EVAPCO ATC-E Operating and maintenance instructions

Bulletin 116R-E Metric
REDUCED EUROPEAN
MAINTENANCE INSTRUCTIONS
For EVAPCO Induced Draft and Forced Draft
Closed Circuit Coolers and Evaporative Condensers
For EVAPCO Authorized Parts and Service,
Contact Your Local Mr. GoodTower®Service Provider
or the EVAPCO Plant Nearest You
The full version of the Maintainance Instructions 116-E, is available for download at:
www.evapco.eu
ATC-E / eco-ATC eco-ATWE LSWA(-H) / LSCE LRW(-H) / LRC ESW4 PMCE/Q PHC-E
ATW / eco-ATW
EVAPCO Products are Manufactured Worldwide
EVAPCO, Inc. (World Headquarters) P.O. Box 1300, Westminster, Maryland 21158 USA
Phone (410) 756-2600 - Fax (410) 756-6450
EVAPCO Europe bvba
Heersterveldweg 19
Industrieterrein Oost
3700 Tongeren, Belgium
Phone: (32) 12 395029
Fax: (32) 12 238527
EVAPCO Europe S.r.l.
Via Ciro Menotti 10
I-20017 Passirana di Rho
Milan, Italy
Phone: (39) 02 9399041
Fax: (39) 02 93500840
EVAPCO Europe A/S
Knøsgårdvej 115
DK-9440 Aabybro,
Denmark
Phone: (45) 9824 49 99
Fax: (45) 9824 49 90
EVAPCO Europe GmbH
Insterburger Straße, 18
D-40670 Meerbusch,
Germany
Phone: (49) 2159-6956-0
Fax: (49) 2159-6956-11
EVAPCO M. East DMCC
Reef Tower, 29th level
Cluster O,
Jumeirah Lake Towers
PO Box 5003310
Dubai, U.A.E.
Phone: (971) 56 991 6584

2
Operation and Maintenance Instructions
Introduction
Congratulations on the purchase of your EVAPCO evaporative
cooling unit. EVAPCO equipment is constructed of the highest
quality materials and designed to provide years of reliable
service when properly maintained.
It is important to establish a regular maintenance program and
be sure that the program is followed.
A clean and properly serviced unit will provide a long service
life and operate at peak efciency.
If you should require any additional information about the
operation or maintenance of this equipment, you can consult
Bulletin 116-E or contact your local EVAPCO representative.
You may also visit www.evapco.eu for more information.
Safety Precautions / Remaining Risks
Qualified personnel should use proper care, procedures and
tools when operating, maintaining or repairing this equipment
in order to prevent personal injury and/or property damage.
The warnings listed below are to be used as guidelines only.
WARNING: Evaporative cooling equipment is considered as “Partly completed machinery”. “Partly completed machinery” is
a totality which almost forms a machinery but in itself cannot fulfil any particular function. The considered cooling
equipment is missing the components to safely connect it to the source of energy and motion in a controlled way.
The considered cooling equipment is custom made but is not designed to address the specific needs and safety
measures for a specific application. Each application requires a unique designed and integrated operational,
control and safety strategy that links all components of the installation and eventually a back-up system in a safe
and controlled way.
WARNING: This equipment should never be operated without fan screens and access doors properly secured, locked and
in place.
WARNING: For assembling or disassembling the unit or unit sections, please follow the rigging instructions or the
instructions on the yellow labels on the individual unit sections.
WARNING: During maintenance operations, the worker must use adequate personal protection equipment (PPE - A
minimum, but not limited list of PPE are safety shoes, glasses, gloves, respiration protection, helmet) as
prescribed by local authorities.
WARNING: For any exceptional, non routine work to be carried out, protection and adequate safety measures should be
considered and a Last Minute Risks Assessment (LMRA) must be made by an authorized person in accordance
with safety requirements of the country.
WARNING: A lock-out / tag-out procedure, integrated with the Process Control System, must be foreseen by the
customer. A lockable disconnect switch should be located within sight of the unit for each fan motor
associated with this equipment. Before performing any type of service or inspection of the unit, make
certain that all power has been disconnected and locked in the “OFF” position.
WARNING: The top horizontal surface of any unit is not intended to be used as a working platform. No routine service
work is required from this area. For any exceptional, non routine work to be carried out on top of the
unit, use ladders, PPE and adequate safety measures against the risk of a fall, in accordance with safety
requirements of the country in question.
WARNING: The recirculating water system may contain chemicals or biological contaminants including Legionella
Pneumophila, which could be harmful if inhaled or ingested. Direct exposure to the discharge airstream
and the associated drift generated during operation of the water distribution system and/or fans,
or mists generated while cleaning components of the water system, require respiratory protection
equipment approved for such use by governmental occupational safety and health authorities.
WARNING: To avoid water and air contamination as a result of biological fouling, the cooling equipment must be
maintained in accordance, but not limited to the operating and maintenance instructions. All local
legislation related to evaporative cooling equipment must be respected.
WARNING: Accessories like platform and ladders are optional. In case these options are not taken in consideration, the
customer must design the installation to comply with local safety and access requirements and legislation.
WARNING: Sound reducing options are available. In case these options are not taken in consideration, the customer
must design the installation to comply with local sound requirements and legislation.
WARNING: Building water systems receive potable and non-potable water from either a public or private entity for their
water supply. This water supply for the building water system can contain various waterborne pathogens,
including Legionella bacteria, which can cause or contribute to various illnesses if aspirated, ingested or
inhaled. Since evaporative cooling equipment uses the same building water, there is some potential that these
pathogens might propagate in the equipment. Therefore, careful consideration should be undertaken with
respect to equipment location and the implementation of effective water management, inspection and cleaning
protocols. (See Control of Biological Contaminants in these Operation and Maintenance Instructions.)

3
Operation and Maintenance Instructions
WARNING: In order to avoid excessive pressure, proper safety valves should be foreseen in the cooling installation.
These safety measures are not delivered by Evapco and are the responsibility of the customer/contractor.
The application of these safety measures has to be evaluated for the cooling system as a whole and not
limited to the partly completed machinery.
WARNING: Atmospheric corrosion and corrosion due to the use of corrosive media at the inside/or outside of the
coils is forbidden and voids the PED certification.
WARNING: Every handling that effects the integrity of the pressure vessel (example, but not limited to, welding,
grinding, drilling, ... ) is forbidden and voids the PED certification.
Installation Precautions
WARNING: The coil connections are not designed to support piping. The water / glycol / refrigerant piping always
need to be supported (by others). See also Bulletin 131-E “Piping Evaporative Condensers”.
Storage Precautions
WARNING: Never use plastic sheets or tarps to protect a unit during storage. This practice can trap heat inside the
unit and could potentially cause damage to plastic components.
Label on the coil section(s)
WARNING: Do not operate the pressure vessel at service conditions outside of the PED nameplate located
at the coil connection. See position 1 for the location of the PED nameplate.
WARNING: Maximum working temperature of the pressure vessel as mentioned on the PED nameplate exceeds
the nominal operating temperature of the unit. Never apply pressure vessel temperatures above 65°C
or consult the factory for approval.
WARNING: Legal periodic controls of the pressure vessel need to be performed according to the legal requirements
of the country.
WARNING: To avoid damage of the spray system components, the spray water inlet pressure should never exceed
0,7 bar.
TEST bar DATE
PRESSURE
TEMPERATURE -10°C/ +120°C
WORKING
DESIGNTEMPERATURE -20°C / +140°C
FLUID
VOLUME
INDUSTRIETERREINOOST4010
EUROPEN.V.EVAPCO
DWG.
S.N.
MODEL
YEAR
0036
BELGIUM
B-3700TONGEREN
MAXWORKING PRESSURE bar
FLUIDOU T
SORTIE DU FLUIDE
FLUESSIGKEIT AUS
USCITAFLUIDO
12A
FLUIDIN
ENTREE DU FLUIDE
FLUESSIGKEIT EIN
ENTRATA FLUIDO
11A
2A (2)
2(2)
35
17A
1
12A
11A
34
1.
PED NAMEPLATE/SERVICE CONDITIONS
2. EVAPCO LOGO (both sides)
2A. RIGGING INSTRUCTIONS (both ends)
11A. FLUID IN
12A. FLUID OUT
17A. WARNING ELIMINATORS
34. WARNING PVC PIPE
35. DO NOT COVER ELIMINATORS

