Daikin WDC User manual

Installation, Operation,
and Maintenance Manual
Centrifugal Chillers
Model WDC, WCC, A Vintage
600 to 2700 Tons (2100 to 9500 kW)
R-134a or R-513A Refrigerant
60/50 Hz
IOM 1281-2
Group: Chiller
Part Number: IOM1281-2
Date: July 2023

IOM 1281-2 • CENTRIFUGAL WATER CHILLERS 2 www.DaikinApplied.com
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©2023 Daikin Applied, Minneapolis, MN. All rights reserved throughout the world.This document contains the most current product information as
of this printing. Daikin Applied Americas Inc. has the right to change the information, design, and construction of the product represented within the
document without prior notice. For the most up-to-date product information, please go to www.DaikinApplied.com.
™® MicroTech, SiteLine, and Daikin Applied are trademarks or registered trademarks of Daikin Applied Americas Inc. The following are trademarks
or registered trademarks of their respective companies: BACnet from American Society of Heating, Refrigerating and Air-Conditioning Engineers,
Inc.; Echelon, LonWorks, LonMark, and LonTalk from Echelon Corporation; Modbus from Schneider Electric; and Windows from Microsoft
Corporation.
Table of Contents
Introduction .................................5
 ...............5
General Description .........................6
Installation ..................................7
Receiving and Handling ......................7
Location ..................................8
Operating Limits............................9
Field Insulation.............................9
Water Piping..............................10
Water Quality Guidelines ....................10
Vessel Drains at Startup ....................11
Flow Switches ............................11
Variable Fluid Flow Rates ...................11
System Water Volume ......................11
System Pumps............................11
Condenser Water Temperature Control .........11
Cooling Tower Control ......................12
Water Side Economizer Cycle Operation........12
Relief Valves .............................13
Oil Coolers ...............................14
Oil Heater................................15
Field Wiring ..............................18
Building Automation Systems (BAS) ...........19
Use with On-Site Generators .................19
Field Wiring, Controls & Starters ..............20
 ........................25
Operation .................................33
Dual/Multi-Chiller Operation..................33
Ice Mode Operation ........................34
Operator Responsibilities....................34
Operator Schools ..........................34
Unit Enabling/Disabling .....................34
Human Machine Interface (HMI) ..............35
Tower Control Settings .....................50
Alarms ..................................56
Controller Inputs and Outputs ................61
Maintenance ...............................63
Routine Maintenance .......................63

Pre-Start Checklist – Centrifugal Chillers
Must be completed, signed and returned to Daikin Applied service dept. at least 2 weeks prior to requested start date.
Job Name
Installation Location
Customer Order Number
Model Number(s)
G.O. Number(s)
Chilled Water
Yes
No
N/A
Initials
Piping Complete
Water System – flushed, filled, vented; Water treatment in place
Pumps installed and operational (rotation checked, strainers installed and cleaned)
Controls operational (3-way valves, face/bypass dampers, bypass valves, etc.)
Water system operated and tested; flow meets unit design requirement
Flow switch installed, wired, and calibrated
Condenser Water
Yes
No
N/A
Initials
Cooling tower flushed, filled, vented; Water treatment in place
Pumps installed and operational (rotation checked, strainers installed and cleaned)
Controls (3-way valves, bypass valves, etc.) operable per IM/IOM
Water system operated and flow balance to meet unit design requirement
Flow switch installed, wired, and calibrated
Electrical
Yes
No
N/A
Initials
115 volt service completed, but not connected to control panel (remote mounted starters)
Line Power Leads connected to starter; load leads (b) run from starter to compressor, ready for
connection by Service (Do not connect load leads to starter or compressor terminals).
(See Notes 1 & 4)
All interlock wiring complete and compliant with Daikin Applied specifications
Starter complies with Daikin Applied specifications
*Oil cooler solenoid wired to control panel as shown on wiring diagram
(See Notes)
Pump starter and interlocks wired
Cooling tower fans and controls wired
Wiring complies with National Electrical Code and local codes
(See Note 4)
Condenser pump starting relay (CP1,2) installed and wired
(See Note 3)
Miscellaneous
Yes
No
N/A
Initials
*Oil cooled water piping complete. (Units with water-cooled oil coolers only)
Relief valve piping complete (per local codes)
Thermometers, wells, gauges, control, etc., installed
Minimum system load of 80% capacity available for testing/adjusting controls
SiteLineTM cloud-connected controls included and needs to be commissioned
Document Attached: Technical Breakdown from Daikin Tools
Document Attached: Final Order Acknowledgement
Notes: The most common problems delaying start-up and affecting unit reliability are:
1. Field installed compressor motor power supply leads too small. Questions: Contact the local Daikin Applied sales representative. State size, number and type of
conductors and conduits installed:
a. From Power supply to starter
b. From starter to chiller unit (remotemounted)
2. Centrifugal chillers with water cooled oil coolers must have a 115 volt normally closed water solenoid valve installed in the oil cooler water supply line. Daikin
Applied recommends ASCO Type 8210B27 solenoid valve or approved equal and 40-mesh strainer. Daikin Applied does not supply these components.
3. A 115-volt field-supplied relay (CP1,2) must be used to start/stop condenser water pump on most applications. Cold condenser water must not flow through
condenser during compressor off cycle. Provisions have been made in control center for connecting CP relay, but must not have a rating in excess of 100 VA.
4.
Refer to NEC Article 430-22 (a)
*Does Not Apply to Magnetic Bearing Chillers (WMC/WME)
Contractor Representative Daikin Applied Sales Representative
Signed:
Signed:
Name: Name:
Company: Company:
Date: Date:
Phone/Email:
Phone/Email:
©2022 Daikin Applied Form SF-18004 19 SEPT 2022
Cut Here 

