Johnson Controls York YK Operation And Maintenance
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Summary of Contents for Johnson Controls York YK
- Page 1 Model YK (Style H), R-134a and R-513A With OptiView Control Center for Electromechanical Starter, Solid-State Starter, and Variable Speed Drive 035-27332-100 Operations and Maintenance Form Number: 160.76-O1 (421) Issue Date: 2021-04-25 Supersedes: 160.76-O1 (321)
- Page 2 Model YK (Style H), R-134a and R-513A...
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Page 3: Table Of Contents
Contents General safety guidelines..........................5 C o n t e n t s Safety symbols............................. 5 Changeability of this document......................6 Revision notes............................6 Associated literature........................... 6 Conditioned based maintenance...................... 7 Nomenclature............................8 Description of system and fundamentals of operation................9 System operation description...................... - Page 4 Oil charging procedure........................25 Troubleshooting............................26 Maintenance..............................28 Renewal parts............................ 28 Checking system for leaks........................ 28 Conducting a system pressure test....................28 System evacuation..........................31 Refrigerant charging......................... 36 Checking and trimming the refrigerant charge................38 Checking the refrigerant charge during unit shutdown.............. 39 Handling refrigerant for dismantling and repairs................
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Page 5: General Safety Guidelines
General safety guidelines Important: Read before proceeding. This equipment is a relatively complicated apparatus. During rigging, installation, operation, maintenance, or service, individuals may be exposed to certain components or conditions including, but not limited to: heavy objects, refrigerants, materials under pressure, rotating components, and both high and low voltage. -
Page 6: Changeability Of This Document
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. -
Page 7: Conditioned Based Maintenance
Traditional chiller maintenance is based upon assumed and generalized conditions. In lieu of the traditional maintenance program, a Johnson Controls YORK Conditioned Based Maintenance (CBM) program can be substituted. This CBM service plan is built around the specific needs for the chiller, operating conditions, and annualized impact realized by the chiller. -
Page 8: Nomenclature
Nomenclature Note: * Refer to YK Engineering Guide (Form 160.76-EG1) for shell, motor, and compressor combinations. Model YK (Style H), R-134a and R-513A... -
Page 9: Description Of System And Fundamentals Of Operation
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. -
Page 10: Capacity Control
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. Pre-rotation vanes (PRV), located at the entrance to the compressor impeller, compensate for variation in load. See Figure 1. -
Page 11: System Operating Procedures
System operating procedures Oil heaters If the oil heater is de-energized during a shutdown period, it must be energized for 12 hours before starting compressor, or remove all oil and recharge compressor with new oil. See Oil charging procedure. Oil heater operation The oil heater operation is controlled by the OptiView™... -
Page 12: Start-Up
If the load continues to decrease, after the pre-rotation vanes are entirely closed, the chiller is shut down by the Leaving Chilled Liquid – Low Temperature Control. The coolant temperature inside any Johnson Controls supplied liquid-cooled motor starter must be maintained above the dewpoint temperature in the equipment room to prevent condensing water vapor inside the starter cabinet. -
Page 13: Condenser Water Temperature Control
An optional status printer is available for this purpose or Figure 4 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 160.54-MR1 and may be obtained through the nearest Johnson Controls office. -
Page 14: Operating Inspections
Figure 4: Liquid chiller log sheets 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. Operating inspections By following a regular inspection using the display readings of the Microcomputer Control Center, and maintenance procedure, the operator can avoid serious operating difficulty. - Page 15 Monthly Leak check the entire chiller. Check the oil return system operation. Check the operation of the motor starter. Check the sump heater and thermostat operation. Check the three-phase voltage and current balance. Verify the correct operation, setting, and calibration of safety controls. Verify the condenser and evaporator water flows.
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Page 16: Need For Maintenance Or Service
Johnson Controls District Office. Failure to report constant troubles could damage the unit and increase the cost of repairs. -
Page 17: System Components Description
System components description 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. -
Page 18: Oil Pump
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. - Page 19 Figure 6: System components, rear view Callout Description Callout Description Motor Liquid line Oil filter Oil pump housing Compressor Condenser Discharge line Model YK (Style H), R-134a and R-513A...