4
Operation and Maintenance Instructions
Initial Storage and/or Idle Period
Recommendations
If the unit will sit for idle periods of time it is recommended
that the following be performed in addition to all component
manufacturers recommended maintenance instructions.
• The fan/motor/pump bearings and motor bearings need
to be turned by hand at least once a month. This can be
accomplished by tagging and locking out the unit’s discon-
nect, grasping the fan assembly (or removing the pump
motor fan guard), and rotating it several turns.
• If unit sits longer than a few weeks, run gear reducer (if
equipped) for 5 minutes weekly.
• If unit sits longer than 3 weeks, completely fill gear reducer
with oil. Drain to normal level prior to running.
• If unit sits longer than one month, insulation test motor
windings semi-annually.
• If fan motor sits idle for at least 24 hours while the spray
pumps are energized distributing water over the coil, motor
space heaters (if equipped) should be energized. Alternatively,
fan motors may be energized for 10 minutes, twice daily, to
drive any moisture condensation out of the motor windings.
• If coil sits longer than one month, nitrogen charge the coil.
• Energize fan motors space heaters.
International Building Code Provisions
The International Building Code (IBC) is a comprehensive set
of regulations addressing the structural design and installation
requirements for building systems – including HVAC and
industrial refrigeration equipment. The code provisions
require that evaporative cooling equipment and all other
components permanently installed on a structure must meet
the same seismic design criteria as the building. All items
attached to EVAPCO Closed Circuit Coolers or Evaporative
Condensers must be independently reviewed and isolated
to meet applicable wind and seismic loads. This includes
piping, ductwork, conduit, and electrical connections. These
items must be flexibly attached to the EVAPCO unit so as not
to transmit additional loads to the equipment as a result of
seismic or wind forces.
Initial and Seasonal Start-Up Checklist
General
1. Verify that the overall installation reflects the requirements
of the installation guidelines found in EVAPCO Bulletin 311
– Equipment Layout Manual, available at www.evapco.eu.
2. For multi-speed fan motors, verify that 30 second or
greater time delays are provided for speed changes
when switching from high to low speed. Also check to
see if interlocks are provided to prevent simultaneously
energizing high and low speed, and confirm both speeds
operate in the same direction.
3. Verify all safety interlocks work properly.
4. For units operating with a variable frequency drive, make
certain that minimum speed requirements have been
set. Check with VFD manufacturer for recommended
minimum speeds and for recommendations on locking out
resonance frequencies.
5. Verify that a water treatment plan has been implemented
including passivation of galvanized steel units.
See “Water Treatment” section for more details.
6. For units subject to freezing climates, high humidity
climates, or idle periods lasting 24 hours or more,
motor space heaters are suggested and (if equipped)
should be energized. Alternatively, fan motors may be
energized for 10 minutes, twice daily, to drive any moisture
condensation out of the motor windings.
7. If the unit is going to sit idle for an extended period of
time, follow all manufacturers’ fan motor and pump
instructions for long term storage. Plastic sheets or tarps
should never be used to protect a unit during storage. This
practice can trap heat inside the unit, and could potentially
cause damage to plastic components.
See your local EVAPCO representative for additional
information on unit storage.
BEFORE BEGINNING ANY MAINTENANCE, BE CERTAIN
THAT THE POWER IS TURNED OFF AND THE UNIT IS
PROPERLY LOCKED AND TAGGED OUT!
Initial and Seasonal Start-Up
1. Clean and remove any debris, such as leaves and dirt from
the air inlets.
2. Flush the cold water basin (with the strainer screens in
place) to remove any sediment or dirt.
3. Remove the strainer screen, clean and reinstall.
4. Check mechanical float valve to see if it operates freely.
5. Inspect water distribution system nozzles and clean as
required. Check for proper orientation.
(This is not required at initial start-up. The nozzles are
clean and set at the factory).
6. Check to ensure drift eliminators are securely in place.
7. Adjust fan belt tension as required. See “Fan Belt
Adjustment” section.
8. Lubricate fan shaft bearings prior to seasonal start-up.
9. Turn the fan(s) and pump(s) by hand to insure it turns
freely without obstructions.
10. Visually inspect the fan blades. Blade clearance should be
approximately 10 mm (6 mm minimum) from tip of blade to
the fan cowl. The fan blades should be securely tightened
to the fan hub.
11. If any stagnant water remains in the system including
“dead legs” in the piping, the unit must be disinfected
prior to the fans being energized. Please refer to ASHRAE
Guideline 12 and CTI Guideline WTP-148 for more
information and consult local legislation prior to start-up.
12. Fill the cold water basin manually up to the overflow
connection.
13. For closed circuit coolers only, fill the heat exchanger coil
with the specified fluid and “burp” air from the system
before pressurizing, using vents on coil inlets. Do not do
this for evaporative condensers.
14. All new evaporative cooling equipment and associated
piping should be pre-cleaned and flushed to remove
grease, oil, dirt, debris and other suspended solids prior
to operation. Any pre-cleaning chemistry should be
compatible with the cooling equipment’s materials of
construction. Alkaline formulations should be avoided
for systems which include galvanized materials of
construction.

