Daikin EWWD VZ Series Operating and maintenance manual

Water-cooled water chillers with stepless compressor rotation
speed
EWWD - VZ
Cooling capacity from 500 to 2100 kW
50Hz - Refrigerant: HFC R134a
Original Instructions
Installation, maintenance and operating manual
D–EIMWC003D01-17EN-AR

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Contents
Introduction....................................................................................................................................................................... 6
General Description ......................................................................................................................................................... 6
Application........................................................................................................................................................................ 6
Installation Safety.............................................................................................................................................................6
Installation......................................................................................................................................................................... 7
Storage............................................................................................................................................................................. 7
Receiving and handling.................................................................................................................................................... 7
Lifting instructions ............................................................................................................................................................8
Positioning and assembly.................................................................................................................................................9
Shock absorbers............................................................................................................................................................ 10
Anchoring....................................................................................................................................................................... 10
Water pipes.................................................................................................................................................................... 10
Water treatment ............................................................................................................................................................. 11
Temperature limits and water flow ................................................................................................................................. 12
Operating limits.............................................................................................................................................................. 13
Minimum water content in the system............................................................................................................................ 14
Condenser protection and design considerations .......................................................................................................... 15
Condensation control with evaporative cooling tower .................................................................................................... 15
Condensation control with well water............................................................................................................................. 16
Chilled water control sensor........................................................................................................................................... 17
Safety Valve................................................................................................................................................................... 17
Open the isolation and/or shut off valves ....................................................................................................................... 17
Electrical connections..................................................................................................................................................... 17
Phase imbalance............................................................................................................................................................ 17
Control circuit................................................................................................................................................................. 18
Operation......................................................................................................................................................................... 19
Operator’s responsibilities .............................................................................................................................................. 19
Unit description .............................................................................................................................................................. 19
Cooling cycle description................................................................................................................................................ 20
Evaporator...................................................................................................................................................................... 20
Condenser...................................................................................................................................................................... 20
Expansion valve............................................................................................................................................................. 20
Compressors.................................................................................................................................................................. 20
Oil management system................................................................................................................................................. 21
Oil recovery system........................................................................................................................................................ 22
Electrical Control Panel.................................................................................................................................................. 22
Compressor alternation.................................................................................................................................................. 24
High pressure condensation control............................................................................................................................... 24
High pressure mechanical safety pressure switch ......................................................................................................... 24
Compressor motor protection......................................................................................................................................... 24
Maintenance.................................................................................................................................................................... 25
Pressure/Temperature Table ......................................................................................................................................... 25
Routine maintenance ..................................................................................................................................................... 25
Refrigerant charge ......................................................................................................................................................... 28
Electrical Installation ...................................................................................................................................................... 29
Cleaning and Storage .................................................................................................................................................... 29
Seasonal maintenance................................................................................................................................................... 29
Service schedule............................................................................................................................................................. 31
Maintenance Schedule ................................................................................................................................................... 32
Pre-start checks.............................................................................................................................................................. 34
Mandatory periodic checks and commissioning of pressure vessels....................................................................... 35
Important information on the used refrigerant............................................................................................................. 36
Demolition and disposal................................................................................................................................................. 38
Duration........................................................................................................................................................................... 38
Index of figures
Fig. 1 –Lifting instructions .................................................................................................................................................. 8
Fig. 2 - Unit positioning ....................................................................................................................................................... 9
Fig. 3 –Condenser control scheme with cooling tower..................................................................................................... 15
Fig. 4 –Condensation control scheme with well water ..................................................................................................... 16
Fig. 5 - Unit interface......................................................................................................................................................... 23
Fig. 6 - Typical single circuit cooling circuit……………………………………………………………………………………… 26
Fig. 7 - Typical dual circuit cooling circuit…………………………………………………………………………………………..27

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Description of the labels applied to the unit
Single circuit unit

