RefPlus Opti-Mist Plus User manual

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INSTALLATION, OPERATION
AND MAINTENANCE
MANUAL
ADIABATIC PRE-COOLING
SYSTEM
Opti-Mist Plus

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TABLE OF CONTENTS
ADIABATIC SYSTEM MAIN COMPONENTS.................................................................................. 3
PUMPING STATION & WATER TREATMENT MAIN COMPONENTS ............................................ 4
1. INTRODUCTION.......................................................................................................................... 5
2. SAFETY CONSIDERATIONS ...................................................................................................... 5
3. PRODUCT DESCRIPTION .......................................................................................................... 5
4. INSTALLATION ............................................................................................................................ 5
4.1 LOCATING AND SECURING THE PUMPING STATION ........................................................................................ 5
4.2 PIPING .................................................................................................................................................................... 6
4.3 WIRING ................................................................................................................................................................... 6
5. START-UP.................................................................................................................................... 6
6. WATER PRESSURE ADJUSTMENT........................................................................................... 7
7. MAINTENANCE ........................................................................................................................... 8
8. SYSTEM SETUP & ADJUSTMENTS........................................................................................... 8
9. TROUBLESHOOTING ................................................................................................................. 9
REPLACEMENT PARTS.................................................................................................................. 12
STARTUP REPORT FORM ............................................................................................................. 13
UNIT DIMENSIONS ......................................................................................................................... 14
WIRING DIAGRAMS........................................................................................................................ 15
PIPING DIAGRAM ........................................................................................................................... 18
WARRANTY..................................................................................................................................... 19

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AdiAbAtic SyStem mAin componentS
PIPING
NETWORK
PUMPING AND
WATER TREATMENT
STATION
ATOMIZING NOZZLES

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WATER PRESSURE
REGULATING VALVE
UV LIGHT
WATER INLET
(City water or tank)
PUMP
PULSING VALVE
WATER PARTICLE FILTER
PRESSURE DIFFERENTIAL
SWITCH
GUARDIAN+
RC-A CONTROLLER
DEMINERALIZER
(ANTI-SCALING)
WATER OUTLET
(To heat rejection unit)
DRAIN
DRAIN (UV light flush)
pumping StAtion & WAter treAtment mAin componentS

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1. INTRODUCTION
Congratulations on purchasing an Opti-Mist+®Adiabatic
Pre-Cooling System from RefPlus®. Your system has been
thoroughly inspected and leak tested before shipment to
ensure peak performance.
These instructions describe installation, start-up, operation,
service and troubleshooting of an adiabatic system.
2. SAFETY CONSIDERATIONS
Installing, starting up, and servicing equipment can be
hazardous due to electrical components and equipment
location (roofs, elevated structures, etc.). Only trained and
qualied installers as well as service technicians should
install, start-up and service this equipment.
When working on the equipment, observe precautions found
in the literature, on the tags, stickers, and labels attached to
the equipment.
Follow all safety codes. Wear safety glasses and work
gloves. Keep quenched cloths and re extinguisher nearby
when brazing. Use care in handling, rigging, and setting
bulky equipment.
WARNING! Before installation, always check to
make sure main power to systems is OFF.
Electrical shock can cause injury or death.
3. PRODUCT DESCRIPTION
Opti-Mist+®is a supplementary cooling system that
considerably increases a heat exchanger's capacity,
specially in hot ambient conditions. It can be tted to any air-
cooled condenser, uid cooler or gas cooler (CO2or other).
It uses a natural air cooling process by evaporating a small
amount of water to pre-cool air entering a heat exchanger.
A series of headers with atomizing nozzles generates a fog
of ultra-ne water droplets in the entering air of the unit. The
nozzles are installed under a horizontal coil or on the side
of V or W shape coils. This array has a free draining gravity
purging header for the colder months. A system of NO and
NC solenoid valves are provided; this ensure a free drain in
case of power failure.
The system comprises a pump, a piping network with
atomizing nozzles as well as a Guardian+ RC-A controller
(PLC controller). Opti-Mist+ is also equipped with a complete
water treatment system. The water ltration system includes
a particle lter, a demineralizer (water descaler) to avoid
limestone formation on the coil surface and to prevent
nozzles from clogging as well as a UV light to get rid of
bacteria and/or viruses.
The Guardian+ RC-A controller constantly makes
adjustments according to the job requirement, allowing the
system to use just the minimum amount of water required to
achieve the desired temperature. Each system is equipped
with a 4 or 8 USGPM hydraulic circuit.
The pumping station is not designed for outdoor
installations.
A unit-mounted interlock authorizes the system to run. A
uid temperature and an outside temperature sensors vary
the required USGPM to cool the air before entering the heat
exchanger to the preset temperature.
4. INSTALLATION
The pumping station internal piping comes pre-installed on
your unit. To nalize the installation, carry out the following
steps:
4.1 Locating and securing the pumping station
4.2 Piping
4.3 Wiring
4.1 LOCATING AND SECURING THE PUMPING STATION
Always locate the station indoors, protected from the
elements. It should be located as close as possible to the
unit (uid cooler, condenser, etc). Always consider the
pressure loss caused by the piping installation (elbows, etc)
and by the water column. If the pumping station is located
below the heat rejection unit, consider a pressure loss equal
to approximately 0.5 psi per vertical foot of tubing.
Secure the pumping station cabinet to the oor using 4 bolts,
as shown below.
Figure 1 Securing the pumping station
INSTALLATION

