Johnson Controls YORK YK Style G OPTIVIEW Operation And Maintenance

MODEL YK (STYLE G)

R-134a

WITH OPTIVIEW

TM

CONTROL CENTER

FOR ELECTRO-MECHANICAL STARTER,

SOLID STATE STARTER AND VARIABLE SPEED DRIVE

CENTRIFUGAL LIQUID CHILLERS

OPERATIONS AND MAINTENANCE Supersedes: 160.75-O1 (508) Form 160.75-O1 (211)

LD15222

FORM 160.75-O1 (211)

JOHNSON CONTROLS

2

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 respon-

sibility 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

IMPORTANT!

READ BEFORE PROCEEDING!

GENERAL SAFETY GUIDELINES

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 in-

dividual posseses independent training that will enable

them to perform their assigned tasks properly and safe-

ly. It is essential that, prior to performing any task on

this equipment, this individual shall have read and un-

derstood this document and any referenced materials.

This individual shall also be familiar with and comply

with all applicable governmental standards and regula-

tions 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.

Indicates a potentially hazardous situa-

tion which will result in possible injuries

or damage to equipment if proper care is

not taken.

Identies a hazard which could lead to

damage to the machine, damage to other

equipment and/or environmental pollu-

tion if proper care is not taken or instruc-

tions and are not followed.

Highlights additional information useful

to the technician in completing the work

being performed properly.

External wiring, unless specied 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 specications and must be performed only by a qualied

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.

JOHNSON CONTROLS

3

FORM 160.75-O1 (211)

CHANGEABILITY OF THIS DOCUMENT

In complying with Johnson Controls’ policy for contin-

uous product improvement, the information contained

in this document is subject to change without notice.

While Johnson Controls makes no commitment to up-

date 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 responsi-

bility 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

MANUAL DESCRIPTION FORM NUMBER

Variable Speed Drive – Operation 160.00-O1

Solid State Starter – Operation and Maintenance 160.00-O2

Floor Mounted MV SSS – Operation 160.00-O5

Unit Mounted MV SSS – Operation 160.00-O7

Installation – Unit 160.75-N1

Optiview™ Control Center – Operation and Maintenance 160.54-O1

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

160.75-PW1

Wiring Diagram – Field Connections for YK Chiller (Style G) OptiView Control Center with Remote

Medium Voltage SSS

160.75-PW2

Wiring Diagram – Field Connections for YK Chiller (Style G) OptiView Control Center with Remote

Medium Voltage VSD

160.75-PW3

Wiring Diagram – Field Control Modications for YK Chiller (Style G) 160.75-PW4

Wiring Diagram – YK Chiller (Style G) OptiView Control Center with Remote Low or Medium Voltage EMS 160.75-PW5

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

160.75-PW6

Wiring Diagram – YK Chiller (Style G) OptiView Control Center with LTC I/O Board with Remote Low or

Medium Voltage EMS

160.75-PW7

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

160.75-PW8

Renewal Parts – Unit 160.75-RP1

Renewal Parts – OptiView Control Center 160.54-RP1

FORM 160.75-O1 (211)

JOHNSON CONTROLS

4

NOMENCLATURE

YK KC K4 H9 – CY G

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 160.75-EG1)

Shell/Motor/Compressor combinations.

JOHNSON CONTROLS

5

FORM 160.75-O1 (211)

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 ........................................................................................... 11

Oil Heaters ..................................................................................................................................................... 11

Oil Heater Operation ...................................................................................................................................... 11

Checking The Oil Level In The Oil Reservoir ................................................................................................. 11

Start-Up Procedure ........................................................................................................................................ 11

Start-Up .......................................................................................................................................................... 11

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

FORM 160.75-O1 (211)

JOHNSON CONTROLS

6

LIST OF FIGURES

LIST OF TABLES

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 ............................................................................................................................... 11

FIGURE 6 - Chiller Starting Sequence And Shutdown Sequence (Em Starter And Solid State Starter) ................ 12

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

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

TABLE OF CONTENTS (CONT'D)

TABLE 1 - Operation Analysis Chart .......................................................................................................................25

TABLE 2 - System Pressures .................................................................................................................................28

TABLE 3 - Bearing Lubrication ................................................................................................................................35

JOHNSON CONTROLS

7

FORM 160.75-O1 (211)

nent to operation of the chiller are automatically dis-

played 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 start-

er, 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.