5
Operation and Maintenance Instructions
15. Closed hydronic systems connected to either a closed-
circuit cooler or dry cooler should be pre-cleaned and
flushed to remove debris, grease, flash rust, oil, and other
suspended solids prior to operation. Evapco recommends
the use of inhibitor chemistry or inhibited glycol to
minimize corrosion and scale during normal operation.
EVAPCO recommends a minimum of 25% inhibited glycol
to minimize corrosion.
For eco-WE & eco-W with optional controls, see controls O&M
for proper start up procedure.
After the unit has been energized, check the following:
1. Adjust mechanical float valve as required to the proper
water level.
2. Unit basin should be filled to the proper operating level.
See “Recirculating Water System Operating Levels”
section for more details.
3. Verify fan is rotating in proper direction.
4. Start the spray water pump and check for proper rotation
as indicated by the arrow on the front cover.
5. Measure voltage and current on all three power leads of
pump and fan motor. The current should not exceed the
motor nameplate full load amp rating taking the service
factor into account.
6. Adjust bleed valve to proper flow rate. Consult your
qualified water treatment company to fine tune the
minimum bleed necessary, see “Water Treatment and
Water Chemistry” section.
7. See fan and pump motor manufacturer maintenance
and long term storage instructions for more detailed
information. The motors should be lubricated and serviced
in accordance with manufacturers instructions.
Basic Closed Circuit Cooler / Condenser
Sequence of Operation for Wet or
Evaporative Mode
System Off / No Load
The system pumps and fans are off. If the basin is full of
water a minimum basin water temperature of 40ºF (4°C) must
be maintained to prevent freezing. This can be accomplished
with the use of optional basin heaters. See the “Cold Weather
Operation” section of this bulletin for more details on cold
weather operation and maintenance.
System/Condensing Temperature Rises
The recirculation pump turns on. The unit will provide
approximately 10% cooling capacity with only the pump
running. If the unit has positive closure dampers they should
be fully opened before the pumps turn on.
If the system temperature continues to rise, the unit fan is
cycled on. For a variable speed controller, the fans are turned
on to minimum speed. See the “Fan System – Capacity
Control” section of this bulletin for more details on fan speed
control options. If the system temperature continues to rise,
then the fan speed is increased as required, up to full speed.
NOTE: During sub-freezing weather the minimum
recommended speed for variable speed controllers is 50%.
ALL FANS IN OPERATING CELLS OF MULTIPLE CELL UNITS
MUST BE CONTROLLED TOGETHER TO PREVENT ICING ON
THE FANS.
System/Condensing Temperature Stabilizes
Control the leaving fluid temperature (closed circuit coolers)
or condensing temperature (evaporative condensers) by
modulating the fan speeds with variable speed drives or by
cycling fans on and off with single or two-speed drives.
System/Condensing Temperature Drops
Decrease the fan speed, as required.
System Off / No Load
The system pump turns off. The starter interlock will energize
any optional basin heaters in cold weather.
The recirculation pump should not be used as a means
of capacity control, and should not be cycled frequently.
Excessive cycling can lead to scale build-up, and reduce wet
and dry performance.
Dry Operation
During colder winter months it is possible to turn off the spray
pump, drain the cold water basin, and just cycle the fans. Be
sure to leave the basin drain open during this time to prevent
collection of rain water, snow, etc. If the unit has positive
closure dampers they should be fully opened before the fans
turn on. If dry operation will be used on a centrifugal fan,
forced draft unit, be sure to verify that the motor and drives
have been properly sized to handle the reduction in static
pressure experienced when the spray water is turned off.
NOTE: Minimum control point for process fluid should never
be lower than 42º F (6°C).
NOTE: When a unit is provided with a discharge damper
assembly, the control sequence should cycle the dampers
open and closed once a day regardless of capacity
requirements to prevent the assembly from seizing. The fan
motor should be shut off whenever the dampers are closed.
NOTE: ESW4 or PHC-E product lines should not operate dry.
NOTE: The eco-ATW/eco-ATWE sequence of operation is
unique and is explained in detail in the Sage2, Sage3 Panel
Control Manual

6
Operation and Maintenance Instructions
Fan System
The fan systems of both centrifugal and axial driven units
are rugged; however, the fan system must be checked
regularly and lubricated at the proper intervals. The following
maintenance schedule is recommended.
Fan Motor Bearings
EVAPCO evaporative cooling units use either a totally
enclosed air over (TEAO) or a totally enclosed fan cooled
(TEFC) fan motor. These motors are built to “Cooling Tower
Duty” specifications. They are supplied with permanently
lubricated bearings and special moisture protection on the
bearings, shaft and windings. After extended shut-downs, the
motor should be checked with an insulation tester prior to be
restarted.
Fan Shaft Ball Bearings
For induced draft units, lubricate the fan shaft bearings every
1,000 hours of operation or every three months for induced
draft units. Lubricate the fan shaft bearings every 2,000 hours
of operation or every six months for forced draft units. Use any
of the following synthetic waterproof, inhibited greases which
are suitable for operation between -29°C and 177°C. (For
colder operating temperatures, contact the factory).
- Mobil - Polyrex EM - Timken Pillowblock Grease
- Chevron - SRI
Feed grease slowly into the bearings or the seals may be
damaged. A hand grease gun is recommended for this
process. When introducing new grease, all grease should
be purged from the bearings.
Most EVAPCO units are supplied with extended grease lines
to allow easy lubrication of the fan shaft bearings as shown in
Table 1.
Fan Shaft Sleeve Bearings
(1,2 m LS units only)
Lubricate the intermediate sleeve bearing(s) before unit start
up. The reservoir should be checked several times during
the first week to ensure that the oil reserve is brought to
full capacity. After the first week of operation, lubricate the
bearing(s) every 1.000 hours of operation or every three
months (whichever occurs first).
Use one of the following industrial grade, non-detergent mineral
oils. Do not use a detergent based oil or oils designated
heavy duty or compounded. Different oils may be required
when operating at temperatures below 0°C continuously.
Table 1 provides a short list of approved lubricants for each
temperature range.
Ambient Temp Texaco Mobil Exxon Total
-32°C to 0°C - DTE Heavy - -
-17°C to 43°C - - - -
0 to 38°C Regal R&O 220 DTE Oil BB Teresstic 220 -
All bearings used on EVAPCO equipment are factory adjusted
and self aligning. Do not disturb bearing alignment by
tightening the sleeve bearing caps.
Fan Belt Adjustment (Direct drive units do not re-
quire any adjustment)
The fan belt tension should be checked at start up and again
after the first 24 hours of operation to correct for any initial
stretch. To properly adjust the belt tension, position the fan
motor so that the fan belt will deflect approximately 10 mm
when moderate pressure is applied midway between the
sheaves. Belt tension should be checked on a monthly basis.
A properly tensioned belt will not “chirp” or “squeal” when the
fan motor is started.
Gear Drives
Induced draft units with gear drive systems require special
maintenance. Please refer to the gear manufacturers
recommended maintenance instructions. These will be
enclosed and shipped with the unit.
Air Inlet
Inspect the air inlet louvers (induced draft units) or fan screens
(forced draft units) monthly to remove any paper, leaves or
other debris that may be blocking airflow into the unit.
Coil Inlet
Inspect the top coil, air inlet and spray section on all PHC-E
units monthly.
Fan System - Capacity Control
There are several methods for capacity control of the
evaporative cooling unit. Methods include: Fan motor
cycling, the use of two speed motors, and the use of variable
frequency drives (VFD’s).
Note: for the eco-ATW with Sage2and eco-ATWE with Sage3
consult the manual.
1. Fan Motor Cycling
Fan Motor Cycling requires the use of a single stage
thermostat which senses the fluid temperature (closed
circuit coolers) or condensing temperature (evaporative
condensers). The contacts of the thermostat are wired in
series with the fan motor’s starter holding coil.
For individual fan motor cyclings interlock fan motors
before fan start to prevent issues with reversing idle fans.
In this method, there are only two stable levels of
performance: 100% of capacity when the fan is on, and
approximately 10% of capacity when the fan is off.
Please note that rapid cycling of the fan motors can cause
the fan motor to overheat.
Controls should be set to only allow a maximum of six
start/stop cycles per hour.
IMPORTANT:
THE RECIRCULATION PUMP MAY NOT BE USED AS A
MEANS OF CAPACTY CONTROL AND SHOULD NOT BE
CYCLED MORE THEN SIX START/STOP CYCLES PER HOUR.
EXCESSIVE CYCLING CAN LEAD TO SCALE BUILD-UP,
RESULTING IN REDUCED WET AND DRY PERFORMANCE.
Table 1 – Sleeve Bearing Lubricants