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Double circuit unit
1
Low pressure transducer
13
Oil level
2
Oil injection solenoid valve
14
VVR solenoid valve (3.1 VR)
3
Oil flow sight glass
15
VVR solenoid valve (2.4 VR)
4
Evaporator leaving water temperature sensor
16
VVR solenoid valve (1.8 VR)
5
Evaporator entering water temperature sensor
17
High pressure switch
6
Air purge
18
Discharge temperature sensor
7
Water drain
19
Oil Pressure Transducer
8
Liquid line shut-off valve
20
Suction temperature sensor
9
High pressure safety valves
21
Low Pressure safety valves
10
Refrigerant charge service valve
22
Service valve
11
Oil discharge service valve
23
Jet pump valve
12
Oil line shut-off valve
24
High pressure transducer

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Description of the labels applied to the electric panel
Single circuit unit
Double circuit unit
Identification of labels
1 –Manufacturer’s logo
6–Wire tightness check
2–Electricity warning
7 -Shutoff valve position
3–Emergency button
8–Shock hazard
4–Type of gas
9–Lifting instructions
5–Non flammable gas
10 –Unit nameplate

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Introduction
This manual provides information about the capabilities and standard procedures for all units in the series and
is an important support document for qualified personnel but it is not intended to replace such personnel.
All units are supplied complete with wiring diagrams and dimensional drawings that provide information about
the size and weight of each model.
In case of discrepancies between the content of the manual and the documentation that came with the unit,
always rely to the wiring diagram and dimensional drawings because they are an integral part of this manual.
Read this manual carefully before installing and starting up the unit.
Improper installation can cause shock, short circuits, leaks, fire or other damages
to the equipment or personal injury.
The unit must be installed by professionals/professional technicians in accordance with current laws of the
country of installation.
The unit must also be started by authorized and trained personnel and all activities must be conducted in
accordance and in full compliance with local standards and laws.
IF THE INSTRUCTIONS IN THIS MANUAL ARE NOT ABSOLUTELY CLEAR, DO NOT INSTALL AND/OR
START UP THE UNIT.
If in doubt, for service and further information, contact the manufacturer's authorized representative.
General Description
Daikin water chillers with screw compressor Inverters, are completely factory assembled and tested before
shipment.
The EWWD VZ range consists of models with a single cooling circuit and single compressor (from 500 to 1050
kW) and models with two compressors and two independent cooling circuits (1150 to 2100 kW)
The machine, extremely compact, uses R134a refrigerant suitable for the entire machine application range.
The controller is pre-wired, set and tested at the factory. Only normal connections are required on site such as
piping, electrical connections and pump interlocks, making installation easier and more reliable. All operating
safety and control systems are factory installed in the control panel.
The instructions in this manual apply to all models of this series unless otherwise indicated.
Application
The EWWD VZ units with single screw compressor and adjustment inverters are designed and constructed to
cool and/or heat buildings or industrial processes. Daikin technicians, specifically trained for this purpose, must
start the final system for the first time. Failure to follow this starting procedure affects the warranty.
The standard warranty covers parts of this equipment with proven defects in material or workmanship. Materials
subject to natural consumption are not, however, covered by the warranty.
The cooling towers used with Daikin units with screw compressor must be selected for a wide scope of
application, as described in the "Operating limits" section. From an energy savings point of view it is always
preferable to keep the temperature difference between the hot circuit (condenser) and the cold circuit
(evaporator) to a minimum. However, it is always necessary to verify that the machine works in the temperature
range specified in this manual.
Installation Safety
All EWWD VZ machines are built in accordance with the main European Directives (Machinery Directive, Low
Voltage Directive, Electromagnetic Compatibility Directive for PED pressurized equipment), make sure you also
receive the declaration of product conformity with the directives along with the documentation.
Before machine installation and commissioning, the people involved in this activity must have acquired the
information necessary to carry out these tasks, applying all the information collected in this book.
Do not allow unauthorized and/or unskilled personnel to access the unit.
Always protect the operating personnel with personal protective equipment appropriate for the tasks to be
performed. Common individual devices are: Helmet, goggles, gloves, caps, safety shoes. Additional individual
and group protective equipment should be adopted after an adequate analysis of the specific risks in the area of
relevance, according to the activities to be performed.