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Page 20: Oil Heater
Figure 7: Schematic drawing – (YK) Compressor lubrication system 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 increases. -
Page 21: Motor Driveline
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 Manual (160.76-O2). Motor driveline The compressor motor is an open-drip-proof, squirrel cage, induction type constructed to YORK design specifications. -
Page 22: Optional Service Isolation Valves
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. -
Page 23: Variable Speed Drive (Optional)
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 pre-rotation vane position by controlling the frequency and voltage of the electrical power to the motor. Operational information is contained in the Variable Speed Drive –... -
Page 24: Operational Maintenance
Operational maintenance Oil return system The oil return system continuously maintains the proper oil level in the compressor oil sump. See Figure 8. 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: Isolate the dehydrator at the stop valves. -
Page 25: The Oil Charge
The oil charge The nominal oil charge for Q3-Q8 compressors is 11 gal, P7-H9 compressors is 17.5 gal, K1-K4 compressors is 20 gal, and K7 compressors is 24 gal. New YORK refrigeration oil must be used in the centrifugal compressor. Since oil absorbs moisture when exposed to the atmosphere, keep the oil tightly capped until you use it. -
Page 26: Troubleshooting
Troubleshooting Table 1: Operation analysis chart Results Possible cause Remedy 1. Symptom: abnormally high discharge pressure The temperature difference between the condensing temperature and water off condenser Air is in the condenser. is higher than normal. Clean condenser tubes. Check water Condenser tubes dirty or scaled. - Page 27 Table 1: Operation analysis chart Results Possible cause Remedy 9. Symptom: oil pressure system ceases to return an oil/refrigerant sample Filter-drier in oil return system Replace old filter-drier with new. dirty. Oil refrigerant return not functioning. Jet or orifice of oil return jet Remove jet, inspect for dirt.
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Page 28: Maintenance
Maintenance Renewal parts Order all replacement parts at http://www.hvacnavigator.com. See Figure 10. Figure 10: Parts navigator Checking system for leaks Leak testing The refrigerant side of the system is carefully pressure tested and evacuated at the factory. After the system has been charged, use a leak detector that is compatible with the refrigerant to ensure that that all of the joints are tight. - Page 29 Conducting the gas pressure hold test Install a high-quality high-resolution analog pressure gauge on one of the shells to monitor the system pressure over time. Ensure that the pressure gauge has a resolution of 2 psi increments with a dial face at 3 in. (7.6 cm) in diameter or greater. Before proceeding, ensure that the unit is at the initial evacuation level of 5 mmHg.
- Page 30 Figure 11: Leak test hold time Optional trace gas leak test Install a high-quality high-resolution analog pressure gauge on one of the shells to monitor the system pressure over time. Ensure that the pressure gauge has a resolution of 2 psi increments with a dial face at 3 in.
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Page 31: System Evacuation
With the system evacuated, charge with a vapor only for a 10% trace gas (R-134a) into the chiller until the system pressure reaches 10 psig (69 kPa). When using a refrigerant based trace gas, you must always charge with vapor only to reach the initial 10 psig pressure. - Page 32 method produces one of the best results, and provides accurate readings as to the extent of dehydration. The equipment required for this method of dehydration consists of the following items: • High resolution vacuum gauge (microns below 500) • Chart that shows the relationship between dew point temperature and pressure in microns (vacuum), see Table 2 •...
- Page 33 Table 2: System pressures Gauge* Absolute Boiling Inches of mercury (Hg) temperatures Millimeters of below one standard psia Microns of water (°F) mercury (Hg) atmosphere (in.) 14.696 760.0 760,000 10.24 9.629 500.0 500,000 22.05 3.865 200.0 200,000 25.98 1.935 100.0 100,000 27.95 0.968...
- Page 34 Dehydration The dehydration process is only needed if the following has occurred. It should only be done after the system has been thoroughly leak checked so that there is confidence in the vacuum decay related to moisture boiling off: The nitrogen holding charge on shipments other than Form 1 has been lost. The system has been open to the atmosphere for any length of time.
- Page 35 it to atmospheric pressure and the indicator temperature will return to approximately ambient temperature. Close off the system again, and start the second evacuation. The relatively small amount of moisture left is carried out through the vacuum pump and the temperature or pressure shown by the indicator drops uniformly until it reaches a temperature of 35°F (1.6°C) or a pressure of 5000 μm.
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Page 36: Refrigerant Charging
Operate the vacuum pump to evacuate the system to the best attainable vacuum. The vacuum must be less than 500 μm but if that cannot be attained, a vacuum at 1,000 μm or lower is acceptable. Close the system charging valve connection to the vacuum pump to start the 8-hour vacuum hold test. - Page 37 The charging line must also contain a sight-glass so that when liquid charging is performed, you can monitor the charging line to determine when the liquid is no longer being transferred to the chiller. The refrigerant charge is specified for each chiller model on the unit data plate or in the Factory Order Form (FOF) that is provided for every new sale.
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Page 38: Checking And Trimming The Refrigerant Charge
Table 4: R-513A pressure to saturated temperature conversion Pressure Temp. avg. Pressure Temp. avg. Pressure Temp. avg. Pressure Temp. avg. psig (bar) °F (°C) psig (bar) °F (°C) psig (bar) °F (°C) psig (bar) °F (°C) 0.0 (0.0) -20.5 (-29.1) 130 (8.96) 99.3 (37.4) 260 (17.93) -
Page 39: Checking The Refrigerant Charge During Unit Shutdown
• CDT = Compressor discharge temperature • CST = Condenser saturation temperature The parameters can be viewed on the OptiView control center. The chiller must be at full load design operating conditions so that the correct refrigerant charge level can be properly determined when operating. - Page 40 Figure 14: Motor starter temperature and insulation resistances Model YK (Style H), R-134a and R-513A...