Introduction
This manual provides installation, operation, and maintenance
information for Daikin Applied centrifugal chillers with the
MicroTech® controller.
NOTE: Installation and maintenance are to be performed
only by licensed, if required by local codes and

with local codes and regulations and are experienced
with this type of equipment.
DANGER
LOCKOUT/TAGOUT all power sources prior to service, pressurizing,
de-pressuring, or powering down the unit. Failure to follow this warning
exactly can result in serious injury or death. Disconnect electrical power
before servicing the equipment. More than one disconnect may be required
to denergize the unit. Be sure to read and understand the installation,
operation, and service instructions within this manual.
WARNING
Electric shock hazard. Improper handling of this equipment can cause
equipment damage, personal injury, or death. This equipment must be
properly grounded. Connections to and service of the MicroTech control
panel must be performed only by personnel that are knowledgeable in the
operation of the equipment being controlled.
WARNING
Polyolester Oil, commonly known as POE oil is a synthetic oil used in many
refrigeration systems, and may be present in this Daikin Applied product.
POE oil, if ever in contact with PVC/CPVC, will coat the inside wall of PVC/
CPVC pipe causing environmental stress fractures. Although there is no
PVC/CPVC piping in this product, please keep this in mind when selecting
piping materials for your application, as system failure and property
damage could result. Refer to the pipe manufacturer’s recommendations to
determine suitable applications of the pipe.
CAUTION
Static sensitive components. A static discharge while handling electronic
circuit boards can cause damage to the components. Discharge any
static electrical charge by touching the bare metal inside the control panel
before performing any service work. Never unplug any cables, circuit board
terminal blocks, or power plugs while power is applied to the panel.
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DANGER
Danger indicates a hazardous situation, which will result in death or serious
injury if not avoided.
WARNING
Warning indicates a potentially hazardous situations, which can result in
property damage, personal injury, or death if not avoided.
CAUTION
Caution indicates a potentially hazardous situations, which can result in
minor injury or equipment damage if not avoided.
NOTICE
Notice indicates practices not related to physical injury.
NOTE: Indicates important details or clarifying statements for
information presented.
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www.DaikinApplied.com 5 IOM 1281-2 • CENTRIFUGAL WATER CHILLERS

General Description
Daikin Applied Centrifugal Water Chillers are complete, self-
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is completely assembled and factory tested before shipment.
The WDC series is equipped with two compressors operating
in parallel on a single evaporator and condenser. The WCC
series is equipped with two compressors, each operating
on one refrigerant circuit of a two circuit evaporator and
condenser. In the series, each unit has one compressor
connected to a condenser and evaporator. The basic sizes of
compressors are the 079, 087, 100, 113,and 126. They provide
a cooling capacity range from 600 to 2700 tons. The chillers
use R-134a or R-513A refrigerant.
The controls are pre-wired, adjusted and tested. Only normal

are required, thereby simplifying installation and increasing
reliability. Most necessary equipment protection and operating
controls are factory installed in the control panel.
All Daikin Applied centrifugal chillers are factory tested prior to
shipment and must be initially started at the job site by a
factory trained Daikin Applied service technician. Failure to
󰀨
The standard limited warranty on this equipment covers parts
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details of this warranty can be found in the warranty statement
furnished with the equipment.
Figure 1: WDC Major Component Locations
IOM 1281-2 • CENTRIFUGAL WATER CHILLERS 6 www.DaikinApplied.com
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www.DaikinApplied.com 7 IOM 1281-2 • CENTRIFUGAL WATER CHILLERS
Installation
Receiving and Handling
The unit should be inspected immediately after receipt for
possible damage.
All Daikin Applied centrifugal water chillers are shipped FOB
factory and all claims for handling and shipping damage are
the responsibility of the consignee. For knockdown options,



• The unit nameplate is located on the side of the Unit
Control Panel. It has a Style No. and Serial No.; both
are unique to the unit. These numbers should be used to
identify the unit for service, parts, or warranty questions.
This plate also lists the unit refrigerant charge.
• Vessel nameplates are located on the evaporator and
condenser, listing National Board Number (NB) and serial
number. Either number can identify the vessel (but not
the entire unit).
• A compressor nameplate is located on each compressor.
Insulation corners from the evaporator’s rigging hole locations
are shipped loose and should be glued in place after the unit is

Check that these items have been delivered with the unit.
If so equipped, leave the shipping skid in place until the unit is

Lifting and Rigging
CAUTION
Extreme care must be used when rigging the unit to prevent
damage to the control panels and refrigerant piping. See the

the weights and center of gravity of the unit. If the drawings
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for assistance.
Spreader bars must be used between the rigging lines to keep
lifting straps vertical and prevent damage to the control panels,
electrical panels, unit piping,and motor terminal boxes. The unit
can be lifted by fastening rigging hooks to the outermost four
rigging holes (see Figure 1). The spreader-bar length should
be equal to, or no more than 1-foot shorter than, the distance
between the lifting holes located at opposite ends of the chiller.
The unit will require a double spreader-bar of this length
capable of supporting 1.5 times the shipping weight of the unit.
Separately, all cables and hooks by themselves must also be
capable of supporting 1.5 times the shipping weight of the unit.
NOTE: The spreader bars in Figure 2 are a representation

spreader bars needed.
If a knockdown option was ordered on the unit, reference the
 section starting on page 25 for more
information.
Figure 2: Representative Unit Lifting and Rigging
BACK VIEW
END VIEW
BACK VIEW
END VIEW
NOTES:
DAIKIN APPLIED IS NOT A LICENSED NOR CERTIFIED RIGGING SPECIALIST. IT IS THE CUSTOMER'S 1.
RESPONSIBILITY TO CONSULT A CERTIFIED RIGGING CONTRACTOR TO RIG, LIFT, AND MOVE COMPONENTS &
SUBCOMPONENTS PROPERLY AND SAFELY.
LIFT THE UNIT BY ATTACHING CHAIN HOISTS TO THE ROUND LIFTING HOLES LOCATED ON THE TUBESHEETS. 2.
FULL UNIT - LIFTING
FULL UNIT - RIGGING