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4.2 PIPING
System piping must be done following industry standards
for good piping practices as well as comply with local codes.
Refer to page 18 for a typical eld piping diagram. After
piping is completed all joints and connections should be leak
tested.
Use top quality copper tubing that is internally free of dirt or
other contaminants.
Equivalent pressure drop from piping should be 15 psi or
lower.
Connect 7/8" OD inlet piping to city water or tank supply.
Connect 5/8" OD outlet piping to unit (7/8" OD for pumping
station with 8 GPM pump).
Connect both 5/8" OD drain outlets.
WATER IN (7/8” OD)
CITY WATER OR TANK
WATER OUT
(5/8” OD - 4 GPM)
(7/8” OD - 8 GPM)
DRAIN (5/8” OD)
DRAIN (5/8” OD)
Figure 2 Piping connections
All piping should have a minimum slope of 1/4"/12" away
from the heat rejection unit (fluid/gas cooler or condenser).
12”
1/4”
AWAY FROM COOLING UNIT
Figure 3 Piping slope
4.3 WIRING
IMPORTANT: Wire connections may have come loose
during transit. Check all screws for tightness prior to
starting up the unit.
The pumping station must be grounded.
All system wiring must follow applicable local and
national codes.
Internal wiring of pumping station has been completed at
the factory. Wiring connection ends on terminal blocks in the
control panel and are clearly labeled. Check the nameplate
with the current characteristics to be used for wiring.
Connect the pumping station in accordance with supplied
wiring diagrams.
Systems are available for 120V/1PH/60Hz, 230V/1PH/60Hz
and 208V/3PH/60Hz. Other voltages may be available upon
special request.
IMPORTANT: For a 230V/1PH/60Hz system, 208V/1PH/60Hz
is not acceptable and must be avoided as this could damage
the pump.
5. START-UP
Before starting the adiabatic pre-cooling system for the rst
time, or after system was shut down a long period, always
carry out the following start-up procedure:
• Check water supply
• Check air vent (proper connection)
• Check proper interlock connection
• Check uid and outside temperature sensors (proper
connection)
• Check pulsing valve for proper operation
• Check water particle lter (properly in place)
• Check pump current (consumed)
• Check water pressures (see section 6 below).
• Check unit voltage and compare to wiring diagram
• Check atomizing nozzles for leaks (properly tightened).
Also, make sure nozzles are aiming away from the coil,
at 180o, as shown in gure 4. Pipes may have shifted
during transportation.
IMPORTANT: Each adiabatic pre-cooling system comes
with a start-up report form that must be completed during
installation and sent back to RefPlus. This is to insure
proper follow-up from the manufacturer and to activate
the warranty. This form is also available at the end of this
manual or online at refplus.com, under the Service tab.
INSTALLATION START-UP

