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JOHNSON CONTROLS

11

SECTION 2 - SYSTEM OPERATING PROCEDURES

FORM 160.76-O1 

ISSUE DATE: 6/15/2015

2

For display messages and information pertaining to the 

operation refer to 

Optiview™ Control Center – Opera-

tion and Maintenance (Form 160.54-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 actua-

tor under the control of the Microprocessor Board. The 

vane control routine employs proportional plus deriva-

tive (rate) control action. A drop in chilled liquid tem-

perature will cause the actuator to close the Prerotation 

Vanes to decrease chiller capacity. When the chilled 

liquid temperature rises, the actuator will open the Pre-

rotation Vanes to increase the capacity of the chiller.
However, the current draw (amperes) by the compres-

sor motor is also limited to FLA setpoint by the micro-

processor.
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.
The coolant temperature inside any JCI-supplied liq-

uid-cooled motor starter must be maintained above  the 

dewpoint temperature in the equipment room to pre-

vent condensing water vapor inside the starter cabinet. 

Therefore, an additional temperature-controlled throttle 

valve is needed in the flow path for the starter heat ex-

changer to regulate cooling above the equipment room 

dewpoint for applications using cooling sources other 

than evaporative air-exchange methods, such as wells, 

bodies of water, and chilled water. The temperature 

control valve should be the type to open on increasing 

drive coolant temperature, fail-closed, and set for a tem-

perature above dewpoint. It can be requested as factory- 

supplied on a chiller order by special quotation.

CONDENSER WATER TEMPERATURE  

CONTROL

The YORK chiller is designed to use less power by tak-

ing 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 + 6.6 (     )

ECWT = Entering Condensing Water Temperature 
LCWT = Leaving Chilled Water Temperature
C Range =  Condensing water temperature range at the 

given load condition.

% Load

100

% Load

100

At start-up, the entering condenser water temperature 

may be as much as 25°F (14°C) colder than the stand-

by return chilled water temperature. Cooling tower fan 

cycling will normally provide adequate control of the 

entering condenser water temperature on most instal-

lations.
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 condi-

tions (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 6 on Page 12 

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 160.44-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 ref-

erence for operating the system. Readings taken when 

a system is newly installed will establish normal condi-

tions with which to compare later readings.
For example, an increase in condenser approach tem-

perature (condenser temperature minus leaving con-

denser water temperature) may be an indication of 

dirty condenser tubes.

Summary of Contents for YK Series

Page 1: ...WITH OPTIVIEWTM CONTROL CENTER FOR ELECTRO MECHANICAL STARTER SOLID STATE STARTER AND VARIABLE SPEED DRIVE CENTRIFUGAL LIQUID CHILLERS OPERATIONS AND MAINTENANCE New Release Form 160 76 O1 615 LD15222...

Page 2: ...his document and any referenced materials This in dividual shall also be familiar with and comply with all applicable industry and governmental standards and regulations pertaining to the task in ques...

Page 3: ...Chillers Style H Q3 Q7 with Low Voltage VSD 160 75 PW7 Renewal Parts Unit 160 76 RP1 Renewal Parts OptiView Control Center 160 54 RP1 CHANGEABILITY OF THIS DOCUMENT In complying with Johnson Controls...

Page 4: ...6 15 2015 NOMENCLATURE YK 6A 6Q Q7 EM H MOTOR CODE POWER SUPPLY for 60 Hz 5 for 50 Hz COMPRESSOR CODE CONDENSER CODE EVAPORATOR CODE MODEL STYLE Design Level Refer to YK Engineering Guide for Form 16...

Page 5: ...13 Stopping The System 13 Prolonged Shutdown 13 SECTION 3 SYSTEM COMPONENTS DESCRIPTION 15 General 15 Compressor 15 Capacity Control 15 Compressor Lubrication System 15 Oil Pump 15 Oil Heater 19 Moto...

Page 6: ...10 Oil Return System 21 FIGURE 11 Charging Oil Reservoir With Oil 22 FIGURE 12 Evacuation Of Chiller 25 FIGURE 13 Saturation Curve 27 FIGURE 14 Diagram Megging Motor Windings 28 FIGURE 15 Motor Start...

Page 7: ...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 SECTION 1 DESCRIPTIO...

Page 8: ...owers ext jci com 717 771 7535 YK Mod G Refrigerant Flow Thru Cross Section Diagram Falling Film Evaporator LEGEND High Pressure Vapor High Pressure Liquid Refrigerant Low Pressure Liquid Refrigerant...

Page 9: ...turn 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 chill er When the start switch i...

Page 10: ...hutdowns Refer to Display Messages in manual Optiview Control Center Operation and Maintenance Form 160 54 O1 Figure 5 CHILLER STARTING SEQUENCE AND SHUTDOWN SEQUENCE VARIABLE SPEED DRIVE 0 10 13 45 5...

Page 11: ...he YORK chiller is designed to use less power by tak ing advantage of lower than design temperatures that are naturally produced by cooling towers throughout the operating year Exact control of conden...

Page 12: ...ndenser 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 ope...

Page 13: ...he OptiView panel or rapid stop with the COM PRESSOR STOP RESET switch The compressor will stop automatically The oil pump will contin ue to run for coastdown period The oil pump will then stop automa...

