Western Zeta Rev HE FC User guide

Zeta Rev HE FC
46÷149 kW
General
High efciency, air-condensed free cooling water
chiller unit, with scroll compressors and plate
heat exchanger.
Congurations
LN: low noise unit
NG: unit without glycol on user circuit
Strengths
►Patented free cooling system
►Reduced refrigerant charge
►Advanced Bluethink controller with integrated
web server
►Multilogic/Multifree functionality for multi-unit
systems
►Blueye supervision system
►Flowzer: system with variable water ow rate
►Glycol-free version available

1
Application and operating principle 3
Zeta Rev HE FC
Product description 5
Description of accessories 8
Refrigerant circuit accessories 8
Fan accessories 9
Hydraulic circuit accessories 10
Electrical accessories 12
Other accessories 15
Technical specications 18
Zeta Rev HE FC 18
Zeta Rev HE FC/NG 19
Electrical specications 20
Pump data 21
User-side exchanger ow rate elds 22
Operating limits 23
Noise levels 24
Installation advice 26
Water characteristics 26
Glycol mixtures 26
Minimum water content in the system 27
Installation site 28
Installations that require the use of treated coils 29
Aeraulic head losses and options available for the ventilating section 30
Dimensional diagrams 32

2

3
APPLICATION AND OPERATING PRINCIPLE
Free cooling units meet growing demands for energy sav-
ings, since they have been designed to reduce the oper-
ating costs of refrigerating machines that work to serve
process applications or in the IT eld.
A strong point of our free cooling units is certainly the con-
trol system that allows maximum use to be made of the
free resource, consisting of outside air, so minimizing the
energy used by the compressors. The controller of the unit
activates the chiller section and the free cooling section,
also in combined mode, based on the actual external air
temperatures, the set point and the required load level.
The free cooling section is hydraulically in series with the
evaporator and this allows a benet to be obtained from
its activation even when the outside air temperature is
sufcient to carry out only a pre-cooling of the water. The
missing amount of capacity, in any case lower than the
total required, will be provided by the compressors.
As the outside air temperature goes down, the amount of
capacity that the free cooling section will be able to trans-
fer to the water will gradually increase. Consequently, the
amount of capacity that will have to be covered by the
compressors will always be lower.
When the TFT (Total Free-cooling Temperature) is reached,
the free cooling section will be able to fully meet the cool-
ing capacity requirement and therefore the compressors
can be switched off. In this condition, the unit will be able
to provide the system with a cooling capacity equal to that
required at design conditions, but with current drawn by
the fans alone.
How the unit behaves in the various scenarios is explained
briey below.
ZETA REV HE FC
Chiller only mode
When the ambient temperature is higher than the tem-
perature of the water returning from the system, all the
required cooling capacity must be produced by the com-
pressors.
In this mode, the damper that controls the air ow rate
at the free cooling coil is fully closed, whereas the one in
front of the condensing coil is fully open.
The 3-way valve bypasses the free cooling coil (to pre-
vent unnecessary head losses) and condensation control
is done, when necessary, through modulation of the fans.
Mixed mode
When the ambient temperature is lower than the tempera-
ture of the water returning from the system, the controller
activates the free cooling section.
The controller switches over the 3-way valve to put the
free cooling coil in series with the evaporator, fully opens
the free cooling damper and pushes the fans to maximum
speed. In this way, extraction of maximum cooling capac-
ity from the outside air is ensured.
The water leaving the free cooling coil will be the water
that enters the evaporator. Since the water is "pre-cooled",
the amount of capacity required of the chiller section will
be lower and therefore this will be able to operate with
reduced capacity.
Since the fans must be kept at 100% to ensure the max-
imum capacity at the water coil, condensation control is
done by modulating the opening of the damper situated in
front of the condensing coil.
Free cooling only mode
Below a certain outside air temperature, the unit operates
exclusively in free cooling mode.
The capacity given by the water coil fully meets the re-
quirement of the system, and therefore the damper in
front of the condenser is fully closed and the compressors
are kept switched off.
Also, through fan speed modulation, the controller of the
unit will manage the capacity given by the free cooling
section that, with the lowering of the outside air tempera-
ture, could be excessive.

