Daikin DWSC079 User manual

Original Instructions
Single/Dual Compressor Centrifugal Chillers – Vintage B
DWSC/DWDC 079, 087, 100, 113, 126, Cooling Only
REV
09
Date
January 2020
Supersedes
D-EIMC00808-16_08EN
Installation, Operation and Maintenance Manual
D-EIMWC00808-16_09EN

D–EIMWC00808-16HU - 3/64
IMPORTANT
The units described in the present manual represent a valuable investment. Maximum care should be taken to ensure correct
installation and appropriate working conditions of the units.
THIS MANUAL, WIRING DIAGRAMS AND DIMENSIONAL DRAWINGS MUST BE CONSIDERED ESSENTIALS,
KEEP ACOPY OF THESE DOCUMENTS ALWAYS AVAILABLE INSIDE THE UNIT.
Installation and maintenance must be performed by qualified and specifically trained personnel only.
Correct maintenance of the unit is indispensable for its safety and reliability. Manufacturer’s service centres are the only having
adequate technical skill for maintenance.
The unit is made of metal, plastic and electronic parts. All of these components must be disposed of in accordance with local
disposal laws and if in scope with the national laws implementing the Directive 2012/19/EU (RAEE).
Lead batteries must be collected and sent to specific waste collection centres.
Avoid the escape of refrigerant gases into the environment by using suitable pressure vessels and tools for transferring the fluids
under pressure. This operation must be carried out by qualified personnel in refrigeration systems and in compliance with the
laws in force in the country of installation.
IMPORTANT
READ THIS DOCUMENT IN ITS ENTIRETY BEFORE BEGINNING ANY WORK ON THE UNIT.
ALL FEDERAL, STATE, LOCAL ENVIRONMENTAL AND SAFETY REGULATIONS INCLUDING DAIKIN
SAFETY RULES MUST BE FOLLOWED.
All appropriate Personal Protective Equipment (“PPE”) must be used, and a Job Hazard Analysis (“JHA”) must be completed,
before beginning any work on the unit.
Technicians performing this work must be properly trained on Daikin WSC, WDC, DWSC, DWDC Centrifugal equipment.
Important Note: In case of any procedure requires accessing the refrigerant circuit of these units, remember that refrigerant is under
pressure and oils are contained in these circuits.
Ensure that all appropriate pump-down or pump-out service valves are in the correct position, open or closed as required and
holding.
Solenoid valves and expansion valves can trap refrigerant and oils, these devices must be operated manually to release any trapped
gases and oils while in pump-down or pump-out operation.
All refrigerant lines and components of the unit must be evacuated to at least 30 kPa vacuum and verified before opening any
charging valves, venting schrader valves or testing ports.
These devices must be open and vented while accessing the refrigerant system. In some cases, cross connection lines may be
required to ensure recovery of all refrigerant in all sections of the affected system or components.

D–EIMWC00808-16HU - 4/64
CAUTION
All units are delivered from factory as complete sets which include wiring diagrams and dimensional drawings with
size, weight and features of each model.
In case of any discrepancy between this manual and the two aforesaid documents, please refer to the wiring diagram
and dimensional drawings.
Power Wiring
•Qualified and licensed electricians must perform wiring. Shock hazard exists.
•Connections to terminals must be made with copper lugs and copper wire.
•Before any installation and connection work, the system must be switched off and secured. After
switching off the unit, when an inverter is installed, the intermediate circuit capacitors of the inverter
are still charged with high voltage for 5 minutes.
•Before taking any action, switch off the main switch to cut off electricity to the machine.
When the machine is off but the disconnecting switch is in the closed position, unused circuits are always live.
Never open the terminal board box of the compressors unless the main switch of the machine has been switched off.
•The units of the series can be provided with non-linear high power electrical components (inverters)
which introduce higher harmonics, can cause considerable leakage to earth, (higher than 300 mA). The
electricity supply system protection must take the above values into account.
WARNING
Before starting the installation of the unit, please read this manual carefully. Starting up the unit is absolutely
forbidden if all instructions contained in this manual are not clear.
•Commissioning of the unit (first start up) must be performed by Daikin representative
•It is absolutely forbidden to remove all the protections of the moving parts of the unit
•If the unit mounts suction and discharge valves they need to be secured in open position when the unit is installed,
by means of a lead seal or equivalent. This to avoid they are put in closed position. The use of this valve is
intended for compressor maintenance.
•If refrigerant charge of the unit is more than 500 kg it is necessary to install gas sensor on water circuit to catch
an eventual gas leakage.
•Verify that the unit has not zero pressure in the refrigerant circuit before charging water into the heat exchangers.
In case there is not pressure in the refrigerant circuit, do not charge water.
•Do not use oxygen or a mixture of R-22 and air to build up pressure as explosion can occur causing serious
personal injury.
Warnings for the operator
The operator must read this manual before using the unit.
The operator must be trained and instructed on how to use the unit.
The operator must strictly follow local safety regulation and laws.