IOM 1281-2 • CENTRIFUGAL WATER CHILLERS 8 www.DaikinApplied.com
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Location
The chillers are designed for indoor installation only. Special
procedures must be executed to prevent damage if freezing
indoor temperatures are possible.
NOTE: Excessive humidity in the mechanical room should
be avoided. A limit of 90% non-condensing humidity
should be met to minimize electrical components
exposure to water condensing in panels. Humidity
levels in the mechanical room, even if lower than
90%, can cause water to condense on/near all cool
surfaces and potentially lead to premature component
wear. If possible, the mechanical room should be
conditioned which can extend the useful lifetime for
all mechanical room equipment.
Radiant heat from boilers or piping that would
adversely raise component surface temperatures
beyond ambient limits must also be avoided.
Table 1: Equipment Room Guidelines
WDC - WCC 
R-513A R-134a
Equipment room operating temperature: 40-104 °F (4.4-40 °C)
Equipment room temperature, standby,
with water in vessels and oil cooler:
40-104 °F (4.4-40 °C)
Equipment room temperature, standby,
without water in vessels and oil cooler:
0-113 °F (-17.7-45 °C)
Clearance
The unit must be located to provide adequate service
clearance around the unit. See Figure 3 for clearance
requirements around the sides of the chiller, including the
length of the vessels allowed at one end for tube service.
Doors and removable wall sections can be utilized to meet
these clearance requirements. There must be a minimum
3-feet clearance above the top of the chiller. The U.S. National
Electric Code (NEC) or local codes can require more clearance
in and around electrical components and must be checked for
compliance.
Mounting
The unit must be mounted on a level concrete or steel base.

support the full operating weight of the complete unit.
It is not necessary to bolt the unit to the mounting slab or

mounting holes are provided in the unit support at the four
corners.
NOTE: Units are shipped with refrigerant and oil valves

must remain closed until start-up by the Daikin
Applied technician.
The neoprene vibration pads (shipped loose in the power
panel) should be placed under the corners of the unit (unless


WDC/WCC units have six mounting feet although only the
outer four are required. Six pads are shipped and the installer
can place pads under the middle feet if desired.
When mounted, the base pad of the unit must be level to within
± 1/2 inch (12.7 mm) across the length and width of the unit.
Figure 3: Minimum Clearances Based on Standard Waterboxes - Representative Schematic
NOTE: 󰀨
Daikin Applied sales representative for details.
Minimum 17’ Clearance on one end for tube service (models with 16’ length vessels)
Minimum 21' Clearance on one end for tube service (models with 20' length vessels)
TOP VIEW
Minimum 3’ Clearance
Minimum 3’ Clearance
Minimum 4’ Clearance
in front of control boxes and electrical panels


www.DaikinApplied.com 9 IOM 1281-2 • CENTRIFUGAL WATER CHILLERS

Figure 4: Operating/Standby Limits
1R-513A R-134a
Condition  Description 
°F (°C)

°F (°C)

°F (°C)

°F (°C)
Standby
Evaporator Entering Fluid 35 (1.7) 86 (30) 35 (1.7) 90 (32.2)
Entering Fluid w/ Antifreeze220 (-6.7) 86 (30) 20 (-6.7) 90 (32.2)
Equipment Room Air w/ Water in Vessels & Oil Cooler 40 (4.4) 104 (40) 40 (4.4) 104 (40)
Air w/ no Water in Vessels & Oil Cooler 0 (-17.8) 0 (-17.8) 0 (-17.8) 113 (45)
Startup
Evaporator Entering Fluid 38 (3.3) 100 (37.8) 38 (3.3) 100 (37.8)
Entering Fluid w/ Antifreeze220 (-6.7) 100 (37.8) 20 (-6.7) 100 (37.8)
Condenser Entering Fluid 35 (1.7) 110 (43.3) 35 (1.7) 111 (43.9)
Oil Cooler Entering Fluid 35 (1.7) 80 (26.7) 35 (1.7) 80 (26.7)
Equipment Room Air 40 (4.4) 104 (40) 40 (4.4) 104 (40)
Operating
Evaporator
Entering Fluid 38 (3.3) 86 (30) 38 (3.3) 90 (32.2)
Leaving Fluid 38 (3.3) 60 (15.6) 38 (3.3) 60 (15.6)
Entering Fluid w/ Antifreeze220 (-6.7) 86 (30) 20 (-6.7) 90 (32.2)
Leaving Fluid w/ Antifreeze220 (-6.7) 60 (15.6) 20 (-6.7) 60 (15.6)
Condenser Entering Fluid 55 (12.8) 104 (40) 55 (12.8) 105 (40.6)
Leaving Fluid See Note3110 (43.3) See Note3111 (43.9)
Oil Cooler Entering Fluid 35 (1.7) 80 (26.7) 35 (1.7) 80 (26.7)
Equipment Room Air 40 (4.4) 104 (40) 40 (4.4) 104 (40)
NOTES:
1
heat recovery mode limits)
2Antifreeze temperature limits must have appropriate glycol concentration
3
Field Insulation
If the optional factory-installation of thermal insulation is not

loss and prevent condensation from forming. Insulation should
cover:
• motor barrel
• the evaporator barrel, tube sheet, and waterboxes.
• the suction line from the top of the evaporator to the