7
Operation and Maintenance Instructions
2. Two Speed Motors
The use of a two-speed motor provides an additional step
of capacity control when used with the fan cycling method.
The low speed of the motor will provide approximately
60% of full speed capacity.
Two-speed capacity control systems require not only a two-
speed motor, but also a two-stage thermostat and the proper
two-speed motor starter.
It is important to note that when two-speed motors are to
be used, the motor starter controls must be equipped with
a decelerating time delay relay. The time delay should be a
minimum of a 30 second delay when switching from high
speed to low speed.
3. Variable Frequency Drives
The use of a variable frequency drive (VFD) provides the
most precise method of capacity control. A VFD is a
device that converts a fixed AC voltage and frequency into
an adjustable AC voltage and frequency used to control
the speed of an AC motor. By adjusting the voltage and
frequency, the AC induction motor can operate at many
different speeds.
VFD technology has particular benefit on evaporative
cooling units operating in cold climates where airflow can
be modulated to minimize icing and reversed at low speed
for de-icing cycles. Applications using a VFD for capacity
control must also use an inverter capable motor built in
compliance with NEMA standard MG-1.
The VFDs need to have a pre-set shutoff to prevent water
temperatures from becoming too cold and to prevent
the drive from trying to turn the fan at near zero speed.
Operating below 25% of motor speed achieves very little
return in fan energy savings and capacity control. Check
with your VFD supplier if operating below 25% is possible.
NOTE:Pump Motors: VFD’s should not be used on pump
motors. The pumps are designed to be operated at full
speed and are not intended to be used as capacity control.
The type of motor, manufacturer of the VFD, motor lead
lengths (between the motor and the VFD), conduit runs and
grounding can dramatically affect the response and life of
the motor. Select a high quality VFD that is compatible with
the fan motor(s) in the EVAPCO unit(s). Many variables in
the VFD configuration and installation can affect motor and
VFD performance. Two particularly important parameters
to consider when choosing and installing a VFD are
switching frequency and the distance between the motor
and VFD often referred to as lead length. Consult the VFD
manufacturer’s recommendations for proper installation
and configuration. The motor lead length restrictions
can vary with the vendor. Regardless of motor supplier,
minimizing lead length between the motor and drive is
good practice.
VFD Lockout Notification
Sequence of Operations / Guidelines for Multi-fan Units with a
VFD during Peak Load
For eco-ATWE, see Sage2/Sage3control Panel O&M:
1. Both fan motors off – Pump running on one cell.
2. Both fan motors off – Pump running on both cells.
3. Both VFDs turn on at the manufacturer’s recommended
minimum operating speed (25%) – Pump running on both
cells.
4. Both VFDs speed up uniformly (they should be
synchronized on start-up) – Pump running on both cells.
5. Both VFDs are on full speed – Pump running on both cells.
NOTE:The VFDs need to have a preset shutoff to prevent
water temperatures from becoming too cold and to prevent
the drive from trying to turn the fan at near zero speed.
Operating below 25% of motor speed achieves very little
return in fan energy savings and capacity control. Check with
your VFD supplier if operating below 25% is possible.

8
Operation and Maintenance Instructions
Variable Frequency Drive Lock-out Notification
WARNING: Qualified personnel should use proper care,
procedures and tools when maintaining
the Fan/Drive System in order to prevent
personal injury and/or property damage.
WARNING: Identify and Lock-out Harmful Resonant
Frequencies
A Variable Frequency Drive (VFD) fan system, unlike traditional
xed-speed systems, is designed to operate between 25%
(15Hz) and 100% (60Hz) speeds, which creates an opportunity
for operation where resonant frequencies exist. Sustained op-
eration at resonant frequencies may lead to excessive vibration,
fatigue of structural components and/or drive system noise and
failure. Owners and operators must anticipate the existence of
resonant frequencies and lock out frequencies during start-up
and commissioning in order to prevent drive system operational
problems and structural damage. As a part of the normal start-
up and commission processes, resonant frequencies should be
identied and locked-out in the VFD’s software.
The unit’s supporting structure, external piping, and accesso-
ries contribute to the overall harmonic make-up and stiffness
of the system. The choice of VFD will also have a signicant
influence on how the system behaves. Consequently, not all
resonant frequencies can be determined in advance at the
manufacturer’s factory during nal inspection and testing. Rel-
evant resonant frequencies (if they occur) can only be identi-
ed accurately after the installation in the system.
To check for resonant frequencies in the eld, a run-up and
run-down test must be performed. Additionally, VFD carrier
frequencies should be adjusted to best align the VFD with the
electrical system. Refer to your drive’s start-up procedures for
additional information and instruction.
The procedure of checking for resonant frequencies requires
stepping through the VFD’s operating range at (2) Hz intervals
from the lowest operating frequency to full speed. At each step,
pause long enough for the fan to reach steady-state. Note
changes in unit vibration during this time. Repeat from full speed
to minimum speed. Should vibration-inducing frequencies exist,
the run-up and run-down test will isolate the resonant frequencies
which then must then be locked-out in the VFD programming.
Two-Speed Motors
The use of a two-speed motor provides an additional step of
capacity control when used with the fan cycling method. The
low speed of the motor will provide approximately 60% of full
speed capacity.
Two-speed capacity control systems require not only a two-
speed motor, but also a two-stage thermostat and the proper
two-speed motor starter. The most common two-speed motor
is a single winding type. This is also known as a consequent
pole design. Two-speed two-winding motors are also
available. All multi-speed motors used in evaporative cooling
units should be variable torque design.
NOTE: When two-speed motors are to be used, the motor
starter controls must be equipped with a decelerating time
delay relay. The time delay should be a minimum of 30
seconds when switching from high speed to low speed.
Sequence of Operations / Guidelines for Multi-fan Units
with a VFD during Peak Load
For eco-ATWE, see Sage2/Sage3control Panel O&M:
1. Both fan motors off – Pump running on one cell.
2. Both fan motors off – Pump running on both cells.
3. One fan motor on low speed, one fan motor off – Pump
running on both cells.
4. Both fan motors on low speed – Pump running on both
cells.
5. One fan motor on high speed, one fan motor on low speed
– Pump running on both cells.
6. Both fan motors on full speed – Pump running on both
cells.
Recirculated Water System -
Routine Maintenance
Suction Strainer in Cold Water Basin
The pan strainer should be removed and cleaned monthly
or as often as necessary. Make certain that the strainer is
properly located over the pump suction, alongside the anti-
vortexing hood.
Cold Water Basin
The cold water basin should be flushed out quarterly, and
checked monthly or more often if necessary, to remove any
accumulation of dirt or sediment which normally collects
in the basin. Sediment can become corrosive and cause
deterioration of basin materials. When flushing the basin, it is
important to keep the suction strainers in place to prevent any
sediment from entering the system. After the basin has been
cleaned, the strainers should be removed and cleaned before
refilling the basin with fresh water.