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Installation
Storage
Should it be necessary to store the unit prior to installation, it is necessary to observe some precautions.
Do not remove the protective plastic
Do not leave the unit exposed to the elements
Do not expose the unit to direct sunlight
Do not use the machine near a heat source and/or open flame
Keep in places where room temperature is between + 5° C to 55° C (room temperature over the
maximum limit may trigger the safety valve resulting in loss of refrigerant.
Receiving and handling
Inspect the unit immediately after delivery. In particular, make sure the machine is intact in all its parts and that
there are no deformations due to collisions. Should damages be found upon receipt, immediately file a written
complaint with the carrier.
Machine returns are Ex factory Daikin Applied Europe S.p.A.
Daikin Applied Europe S.p.A. cannot be held liable for any equipment damages incurred during transportation to
the place of destination.
The isolation of the evaporator corners, where the lifting holes are located, are shipped separately and must be
assembled on site after the unit has been permanently installed. Even the anti-vibration pads (optional) are
shipped separately. Make sure these items, if required, are delivered with the unit.
Use extreme caution when handling the unit to prevent damage to the control panel and the refrigerant pipes.
The unit must be lifted by inserting a hook in each of the four corners, where the lifting holes are located (see
lifting instructions). Distancer bars must be used along the line connecting the lifting holes to prevent damages
to the electrical panel and the compressor terminal box (see figure). Do not use any other point to lift the
machine.
During the lifting phase, check that the lifting cords and/or chains do not touch the electrical panel and/or piping.
If, to move the machine, slides or shoes are used, just push the base of the machine without touching the
copper and steel pipes, compressors and/or electric panel.
Be careful not to hit, during handling, pipes, cables and installed accessories.
All the necessary devices guaranteeing personal safety must be provided during machine handling.
Important note
Refer to the dimensional drawing for hydraulic and electrical unit connections. The
overall machine dimensions, as well as the weights described in this manual, are
purely indicative. The contract dimensional drawing and relevant wiring diagram are
provided to the customer when ordering.

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Lifting instructions
Single circuit unit
Double circuit unit
Fig. 1 –Lifting instructions

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Lifting instructions:
1) Equipment, ropes, lifting accessories and handling procedures must
comply with local regulations and legislation.
2) To lift the machine, use only the holes on the heat exchangers.
3) Any lifting points should be used during handling.
4) Use lifting hooks with closing device exclusively. The hooks must be safely
secured prior to handling.
5) The ropes and hooks used must have capacity suited to the load.
Check the nameplate on the unit that indicates the machine weight.
6) The installer must correctly select and use lifting
equipment. We recommend using cables with minimum vertical capacity equal to
the total machine weight.
7) The machine must be lifted slowly and well leveled. Adjust the lifting equipment,
if necessary, to ensure the leveling.
Positioning and assembly
The unit must be mounted on a level cement or steel base, suitable to support the overall weight of the complete
machine in operation, and must be positioned so as to provide space for maintenance at one end of the unit, to
allow the cleaning and/or the removal of the evaporator and the condenser pipes. Refer to the figure below for
the areas of respect. The condenser and evaporator pipes are expanded inside the pipe plate to allow
replacement, if necessary.
Fig. 2 - Unit positioning
The machine position should be designed to ensure access to all the safety and control devices. Never cover
the safety devices (safety valves, pressure switches), which, due to their importance, are subject to periodic
checks. The safety valves must be connected externally. For safety valve outlet pipe dimensions, we
recommend applying harmonized standards EN378 and EN13136.
These units include the installation of two safety valves for each exchanger, installed on an exchange tap, which
always maintains an active valve. Thus, both safety valves on each exchanger must be connected outside the
engine room. These pipes must be installed so that, in case the valve opens, the discharged refrigerant flow not
invest people and/or things, or can enter the building through windows and/or other openings.
The engine room must be adequately ventilated to prevent refrigerant accumulation inside that can deprive air of
the right oxygen content that can cause asphyxiation. In this regard, we recommend the application of
harmonized standard EN378-3 (Safety and Environmental Requirements - Installation and protection of persons)
or equivalent.
DANGER
The air contaminated by a high percentage of refrigerant (see refrigerant safety sheet), can cause asphyxiation,
loss of mobility and consciousness if inhaled. Avoid eye and skin contact.
Unit type
A (m)
EWWD450÷C11VZ
3.5
EWWDC13÷C21VZ
4.5