• the compressor support brackets welded to the
evaporator.
• the liquid line from the expansion valve to the evaporator
inlet, including the expansion valve.
• the part load balance valve to the evaporator.
Approximate total square footage of insulation surface required
for individual packaged chillers is tabulated by evaporator code
and can be found in Table 2.
Table 2: Insulation Area Required for Vessels
Evaporator Code Insulation Area
2)
E3016 207 (19.2)
E3620 207 (19.2)
E4216 264 (24.5)
E4220 330 (30.6)
E4816 302 (28.1)
E4820 377 (35.0)

IOM 1281-2 • CENTRIFUGAL WATER CHILLERS 10 www.DaikinApplied.com

Water Piping
All evaporators and condensers have OGS-type grooved water
connections (adhering to Standard AVVWA C606) or optional

matching mechanical connections. Be sure that water inlet

markings. PVC/CPVC piping should not be used.
CAUTION
Polyolester Oil, commonly known as POE oil is a synthetic
oil used in many refrigeration systems, and may be present
in this Daikin Applied product. POE oil, if ever in contact with
PVC/ CPVC, will coat the inside wall of PVC/CPVC pipe
causing environmental stress fractures. Although there is
no PVC/ CPVC piping in this product, please keep this in
mind when selecting piping materials for your application, as
system failure and property damage could result.
CAUTION
          
connections:
1. Remove the solid-state temperature sensor,

switches from the wells to prevent damage to those
components.
2. Properly ground the unit or severe damage to the
MicroTech®unit controller can occur.
NOTE: 
performed on a vessel shell or tube sheet.
The water heads can be interchanged (end for end) so that
the water connections can be made at either end of the unit.
If this is done, use new head gaskets and relocate the control
sensors.
Field installed water piping to the chiller must include:
• air vents at the high points.
• a cleanable water strainer upstream of the evaporator
and condenser inlet connections.
• 
condenser. Flow switches, thermal dispersion switches,
or Delta-P switches can be used. Note that thermal


series with the ones already provided. Connect additional


discussed on page 68.
• water pressure gauge connection taps and gauges at the
inlet and outlet connections of both vessels for measuring
water pressure drop.
• 󰀩󰀨
chiller must be capable of draining the water from the
evaporator or condenser without draining the complete
system.
• Piping must be supported to eliminate weight and strain

• Chilled water piping must be adequately insulated.

• thermometers at the inlet and outlet connections of both
vessels.
CAUTION
When common piping is used for both building heating and
cooling modes, care must be taken to provide that water

this hot can damage controls or cause the relief valve to
discharge refrigerant.

a shell and tube evaporator with carbon steel shell and

the wetted surfaces of the heat exchangers must be clean
and non-corrosive to the standard materials of construction.
Daikin Applied makes no warranty as to the compatibility


standard materials of construction is in question, a professional
corrosion consultant should administer the proper testing and
evaluate compatibility.
Water Quality Guidelines
The water quality provided by the owner/occupant/operator/
user to a chiller system should minimize corrosion, scale
󰀩
of HVAC equipment without creating a hazard to operating
personnel or the environment. Strainers must be used to
protect the chiller systems from water-borne debris. Daikin
Applied will not be responsible for any water-borne debris
damage or water side damage to the chiller heat exchangers
due to improperly treated water.


during initial chiller installation/commissioning and maintained
on a continuous basis by water treatment professionals (see
Limited Product Warranty)
CAUTION
The improper use of detergents, chemicals, and additives
       󰀨 
performance and potentially lead to repair costs not covered
by warranty. Any decision to use these products is at the
discretion of the owner/occupant/operator/user and as such
they assume full liability/responsibility for any damage that
may occur due to their use.


www.DaikinApplied.com 11 IOM 1281-2 • CENTRIFUGAL WATER CHILLERS
Vessel Drains at Startup
The unit is drained of water at the factory. Drain plugs for each
vessel head are shipped separately in the control box. Units
are shipped with the drain plug in the top water box drain hole
and no plug in the bottom drain hole. Install the bottom drain
Figure 5
Figure 5: Drain Plug Installation
Flow Switches

wired. See the Field Wiring Diagram on page 32 or on the
cover of the control panel for proper connections. The purpose

until such time as both the evaporator water and condenser




started. See 
68 for further information.
Variable Fluid Flow Rates



power, and potential tube erosion or corrosion damage.

be avoided as they will result in poor heat transfer, high
compressor power, sedimentation and tube fouling.



rate should not exceed 50% of the current value per minute.