9
Operation and Maintenance Instructions
Operating Level of Water in Cold Water Basin
The operating level should be checked monthly to make sure the water level is correct. Refer to Table 2 for unit specific levels.
Evaporative Condenser
Model Number Closed Circuit Cooler Footprint Operating Water Level*
(inch)
Operating Water Level*
(mm)
ATC-E Products
50E to 165E,
170E to 3714E
ATWB, eco-ATW & eco-ATWE Products
3’ and 4’ wide units**
8.5’ wide to “7’ wide thru 24’ wide”
9”
11”
229
279
ATC-DC
8.5’ Wide to 24’ Wide 11” 279
eco-ATC Products
122A to 3846A
eco-ATWB-E
8.5’ wide thru 24’ wide 11” 279
LRC Products
25 to 379
LRWB Products
3’ wide thru 8’ wide units 8” 203
LSC-E Products
36 to 170
185 to 385
400 to 515, 800 to 1030
550 to 805, 1100 to 1610
PMC-E, eco-PMC
175E to 375E, 183 to 387
332E to 2019E, 275 to 2191
LSW Products
4’x6’ thru 4’x12’
5.5’x12’, 5.5’x18’
8’x12’, 8’x24’, 10’x12’, 10’x24’
8’x18’, 8’x36’, 10’x18’, 10’x36’
11”
11”
12”
15”
10”
14”
279
279
305
381
254
356
—
ESW4 Products
8.5’ and 14’ wide units
12’ wide unit
9”
10”
229
254
PHC-E Products
S-79 to S-1236
D-1224 to D-2826
9”
10”
229
254
Table 2 - Recommended Operating Water Level
* Measured from lowest point on basin floor.
** Not available on eco-ATWE.
At initial start up or after the unit has been drained, the unit must
be filled to the overflow level. Overflow level is above the normal
operating level and accommodates the volume of water normally
in suspension in the water distribution system and the riser piping.
The water level should always be above the strainer. Check by
running the pump with the fan motors off and observing the water
level through the access door or remove the air inlet louver.
Water Make Up Valve
A mechanical float valve assembly is provided as standard
equipment on the evaporative cooling unit (unless the unit has
been ordered with an optional electronic water level control
package or the unit is arranged for remote sump operation).
The make up valve is easily accessible from outside the unit
through the access door or removable air inlet louver. The
make up valve is a bronze valve connected to a float arm
assembly and is activated by a large foam filled plastic float.
The float is mounted on an all-thread rod held in place by wing
nuts. The water level in the basin is adjusted by repositioning
the float and all-thread using the wing nuts. The bottom center
of the float should be set at 1” (25mm) below the middle of the
overflow. At its highest point, float arm should be parallel to
the water level.
The make up valve assembly should be inspected monthly
and adjusted as required. The valve should be inspected
annually for leakage and if necessary, the valve seat should
be replaced. The make up water pressure for the mechanical
valve should be maintained between 140 and 340 kPa.
Drift Eliminators
Check the drift eliminators quarterly to make sure the drift
eliminators are still in the correct position and not clogged
by any debris. If required after inspection, drift eliminators
must be removed, cleaned and reinstalled correctly.On forced
draft models, the worker must use personal precautions
and adequate safety measures against the risk of a fall,
in accordance with local regulations. Remove one or two
eliminator sections from the top of the unit, protect the fill by
use of a hard board before entering the unit and walking on
the fill. Never walk on the eliminators! Once standing on the
fill, the remaining drift eliminators can be removed. On induced
draft models, lifting handles are provided along the top
layer of eliminators. Remove one or two eliminator sections,
protect the fill by use of a hard board before entering the unit
and walking on the fill. Never walk on the eliminators! Once
standing on the fill, the remaining drift eliminators can be
easily removed through the access door.
Pressurized Water Distribution Systems
Check the water distribution system monthly to make sure it
is operating properly. Always check the spray system with the
pump on and the fans off (locked and tagged out).
On forced draft models, remove one or two eliminator sections
from the top of the unit and observe the operation of the water
distribution system.
On induced draft models, lifting handles are provided along
the top layer of eliminators. Eliminators can be easily removed

10
Operation and Maintenance Instructions
from the access door and the distribution system observed.
The diffusers are essentially non-clogging and should seldom
need cleaning or maintenance.
If the water diffusers are not functioning properly, it is a sign
that the pan or system strainer has not been working properly
and that foreign matter or dirt has accumulated in the water
distribution pipes. The nozzles can be cleared by taking a
small pointed probed and moving it rapidly back and forth in
the diffuser opening, with the pump(s) running and the cooling
load and fan(s) off.
If an extreme build-up of dirt or foreign matter occurs, remove
the end cap in each branch to flush the debris from the header
pipe. The branches or header can be removed for cleaning,
but do so only if necessary. Check the strainer in the pan to
make sure it is in good condition and positioned properly so
that cavitation or air entrainment does not occur.
All Evaporative Condensers and Closed Circuit Coolers, except
the ESW4 Closed Circuit Cooler, are supplied with ZM II®spray
nozzles as standard. The ZM II®spray nozzles do not need to
be oriented a specific way to achieve proper coil coverage.
Figure 1 shows the proper spacing of the ZM II® spray nozzles.
For the ESW4, wide orifice water diffusers are supplied. When
inspecting and cleaning the water distribution system, always
check that the orientation of the water diffusers is correct as
shown in Figure 2.
Bleed-Off Valve
The bleed-off valve, whether factory or field installed, must be
checked weekly to make sure it is functioning and set properly.
Keep the bleed-off valve wide open unless it has been
determined that it can be set partially open without causing
scaling or corrosion. Additional information can be found
under “Water Treatment and Water Chemistry”.
Pump (When Supplied)
The pump and pump motor should be lubricated and serviced
in accordance with the pump manufacturer’s instructions.
The recirculation pump should not be used as a means
of capacity control, and should not be cycled frequently.
Excessive cycling can lead to scale build-up, and reduce
wet and dry performance. On 18’ long ESW4’s supplied with
two pumps per cell, both pumps should be energized at
the same time. One pump should not be on while the other
pump is off. The pump motor shaft and impeller should be
turned by hand if the pump assembly sits idle (for a month or
more). Disconnect the power and lockout/tagout the pump
disconnect. Remove the pump motor fan guard and rotate the
pump fan/shaft several turns by hand. Reassemble the fan
guard and return to service.
Note: for the eco-ATW(E), please consult the Sage2and Sage3
manual.
Coils
Contact Evapco in case of damage to the pressure vessel.
Do not affect the integrity of the pressure vessel without
approval of Evapco.
Evaporative Coil(s)
Check coil surface periodically, but at least twice a year. Inspect
the coil surface for scale and/or corrosion.
Dry Coils (optional)
Depending on outdoor conditions and unit type, the dry coil
should be inspected and cleaned at least twice a year. If the
unit is located near trees, construction, etc., the required
cleaning may be more frequent. The coil should be visually
inspected monthly along with inlet louvers and inlet screens.
The best cleaning solution for the dry coil is plain water. If the
coil has maintained and cleaned at regular intervals, water is
sufficient to remove dirt and debris from the fins. Heavy build
up on the exterior of the fins can be removed with a brush. If a
pressure washer is used, make sure the equipment is set to a
low pressure setting and that the nozzle is set to the fan spray,
not stream, otherwise damage to the fins could result.
Figure 1 - ZM II®Spray Nozzle Orientation.
All Coil Products except the ESW4
Figure 2 - Proper Water Diffuser Orientation
(2A Nozzles) ESW4 Models