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Shock absorbers
The anti-vibration rubber mats (optional), shipped separately, should be placed under the corners of the unit
(except for special specifications). These mats provide a minimum insulation. Mats are recommended on all
installations where the transmission of vibrations can be considerable. Also install the anti-vibration joints on
water pipes to reduce the stress on pipes, vibrations and noise.
WARNING
The units are shipped with refrigerant and oil valves closed to isolate such fluids during shipment. The valves
must remain closed until such time as an authorized Daikin technician, after inspecting the machine and
checked its installation, commissions the machine.
Anchoring
After positioning, the machine must be firmly anchored to the ground or foreseen metal structure to support the
machine. In this regard, 22 mm diameter holes are included on the machine base to ensure the anchoring.
Water pipes
Evaporator and condenser water pipes
The condensers and evaporators are provided with grooved sleeves for Victaulic connections or optionally with
flanged connections. The installer must provide the mechanical coupling with the connections appropriately
sized to the system.
Important notes regarding welding
1. If the connection flanges require welding, remove the temperature sensors from the wells, to prevent
damage to the controller electronic boards.
2. Grounding must be done correctly to avoid damage to the electronic controller.
Some pressure couplings are included on both the inlet and outlet of the exchangers heads. These couplings
control water load loss. Water load loss and flow for condensers and evaporators are shown in the relevant
product manual. To identify the heat exchanger refer to its plate.
Make sure that the water inlet and outlet connections agree with the dimensional drawing and the indications
found on the connections. Incorrect water pipe installation could create machine malfunctions and/or reduce
performance.
NOTE
When using a hydraulic connection shared with the heating system, make sure the temperature of the water
flowing into the evaporator does not exceed the maximum allowed value. This phenomenon might cause the
safety valve to open and thus the refrigerant to discharge into the atmosphere.
The pipes, before being attached to the machine, must be supported to reduce the weight and the stress on
connections. In addition, the pipes must be adequately insulated. A water filter that can be inspected must also
be installed on both inputs (evaporator and condenser). Install shutoff valves on both heat exchangers with
suitable dimensions to permit draining and inspection without having to completely drain the system in addition
to the water pressure gages.
WARNING
To prevent damage to exchanger pipes, install a mechanical filter that can be inspected on each input, able to
filter solid objects greater than 1.2 mm in size

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Flow Switch
A flow switch must be installed on the evaporator inlet pipe to ensure the correct water flow rate, before the unit
is started. Furthermore, this device shuts off the unit when water flow is interrupted, protecting the machine from
the evaporator freezing.
WARNING
The flow switch must not be used as a machine control system
The absence of the flow switch on the evaporator water connection, voids the warranty for frost damage.
CAUTION
The evaporator and condenser are not self-draining; both must be purged
Thermometers and pressure gages must be installed on the water pipes near the heat exchangers connections.
Furthermore, breather valves must also be installed at the highest points on the pipe.
If necessary, only the evaporator water caps can be reversed. If this operation is completed, new gaskets and
control sensors have to be repositioned.
WARNING
Condenser inlet and outlet water connections cannot be reversed. The particular condenser configuration only
provides optimal machine operations in countercurrent. The wrong water flow direction in the condenser reduces
the overall efficiency of the machine.
Should water pump noise be excessive, we recommend using rubber insulating joints at both pump inlet and
outlet. In most cases it is not necessary to install anti-vibration joints on condenser pipe inlet and outlet but,
where the noise and vibration are critical (for example where a buried pipe passes through a wall in an inhabited
area), it may be necessary.
If a cooling tower is used, a balancing valve must be installed. A temperature control system is required if the
water tower is very cold. The controller installed on the machine manages tower fan on/off or continuously
manages a control vale or fan speed controller by means of a 0-10 V DC analog signal. We recommend that you
carry out the connection, allowing fan management by the machine controller (see wiring diagram for
connection).
Water treatment
Before commissioning the machine, clean the water circuits. Make sure that the tower purge and emptying
system is operational. Atmospheric air contains many contaminants so you need a good water purifier. The use
of untreated water can result in: corrosion, erosion, mud, fouling and formation of algae. Daikin Applied Europe
is not liable for equipment damage or malfunction due to a lack of a water purifier or water not properly purified.
Glycol solution WARNING
Use industrial glycol only. Do not use automotive antifreeze. Automotive antifreeze contains inhibitors which
cause a plating on copper pipes. Used glycol handling and disposal must be in accordance with current
regulations