All chilled water systems need adequate time to recognize a
load change, respond to that load change and stabilize, without
undesirable short cycling of the compressors or loss of control.
In air conditioning systems, the potential for short cycling
usually exists when the building load falls below the minimum
chiller plant capacity or on close-coupled systems with very
small water volumes.
Some of the things the designer should consider when looking
at water volume are the minimum cooling load, the minimum
chiller plant capacity during the low load period and the desired
cycle time for the compressors.
Assuming that there are no sudden load changes and that
the chiller plant has reasonable turndown, a rule of thumb of
“gallons of water volume equal to three to four times the chilled

A properly designed storage tank should be added if the
󰀩

Operation of the chilled water pump can be to 1) cycle the
pump with the compressor, 2) operate continuously, or 3) start
automatically by a remote source.
The cooling tower pump must cycle with the machine. The
holding coil of the cooling tower pump motor starter must be
rated at 115 volts, 60 Hz, with a maximum volt-amperage rating
of 100. A control relay is required if the voltage-amperage

cover of control panel for proper connections.
All interlock contacts must be rated for no less than 10
inductive amps. The alarm circuit provided in the control center
utilizes 115-volts AC. The alarm used must not draw more than
10 volt amperes.

Control
Condenser water control is an important consideration in chiller
plant design since condenser water temperature will directly
󰀩
wet bulb temperature is lower than peak design, the entering
condenser water temperature from the cooling tower can
be allowed to fall, improving chiller performance. However,
operational issues may occur when the condenser water
temperatures are either too high or too low. The centrifugal
chiller provides several options to assist the chiller plant
designer in providing the optimum control of condenser water
temperature.

IOM 1281-2 • CENTRIFUGAL WATER CHILLERS 12 www.DaikinApplied.com

Cooling Tower Control
Control of the cooling tower is required to maintain stability and
avoid operational issues. This can be achieved through a BAS
or by using the MicroTech®II controller. For systems utilizing a
common condenser water loop for multiple purposes, the BAS
contractor must provide the control but use of the MicroTech®
output signal is still recommended.
The preferred cooling tower control utilizes a variable speed
fan. MicroTech® II will provide a control signal to determine the
proper fan speed. It can also control up to three stages of fan
cycling. Note that fan cycling can cause cooling tower water
󰀨
instability to the system.
Special consideration must be given to starting the chiller when
cold condenser water is present, such as with inverted starts
or changeover from free (tower) cooling to mechanical cooling.
Daikin Applied chillers will start with entering condenser water
temperature as low as 55°F (42.8° C) providing the chilled
water temperature is below the condenser water temperature.
The minimum entering condenser water temperature while
operating is a funcion of the leaving chilled water temperature
and load. It is required that some method be used to control
the condenser water to maintain proper head pressure as
indicated by the MicroTech®II controller. Refer to “Tower
for control strategy details in
the HMI.
Each of the following acceptable methods can be controlled by
the MicroTech® II or through a BAS utilizing the MicroTech®
output signals:
1. Three-Way Bypass Valve Operation. A traditional method
for building condenser pressure at startup with colder
condenser water is with the use of a three-way bypass
valve. The device blends warmer water leaving the
condenser with cooler water from the cooling tower at the
condenser inlet. The bypass valve position will change

The MicroTech®II provides only the valve position control
signal. Main power to drive the valve’s actuator must be
provided by the installer. The three-way valve should be
located close to the chiller within the equipment room to
minimize the volume of water.
2. Two-Way Valve Operation
Another condenser control method is to use a modulating
two-way control valve located on the outlet connection of
the condenser. The valve will be nearly closed at startup

the condenser until an acceptable minimum condenser
pressure is reached. As heat builds, the valve will open

is established. A separate power source is required to
provide power to the valve actuator.
NOTE: To ensure proper operation, caution should be
used when utilizing the two-way valve option.
3. VFD Operating with a Condenser Water Pump
A third method of condenser control for startup is
utilizing a variable frequency drive with the condenser
water pump. The speed will change as directed by the

Speed adjustments may be required during the initial
chiller startup as determined by the service technician.
NOTE: Not using the MicroTech® II logic to control valves
and variable frequency drives may result in system
instability, capacity reduction, and issues starting the
chiller with cold condenser water temperature.

It is recommended to utilize the logic built into the MicroTech®
II controller to start the condenser pump. MicroTech®II has the
capability to operate a primary pump and a secondary standby

󰀨
refrigerant from migrating to the condenser. Moisture in the
air can condenser on the cooler surfaces of the un-insulated


Operation
Water side economizers are commonly used for ASHRAE 90.1
compliance and energy savings. This system utilizes a heat
exchanger external to the chiller when cold cooling tower water
is available to provide cooling. The most common system
has a heat exchanger used in conjunction with the chiller’s
evaporator.
The BAS contractor will need to provide controls for the heat
exchanger including isolation valves and temperature control.
The BAS contractor will also need to control the isolation
valves for the chiller. It is important to use slow-acting type

from economizer cooling to mechanical cooling requires one
of the methods previously mentioned to maintain suitable
condenser head pressure.
Contact your local Daikin Applied representative for more
information on this application.


www.DaikinApplied.com 13 IOM 1281-2 • CENTRIFUGAL WATER CHILLERS
Relief Valves
As a safety precaution and to meet code requirements, each
chiller is equipped with pressure relief valves located on
the condenser and evaporator for the purpose of relieving
excessive refrigerant pressure (caused by equipment

Table 3: WDC, WCC A Vintage Relief Valve Data
Evaporator Condenser 
Location Top Top Top
Setting (psi) 200 225 200
Discharge Capacity
(lb/min air) 75.5 84.4 5
Qty 2 for 16’ shells
2 for 20’ shells
4 for 16’
shells
4 for 20’
shells
1 for
079-126
models
Connection Size 1.0-inch NPT 3/8-inch
NPT
Most codes require that relief valves be vented to the outside
of a building. Relief piping connections to the relief valves must