11
Operation and Maintenance Instructions
Water Treatment and Water Chemistry
Proper water treatment is an essential part of the maintenance
required for evaporative cooling equipment. A well designed
and consistently implemented water treatment program will
help to ensure efficient system operation while maximizing the
equipment’s service life. A qualified water treatment company
should design a site specific water treatment protocol based
on equipment (including all metallurgies in the cooling system),
location, makeup water quality, and usage.
Bleed or Blowdown
Evaporative cooling equipment rejects heat by evaporating a
portion of the recirculated water into the atmosphere as warm,
saturated discharge air. As the pure water evaporates it leaves
behind the impurities found in the system’s makeup water and
any accumulated airborne contaminants. These impurities
and contaminants, which continue to recirculate in the system,
must be controlled to avoid excessive concentration which
can lead to corrosion, scale, or biological fouling.
Evaporative cooling equipment requires a bleed or blowdown
line, located on the discharge side of the recirculating pump,
to remove concentrated (cycled up) water from the system.
EVAPCO recommends an automated conductivity controller
to maximize the water efficiency of your system. Based on
recommendations from the water treatment company, the
conductivity controller should open and close a motorized
ball or solenoid valve to maintain the conductivity of the
recirculating water. If a manual valve is used to control the
bleed rate, it should be set to maintain the conductivity of the
recirculating water during periods of peak load at the maximum
level recommended by the water treatment company.
Galvanized Steel – Passivation
‘White Rust’ is a premature failure of the protective zinc layer
on hot dip or mill galvanized steel which can occur as a result
of improper water treatment control during the start-up of
new galvanized equipment. The initial commissioning and
passivation period is a critical time for maximizing the service
life of galvanized equipment. EVAPCO recommends that the
site specific water treatment protocol includes a passivation
procedure which details water chemistry, any necessary
chemical addition, and visual inspections during the first six
(6) to twelve (12) weeks of operation. During this passivation
period, recirculating water pH should be maintained above
7.0 and below 8.0 at all times. Since elevated temperatures
have a harmful effect on the passivation process, the new
galvanized equipment should be run without load for as much
of the passivation period as is practical.
The following water chemistry promotes the formation of white
rust and should be avoided during the passivation period:
1. pH values in the recirculating water greater than 8.3.
2. Calcium hardness (as CaCO3) less than 50 ppm in the
recirculating water.
3. Anions of chlorides or sulfates greater than 250 ppm
in the recirculating water.
4. Alkalinity greater than 300 ppm in the recirculating
water regardless of pH value.
Changes in water chemistry control may be considered after
the passivation process is complete as evidenced by the
galvanized surfaces taking on a dull gray color. Any changes
to the treatment program or control limits should be made
slowly, in stages while documenting the impact of the changes
on the passivated zinc surfaces.
• Operating galvanized evaporative cooling equipment
with a water pH below 6.0 for any period may cause
removal of the protective zinc coating.
• Operating galvanized evaporative cooling equipment
with a water pH above 9.0 for any period may destabilize
the passivated surface and create white rust.
• Re-passivation may be required at any time in the
service life of the equipment if an upset condition occurs
which destabilizes the passivated zinc surface.
Water Chemistry Parameters
The water treatment program designed for evaporative cooling
equipment must be compatible with the unit’s materials of
construction, as well as other equipment and piping used
in the system. Control of corrosion and scale will be very
difficult if the recirculating water chemistry is not consistently
maintained within the ranges noted in Table 3.
Property Z-725 Type 304 Type 316
Galvanized Steel Stainless Steel Stainless Steel
pH 7.0 – 8.8 6.0 – 9.5 6.0 – 9.5
pH During Passivation 7.0 – 8.0 N/A N/A
Total Suspended Solids (ppm)* <25 <25 <25
Conductivity (Micro-Siemens/cm) ** <2,400 <4,000 <5,000
Alkalinity as CaCO3(ppm) 75 - 400 <600 <600
Calcium Hardness CaCO3(ppm) 50 - 500 <600 <600
Chlorides as Cl-(ppm) *** <300 <500 <2,000
Silica (ppm) <150 <150 <150
Total Bacteria (cfu/ml) <10,000 <10,000 <10,000
* Based on standard EVAPAK®fill
** Based on clean metal surfaces. Accumulations of dirt, deposits, or sludge will increase corrosion potential
*** Based on maximum coil fluid temperatures below 49°C
Table 3 - Recommended Water Chemistry Guidelines

12
Operation and Maintenance Instructions
If a chemical water treatment program is used, all chemicals
selected must be compatible with the unit’s materials of
construction as well as other equipment and piping used
in the system. Chemicals should be fed through automatic
feed equipment to a point which ensures proper control and
mixing prior to reaching the evaporative cooling equipment.
Chemicals should never be batch fed directly into the basin of
the evaporative cooling equipment.
Evapco does not recommend the routine use of acid due to
the destructive consequences of improper feeding; however,
if acid is used as part of the site specific treatment protocol,
it should be pre-diluted prior to introduction into the cooling
water and fed by automated equipment to an area of the
system which ensures adequate mixing. The location of the
pH probe and acid feed line should be designed in conjunction
with the automated feedback control to ensure that proper
pH levels are consistently maintained throughout the cooling
system. The automated system should be capable of storing
and reporting operational data including pH reading and
chemical feed pump activity. Automated pH control systems
require frequent calibration to ensure proper operation and to
protect the unit from increased corrosion potential.
The use of acids for cleaning should also be avoided. If acid
cleaning is required, extreme caution must be exercised and
only inhibited acids recommended for use with the unit’s
materials of construction should be used. Any cleaning
protocol, which includes the use of an acid, shall include a
written procedure for neutralizing and flushing the evaporative
cooling system at the completion of the cleaning.
Flume/equalizer DO NOT ensure proper controlled mixing of
water in multiple cells. Operate multiple cells individually.
Control of Biological Contamination
Evaporative cooling equipment should be inspected regularly
to ensure good microbiological control. Inspections should
include both monitoring of microbial populations via culturing
techniques and visual inspections for evidence of biofouling.
Poor microbiological control can result in loss of heat transfer
efficiency, increase corrosion potential, and increase the
risk of pathogens such as those that cause Legionnaires’
disease. The site specific water treatment protocol should
include procedures for routine operation, startup after a shut-
down period, and system lay-up, if applicable. If excessive
microbiological contamination is detected, a more aggressive
mechanical cleaning and/or water treatment program should
be undertaken.
It is important that all internal surfaces, particularly the basin,
be kept clean of accumulated dirt and sludge. Additionally,
drift eliminators should be inspected and maintained in good
operating condition.
Gray Water and Reclaimed Water
The use of water reclaimed from another process as a
source of makeup water for evaporative cooling equipment
can be considered as long as the resultant recirculating
water chemistry conforms to the parameters noted in
Table 3. It should be noted that using water reclaimed from
other processes may increase the potential of corrosion,
microbiological fouling, or scale formation. Gray water or
reclaimed water should be avoided unless all of the associated
risks are understood and documented as part of the site
specific treatment plan.
Air Contamination
Evaporative cooling equipment draws in air as part of normal
operation and can scrub particulates out of the air. Do not
locate the unit next to smokestacks, discharge ducts, vents,
flue gas exhausts, etc. because the unit will draw in these
fumes which may lead to accelerated corrosion or deposition
potential within the unit. Additionally, it is important to locate
the unit away from the building’s fresh air intakes to prevent
any drift, biological activity, or other unit discharge from
entering the building’s air system.
Cold Weather Operation & Ice Management
EVAPCO counterflow evaporative cooling equipment is well
suited to operate in cold weather conditions. The counterflow
design encases the heat transfer media (fill and/or coils)
completely, and protects it from the outside elements such as
wind which can cause freezing in the unit.
When the evaporative cooling unit is going to be used during
cold weather conditions, several items need to be considered
including unit layout, recirculating water, unit recirculating
piping, unit heat transfer coils, unit accessories and capacity
control of the units.
More information can be found in Bulletin 116-E, pages 21-26.
Freeze Protection of Recirculating Water
The simplest and most effective way of keeping the
recirculated water from freezing is to use a remote sump.
With a remote sump, the recirculating water pump is
mounted remotely at the sump and whenever the pump
is shut off, all recirculating water drains back to the sump.
Recommendations for sizing the remote sump tank and
recirculating water pumps for coil products are presented
for Evaporative Condensers and Closed Circuit Coolers in
their respective catalog. The pressure drop through the water
distribution system measured at the water inlet is as follows in
Table 4 (See next page).
If a remote sump cannot be used, basin heaters are available
to keep the recirculating water from freezing when the pump
is turned off. Electric heaters may be used to heat the basin
water when the unit is shut down. The make-up water supply,
overflow and drain lines, as well as the pump and pump piping
up to the overflow level must be heat traced and insulated
to protect them from damage. Any other connections or
accessories at or below the water level, such as electronic
water level controllers, must also be heat traced and insulated.
Note: Using basin heaters will not prevent the fluid in the
coils, nor the residual water in the pump or pump piping
from freezing.
A condenser or cooler cannot be operated dry (fans on, pump
off) unless the water is completely drained from the pan. The
pan heaters are sized to prevent pan water from freezing only
when the unit is completely shut down.