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Temperature limits and water flow
The EWWD VZ units are designed to operate with an evaporator outlet water temperature between -3° C and
+20° C and a condenser outlet water temperature between 15° C and 50° C (standard units) and between 15° C
and 65° C in case the "High Temperature" kit is installed. However, the minimum temperature difference
between the evaporator outlet water temperature and the condenser inlet water temperature must not be less
than 15° C. Always check the exact operating point with the selection software. Some simultaneous operating
conditions (high evaporator inlet water temperature and high condenser inlet water temperature) may be
inhibited.
Glycol must be used for all applications with the evaporator outlet fluid below 4° C. The maximum permissible
water temperature in the evaporator with the machine off is 50° C. Higher temperatures could cause the safety
valves on the evaporator sleeve to open.
Water flow rate under the minimum value indicated in the condenser and evaporator load loss diagram can
cause freezing problems, incrustations and poor control. Water flow rate higher than the maximum value
indicated in the condenser and evaporator load loss diagram results in an unacceptable load loss and excessive
erosion of the pipes and vibrations that can cause breakage.

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Operating limits
Legend
ELWT Evaporator outlet water temperature
CLWT Condenser outlet water temperature
Ref.1 Standard unit
Ref.2 Brine version standard unit (option 08)
Ref.3 Standard unit with High Temperature Kit (Option 111)
Ref.4 Standard unit with High Temperature kit plus Brine version (Option 111 + Option 08)

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Minimum water content in the system
For correct EWWDxxxVZ machine operations and the necessary operating stability, it is important to ensure a
minimum water content in the system. An accumulation tank with suitable volume may be required for this
purpose.
The minimum water content must be calculated by considering the following specifications:
Application
EWWD 450÷C11
EWWD C13÷C21
Conditioning
3.3 lt/kW
2.5 lt/kW
Process
6.6 lt/kW
5.0 lt/kW
Variable capacity
6.6 lt/kW
5.0 lt/kW
Note: The EWWD450 ÷ C11 units are machines with a single compressor
The EWWDC13 ÷ C21 units are machines with two compressors
Calculation example for EWWDC11VZ XS units
Cooling capacity at 100% = 1053 kW
Minimum system volume for conditioning: 1053 x 3.3= 3475 lt
Minimum system volume for processing: 1053 x 6.6= 6950 lt
Minimum system volume at variable capacity: 1053 x 6.6= 6950 lt
Note: The calculation formula described above, takes into account several factors such as the compressor stop
time and the admissible temperature difference between the last compressor stop and start. In this regard, the
minimum water content calculated refers to the machine operations in a normal climate control system. If the
machine is used for process activities or if higher operating stability is required, we recommend doubling the
calculated water content. In very simple systems, an inertial accumulation tanks may be necessary on the
hydraulic circuit to reach the required minimum water volume. Adding this component must guarantee correct
water mixing and, therefore, we recommend you select a tank that includes an internal diaphragm for this
purpose.
Note: If the evaporator water circuit operates in a variable flow system, the minimum water flow rate must not be
less than 50% of the water flow rate at nominal conditions and the variation should not be greater than 10% of
the nominal flow per minute.
Note: If the evaporator water circuit operates in a variable flow system, the minimum water flow rate must not be
less than 50% of the water flow at nominal conditions, and the variation should not be greater than 10% of the
nominal flow per minute.