CAUTION
Units are shipped with refrigerant valves closed to isolate the
refrigerant in the unit condenser. Valves must remain closed
until startup by the factory service technician.
Remove plastic shipping plugs (if installed) from the inside of
the valves prior to making pipe connections. Whenever vent
piping is installed, the lines must be in accordance with local
code requirements; where local codes do not apply, the latest
issue of ANSI/ASHRAE Standard 15 code recommendations
must be followed.
Condenser Relief Valves
In order to ensure proper installation, it is important to know
how the three-way relief valve functions. One valve remains
active at all times and the second valve acts as a standby.
When the stem of the three-way valve is pushed into the


in Figure 6. When the stem of the three-way valve is pulled


Figure 7.
Figure 6: Condenser Three-Way Relief Valve
Figure 7: Three-Way Valve, Front Seated Position Three
Way Valve, Back Seated Position
Three-Way Valve
Relief Valves

IOM 1281-2 • CENTRIFUGAL WATER CHILLERS 14 www.DaikinApplied.com

When the valve stem is not pushed forward or pulled back
Figure 8
CAUTION
Do not operate the system with the three-way valve stem in the Mid
Position.
Figure 8: Three-Way Valve, Mid Position
Oil Coolers
WARNING
This unit contains POE lubricants that must be handled carefully and the
proper protective equipment (gloves, eye protection, etc.) must be used
when handling POE lubricant. Failure to do so can result in personal injury.
POE must not come into contact with any surface or material that might
be harmed by POE, including certain polymers (e.g. PVC/CPVC and
polycarbonate piping).
Daikin Applied centrifugal chillers have a factory-mounted,
water-cooled oil cooler, temperature-controlled water regulating
valve and solenoid valve per compressor. All WDC units have
oil cooler connections located on the right hand tube sheet
under the evaporator Figure 9 or above the condenser Figure
10.
Field water piping to the inlet and outlet connections must be
installed according to good piping practices and include stop


installed. The water supply for the oil cooler should be from
the chilled water circuit or from a clean, independent source,
no warmer than 80°F (27°C), such as city water. When using
chilled water, it is important that the water pressure drop across
the evaporator is greater than the pressure drop across the oil
󰀩
drop across the evaporator is less than the oil cooler, the oil
cooler must be piped across the chilled water pump, provided
󰀩
oil cooler will be adjusted by the unit’s regulating valve so that
the temperature of oil supplied to the compressor bearings
(leaving the oil cooler) is between 95°F and 105°F (35°C and
40°C).
Table 4: Oil Cooler Data

Hot Side
POE
Lube
Cold Side Water Options to

079 - 087
Flow, gpm 9.9 11.9 2.9 2.0 1.54
Inlet Temp, °F 118.0 80.0 65.0 55.0 45.0
Outlet Temp, °F 100.0 87.3 94.5 98.3 101.4
Pressue Drop, psi - 4.3 0.3 0.14 0.09
100 - 126
Flow, gpm 15.8 21.9 5.1 3.5 2.7
Inlet Temp, °F 120.0 80.0 65.0 55.0 45.0
Outlet Temp, °F 100.0 87.0 95.0 99.0 102.3
Pressue Drop, psi - 3.78 0.23 0.11 0.07
Table 5: Cooling Water Connection Sizes
Model WDC 079-087 WDC/WCC 100-126
Conn Size 1 in. 1 1/2 in.
Compressors using chilled water for oil cooling will often start

loop temperature is pulled down. Data given above includes
that condition. As can be seen, with cooling water in the 45°F
to 65°F (7°C to 18°C) range, considerably less water will be
used, and the pressure drop will be greatly reduced.
When supplied with city water, the oil piping must discharge
through a trap into an open drain to prevent draining the cooler
by siphoning. The city water can also be used for cooling tower
makeup by discharging it into the tower sump from a point
above the highest possible water level.
NOTE: Particular attention must be paid to chillers with


󰀩
In this case an auxiliary booster pump can be used or
city water employed.


www.DaikinApplied.com 15 IOM 1281-2 • CENTRIFUGAL WATER CHILLERS
Oil Heater
The oil sump is equipped with an immersion heater that is installed in a tube so that it can be removed without disturbing the oil.
Figure 9: Oil Cooler Water Connection - Right side
Figure 10: Oil Cooler Water Connection - Middle

IOM 1281-2 • CENTRIFUGAL WATER CHILLERS 16 www.DaikinApplied.com

Figure 11: Oil Cooler Piping Across Chilled Water Pump - Models 079-126
Figure 12: Oil Cooler Piping With City Water - Models 079-126


www.DaikinApplied.com 17 IOM 1281-2 • CENTRIFUGAL WATER CHILLERS
Figure 13: Typical Refrigerant Flow Diagram - Models 079-126
COMPRESSOR CONTROLLER
BUBBLE
NO. DESCRIPTION
P201 EVAPORATOR PRESSURE
P202 CONDENSER PRESSURE
P102 COMPRESSOR SUCTION TEMPERATURE
P102 COMPRESSOR DISCHARGE TEMPERATURE
P104 EVAPORATOR LEAVING WATER TEMPERATURE
UNIT CONTROLLER
BUBBLE
NO. DESCRIPTION
P104 EVAPORATOR ENTERING WATER TEMPERATURE
P104 CONDENSER ENTER ING WATER TEMPERATURE
P104 CONDENSER LEAVIN G WATER TEMPERATUR E
P104 LIQUID LINE TEMPERATURE
C HE CK VA L V E
CONDENSER
EVAPORATOR
SHUTOFF VALVE
ELECTRONIC
EXPANSION VALVE
TEMPERATURE
SENSOR
S I GHT GL AS S
LIQUID LINE
RELIEF VALVE
LIQUID INJECTION LINE
MOTOR COOLING LINE
SERVICE VALVE
THREE-WAY VALVE
BALL VA LVE
STRAINER
SOLENOID VALVE
D IS C HA RG E LI N E
FILTER DRYER
MOTOR DRAIN LINE
P104
P102
P102
FLOW SENSOR
P104
P104
HOT GAS BYPASS LINE (OPTONAL)
F LO W CH A R T L E G E N D
P RE SS UR E SE N SO R
P202
INLET
OUTL ET
P104
P104
INLET
OUTLET
P201
COMPRESS OR
SUCTION LINE
WATER
CONNECTION
POINT