13
Operation and Maintenance Instructions
Table 4 - Required Recirculating Water Pump Sizing for Remote Sump Application - Coil Products Only
For multi-cell units, the inlet pressure shown is per cell.
** Not available as eco-ATWE
Evaporative Condenser
Model Number
Closed Circuit Cooler
Footprint
Required
Inlet Pres-
sure (psi)
Required
Inlet Pres-
sure (kPa)
ATC-E Products
50E to 165E
170E to 247E
218E to 305E
246E to 473E
486E to 630E
508E to 755E
643E to 950E
639E to 926E
XE298E to XC462E, XE596E to XC925E
XE406E to XC669E, XE812E to XC1340E
428E to 892E
858E to 1784E
857E to 1783E
1879E to 3459E
791E to 967E, 1625E to 1925E
1616E to 1915E, 2855E to 3714E
eco-ATC-A Products
122A to 263A
160A to 326A
205A to 504A
395A to 671A
451A to 804A
444A to 1013A
441A to 988A
300-501A to 642-1002A
391-694A to 879-1388A
325 to 632A, 408 to 685A, 432 to 923A
650 to 1263A, 770 to 1369A, 1020 to 1847A
710 to 1264A, 816 to 1370A, 1021 to 1848A
1293 to 2515A, 1493 to 2654A, 2182 to 3583A
585 to 1001A, 1120 to 1993A
1159 to 1983A, 2247 to 3846A
ATWB, eco-ATW &
eco-ATWE Products
3’ and 4’ wide units**
8.5’x7.5’
8.5’x9’
8.5’x10.5’, 8.5’x12’, 8.5’x14’
8.5’x18’
8.5’x21’
8.5’x24’, 28’
17’x12’, 17’x14’
10’x12’, 10’x24’, 20’x12’
10’x18’, 10’x36’, 20’x18’
12’x12’, 12’x14’, 12’x18’
12’x24’ 12x28’, 12’x36’
24’x12, 24’x14’, 24’x18’
24’x24’, 24’x28’, 24’x36’
12’x20’, 12’x40’
24’x20’, 24’x40’
2.0
2.0
2.0
2.0
3.0
4.0
2.5
2.5
3.7
5.7
3.5
2.5
3.0
2.5
3.5
3.5
13.8
13.8
13.8
13.8
20.7
27.6
17.2
17.2
25.5
39.3
24.1
17.2
20.7
17.2
24.1
24.1
CATC Products
181 thru 373
362 thru 504
CATW Products
7.5’x8’, 7.5’x12’, 7.5’x14’
7.5’x18’
2.0
3.0
13.8
20.7
LRC Products
25 to 72
76 to 114
108 to 183
190 to 246
188 to 379
LRWB Products
3’ wide units
5’x6’
5’x9’
5’x12’
8’ wide units
1.0
2.0
2.0
2.0
2.0
6.9
13.8
13.8
13.8
13.8
LSC-E Products
36 to 80
90 to 120
135 to 170
185 to 385
400 to 1610
LSWE Products
4’x6’
4’x9’
4’x12’, 4’x18’
5.5’x12’, 5.5’x18’
10’x12’, 10’x18’, 10’x24’, 10’x36’
8’x12’, 8’x18’, 8’x24’, 8’x36’
1.5
1.5
1.5
2.0
2.5
3.0
10.3
10.3
10.3
13.8
17.2
20.7
–
ESW4 Products
8.5’x6’
8.5’x9’
8.5’x12’
8.5’x18’
12’x12’
12’x18’
14’x22’
3.0
2.5
2.5
3.0
2.0
3.0
2.0
20.7
17.2
17.2
20.7
13.8
20.7
13.7
PMC-E Products
175E to 375E
332E to 1586E
420E to 2019E
eco-PMC Products
183 to 387
275 to 1662
314 to 2191
–
2.0
4.0
3.5
13.7
27.6
24.1
PHC-E Products
S79-107E to 161E
S712-151E to 210E
S718-224E to 335E
S1212-282E to 422E, S1224-565E to 844E
S1218-414E to 616E, S1218-438E-2P to 652E-2P, S1236-828E to1232E
D1224-718E to 879E, D2424-1436E to 1758E
D1426-828E to 1060E, D2826-1656E to 2120E
–
3.5
4.0
3.5
3.0
4.0
5.0
4.5
24
27.6
24
20.7
27.6
34.5
31