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Evaporator frost protection
1. If the machine is idle during the winter, drain and rinse the evaporator and chilled water pipes with glycol.
Drain and air vent connections are included on the evaporator for this purpose.
2. We recommend adding glycol in proper proportion to the condenser cooling system. The freezing
temperature, of the water-glycol solution, must be at least 6° C lower than the expected minimum ambient
temperature.
3. Insulate pipes especially chilled water ones to avoid condensation.
Note: Damage caused by freezing is not covered by warranty, therefore, Daikin Applied Europe SpA
cannot be held liable.
Condenser protection and design considerations
If lake, river or ground water is used as the cooling fluid and the water valves have a leak, the condenser and
liquid refrigerant line temperatures could drop under room temperature when the machine is off. This problem
occurs when cold water circulates through the condenser and the unit remains off waiting load. If this happens:
1. Turn off the condenser water pump when the compressor is off.
2. Check that the liquid line expansion valve is working properly.
Condensation control with evaporative cooling tower
The minimum condenser inlet water temperature should not be less than 20° C at full water tower flow rate.
If the water temperature must be lower, even the water flow must be reduced proportionately.
To modulate the water flow to the condenser, install a three-way by-pass valve. The figure shows how the three-
way valve is applied to cool the condenser. The three-way valve can be activated by a pressure actuator which
guarantees proper condensing pressure in the case where the water temperature entering the condenser is less
than 20° C.
In place of a valve with pressure actuator you might use a three-way servo-operated valve or a circulation pump
controlled by an inverter. Both of these two devices may be controlled by an analog 0-10 Vdc signal issued by
the machine's electronic controller according to the water temperature entering the condenser.
Fig. 3 –Condenser control scheme with cooling tower
1
2
1 –Cooling Tower
2 - Condenser

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Condensation control with well water
If ground water is used to cool the condenser, install a normally regulating control valve, direct drive, at
condenser outlet. This regulating valve must ensure an adequate condensing pressure in the case where the
water temperature entering the condenser is less than 20° C.
A service valve with pressure outlet is provided on the condenser sleeve for this purpose.
The valve must modulate its opening according to condensing pressure. When the machine shuts down, the
valve will close preventing the condenser from emptying.
Fig. 4 –Condensation control scheme with well water
1
From the main condenser pump
2
Service valve
3
Direct acting water regulating valve
4
Configuration required when the regulating valve is not used
5
At Drain
2
1
3
5
4

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Chilled water control sensor
The water cooled EWWD VZ unit is equipped with a microprocessor. Be careful when working around the unit to
avoid damaging cables and sensors. Check cables before starting the unit. Prevent rubbing of the cables on the
frame or other components. Make sure the cables are securely locked. If the temperature sensor is removed for
maintenance, do not eliminate the conductive paste in the well and replace the sensor correctly. After replacing
the sensor, tighten the lock nut to prevent accidental slipping.
Safety Valve
Each exchanger (evaporator and condenser) is provided with a safety valve installed on an exchange valve that
allows maintenance and periodic checks, without losing a significant amount of refrigerant. Do not leave the
safety valve in the intermediate position.
WARNING
To prevent damage due to R134a gas inhalation, do not release the refrigerant in the air or other indoor places.
The safety valves must be connected externally in accordance with the regulations in the place of installation.
The installer is responsible for connecting the safety valve to the purge pipe and pipe dimensioning. In this
regard, refer to the harmonized standard EN13136 to dimension the drain pipes to be connected to the safety
valves
Open the isolation and/or shut off valves
Before powering the machine and thus starting the compressors, open all valves that were closed at the factory
for shipping.
The valves to be opened are:
1. Valve (optional) installed on the compressor line
2. Oil return pipe shutoff valves (jet pump). These valves are positioned below the evaporator sleeve in the
vicinity of the jet pump.
3. Liquid line valve installed under the condenser.
4. Oil valves installed on the line that feeds the compressor lubrication system. This line comes from the
bottom of the oil separator located inside the condenser.
5. Valve (optional) installed on the compressor pump line.
Electrical connections
The unit must be connected with in the proper section copper cables relative to the plate absorption values and
in accordance with applicable electrical regulations.
Daikin Applied Europe S.p.A. cannot be held liable for improper electrical connections.
Warning
The connections to the terminals must be made with copper terminals and cables.
The electrical connection must be made by qualified personnel.
There is a risk of electric shock
The electrical panel must be connected keeping the correct phase sequence.
Phase imbalance
In a three-phase system, excessive imbalance between the phases is the cause of motor overheating. The
maximum allowed voltage imbalance is 2%, calculated as follows:
imbalance %= (Vx-Vm) x 100 =
Vm
Vx = phase with greatest imbalance