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 opera-

tion. The Control Center is programmed by the opera-

tor to suit job specifications. Automatic timed start-ups

and shutdowns are also programmable to suit night-

time, weekends, and holidays. The operating status,

temperatures, pressures, and other information perti-

1

LD15222

CONDENSER

CONTROL

CENTER

COMPRESSOR

MOTOR

EVAPORATOR

FIGURE 1 - MODEL YK CHILLER

FORM 160.75-O1 (211)

JOHNSON CONTROLS

8

SECTION 1 - DESCRIPTION OF SYSTEM AND FUNDAMENTALS OF OPERATION

7619A(D)

FIGURE 2 - COMPRESSOR PREROTATION VANES

The refrigerant vapor, which is produced by the boil-

ing action in the evaporator, flows to the compressor

where the rotating impeller increases its pressure and

temperature and discharges it into the condenser. Wa-

ter flowing through the condenser tubes absorbs heat

from the refrigerant vapor, causing it to condense. The

condenser water is supplied to the chiller from an ex-

ternal 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 han-

dle 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 rela-

tively small part of the time the unit is in operation.

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 leav-

ing 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 lo-

cated 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.

SECTION 1 - DESCRIPTION OF SYSTEM AND FUNDAMENTALS OF OPERATION

JOHNSON CONTROLS

9

FORM 160.75-O1 (211)

1

Refrigerant Flow-Thru Chiller

(Falling Film Evaporator)

FIGURE 3 - REFRIGERANT FLOW-THRU CHILLER (FALLING FILM EVAPORATOR)

Rev. 2 (10-11-2010)

Dan Sowers

dan.sowers-e[email protected]

(717) 771-7535

YK Mod G

Refrigerant Flow-Thru Cross-Secon Diagram

(Falling-Film Evaporator)

COMPRESSOR

EVAPORATOR

DISCHARGE

PRE-ROTATION

VANES

SUCTION

BAFFLE

SUB-COOLER

LIQUID LEVEL

CONDENSER

LIQUID LEVEL

VALVE

HOT GAS

BYPASS VALVE

LIQUID LEVEL

SUCTION

OPTIONAL

ISOLATION

VALVE

OPTIONAL

ISOLATION

VALVE

OPTIONAL HOT GAS

BYPASS LINE

LD00924A

FORM 160.75-O1 (211)

JOHNSON CONTROLS

10

SECTION 1 - DESCRIPTION OF SYSTEM AND FUNDAMENTALS OF OPERATION

Refrigerant Flow-Thru Chiller

(Flooded Evaporator)

FIGURE 4 - REFRIGERANT FLOW-THRU CHILLER (FLOODED EVAPORATOR)

Rev. 2 (12-09-2010)

Dan Sowers

dan.sowers-e[email protected]

(717) 771-7535

YK Mod G

Refrigerant Flow-Thru Cross-Secon Diagram

(Flooded Evaporator)

COMPRESSOR

EVAPORATOR

DISCHARGE

PRE-ROTATION

VANES

MESH ELIMINATORS or

SUCTION BAFFLE

SUB-COOLER

LIQUID LEVEL

CONDENSER

SUCTION

LIQUID LEVEL

VALVE

LIQUID LEVEL

OPTIONAL

ISOLATION

VALVE

OPTIONAL

ISOLATION

VALVE

HOT GAS

BYPASS VALVE

OPTIONAL HOT GAS

BYPASS LINE

LD00924B

JOHNSON CONTROLS

11

FORM 160.75-O1 (211)

• 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 refrigera-

tion system oil!

START-UP PROCEDURE

Pre-Starting

Prior to starting the chiller, observe the Optiview™

Control Center – Operation and Maintenance (Form

160.54-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 bafe damage.

START-UP

1. If the chilled water pump is manually operated,

start the pump. The Control Center will not al-

lowthechillertostartunlesschilledliquidowis

established through the unit. If the chilled liquid

pump is wired to the Microcomputer Control Cen-

ter 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 chill-

er.) When the start switch is energized, the Con-

trol Center is placed in an operating mode and

any malfunction will be noted by messages on a

graphic display.

SECTION 2 - SYSTEM OPERATING PROCEDURES

OIL HEATERS

If the oil heater is de-energized during a shutdown pe-

riod, it must be energized for 12 hours prior to starting

compressor, or remove all oil and recharge compres-

sor with new oil. (Refer to Oil Charging Procedure on

Page 24.)

OIL HEATER OPERATION

The oil heater operation is controlled by the OptiV-

iew™ 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 tem-

perature. This target value is maintained by the control

panel.

If the target value is greater than 160°F (71°C), the tar-

get 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 con-

trol 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).

FIGURE 5 - OIL LEVEL INDICATOR

LD08647

2

FORM 160.75-O1 (211)

JOHNSON CONTROLS

12

SECTION 2 - SYSTEM OPERATING PROCEDURES

LD15609

FIGURE 6 - CHILLER STARTING SEQUENCE AND SHUTDOWN SEQUENCE (EM STARTER AND SOLID

STATE STARTER)

** Not for all shutdowns. Refer to “Display Messages” in manual Optiview™ Control Center – Operation and Maintenance (Form 160.54-O1).