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Page 41: Megging The Motor
Megging the motor Proceed in accordance with the type of starter. Mechanical starter Open the main disconnect switch and the compressor motor starter and meg the motor as follows: Using a megohm meter (megger), meg between phases and each phase to ground. See Figure 15. - Page 42 Condensers and evaporators in general Maintenance of condenser and evaporator shells is important to provide trouble free operation of the chiller. The water side of the tubes in the shell must be kept clean and free from scale. Proper maintenance such as tube cleaning, and testing for leaks, is covered on the following pages. Chemical water treatment Since the mineral content of the water circulated through evaporators and condensers varies with almost every source of supply, it is possible that the water being used may corrode the tubes or...
- Page 43 Improved results can be obtained by admitting water into the tube during the cleaning process. This can be done by mounting the brush on a suitable length of 1/8 in. pipe with a few small holes at the brush end and connecting the other end by means of a hose to the water supply. The tubes should always be brush cleaned before acid cleaning.
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Page 44: Compressor
However, if aluminum particles continue to accumulate and the same conditions continue to stop the unit operation after a new filter is installed, notify the nearest Johnson Controls office to request the presence of a Johnson Controls Service Technician. -
Page 45: Preventive Maintenance
Important: If a unit failure occurs due to improper maintenance during the warranty period, Johnson Controls will not be liable for costs incurred to return the system to satisfactory operation. In any operating system it is most important to provide a planned maintenance and inspection of its functioning parts to keep it operating at its peak efficiency. - Page 46 Table 5: Guide to motor greasing and shaft rotation intervals Anti-friction/ Max shaft Grease Alternate Preferred Alternative ball bearing Hours to lube idle time Grease quantity method grease grease grease motor frame preferred method 404/5-5010 8g Operational Mobil Polyrex 1100 90 Days L5010 15g Rest...
- Page 47 Johnson Controls service office prior to attempting the work. Please be aware that this information may be time sensitive and that Johnson Controls reserves the right to revise at any time. Be certain you are working with the latest information.
- Page 48 When the grease is level with the top, this is the number of pumps for one cubic inch of grease. Multiply the number of pumps by 1.5 to get the number of pumps for YORK chiller motor bearings. Note: Over-greasing can be as detrimental as under-greasing, or total lack of greasing. A bearing housing over-filled with grease can run 20°C higher temperature than one with the correct amount of grease.
- Page 49 Operating temperature Normal operating temperature for grease lubricated bearings on YORK chillers is 40°C to 65°C (100°F to 150°F). It is normal to see the temperature elevate immediately after relubrication, and then come down as much as 20°F after a few hours of operation. •...
- Page 50 Using a hand operated grease gun, pump the Polyrex™ EM grease into the grease inlet. See Figure 20. After the re-greasing process is completed, the bearing temperature rises approximately 30°F to 40°F for a period of time. The temperature then returns to a normal operating range depending on motor load.
- Page 51 Figure 19: Grease outlet Figure 20: Grease pumping Model YK (Style H), R-134a and R-513A...
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Page 52: Leak Testing
All electrical controls should be inspected for obvious malfunctions. It is important that the factory settings of controls (operation and safety) not be changed. If the settings are changed without Johnson Controls approval, the warranty will be jeopardized. Maintenance inspections To avoid serious operating difficulty, follow a regular inspection procedure. - Page 53 Daily • Check the OptiView Control Center display. Log the date, time, run hours, and number of starts. Use the daily log in the YK centrifugal liquid chiller log sheet, 160.54-MR1, to log all of the unit • operating data that is outlined in the log. Use this data for the following comparisons: Compare the entering and leaving condenser water temperatures with the job design conditions.
- Page 54 • Clean and backflush the starter heat exchanger. • Replace the starter coolant. • Replace any starter air filters as applicable. • Perform refrigerant analysis. • Replace all oil filters and filter driers. • Perform oil analysis on the compressor lube oil. •...
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Page 55: Unit Conversion
Unit conversion The following factors can be used to convert from English to the most common SI Metric values. Table 6: SI metric conversion Measurement Multiply English unit By factor To obtain metric unit Capacity Tons Refrigerant Effect (ton) 3.516 Kilowatts (kW) Power Horsepower... - Page 56 © 2021 Johnson Controls. 5000 Renaissance Drive, New Freedom, York, PA 17349, USA. Subject to change without notice. All rights reserved.
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I would be grateful if you could provide the exact number of tubes in both the evaporator and condenser sections for the 600 tons liquid chiller. Model Number - YKCFCEQ75C0FS Chiller serial number - 0E70578912