D–EIMWC00808-16HU - 5/64
The operator must strictly follow all instruction and limitation given for the unit.
The operator is not authorized to perform maintenance. Maintenance has to be performed only by trained technicians,
please contact DAIKIN representative.
The operator must apply all the safety standard regarding personal protective equipment and working tools.
Key to symbols
Important note: failure to respect the instruction can damage the unit or compromise functioning
Note regarding safety in general or respect of laws and regulations
Note concerning electrical safety
Note concerning pressure equipment
Safe use and maintenance of the unit, as explained in this manual, is fundamental to prevent accidents during operation
and maintenance and repair work.
Therefore, it is highly recommended that this document be read carefully, complied with and stored safely.

D–EIMWC00808-16HU - 6/64
Description of the labels applied to the electrical panel
Compressor Starter Panel
1 – Manufacturer’s logo
3 – Cable tightening warning
2 – Hazardous Voltage warning
4 – Electrical hazard symbol
Unit Control Panel
1 – Non flammable gas symbol
5 – Unit nameplate data
2 – Electrical hazard symbol
6 – Unit characteristics technical
3 – Gas type
7 – Emergency stop
4 – Control panel code
8 – Label: unit under pressure
Compressor Control Panel
1 – Components layout
3 – Electrical hazard symbol
2 – Hazardous Voltage warning
4 – Compressor control panel code
8

D–EIMWC00808-16HU - 7/64
Motor Terminal Box
1 – Terminal box fixing
3 – Electrical hazard symbol
2 – Manufacturer’s logo
4 – Terminal connection
Label on Compressor
1 – Label: Device Under Pressure
1

D–EIMWC00808-16HU - 8/64
Table of Contents
Warnings for the operator .......................................................................................Errore. Il segnalibro non è definito.
Introduction....................................................................................................................................10
General Description ........................................................................................................................................................10
Application .....................................................................................................................................................................10
Nomenclature..................................................................................................................................................................10
Installation ......................................................................................................................................11
Receiving and Handling .................................................................................................................................................11
Location and Mounting...................................................................................................................................................12
Operating/Standby Limits...............................................................................................................................................12
Safety..............................................................................................................................................................................13
System Water Volume.....................................................................................................................................................14
Low Condenser Water Temperature Operation...............................................................................................................14
Water Piping ...................................................................................................................................................................16
Field Insulation Guide ....................................................................................................................................................20
Physical Data and Weights..............................................................................................................................................22
Oil Coolers......................................................................................................................................................................23
Oil Heater .......................................................................................................................................................................26
Relief Valves...................................................................................................................................................................27
Electrical.........................................................................................................................................................................28
Power Wiring..................................................................................................................................................................28
Remote Starter Display Wiring.......................................................................................................................................30
Control Power Wiring.....................................................................................................................................................30
Multiple Chiller Setup ....................................................................................................................................................35
Prestart System Checklist ...............................................................................................................................................38
Operation ........................................................................................................................................39
Operator Responsibilities................................................................................................................................................39
Standby Power ................................................................................................................................................................39
MicroTech II Control ..................................................................................................................................................39
Capacity Control System ................................................................................................................................................40
Surge and Stall................................................................................................................................................................43
Lubrication System .........................................................................................................................................................43
Hot Gas Bypass ..............................................................................................................................................................44
Condenser Water Temperature........................................................................................................................................45
Maintenance ...................................................................................................................................46
Pressure/Temperature Chart............................................................................................................................................46
Routine Maintenance ......................................................................................................................................................47
Annual Shutdown ...........................................................................................................................................................51
Annual Startup ................................................................................................................................................................52
Repair of System ............................................................................................................................................................52
Oil Analysis ....................................................................................................................................................................56
Maintenance Schedule ...................................................................................................................59
Service Programs ...........................................................................................................................62
Operator Schools............................................................................................................................63
Warranty Statement ......................................................................................................................64
Important information regarding the refrigerant used..............................................................65
Information and illustrations cover the Daikin products at the time of publication and we reserve the right to make changes in design and construction at anytime
without notice.