FIGURE 7 - CHILLER STARTING SEQUENCE AND SHUTDOWN SEQUENCE (VARIABLE SPEED DRIVE)

** Not for all shutdowns. Refer to “Display Messages” in manual Optiview™ Control Center – Operation and Maintenance (Form 160.54-O1).

LD15610

SECTION 2 - SYSTEM OPERATING PROCEDURES

JOHNSON CONTROLS

13

FORM 160.75-O1 (211)

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.

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 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 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.

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 bear-

ing 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

FORM 160.75-O1 (211)

JOHNSON CONTROLS

14

SECTION 2 - SYSTEM OPERATING PROCEDURES

3. Check entering and leaving condenser water pres-

sure 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 tem-

peratures and evaporator pressure for compari-

son 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 tem-

perature 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lterelement.

2. Oil return system.

A. Change dehydrator.

B. Check nozzle of eductor for foreign par-

ticles.

3. Check controls and safety cutouts.

FIGURE 8 - 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.

LD00467

23889A

SECTION 2 - SYSTEM OPERATING PROCEDURES

JOHNSON CONTROLS

15

FORM 160.75-O1 (211)

2

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 manufactur-

ers maintenance and service instruction supplied

with unit)

A. Clean air passages and windings per manu-

facturers instructions.

B. Meg motor windings – Refer to Figure 16 on

Page 30 for details.

C. Lubricate per motor manufacturer recom-

mendations.

4. Inspect and service electrical components as neces-

sary.

5. Perform refrigerant analysis.

If quarterly inspection indicates oil is ne,

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 un-

able 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 near-

est 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 160.54-

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 contin-

ue 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 opera-

tion 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 fol-

lowing 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 sys-

tem should be checked periodically.

2. If freezing temperatures are encountered while

the system is idle, carefully drain the cooling wa-

ter 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 peri-

ods 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 com-

pressor motor, condenser water pump and the

chilled water pump. Open the 115 volt circuit to

the Control Center.

FORM 160.75-O1 (211)

JOHNSON CONTROLS

16

SECTION 2 - SYSTEM OPERATING PROCEDURES

THIS PAGE INTENTIONALLY LEFT BLANK

JOHNSON CONTROLS

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FORM 160.75-O1 (211)

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 pow-

ered 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 over-

speed tested. The inserted type journal and thrust bear-

ings 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 inte-

grally 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 bel-

lows cartridge style with ceramic internal and atmo-

spheric 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 liq-

uid 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 com-

pressor 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 re-

verse).

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 neces-

sary 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 en-

ergized. After a 50 second pre-lube period, the com-

pressor 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 sur-

rounding 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 high-

est point in the lubrication system internally in the com-

pressor. It provides an oil supply to the various bear-

ings 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

FORM 160.75-O1 (211)

JOHNSON CONTROLS

18

SECTION 3 - SYSTEM COMPONENTS DESCRIPTION

FRONT VIEW

FIGURE 9 - SYSTEM COMPONENTS FRONT VIEW

VARIABLE

SPEED

DRIVE

EVAPORATOR

COMPRESSOR

SUCTION

RELIEF

VALVES

SIGHT

GLASS

VARIABLE SPEED

OIL PUMP

CONTROL BOX

OPTIVIEW CONTROL

CENTER

LD15222

SECTION 3 - SYSTEM COMPONENTS DESCRIPTION

JOHNSON CONTROLS

19

FORM 160.75-O1 (211)

3

LD15223

FIGURE 10 - SYSTEM COMPONENTS REAR VIEW

DISCHARGE

LINE

COMPRESSOR

OIL PUMP

HOUSING

LIQUID LINE

REAR VIEW

MOTOR

CONDENSER

FORM 160.75-O1 (211)

JOHNSON CONTROLS

20

SECTION 3 - SYSTEM COMPONENTS DESCRIPTION

HOT

THERMISTOR

OIL

HEATER

ANGLE

DRAIN VALVE

OIL

FILTER

OIL

SUMP

OIL

PUMP

SUCTION

SUBMERSIBLE

OIL PUMP

WITH 3-PHASE MOTOR

LOW OIL

PRESSURE

TRANSDUCER

SIGHT

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

DOUBLE

BELLOWS

SHAFT SEAL

HIGH SPEED

THRUST COVER

THRUST COLLAR

MAIN JOURNAL

AND THRUST

BEARING

HIGH

PRESSURE

TRANSDUCER

EMERGENCY

OIL RESERVE

COMPRESSOR ROTOR

SUPPORT SECTION

OIL

FIGURE 11 - SCHEMATIC DRAWING – (YK) COMPRESSOR LUBRICATION SYSTEM

LD15200

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Johnson Controls YORK YK Style G OPTIVIEW Operation And Maintenance

Johnson Controls YORK YK Style G OPTIVIEW Operation And Maintenance

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