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6. WATER PRESSURE ADJUSTMENT
Inlet water pressure:
Water pressure is adjusted through a regulating valve on the
unit inlet (1). It should be adjusted so that the inlet pressure
to the pump (2) is at 40 PSI, never below 40 PSI . Avoid
adjusting above 50 PSI.
Outlet water pressure:
When pulsing valve (3) is open (nozzles spraying water),
pressure on the pump outlet (4) should be adjusted between
65 and 75 PSI. Adjust pressure through the by-pass valve
(5) from the pump outlet to the pump inlet.
When pump outlet valve (3) is closed, pressure should not be
above 85 psi. If you are not able to meet this outlet pressure
and if it is too high, lower the inlet water pressure (1) as close
as possible to 40 PSI, but never below.
Water pressure at the heat rejection unit:
Pressure at the heat rejection unit should be kept at 50 PSI
(6). When adjusting pressure, take into account pressure
loss from piping and water filter (clogged filter will reduce
pressure considerably).
WATER PRESSURE ADJUSTMENT
FLAT SLAB MODELS
“V” MODELS “W” MODELS
Figure 4 Proper nozzle orientation
1
2
5
4
3
6
TO HEAT REJECTION UNIT
WATER INLET
WATER OUTLET
Figure 5 Pressure adjustments

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7.0 MAINTENANCE
WARNING - Before cleaning up the unit, make
sure to shut off the unit to eliminate the risk of
getting shocked.
RefPlus recommends a monthly check of the spray nozzles
and the water distribution piping for damage and uniform
spray pattern.
Demineralizer, water particle lter and UV lights must also
be cleaned or replaced periodically.
A status screen on the controller display will show the
operating time of each device since the last maintenance,
as shown below. It is important to reset these counters after
each maintenance. Refer to page 29 of the Adiabatic
Controller programming manual.
TIME SINCE LAST
MAINTENANCE
Water filter: 00000hrs
UV lights:
00000hrs
Demineralizer: 00000hrs
Also, a service alarm for each device will be triggered
when its counter reaches a preset value. These values
must be adjusted according to your needs. Here are the
recommended values:
Water particle lter: 600 hours
UV lights (3M): 8000* hours
Demineralizer (WATTS): 600 hours
Demineralizer (TAC-LER): 600 hours
* UV light total life time is 9000 hours. By default, this value
is set to 8000 hours to allow the user time to order a new UV
light bulb. The counter should be reset to avoid the alarm
from triggering periodically for the next 1000 hours.
Also, reset the counter once the new bulb is installed.
Refer to page 29 of the adiabatic controller programming
manual to modify these values.
The controller will also show the total operation time of the
four main devices, including the pump, as shown below.
These counters can also be reset if desired.
Water pump: 000hs
Water filter: 000hs
UV lights:
000hs
Demineralizer: 000hs
DEVICES RUN HOURS
8. SYSTEM SETUP & ADJUSTMENTS
The adiabatic system is controlled by the Guardian+ RC-A
Controller. The basic conguration of the controller is done
at the factory according to your system selection. Refer
to the Controller's Programming Manual to complete the
conguration and adjustments, such as the temperature
settings, system selection, etc. The programming manual is
supplied with your system but the most recent version can
be downloaded at:
https://refplus.com/en/product/opti-mist-plus/
MAINTENANCE SYSTEM SETUP & ADJUSTMENTS