4
ZETA REV HE FC/NG
Chiller only mode
When the ambient temperature is higher than the tem-
perature of the water returning from the system, all the
required cooling capacity must be produced by the com-
pressors.
In this mode, the damper that controls the ow rate at the
free cooling coil is fully closed, whereas the one in front of
the condensing coil is fully open.
The circulation pump on the free cooling circuit remains
switched off, whereas condensation control is done, when
necessary, through modulation of the fans.
Mixed mode
When the ambient temperature is lower than the tempera-
ture of the water returning from the system, the controller
activates the free cooling section.
The controller switches on the circulation pump of the free
cooling circuit, fully opens the free cooling damper and
pushes the fans to maximum speed. In this way, extrac-
tion of maximum cooling capacity from the outside air is
ensured.
The cooling capacity of the free cooling coil is transferred
to the system water through a decoupling exchanger. This
allows the glycol water circulating in the free cooling cir-
cuit to be separated from the system water that therefore
does not need the addition of antifreeze.
The water leaving the decoupling exchanger will be the
water that enters the evaporator. Since the water is "pre-
cooled", the amount of capacity required of the chiller sec-
tion will be lower and therefore this will be able to operate
with reduced capacity.
Since the fans must be kept at 100% to ensure the max-
imum capacity at the water coil, condensation control is
done by modulating the opening of the damper situated in
front of the condensing coil.
Free cooling only mode
Below a certain outside air temperature, the unit operates
exclusively in free cooling mode.
The capacity given by the water coil fully meets the re-
quirement of the system, and therefore the damper in
front of the condenser is fully closed and the compressors
are kept switched off.
Also, through fan speed modulation, the controller of the
unit will manage the capacity given by the free cooling
section that, with the lowering of the outside air tempera-
ture, could be excessive.