D–EIMWC00808-16HU - 9/64

D–EIMWC00808-16HU - 10/64
Introduction
General Description
Daikin Centrifugal Water Chillers are complete, self-contained, automatically controlled fluid chilling units. Each unit
is completely assembled and factory tested before shipment. Models DWSC/DWDC are cooling-only.
In the DWSC, each unit has one compressor connected to a condenser and evaporator. The DWDC series is equipped
with two compressors operating in parallel on a single evaporator and condenser. Information in this manual referring
to all DWSC and DWDC units except where specifically noted.
The chillers use refrigerant R-134a (or R513A) to reduce the size and weight of the package compared to negative
pressure refrigerants, and since these refrigerants operates at a positive pressure over the entire operation range, no purge
system is required.
The controls are pre-wired, adjusted and tested. Only normal field connections such as piping, electrical and interlocks,
etc. are required, thereby simplifying installation and increasing reliability. Most necessary equipment protection and
operating controls are factory installed in the control panel.
The basic sizes of units are the 079, 087, 100, 113 and 126. They provide a cooling capacity range from 80 tons to 2500
tons. In this manual all references to the DWSC models will equally apply to other models unless specifically referenced
otherwise.
Application
The procedures presented in this manual apply to the standard DWSC/DWDC family of chillers. Refer to the Operating
Manual, OM CentrifMicro II (latest version available on www.daikineurope.com), for details on operation of the
MicroTech IIunit controller.
All Daikin centrifugal chillers are factory tested prior to shipment and must be initially started at the job site by a factory
trained Daikin service technician. Failure to follow this startup procedure can affect the equipment warranty.
The standard limited warranty on this equipment covers parts that prove defective in material or workmanship. Specific
details of this warranty can be found in the warranty statement furnished with the equipment.
Cooling towers used with Daikin centrifugal chillers are normally selected for maximum condenser inlet water
temperatures between 75°F and 90°F (24°C and 32°C). Lower entering water temperatures are desirable from the
standpoint of energy reduction, but a minimum does exist.
Nomenclature
D W D C 079
Centrifugal Compressor
Chiller Model, Based on
Impeller Diameter
W = Water-cooled
D = Dual Compressor
S = Single Compressor
D = Daikin

D–EIMWC00808-16HU - 11/64
Installation
Receiving and Handling
The unit should be inspected immediately after receipt for possible damage.
All Daikin centrifugal water chillers are shipped FOB factory and all claims for handling and shipping damage are the
responsibility of the consignee.
Insulation corners from the evaporator's rigging hole locations are shipped loose and should be glued in place after the
unit is finally placed. Neoprene vibration pads are also shipped loose. Check that these items have been delivered with
the unit.
If so equipped, leave the shipping skid in place until the unit is in its final position. This will aid in handling the
equipment.
Extreme care must be used when rigging the equipment to prevent damage to the control panels or refrigerant piping.
See the certified dimension drawings included in the job submittal for the center of gravity of the unit. Consult the local
Daikin sales office for assistance if the drawings are not available.
The unit can be lifted by fastening the rigging hooks to the four corners of the unit where the rigging eyes are located
(see Figure 1). Spreader bars must be used between the rigging lines to prevent damage to the control panels, piping
and motor terminal boxes.
Figure 1, DWSC Major Component Locations
Unit Control
Panel
Rigging
Locations
(6) Available
Evaporator
Condenser
Rigging
Locations
(6) Available
Compressor Starter,
Mounting Optional
Compressor Control
Panel, At Rear
Operator Interface
Panel

D–EIMWC00808-16HU - 12/64
Figure 2, DWDC Major Component Location
Note: 1. Chilled water and condenser connection location can vary. Check markings on unit or consult unit
certified drawings for connection locations on specific units.
Location and Mounting
The unit must be mounted on a level concrete or steel base and must be located to provide service clearance at one end
of the unit for possible removal of evaporator tubes and/or condenser tubes. Evaporator and condenser tubes are rolled
into the tube sheets to permit replacement if necessary. The length of the vessel should be allowed at one end. Doors
or removable wall sections can be utilized for tube clearance. Minimum clearance at all other points, including the top,
is 3 feet (1 meter). The National Electric Code (NEC) can require four feet or more clearance in and around electrical
components and must be checked.
Operating/Standby Limits
Equipment room temperature, standby
•Water in vessels and oil cooler: 32F to 122F (0C to 50C)
•Without water in vessels and oil cooler: 0F to 140F (-18C to 60C) 55°C
•WSC without water in vessels: 0F to 130F (-18C to 54.4 C)
Equipment room temperature, operating: 32F to 104F (0C to 40C)
Maximum entering condenser water temperature, startup: design plus 5 degrees F (2.7 degrees C)
Maximum entering condenser water temperature, operating: job specific design temperature