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TROUBLESHOOTING
9. TROUBLESHOOTING
PROBLEM POSSIBLE CAUSES POSSIBLE CORRECTIVE STEPS
Fluid outlet
temperature
on cooler (gas
pressure on
condenser) stays
high, won't come
down.
The system does not spray water
and pump is not running.
1. Check if Status on Main Status screen is ON. If not, switch the
system ON and check for alarms and continue troubleshooting.
2. Check Offsets. They should be at zero during normal operation or
can be used to simulate FT and OT to create a Cooling demand.
Refer to page 28 of the adiabatic controller programming
manual.
3. Check that cooling demand (CD) on Main Status Screen is at
least 10%. Adjusted to 10% by default, refer to page 18 of the
Adiabatic Controller programming manual.
4. On Main Status screen, check if drain valve and water treatment
system are CLOSED and ON. If not, you may need to wait for OT
to increase above Drain temp + Drain temp Band (or for tests,
insert OT Offset to simulate the condition). Refer to page 27 for
Drain Temp. and page 28 for Offets and Drain temp. Band of the
adiabatic controller programming manual.
5. Check that no critical alarm is triggered, such as FT or OT sensor
failure, Water inlet LPS alarm or Water high pressure. Identify alarm,
x condition and reset alarm by following instructions on page 32 of
the adiabatic controller programming manual. Check that the cooler
(or condenser) switches the interlock to call for the system to run.
The system sprays water and pump
is running.
1. Check coils for blockage.
2. Check if cooler/condenser fans are all running at full speed.
3. Check if there is excessive water dropping from the spraying
system. If not, increase amount of water delivered to the nozzles.
Refer to the Operation Principle/Sequence of Operation section
of the adiabatic controller programming manual to understand
your conguration and adjust the amount of water by following
instructions on page 17 to page 19. The amount of water
should be enough to make the uid/gas temperature (FT) or
pressure decrease while avoiding too much water dropping from
the cooler/condenser coil.
On the main status
screen, uid tem-
perature reading
(FT) displays an
abnormal reading,
completely out of
range
Badly programmed offset or faulty
sensor.
1. Check FT offset, return offset to zero. Refer to page 28 of the
adiabatic controller programming manual to adjust offsets.
2. Check FT sensor wires, one should be on B2 (port J2) and the other
one on Ground (port J2); no other wire should be in contact with the
wire on B2 (port J2).
3. Check sensor and wiring. Look for open wire or short. Disconnect
wires from B2 and Ground (port J2), read resistance, should be
around 10 Kohms at 25oC, 27K ohms at 0oC. If reading open,
replace sensor.
On the main status
screen, the outside
temperature reading
(OT) displays an
abnormal reading,
completely out of
range.
Badly programmed offset or faulty
sensor.
1. Check OT offset, return offset to zero. Refer to page 28 of the
adiabatic controller programming manual to adjust offsets.
2. Check OT sensor wires, one should be on B1 (port J2) and the
other one on Ground (port J2); no other wire should be in contact
with the wire on B1 (port J2).
3. Check sensor and wiring. Look for open wire or short. Disconnect
wires from B1 and Ground (port J2), read resistance, should be
around 10 Kohms at 25oC, 27K ohms at 0oC. If reading open,
replace sensor.

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TROUBLESHOOTING
PROBLEM POSSIBLE CAUSES POSSIBLE CORRECTIVE STEPS
Great amount of water is dropping
from the nozzles onto the ground.
Too much water to the
nozzles.
Reduce amount of water delivered to the nozzles. Refer to
the Operation Principle/Sequence of Operation section of the
adiabatic controller programming manual to understand your
conguration and adjust the amount of water by following
instructions on page 17 to page 19.
The amount of water should be enough to make the FT or
pressure decrease but without having too much un-atomized
water fall to the ground.
Some nozzles not spraying when
pulsing valve is open. Other nozzles
are spraying properly.
Defective nozzles. Clean or replace faulty nozzles.
Water lter cartridge alarm triggered. Water particle lter is
clogged. Replace cartridge and reset alarm.
Pump is making cavitation sound
(The pump will either produce
a “whining” sound (more mild
conditions) or a “rattling” sound (from
intense implosions) that can sound
like marbles in a can)
Not enough water pressure
at pump inlet.
1. Check for proper water ow. Water inlet to the pump
should be at least 40 PSI (when using city water).
2. Check water lter; may be clogged. Replace if needed.
3. Make sure water inlet pipe dimension is respected
according to the information supplied previously in this
manual.
4. Check for obstruction. Verify if obstructed water lter alarm
is triggered. If so, replace lter and reset alarm.
Water hammer effect on the system
(a loud “thunk” sound and piping
sudden vibration)
Water pressure not
adjusted properly, may be
too high.
Adjust water pressure following instructions on page 7 of
this manual.
The controller does not seem to
control the system.
Ex.: System should spray water but
is not, or vice versa.
Not proper voltage/wiring
1. Check voltage on output of transformers CT1. It should be
between 20.4V and 26.4V AC. 24V is recommended.
2. Check system power input and compare to wiring diagram.
Display shows pump is ON but pump
is not running or too hot.
Input voltage is too low or
too high for the pump.
Pump thermal protection
may be triggered.
Check system input voltage and compare to wiring diagram.