5
Zeta Rev HE FC
High efciency, air-condensed free cooling water
chiller unit, with scroll compressors and plate heat
exchanger.
PRODUCT DESCRIPTION
BODY
The structure of the unit is made of galvanized sheet-iron
coated with polyester powder in RAL 5017/7035 at 180°C,
which makes it highly resistant to weather conditions.
The structure is a load-bearing frame, with removable
panelling lined with sound absorbing expanded polyure-
thane matting.
All screws and bolts are stainless steel.
COMPRESSORS
The compressors are hermetic orbiting spiral scroll com-
pressors connected in tandem, tted with oil level sight
glass, oil equalization line, crankcase heater and electron-
ic protection.
The compressors, enclosed in a soundproof compartment
and separated from the air ow, can be accessed through
special panelling that allows maintenance operations to be
carried out even with units running.
CONDENSING COIL
The source-side exchanger is made with aluminium micro-
channel coil.
The microchannel coils are made using specic aluminium
alloys for the tubes and for the ns. This allows the effects
of galvanic corrosion to be drastically reduced to always
ensure protection of the tubes that conne the refriger-
ant. The entire coil is also subjected to SilFLUX coating
processes (or equivalent) or has zinc added to further in-
crease its corrosion resistance.
The use of microchannel coils compared to convention-
al copper/aluminium coils reduces the total weight of the
unit by about 10% and gives a reduction in refrigerant
charge of at least 30%.
Refer to chapters "Installation advice" and "Description of
accessories" for assessment of any options or treatments
based on the place of installation.
In front of the condensing coil, there is a damper dedicat-
ed to controlling the air ow rate at the exchanger, com-
plete with modulating servo control. Damper management
is done by the controller following the logics of the patent-
ed free cooling system (patent n° IT1855070):
• in chiller mode, the damper is fully open, so allowing
the maximum air ow rate, and condensation control is
carried out by adjusting the speed of the fans
• in mixed mode (chiller + free cooling) the fans operate
at full speed and condensation control is done by mod-
ulating the opening of the damper
• in free cooling mode, the damper is fully closed, so en-
suring the full ow rate at the free cooling coil alone.
FREE COOLING COIL
The free cooling exchanger consists of a row coil with cop-
per tubes and aluminium ns.
Refer to chapters "Installation advice" and "Description of
accessories" for assessment of any options or treatments
based on the place of installation.
This exchanger is put in series with the user-side heat
exchanger by means of a 3-way valve. When the unit is
not working in free cooling mode, the valve allows the
coil to be bypassed to prevent unnecessary hydraulic head
losses.
For /NG version units, the free cooling coil is connected to
a decoupling exchanger situated in series with the evapo-
rator. The coil is supplied by a dedicated circulation pump
that will be switched on only with free cooling active.
The free cooling coil is positioned on the opposite side of
the machine to the condensing coil so that it can be man-
aged completely independently.
In front of the coil, there is a damper dedicated to con-
trolling the air ow rate at the exchanger, complete with
point servo control. Damper management is done by the
controller following the logics of the patented free cooling
system (patent n° IT1855070):
• in chiller mode, the 3-way valve is closed (for the /NG
version, the circulation pump is off), the damper is fully
closed, so ensuring the full air ow rate at the condens-
ing coil alone
• in mixed mode (chiller + free cooling), the 3-way valve
is open (for the /NG version, the circulation pump is
on), the fans work at full speed and the damper is fully
open, so allowing the maximum air ow rate at the free
cooling coil
• in free cooling mode, the damper is fully open and con-
trol of the capacity given by the free cooling coil is done
by the controller of the unit by modulating the speed of
the fans
FANS
The fans are axial fans, directly coupled to a three-phase
6-pole electric motor, with integrated thermal overload
protection (klixon) and IP 54 protection rating.
The fan includes the shroud, designed to optimize its ef-
ciency and reduce noise emission to a minimum, and the
safety guard.
The fans are controlled as standard by a phase cutting
speed adjuster managed by the controller.

6
USER-SIDE HEAT EXCHANGER
The exchanger is a braze-welded stainless steel plate heat
exchanger, insulated with a shroud of closed-cell insulat-
ing material.
The exchanger is equipped with two temperature probes
(one at the inlet and one at the outlet) for controlling the
water temperature and the freeze protection.
The exchanger is protected as standard by an electric anti-
freeze heater managed by the controller of the unit.
REFRIGERANT CIRCUIT
The refrigerant circuit of the basic unit comprises:
• shut-off valve in the liquid line
• 5/16” charging valves
• liquid sight glass
• replaceable solid cartridge dehydrator lter (except for
sizes 3.2, 4.2 and 5.2 where the lter is a weld-on lter)
• thermostatic expansion valve with pressure equaliza-
tion
• high and low pressure switches
The pipes of the circuit and the exchanger are insulated
with extruded closed-cell expanded elastomer.
As an accessory, all the units can be tted with an elec-
tronic expansion valve that allows machine stability to
be reached more quickly and better superheating control
than the mechanical expansion valve, to maximize the use
of the evaporator in all load conditions.
ELECTRICAL CONTROL PANEL
The electrical control panel is made in a painted galva-
nized sheet-iron box with forced ventilation and IP54 pro-
tection rating.
The electrical control panel of the basic unit comprises:
• main disconnect switch
• automatic circuit breakers for compressors with xed
calibration
• fuses for protecting the fans and auxiliary circuits
• fan contactors
• phase-cutting fan speed adjuster
• thermal magnetic circuit breakers for pumps (if pres-
ent)
• phase monitor
• potential-free general alarm contacts
• single potential free operating contacts for compres-
sors, fans and pumps (when present)
• digital input for general ON/OFF
• external air temperature probe
• microprocessor controller with display accessible from
the outside
All the electrical cables inside the panel are numbered and
the terminal board dedicated to the customer's connec-
tions is coloured blue so that it can be quickly identied
in the panel.
Power supply: 400V/3~+N/50Hz for models from 3.2 to
10.2; 400V/3~/50Hz for models 12.2 and 13.2
CONTROL BLUETHINK
Main controller functions
The microprocessor control allows the following functions:
• water temperature adjustment, with outgoing water
control
• freeze protection
• compressor timings
• automatic rotation of compressor starting sequence
• recording of the log of all machine inputs, outputs and
states
• automatic rotation of compressor starting sequence
• recording of the alarm log
• digital input for general ON/OFF
• digital input for hot circuit ON/OFF
• Ethernet serial port with Modbus protocol and integrat-
ed web server preloaded web page
• USB port
For further details on available functions and on displayed
information, you can refer to the specic documentation
of the control.
By default, the serial connections present as standard are
enabled only for reading from BMS. Enabling of writing
from BMS is to be requested when ordering.
Main functions of the webserver
As standard, the Bluethink controller integrates a web-
server with a preloaded web page that is accessed via
password.
The web page allows the following functions to be carried
out (some of these are available only for users with ad-
vanced level rights):
• display of the main information on the unit, such as
serial n°, size, type of refrigerant
• display of the general status of the machine: water inlet
and outlet temperatures, external air temperature, op-
erating mode, evaporating and condensing pressures,
suction and discharge temperatures
• display of the status of compressors, fans, pumps, elec-
tronic expansion valves
• display in real time of the graphs of the main quantities
• display of the graphs of logged quantities
• display of alarm log
• display of the status of all the I/Os of the controller
• management of users on several levels
• remote ON/OFF
• remote set point change
• remote time band change