IOM 1281-2 • CENTRIFUGAL WATER CHILLERS 18 www.DaikinApplied.com

Field Wiring
Unit Mounted Starters
The standard power wiring connection to WDC/WCC chillers
is multi-point. The power conduit entry will be at each starter
panel, whether unit mounted or remote mounted starters. For
unit mounted starters, the power connection point may be at
top of the panel as shown in Figure 14 for general reference as

Wiring diagrams are provided with the chiller.
Correction capacitors are not necessary since VFDs inherently
maintain high power factors and can cause harmful electrical
resonance in the system.
Only copper wiring and lugs should be used for power wiring
connections. Wiring ampacity based on 75°C conductor
rating should be used for voltages less than 2000V; 90°C or
105°C rated conductors should be used for voltages greater
than 2000V. Refer to the unit nameplate and the Daikin Tools
selection report for the correct electrical ratings.
DANGER
      
Disconnect, lockout, and tag all electrical power sources to
the unit before servicing the compressor and/or recovering
refrigerant. An electrical shock hazard exists that can cause
severe injury or death.
Figure 14: Unit Mounted Power Connection Point
NOTE: Wiring, fuse, and wire size must be in accordance
with the National Electric Code (NEC). The voltage to
these units must be within ±10% of nameplate voltage
(415V units must have voltage within -13% and +6%
of nameplate voltage) and the voltage unbalance
between phases must not exceed 2%. Since a 2%
voltage unbalance will cause a current unbalance
of 6 to 10 times the voltage unbalance per the
NEMA MG-1 Standard, it is most important that the
unbalance between phases be kept at a minimum.
CAUTION
A compressor should only be brought up to speed if proper

connections to motor terminals until wiring has been checked
and approved by a Daikin Applied service technician. Serious
damage can result if the compressor starts in the wrong
direction and would not be covered by product warranty.
The compressor is covered under UL 984 by which its terminal
box is determined, per clause 8.1, by the end-use product
standard, which is UL 1995. If exceeding 1000V with controls,
Daikin Applied refers contractor to employ UL508A
The NFPA 70 (NEC) provides information pertaining to
‘minimum wire-bending space.’ Wiring to a terminal box will
vary depending on voltage, see the current version of Daikin
Applied Installation, Operation and Maintenance Manuals,
IOMM 1369 for free-standing starters.
Full Metering
Remote mounted wye-delta, solid state, and across-the-line

display on the chiller’s operator interface panel. The wiring
is from the control board in the starter to the compressor
controller.
Figure 15: Wiring for Optional Display
NOTE:
• The serial card location is in the lower-center of the
compressor controller located in the chiller control panel.
• The control is located in the starter.
• The connections are (-) to (-), (+) to (+) and SCOM to
GND with a shield connection on the starter terminal
board.
• Cable is Belden 9841 or equal (120 OHM characteristic
impedance)
Control Power Wiring Options
The control circuit on the Daikin Applied centrifugal packaged
chiller is designed for 115-volts to the control panel. Control
󰀨
1. If the unit is supplied with a factory-mounted starter or
VFD, the control circuit power supply is factory-wired
from a transformer located in the starter or VFD.
2. A freestanding starter or VFD furnished by Daikin
Applied, or by the customer to Daikin Applied


terminal box.
3. Power can be supplied from a separate circuit and fused
at 25 amps inductive load. The control circuit disconnect
switch must be tagged to prevent current interruption.
Other than for service work, the switch is to remain on
at all times in order to keep oil heaters operative and
prevent refrigerant from diluting in oil.
Power Entry Cover Plate -
Remove to cut hole in
cover plate for conduit
and then replace.


www.DaikinApplied.com 19 IOM 1281-2 • CENTRIFUGAL WATER CHILLERS
DANGER
If a separate control power source is used, the following
must be done to avoid severe personal injury or death from
electrical shock: Place a notice on the unit that multiple
power sources are connected to the unit. Place a notice on
the main and control power disconnects that another source
of power to the unit exists.
In the event a transformer supplies control voltage, it must be

80% power factor and 95% secondary voltage. For control wire
sizing, refer to NEC. Articles 215 and 310. In the absence of
complete information to permit calculations, the voltage drop
should be physically measured.
Table 6: Control Power Line Sizing
 Wire Size (AWG)
0 (0) to 50 (15.2) 12
NOTE:
1. Maximum length is the distance a conductor will traverse
between the control power source and the unit control
panel.
2. Panel terminal connectors will accommodate up to
number 10 AWG wire. Larger conductors will require an
intermediate junction box.
󰀨
󰀨
not desired.
Surge Capacitors
Surge capacitors are an option for some unit-mounted, low

VFDs) to protect compressor motors from electrical damage
resulting from high voltage spikes. If ordered, the capacitors
are factory-mounted and wired in the starter enclosure.

