no refrigerant is present, the tubes and tube sheets may be considered tight. If refrigerant is detected at the vents, the heads must be removed, the leak located (by means of soap test or leak detector) and repaired. EVACUATION AND DEHYDRATION OF UNIT A(D) LD00949 Figure 14 - EVACUATION OF CHILLER JOHNSON CONTROLS 27

28 SECTION 6 - MAINTENANCE FORM O1 (211) Table 2 - SYSTEM PRESSURES *GAUGE INCHES OF MERCURY (HG) BELOW ONE STANDARD ATMOSPHERE *One standard atmosphere PSIA ABSOLUTE MILLIMETERS OF MERCURY (HG) = PSIA = 760 mm Hg. absolute pressure at 32 F = inches Hg. absolute at 32 F MICRONS BOILING TEMPERATURES OF WATER F , " , " , " , " , " , " , " , " , " , " , " " " " " NOTES: PSIA = Lbs. per sq. in. gauge pressure = Pressure above atmosphere PSIA = Lbs. per sq. in. absolute pressure = Sum of gauge plus atmospheric pressure VACUUM TESTING After the pressure test has been completed, the vacuum test should be conducted as follows: 1. Connect a high capacity vacuum pump, with indicator, to the system charging valve as shown in Figure 14 on Page 27 and start the pump. (Refer to Vacuum Dehydration on Page 29.) 2. Open wide all system valves. Be sure all valves to the atmosphere are closed. 3. Operate the vacuum pump in accordance with VACUUM DEHYDRATION until a wet bulb temperature of +32 F or a pressure of 5 mm Hg is reached. Refer to Table 2 on Page 28 for corresponding values of pressure. 4. To improve evacuation circulate hot water (not to exceed 125 F, 51.7ºC) through the evaporator and condenser tubes to thoroughly dehydrate the shells. If a source of hot water is not readily available, a portable water heater should be employed. DO NOT USE STEAM. A suggested method is to connect a hose between the source of hot water under pressure and the evaporator head drain connection, out the evaporator vent connection, into the condenser head drain and out the condenser vent. To avoid the possibility of causing leaks, the temperature should be brought up slowly so that the tubes and shell are heated evenly. 5. Close the system charging valve and the stop valve between the vacuum indicator and the vacuum pump. Then disconnect the vacuum pump leaving the vacuum indicator in place. 6. Hold the vacuum obtained in Step 3 in the system for 8 hours; the slightest rise in pressure indicates a leak or the presence of moisture, or both. If, after 24 hours the wet bulb temperature in the vacuum indicator has not risen above 40 F (4.4 C) or a pressure of 6.3 mm Hg, the system may be considered tight. 7. If the vacuum does not hold for 8 hours within the limits specified in Step 6 above, the leak must be found and repaired. 28 JOHNSON CONTROLS