D–EIMWC00808-16HU - 13/64
Minimum entering condenser water temperature, operating: see page 14.
Minimum leaving chilled water temperature: 38F (3.3C)
Minimum leaving chilled fluid temperature with correct anti-freeze fluid: 15F (9.4C)
Maximum entering chilled water temperature, operating: 90F (32.2C)
Maximum oil cooler/VFD entering temperature: 90F (32.2C)
Minimum oil cooler/VFD entering temperature: 42F (5.6C)
Vibration Pads
The shipped-loose neoprene vibration pads should be located under the corners of the unit (unless the job specifications
state otherwise). They are installed to be flush with the sides and outside edge of the feet. Most DWSC 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.
Mounting
Make sure that the floor or structural support is adequate to support the full operating weight of the complete unit.
It is not necessary to bolt the unit to the mounting slab or framework; but should this be desirable, 1 1/8" (28.5 mm)
mounting holes are provided in the unit support at the four corners.
Note: Units are shipped with refrigerant and oil valves closed to isolate these fluids for shipment. Valves
must remain closed until start-up by the Daikin technician.
Nameplates
There are several identification nameplates on the chiller:
•The unit nameplate is located on the side of the Unit Control Panel. It has a Style No. XXXX and Serial No.
XXXX, both are unique to the unit and will identify it. These numbers should be used to identify the unit for
service, parts, or warranty questions. This plate also has the unit refrigerant charge.
•Vessel nameplates are located on the evaporator and condenser. Along with other information, they have a
National Board Number (NB) and a serial number, either of which identify the vessel (but not the entire unit).
•A compressor nameplate is located on the compressor itself and contains identification numbers.
Safety
The machine must be firmly secured to the ground.
It is essential to observe the following instructions:
- The machine must be raised only by the lifting points. Only these points can support the whole weight of the unit.
- Do not allow unauthorised and/or unqualified personnel to access the machine.
- It is forbidden to access the electrical components without having opened the machine's general disconnecting switch
and switched off the power supply.
- It is forbidden to access the electrical components without using an insulating platform. Do not access the electrical
components if water and/or moisture are present.
- All operations on the refrigerant circuit and on components under pressure must be carried out by qualified personnel
only.
- Replacement of a compressor or addition of lubricating oil must be carried out by qualified personnel only- Sharp
edges can cause wounds. Avoid direct contact.
- Avoid introducing solid bodies into the water pipes while the machine is connected to the system.
- A mechanical filter must be installed on the water pipe connected to the heat exchanger inlet.
- The machine is supplied with safety valves, that are installed on both the high and the low pressure sides of the
refrigerant circuit.

D–EIMWC00808-16HU - 14/64
WARNING
If the unit mounts suction and discharge valves they need to be secured in open position when the
unit is installed, by means of a lead seal or equivalent. This to avoid they are put in closed position.
The use of this valve is intended for compressor maintenance.
In case of sudden stop of the unit, follow the instructions on the Control Manual Operating Manual which is part of
the on-board documentation delivered to the end user with this manual.
It is recommended to perform installation and maintenance with other people. In case of accidental injury or unease, it
is necessary to:
- keep calm
- press the alarm button if present in the installation site
- move the injured person in a warm place far from the unit and in rest position
- contact immediately emergency rescue personnel of the building or if the Health Emergency Service
- wait without leaving the injured person alone until the rescue operators come
- give all necessary information to the the rescue operators
System Water Volume
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 two to three times the chilled water gpm flow rate” is often used.
A properly designed storage tank should be added if the system components do not provide sufficient water volume.
Low Condenser Water Temperature Operation
When ambient wet bulb temperature are lower than design, the condenser water temperature can be allowed to fall.
Lower temperatures will improve chiller performance.
Daikin centrifugal chillers all across the range are equipped with electronic expansion valves (EXV) and will start and
run with enteringcondenser water temperatures as low as shown in Figure 3 or as calculated from the followingequation
on which the curves are based.