7
Human-Machine Interface
The control has a graphic display that allows the following
information to be displayed:
• water inlet and outlet temperature
• set temperature and differential set points
• description of alarms
• hour meter of operation and number of start-ups of the
unit, the compressors and the pumps (if present)
• high and low pressure values, and relevant condensing
and evaporating temperatures
• external air temperature
• superheating at compressor suction.
CONTROLS AND SAFETY DEVICES
All the units are tted with the following control and safety
components:
• high pressure switch with manual reset
• high pressure safety device with automatic reset, for a
limited number of occurrences, managed by the con-
troller
• low pressure safety device with automatic reset and
limited tripping managed by the controller
• high pressure safety valves
• antifreeze probe at the outlet of the user-side heat ex-
changers
• differential pressure switch already tted on the us-
er-side heat exchangers
• overtemperature protection for compressors and fans
TESTING
All the units are factory-tested and supplied complete with
oil and refrigerant.
PACKAGING
The unit is made and shipped on a wooden pallet that al-
lows the unit to be handled using a forklift truck.
The unit is wrapped in a protective transparent polyethyl-
ene stretch lm.
VERSIONS
Zeta Rev HE FC/NG
In addition to the components of the basic version, the /
NG set-up unit has:
• a water/water decoupling plate heat exchanger in place
of the 3-way valve
• a circulation pump dedicated to the free cooling circuit
(closed circuit inside the unit) with shut-off valves up-
stream and downstream of it
• a paddle ow switch to protect the free cooling circuit
• water safety valve to protect the free cooling circuit
• expansion vessel with water pressure gauge to protect
the free cooling circuit
For this version, the intermediate heat exchanger is always
in series with the user-side heat exchanger and therefore
the head losses inside the machine do not change with the
operating mode.
The use of a decoupling exchanger allows only the water
contained in the circuit inside the unit to be glycolated
and to use pure water in the system, thereby obtaining
an immediate economic saving and improving the heat
exchange on individual user points.
OPTIONS
/LN: low noise unit
In the unit with /LN option, the technical compartment
that houses the compressors is fully soundproofed with
sound absorbing material and soundproong material.
HYDRAULIC MODULES
All units can be tted with hydraulic module in various
congurations:
• /1P: hydraulic module with one pump
• /2P: hydraulic module with two pumps
• /1PS: hydraulic module with one pump and buffer tank
• /2PS: hydraulic module with two pumps and buffer tank
All the above-mentioned modules have pumps with stand-
ard discharge head.
Hydraulic modules with one pump have:
• one pump
• a gate valve on the delivery side of the pump
• an expansion vessel
Hydraulic modules with two pumps have:
• two pumps
• a check valve on the delivery side of each pump
• a gate valve on the outlet of the delivery manifold
• an expansion vessel
In the version with 2 pumps, these are always with one
on standby while the other is working. Switching over be-
tween the pumps is automatic and is done by time (to
balance the hours of operation of each one) or in the event
of failure.
Hydraulic modules with tank also have:
• a tank with drain valve and air valve