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Vm = average of the voltages
I.e. the three phases measure 383, 386 and 392 volts respectively, the average is:
383+386+392 = 387V
3
the percentage of imbalance is thus
(392-387) x 100 = 1,29% less than the maximum admitted (2%)
387
WARNING
Before any maintenance and/or electrical connection to the compressor inverter, make sure the system is turned
off and the unit main switch open.
After turning on the main switch, wait at least 20 minutes for the inverter condensers to completely discharge.
Do not perform any maintenance and/or electrical connection in this period of time. Risk of electrocution:
Control circuit
The EWWD VZ unit control circuit is powered at 230 Vac.
The controller ON/OFF switch (Q0) must be rotated to the OFF position whenever machine operations are not
required.
Water flow switch interlock terminals are included in the controller. See the wiring diagram for the correct
connections on the field.
The purpose of the water flow switch interlock is to prevent the compressor from running for enough time to let
the two evaporator and condenser water pumps to operate and ensure the correct water flow. The flow switch
can be supplied on request from Daikin Applied Europe and in any case must be compulsorily installed on the
machine. For better protection against freezing, connecting the evaporator flow switch, contactor clean contact
or pump circuit breaker in series.
It is best to leave pump control to the microprocessor for better system management.
If an external system independently manages pump start, follow this logic.
Evaporator water inlet
turn on the pump 2 minutes before enabling the machine
turn off the pump 5 minutes after disabling the machine
Condenser water pumps:
turn the pump on 30 seconds before enabling the machine
turn the pump off 1 minute after the last compressor is turned off.
With the machine off, the condenser pump must always be turned off.
Testing the control circuit
Each EWWD VZ unit is factory tested. Both the control and power circuits undergo a careful functional test
before the machine is shipped.

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Operation
Operator’s responsibilities
It is important that the operator becomes familiar with the equipment before operating the machine. In addition to
reading this manual, the operator should study the operation manual and the wiring diagram supplied with the
unit to understand commissioning, operation and the shutdown sequence as well as the shutdown mode and
safeties.
During initial machine start-up, the Daikin technician is available to answer any questions and instruct on proper
operating procedures.
The operator should keep an operating data log for each specific machine. Furthermore, an additional
maintenance log should be kept for periodic maintenance and service.
This Daikin unit represents a substantial investment and deserves the attention and care to keep this equipment
in good working order. If the operator observes abnormal or unusual operating conditions, calling Daikin
technical service is recommended.
In any case, it is essential to follow the instructions below during operation and maintenance:
- Do not allow unauthorized and/or unskilled personnel to access the unit.
- It is forbidden to access the electrical components without having opened the unit main switch and switched off
the power supply.
- It is forbidden to access the electrical components without using an insulating platform. Do not access electrical
components if water and/or moisture are present.
- Ensure that all operations on the refrigerant circuit and on components under pressure are exclusively carried
out by qualified personnel.
- Compressors must be replaced and lubricant oil filled by qualified personnel.
- Sharp edges can cause injuries. Avoid direct contact.
- Do not introduce solid objects into the water pipes while the unit is connected to the system.
- A mechanical filter must be fitted to the water pipe connected to the heat exchanger inlet.
- The unit is equipped with high-pressure safety pressure switches on each compressor, which stop it when
triggered when the pressure exceeds the set value. If triggered, reset the pressure switches by pressing the blue
button and then the alarm on the microprocessor.
- It is absolutely forbidden to remove any protection system covering moving parts.
In case of sudden stop of the unit, follow the instructions on the Control Panel Operating Manual which is part of
the on-board documentation delivered to the end user.
It is strongly 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 to a warm place far from the unit and in place him or her in the recovery
position.
- Immediately contact any emergency personnel in the building or the call the Emergency Services.
- Wait until emergency personnel arrive and do not leave the injured person alone.
-
Unit description
The machine is made up of a latest generation, high efficiency, new VVR series single screw compressor,
flooded shell and tube evaporator with the refrigerant outside the tubes and the water to be cooled flowing inside
the tube.
A shell and tube condenser where the refrigerant condenses outside the tubes while the cooling water flows
inside of the high-efficiency tubes.
The compressor is of the mono screw semi-hermetic type and utilizes the suction gas coming from the
evaporator to cool the motor and permit the optimum operations in all machine load conditions. The compressor,
controlled by inverters, changes its cooling load according to the rotational speed decided by the controller. In
this way the machine perfectly adapts to system operating conditions to maximize performance.
The oil injection lubrication system, in addition to allowing normal moving part lubrication, also seals the screw
ensuring gas compression, without the aid of an external oil pump.