D–EIMWC00808-16HU - 15/64
Figure 3, Minimum Entering Condenser Water Temperature (EXV)
Min. ECWT = 5.25 + 0.88*(LWT) - DTFL*(PLD/100) + 22*(PLD/100)2
•ECWT = Entering condenser water temperature
•LWT = Leaving chilled water temperature
•DTFL = Chilled Water Delta-T at full load
•PLD = The percent chiller load point to be checked
For example; at 44F LWT, 10 degree F Delta-T, and 50% full load operation, the entering condenser water temperature
could be as low as 44.5F. This provides excellent operation with water-side economizer systems.
Depending on local climatic conditions, using the lowest possible entering condenser water temperature may be more
costly in total system power consumed than the expected savings in chiller power would suggest, due to the excessive
fan power required.
Cooling tower fans must continue to operate at 100% capacity at low wet bulb temperatures. As chillers are selected
for lower kW per ton, the cooling tower fan motor power becomes a higher percentage of the total peak load chiller
power.
Even with tower fan control, some form of water flow control, such as tower bypass, is recommended.
Figure 5 illustrates two temperature actuated tower bypass arrangements. The “Cold Weather” scheme provides better
startup under cold ambient air temperature conditions. The check valve may be required to prevent entraining air at the
pump inlet.
30,0
35,0
40,0
45,0
50,0
55,0
60,0
65,0
010 20 30 40 50 60 70 80 90 100 110
ECWT, F
Percent Load
Minimum Entering Condenser Water Temperature - 10 F Range
44
LChWT
42
LChWT

D–EIMWC00808-16HU - 16/64
Figure 5, Bypass, Mild Weather Operation
Water Piping
WARNING
If refrigerant charge of the unit is more than 500 kg it is necessary to install gas sensor on
water circuit to catch an eventual gas leakage.
Water Pumps
Avoid the use of 3600/3000-rpm (two-pole motor) pump motors. It is not uncommon to find that these pumps operate
with objectionable noise and vibration.
It is also possible to build up a frequency beat due to the slight difference in the operating rpm of the pump motor and
the Daikin centrifugal motor. Daikin encourages the use of 1750/1460 rpm (four-pole) pump motors.
Vessel Drains at Start-up
Unit vessels are drained of water in the factory and are shipped with the drain plugs in the heads removed and stored in
the control panel or with open ball valves in the drain hole. Be sure to replace plugs or close the valves prior to filling
the vessel with fluid.
Figure 4, Bypass, Cold Weather Operation

D–EIMWC00808-16HU - 17/64
Evaporator and Condenser Water Piping
All evaporators and condensers come standard with Victaulic AWWA C-606
groove nozzles (also suitable for welding), or optional flange connections.
The installing contractor must provide matching mechanical connections or
transitions of the size and type required. A heat recovery chiller, DHSC,
(shown on the right) has two sets of condenser piping; one for the tower, one
for the heating system.
The tower connections are always the inboard pair of connections. In the
figure to the right, the condenser connections are “left-hand” when viewed
from the front of the unit (Unit Control Panel and Interface Panel side), so in
this case, the right-hand condenser connections would be for the tower.
If the condenser connections were on the other end (“right-hand”), the tower
connections would be the left-hand pair of
Important Note on Welding
If welding is to be performed on the mechanical or flange connections, remove
the solid-state temperature sensor and thermostat bulbs from the wells to prevent damage to those components. Also
properly ground the unit or severe damage to the MicroTech II unit controller can occur.
Water pressure gauge connection taps and gauges must be provided in the field piping at the inlet and outlet connections
of both vessels for measuring the water pressure drops. The pressure drops and flow rates for the various evaporators
and condensers are job specific and the original job documentation can be consulted for this information. Refer to the
nameplate on the vessel shell for identification.
Be sure that water inlet and outlet connections match certified drawings and stenciled nozzle markings. The condenser
is connected with the coolest water entering at the bottom to maximize subcooling.
Note: When common piping is used for both heating and cooling modes, care must be taken to provide that
water flowing through the evaporator cannot exceed 110°F which can cause the relief valve to discharge
refrigerant or damage controls.
The piping must be supported to eliminate weight and strain on the fittings and connections. Piping must also be
adequately insulated. A cleanable 20-mesh water strainer must be installed in both water inlet lines. Sufficient shutoff
valves must be installed to permit draining the water from the evaporator or condenser without draining the complete
system.
Flow Switch
A water flow switch must be installed to signal the presence of adequate water flow to the vessels before the unit can
start. They also serve to shut down the unit in the event that water flow is interrupted to guard against evaporator freeze-
up or excessive discharge pressure.
Thermal dispersion flow switches are available from Daikin as a factory-mounted option. It is mounted in an evaporator
and condenser water nozzle and factory wired.
A paddle type flow switch can be supplied by the owner for field mounting and wiring.