Page 14: ...JOHNSON CONTROLS 14 FORM 160 76 O1 ISSUE DATE 6 15 2015 SECTION 2 SYSTEM OPERATING PROCEDURES THIS PAGE INTENTIONALLY LEFT BLANK...

Page 15: ...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 r...

Page 16: ...6 15 2015 SECTION 3 SYSTEM COMPONENTS DESCRIPTION FRONT VIEW Figure 7 SYSTEM COMPONENTS FRONT VIEW VARIABLE SPEED DRIVE EVAPORATOR COMPRESSOR SUCTION RELIEF VALVES SIGHT GLASS VARIABLE SPEED OIL PUMP...

Page 17: ...7 SECTION 3 SYSTEM COMPONENTS DESCRIPTION FORM 160 76 O1 ISSUE DATE 6 15 2015 3 3 LD15223 Figure 8 SYSTEM COMPONENTS REAR VIEW DISCHARGE LINE COMPRESSOR OIL PUMP HOUSING LIQUID LINE REAR VIEW MOTOR OI...

Page 18: ...HT GLASSES OIL COOLER OIL TEMP CONTROL REFRIG THRUST COLLAR BEARING PRV INLET VALVES BEARING PINION GEAR SHAFT IMPELLER H S SHAFT SEAL LOW SPEED THRUST COVER LOW SPEED GEAR LOW SPEED GEAR REAR BEARING...

Page 19: ...ogy to optimize efficiency minimize refrigerant charge and maintain reliable control A specifically designed spray distributor provides uniform distribution of re frigerant over the entire length to y...

Page 20: ...Hot gas bypass is optional and is used to eliminate compressor surge during light load or high head op eration The OptiView control panel will automati cally modulate the hot gas valve open and closed...

Page 21: ...m the evaporator through the dehy drator 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 de...

Page 22: ...harge connection to the oil charg ing valve A located on the remote oil reservoir cover plate Refer to Figure 11 on Page 22 Do not tighten the connection at the charging valve until after the air is f...

Page 23: ...ice problem Remove obstruction Temperature difference between leaving chilled water and refrigerant in the evaporator greater than normal with normal discharge temperature Evaporator tubes dirty or re...

Page 24: ...blocked oil supply inlet 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 ta...

Page 25: ...to be found by the soap test To test with R 134a proceed as follows 1 With no pressure in the system charge R 134a gas into the system through the charging valve to a pressure of 2 PSIG 14 kPa 2 Build...

Page 26: ...es and shell are heated evenly 5 Close the system charging valve and the stop valve between the vacuum indicator and the vac uum pump Then disconnect the vacuum pump leaving the vacuum indicator in pl...

Page 27: ...rior to evacuation then the saturation tempera ture recordings should follow a curve similar to the typ ical saturation curve shown as Figure 13 on Page 27 The temperature of the water in the test tub...

Page 28: ...nt charge should always be checked and trimmed when the system is shut down The refrigerant charge level must be checked after the pressure and temperature have equalized between the condenser and eva...

Page 29: ...e motor should not be run The motor should be heated to 250 F in an effort to remove moisture and obtain an acceptable reading at room ambient This can be done either by baking in a forced hot air ove...

Page 30: ...ribute to erratic performance Condenser In a condenser trouble due to fouled tubes is usually indicated by a steady rise in head pressure over a pe riod of time accompanied by a steady rise in condens...

Page 31: ...ection in the following manner if the location is not definite all the tubes will require investigations 2 Wash off both tube heads and the ends of all tubes with water Do not use carbon tetrachloride...

Page 32: ...it is shutting down on HOT High Oil Temperature or Low Oil Pressure OP change the oil filter element Examine the oil filter element for the presence of aluminum particles Aluminum gas seal rings can c...

Page 33: ...common motors MOTOR RE LUBRICATION INSTRUCTION All motor manufacturers have slightly different re quirements for the exact amount of grease to be added and the exact interval for re greasing The sugge...

Page 34: ...o see old grease coming out from the relief port Operating Temperature Normal operating temperature for grease lubricated bearings on York chillers is 40 65 degrees centigrade or 100 150 degrees Fahre...

Page 35: ...evalu ated similiar to evaporator tubes when the heating circuit is a treated closed loop Fouling could be detected as ability to meet heat load requirements decreases OIL RETURN SYSTEM 1 Change the...

Page 36: ...f applicable X 2 Perform oil analysis on compressor lube oil 1 X Perform refrigeration analysis 1 X Perform vibration analysis X Clean tubes X 2 Perform Eddy current testing and inspect tubes 2 5 Year...

Page 37: ...Fahrenheit to Celsius multiply by 5 9 or 0 5556 Example 10 0 F range x 0 5556 5 6 C range Table 3 SI METRIC CONVERSION MEASUREMENT MULTIPLY ENGLISH UNIT BY FACTOR TO OBTAIN METRIC UNIT Capacity Tons...

Page 38: ...Freedom Pennsylvania USA 17349 800 861 1001 Subject to change without notice Printed in USA Copyright by Johnson Controls 2015 www johnsoncontrols com ALL RIGHTS RESERVED Form 160 76 O1 615 Issue Dat...

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