(BAS)
All MicroTech®controllers with an open protocol platform are
capable of BAS communications, providing easy integration
and comprehensive monitoring, control, and two-way data
exchange with open standard protocols such as LonTalk®,
Modbus® or BACnet®.
Daikin Applied unit controllers strictly conform to the
interoperability guidelines of the LonMark® Interoperability
Association and BACnet® International. They have
W®
communication module.
Protocol Options
The following protocol options are available:
• BACnet®MS/TP
• BACnet®IP
• BACnet®Ethernet
• LW®
• Modbus®RTU
The BAS communication module can be ordered with the

after the chiller unit is installed. Connection to the chiller for all
BAS protocols will be at the unit controller.
If an interface module was ordered, the appropriate BAS
interface installation manual was shipped with the unit. If
󰀩
additional manual or download from www.DaikinApplied.com.
Use with On-Site Generators
Centrifugal Chillers may be run with On-Site Generators when
utility power is lost. The HVAC system and chiller have to
be disconnected from the power grid and connected to the
generator power. Then enable the HVAC system while on the
generator.
Generator Sizing
Natural gas and diesel generators are sensitive to the peak
current loads of the chiller. Use the electric data on the Starters
supplied with the chiller or the chiller performance rating sheet
󰀩
sizing purposes. The reference data will show the RLA and
LRA, which is for each compressor. It is important to size the
generator to handle the LRA for the compressor motor for
starting.
WARNING
Generator must be sized by an electrical engineer familiar
with generator applications.
Transfer Back to Grid Power
If the generator to power grid has synchronous power switch
capability then it can be done at any time. Usually this switch
does not exist so the switch is done by shutting down the
HVAC system including the chiller that is running on the
generator. Then switch the power for the HVAC system to the
power from the grid and then turning the HVAC system back on
including the Chiller.

IOM 1281-2 • CENTRIFUGAL WATER CHILLERS 20 www.DaikinApplied.com

Field Wiring, Controls & Starters
NOTES for Following Wiring Diagram
1. Compressor motor starters are either factory mounted

wiring. If provided by others, starters must comply

735999901. All line and load side power conductors
must be copper with ampacity based on 75°C conductor
rating. Exception: For equipment rated over 2000 volts,
90°C or 105°C rated conductors shall be used.
2. 
starter and the control panel is required. Minimum wire
size for 115 Vac to 220 Vac is 12 gauge for a maximum
length of 50 feet. If greater than 50 feet, refer to Daikin
Applied for recommended wire size minimum. Wire
size for 24 Vac is 18 gauge. All wiring to be installed as
NEC Class 1 wiring system. All 24 Vac wiring must be
run in separate conduit from 115 Vac to 220 Vac wiring.
Main power wiring between starter and motor terminal
is factory-installed when units are supplied with unit-
mounted starters. Wiring of free-standing starter must
be wired in accordance with NEC and connection to
compressor motor terminals must be made with copper
wire and copper lugs only. Control wiring on free-
standing starters is terminated on a terminal strip in the
motor terminal box (not the unit control panel). Wiring
from the unit control panel to the motor terminal is done
in the factory.
3. For optional sensor wiring, see unit control diagram. It is
recommended that DC wires be run separately from 115
Vac to 220 Vac wiring.
4. Customer furnished 24 or 230 Vac power for alarm relay
coil can be connected between UTB1 terminals 84 power
and 86 neutral of the control panel. For normally open
contacts, wire between 82 & 86. For normally closed
contacts, wire between 83 & 86. The alarm is operator
programmable. The maximum rating of the alarm relay
coil is 25 VA.
5. 󰀨
installing a set of dry contacts between terminals 27 and
21 and remove wire jumper.
6. 

from the factory as standard.
7. Customer supplied 24 to 230 Vac, 20 amp power for
optional evaporator and condenser water pump control
power and tower fans is supplied to unit control terminals
(UTBI) 85 power / 86 neutral, PE equipment ground.
8. Optional customer supplied 24 to 220 Vac, 25 VA
maximum coil rated chilled water pump relay (EP 1 & 2)
may be wired as shown. This option will cycle the chilled
water pump in response to chiller demand.
9. The condenser water pump must cycle with the unit. A
customer supplied 24-220 Vac 25 VA maximum coil rated
condenser water pump relay (CP1 & 2) is to be wired
as shown. Units with free cooling must have condenser
water above 60°F before starting.
10. Optional customer supplied 24-220 Vac, 25 VA maximum
coil rated cooling tower fan relays (C1 - C2 standard,
C3 - C4 optional) may be wired as shown. This option
will cycle the cooling tower fans in order to maintain unit
head pressure.
11. For VFD, Wye-Delta, and solid state starters connected
to six (6) terminal motors. The conductors between the
starter and motor carry phase current and selection
shall be based on 58 percent of the motor rated load
amperes (RLA). Wiring of free-standing starter must
be in accordance with the NEC and connection to the
compressor motor terminals shall be made with copper
wire and copper lugs only. Main power wiring between
the starter and motor terminals is factory-installed when
chillers are supplied with unit-mounted starters.
12. Motor current has three selectable options as follows:
0-5V/0- 10V/0- 20mA by build in HMI.
Compressor VFD speed has two selectable options as
follows:0-10V/4 - 20mA.
13. Optional BAS communications modules. The locations
and interconnection requirements for the various
standard protocols are found in their respective
installation manuals, obtainable from the local Daikin
󰀩
Modbus IM 743 LonWorks IM 735 BACnet IM 906
14. 
when free-standing starters are used. Wiring will depend
on chiller and starter type. Consult the local Daikin
󰀩