8
DESCRIPTION OF ACCESSORIES
Refrigerant circuit accessories
The "(S)" symbol indicates that the option is present as standard in the unit, provided this is not in conict with other
selected accessories.
BK Brine Kit
This accessory is compulsory if a water temperature set point lower than +3°C is used (if the unit is provided
with double set point or variable set point, the lower set point is considered).
The accessory consists of increased insulation and suitable sizing and calibration of some components.
The inlet and outlet temperatures of the user-side exchanger must be given on ordering to allow correct set-
ting of the alarm parameters and verication of the sizing of the expansion valve.
The cooling set point can then be changed by the customer in an interval that, compared to the set point given
on ordering, ranges from -1K up to the maximum temperature allowed by the above-stated operating limits.
The unit will be optimized to work at the set point temperature given on ordering. For different set points, the
cooling capacity provided and the level of efciency of the machine could decrease and move away from these
conditions.
MAFR Pressure gauges
The operating pressures of each circuit of the unit can be displayed on the control by accessing the relevant
screens. Also, the machine can be tted with pressure gauges (two for each circuit) installed in a clearly visible
position. These allow reading in real time of the working pressures of the refrigerant gas on the low pressure
side and on the high pressure side of each refrigerant circuit.
RG Fan speed adjuster (S)
The control manages the speed of the fans through a phase cutting speed governor, in order to optimize the
operating conditions and efciency of the unit.
For units equipped with EC fans, the same function is carried out using the electronically commutated motor
of the fans and is supplied as standard.
RIC Liquid receiver
The adoption of this accessory always guarantees correct feeding of the expansion valve even when the unit
is subjected to wide external air temperature ranges.
RPP Refrigerant leak detector with automatic pump down
With this accessory, a refrigerant leak detector is placed inside each compressor compartment. Detection of a
refrigerant leak is managed by the control through a specic alarm and display of a specic icon on the display
of the control. For all the circuits of the unit, the alarm also starts the machine stopping procedure with pump
down, conning all the refrigerant in the coils.
The accessory includes the capacitive backup battery.
The accessory can be applied only to units in LN or SLN set-up.
RPR Refrigerant leak detector
With this accessory, a refrigerant leak detector is placed inside each compressor compartment. Detection of
a refrigerant leak is managed by the controller through a specic alarm and display of a specic icon on the
display of the controller. This alarm stops the unit.
The accessory can be applied only to units in LN or SLN set-up.
RUB Compressor suction and delivery valves
The valves situated on the delivery side and on the suction side of the compressors allow the compressor to
be isolated from the rest of the refrigerant circuit, so making the maintenance operations quicker and less
invasive
VS Liquid line solenoid valve
This accessory prevents refrigerant migration that could damage the compressor on starting.
VTE Electronic expansion valve
The use of this component is particularly advisable on units operating in very variable heat load or operating
mode conditions, as in the case of joint management of air conditioning and high temperature water produc-
tion. The use of an electronic thermostatic valve allows you to:
• maximize heat exchange at the evaporator
• minimize response times to changes in load and operating conditions
• optimize control of overheating
• ensure maximum energy efciency