D–EIMWC00808-16HU - 18/64
Figure 6, Flow Switch Mounting
If flow switches, by themselves, are being used, electrical connections in the Unit Control Panel must be made from the
common T3-S terminal to terminal CF for the condenser switch and T3-S to terminal EF for the evaporator switch. See
Figure 14, Field Wiring Diagram on page 34. The normally open contacts of the flow switch must be wired between
the terminals. Flow switch contact quality must be suitable for 24 VAC, low current (16ma). Flow switch wire must
be in separate conduit from any high voltage conductors (115 VAC and higher).
Table 1, Flow Switch Flow Rates
Pipe Size
(NOTE !)
inch
1 1/4
1 1/2
2
2 1/2
3
4
5
6
8
mm
32 (2)
38 (2)
51
63 (3)
76
102 (4)
127 (4)
153 (4)
204 (5)
Min.
Adjst.
Flow
gpm
5.8
7.5
13.7
18.0
27.5
65.0
125.0
190.0
205.0
Lpm
1.3
1.7
3.1
4.1
6.2
14.8
28.4
43.2
46.6
No
Flow
gpm
3.7
5.0
9.5
12.5
19.0
50.0
101.0
158.0
170.0
Lpm
0.8
1.1
2.2
2.8
4.3
11.4
22.9
35.9
38.6
Max.
Adjst.
Flow
gpm
13.3
19.2
29.0
34.5
53.0
128.0
245.0
375.0
415.0
Lpm
3.0
4.4
6.6
7.8
12.0
29.1
55.6
85.2
94.3
No
Flow
gpm
12.5
18.0
27.0
32.0
50.0
122.0
235.0
360.0
400.0
Lpm
2.8
4.1
6.1
7.3
11.4
27.7
53.4
81.8
90.8
NOTES:
1. A segmented 3-inch paddle (1, 2, and 3 inches) is furnished mounted, plus a 6-inch paddle loose.
2. Flow rates for a 2-inch paddle trimmed to fit the pipe.
3. Flow rates for a 3-inch paddle trimmed to fit the pipe.
4. Flow rates for a 3-inch paddle.
5. Flow rates for a 6-inch paddle
6. There is no data for pipe sizes above 8-inch. A switch minimum setting should provide protection against no flow
and close well before design flow is reached.
Alternatively, for a higher margin of protection, normally open auxiliary contacts in the pump starters can be wired in
series with the flow switches as shown in Figure 14, Field Wiring Diagram on page 34.
CAUTION
Freeze Notice: Neither the evaporator nor the condenser is self-draining;
both must be blown out to help avoid damage from freezing.
The piping should also include thermometers at the inlet and outlet connections and air vents at the high points.
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, new head gaskets must be used and control sensors relocated.
In cases where the water pump noise can be objectionable, vibration isolation sections are recommended at both the inlet
and outlet of the pump. In most cases, it will not be necessary to provide vibration eliminator sections in the condenser
inlet and outlet water lines. But they can be required where noise and vibration are critical.
Flow direction marked
on switch
I in. (25mm) NPT flow
switch connection
Tee

D–EIMWC00808-16HU - 19/64
Cooling Towers
The condenser water flow rate must be checked to be sure that it conforms to the system design. Some form of
temperature control is also required if an uncontrolled tower can supply water below about 65F (18C). If tower fan
control is not adequate, a tower bypass valve is recommended. Unless the system and chiller unit are specifically for
condenser bypass or variable condenser flow is not recommended since low condenser flow rates can cause unstable
operation and excessive tube fouling.
The condenser water pumps must cycle on and off with the unit. See Figure 14, Field Wiring Diagram on page 34 for
wiring details.
Tower water treatment is essential for continued efficient and reliable unit operation. If not available in-house,
competent water treatment specialists can be contracted.

D–EIMWC00808-16HU - 20/64
Field Insulation Guide
Figure 7, Insulation Requirements, Cooling-only Units

D–EIMWC00808-16HU - 21/64