D-EIMWC003D01-17EN-AR - 20/80
The cooling circuit also installs an electronic overflow valve that, in addition to managing the level of refrigerant
in the heat exchangers and guaranteeing the correct operation of the compressor, also manages the PUMP-
DOWN function.
All the described components are managed by an innovative microprocessor control system that, by monitoring
all the machine operating parameters, optimizes operations.
A diagnostic system helps the operator in identifying alarm and fault causes.
WARNING
Before starting the compressors ensure that all valves are open and the closing caps are repositioned and
tightened.
Cooling cycle description
The low temperature refrigerant gas coming from the evaporator is sucked by the compressor and flows through
the electric motor, cooling it. It is subsequently compressed and during this phase the refrigerant mixes with the
oil, injected in the compressor, from the separator.
The high-pressure oil-refrigerant mixture is introduced inside the three-stage high efficiency oil separator which
performs the separation. The oil deposited on the bottom of the separator is sent, by pressure difference, to the
compressor again while the refrigerant separated from the oil is sent to the condenser.
The refrigerant fluid inside the condenser, which crosses the heat exchanger pipes in countercurrent,
desuperheats and starts to condense. The desuperheating heat and condensation is subtracted from the
condensation water which heats accordingly.
The condensed fluid at saturation temperature passes through the subcooling section, where it yields heat to
further increase cycle efficiency. The subcooled fluid flows through the overflow device which, through a
pressure drop, initiates the expansion process by vaporizing a part of the refrigerant liquid.
The result at this point is a mixture of liquid and gas at low pressure and temperature, poor in heat, which is
introduced into the evaporator.
The liquid-vapor refrigerant after being evenly distributed along the tube bundle exchanges heat with the water
to be cooled by reducing the temperature, and it gradually changes state until being fully evaporated.
Reaching the vapor state, it leaves the evaporator to be sucked by compressor again and restart the cycle.
Evaporator
The evaporator is a flooded shell and tube type with water flowing inside the tubes and the gas refrigerant
outside. Normally it does not require any maintenance and service. Should a tube require replacement, the old
tube can be removed and replaced. The water dome gasket must be replaced after tube cleaning and/or
replacement.
Condenser
The condenser is a shell and tube type with water flowing inside the tubes and the refrigerant outside. The
condenser tubes are externally finned and expanded on the tube plate. A subcooler is built into the condenser
on all units. Should a tube require replacement, the old tube can be removed and replaced. The water dome
gasket must be replaced after tube cleaning and/or replacement.
Expansion valve
The expansion valve is electrically controlled by the electronic controller by means of a specifically designed
electronic board. A special algorithm designed for machines with flooded evaporators, manages the refrigerant
flow to the evaporator according to machine operating parameters. In the event of blackout, the expansion valve
automatically closes thanks to an electric power accumulation system placed inside the electronic control board
(supercap)
Compressors
The refrigeration compressor is the single screw type with the rotation shaft directly coupled to the electric
motor.
The vapor flows through the electric motor cooling the windings before entering the suction ports. Sensors able
to constantly monitor temperature are located inside the motor windings to fully protect the motor against