14
Operation and Maintenance Instructions
Freeze Protection of Closed Circuit Cooler Coils
The simplest and most effective way of protecting the heat
exchanger coil from freezing is to use an inhibited ethylene
or propylene glycol anti-freeze. If this is not possible, an
auxiliary heat load and minimum flow rate must be maintained
on the coil at all times so that the water temperature does not
drop below 10°C when the cooler is shut down. See Table 5
for recommended minimum flow rates.
If an anti-freeze solution is not used, the coil must be drained
immediately whenever the pumps are shut down or flow stops.
This is accomplished by having automatic drain valves and air
vents in the piping to and from the cooler. Care must be taken
to ensure that the piping is adequately insulated and sized
to allow the water to flow quickly from the coil. This method
of protection should be used only in emergency situations
and is neither a practical nor recommended method of freeze
protection. Coils should not be drained for an extended
period of time, as internal corrosion may occur.
When the unit is in operation during freezing weather, some
type of capacity control is normally required in order to keep
water temperatures from dropping below 10°C. Operating
dry with a remote sump is an excellent way of reducing unit
capacity at low temperatures. Other methods of capacity
control include two-speed motors, VFDs and fan cycling.
These can be used individually or in combination with dry/
remote sump operation.
Table 5 - Closed Circuit Cooler Minimum Recommended Flow Rate
** Not available as eco-ATWE
Closed Circuit Cooler
Footprint
Minimum Flows
Standard
Flow
GPM
Series Flow
GPM
Standard
Flow
l/s
Series Flow
l/s
ATWB Products, eco-ATW & eco-ATWE
3’x3’**
4’ wide units**
7’ wide units
8.5’x7.5’
8.5’x9’ to 8.5’x21’
17’x12’, 17’x14
10’x12’, 10’x18’
10’x24, 10’x36’, 20’x12’, 20’x18’
20’x24’, 20’x36’
12’x12’, 12’x14’, 12’x18’, 12’x20’
12’x24’, 12’x28’, 12’x36’, 12’x40’
24’x12’, 24’x14’, 24’x18’, 24’x20’
24’x24’, 24’x28’, 24’x36, 24’x40’
—
74
140
148
160
320
188
376
752
232
464
464
928
26
37
70
74
80
160
94
188
376
116
232
232
464
—
4.7
8.8
9.3
10
20
11.9
23.7
47.4
14.6
29.3
11
58.5
1.6
2.3
4.4
4.7
5
10
5.9
11.9
23.7
7.3
14.6
11
29.3
LRWB Products
3’ wide units
5’ wide units
8’ wide units
60
94
148
30
47
74
3.8
5.9
9.3
1.9
3
4.7
LSWE Products
4’x6’, 4’x9’, 4’x12’, 4’x18’
5.5’x12’, 5.5’x18’
8’x12’, 8’x18’
8’x24’, 8’x36’
10’x12’, 10’x18’
10’x24, 10’x36’
66
94
148
296
188
376
30
47
74
148
94
188
66
94
148
296
188
376
30
47
74
148
94
188
ESW4 Products
8.5’x6’-LP
8.5’x9’, 8.5’x12’, 12’x12’-LP, 12’x12’-SP
8.5’x18’, 12’x12’-LF, 12’x12’-SF, 12’x18’-LF, 12’x18’X-SF
12’x18’X-LP, 12’x18’X-SP
12’x18’X-LF, 12’x18’X-SF
14’x22’
100
160
240
320
480
440
50
80
120
160
240
220
6.3
10.1
15.1
20.2
30.3
27.8
3.2
5
7.6
10.1
15.1
13.9

15
Operation and Maintenance Instructions
Unit Accessories
The appropriate accessories to prevent or minimize ice
formation during cold weather operation are relatively simple
and inexpensive. These accessories include cold water
basin heaters, the use of a remote sump, electric water level
control and vibration cut out switches. Each of these optional
accessories ensures that the cooler or condenser will function
properly during cold weather operation.
Cold Water Basin Heaters
Optional basin heaters can be furnished with the unit to
prevent the water from freezing in the basin when the
unit is idle during low ambient conditions. The basin
heaters are designed to maintain 40°F (4°C) basin water
temperature at a 0°F (-18°C) ambient temperature. The
heaters are only energized when the recirculating pumps
are off and no water is flowing over the heat exchanger
coil. As long as there is a heat load and water is flowing
over the heat exchanger coil, the heaters do not need to
operate. Other types of basin heaters to consider would
include: hot water coils, steam coils or steam injectors.
Remote Sumps
A remote sump located in an indoor heated space is an
excellent way to prevent freezing in the cold water basin
during idle or no load conditions because the basin and
associated piping will drain by gravity whenever the
recirculating pump is idle. EVAPCO units built for remote
sump operation do not include recirculating water pumps.
Electric Water Level Control
Optional electric water level control packages can be
furnished to replace the standard mechanical float and
valve assembly. The makeup water pressure for electronic
water level control should be maintained between 5 and
100 psig (35 and 690 kPa). The electric water level control
eliminates the freezing problems experienced by the
mechanical float. In addition, it provides accurate control of
the basin water level and does not require field adjustment
even under varying load conditions. Please note: the
standpipe assembly, make up piping and solenoid valve
must be heat traced and insulated to prevent them from
freezing.
Vibration Cut Out Switches
During severe cold weather conditions, ice can form on
the fans of cooling towers causing excessive vibration.
The optional vibration switch shuts the fan off avoiding
potential damage to or failure of the drive system.
Capacity Control Methods for Cold Weather
Operation
Induced draft and forced draft coolers or condensers require
separate guidelines for capacity control during cold weather
operation.
The sequence of control for a unit operating at low ambient
conditions is much the same as a cooler or condenser
operating under summer conditions provided that the
ambient temperature is above freezing. When the ambient
temperatures are below freezing, additional precautions must
be taken to avoid the potential for damaging ice formation.
The most effective way to avoid ice formation in and on a
closed circuit cooler or condenser during the winter is to
run the unit DRY. In dry operation, the recirculation pump is
turned off, the basin drained, and air passes over the coil.
Instead of using evaporative cooling to cool the process fluid
or condense the refrigerant, sensible heat transfer is utilized,
so there is no recirculation water to freeze. If this method will
be used on a forced draft unit, be sure to verify that the motor
and drives have been properly sized to handle the reduction
in static pressure experienced when the spray water is turned
off.
It is very important to maintain close control of the cooler or
condenser during winter operation. EVAPCO recommends
that an absolute MINIMUM leaving water temperature of 42°
F (6°C) must be maintained for cooler applications. The higher
the leaving temperature from the cooler or condenser, the
lower the potential for ice formation.
Induced Draft Unit Capacity Control
The simplest method of capacity control is cycling the
fan motor on and off in response to the leaving fluid
temperature of the cooler or condenser. However, this
method of control results in larger temperature differentials
and longer periods of down time. During extremely low
ambient conditions, the moist air may condense and freeze
on the fan drive system. Therefore, fans must be cycled
during extremely low ambient conditions to avoid long
periods of idle time when water is flowing over the coil. The
number of start/stop cycles must be limited to no more
than six per hour.
A better method of control is the use of two-speed fan
motors. This allows an additional step of capacity control.
This additional step reduces the water temperature
differential, and therefore, the amount of time the fans
are off. In addition, two-speed motors provide savings
in energy costs, since the cooler or condenser has the
potential to operate on low speed for the reduced load
requirements.
The best method of capacity control during cold weather
operation is the use of a variable frequency drive (VFD).
This allows the closest control of the leaving water
temperature by allowing the fan(s) to run at the appropriate
speed to closely match the building load. As the building
load decreases, the VFD control system may operate for
long periods of time at fan speeds below 50%. Operating a
low leaving water temperature and low air velocity through
the unit can cause ice to form. It is recommended that the
minimum speed of the VFD be set at 50% of full speed to
minimize the potential for ice to form in the unit.
Forced Draft Unit Capacity Control
The most common methods of capacity control are cycling
the single speed fan motors, using two-speed motors
or pony motors and utilizing variable frequency drives to
control the cooler or condenser fans. Although capacity
control methods for forced draft units are similar to those
used for induced draft units, there are slight variations.
The simplest method of capacity control for forced draft
units is to cycle the fan(s) on and off. However, this
method of control results in larger temperature differentials
and periods of time with the fans off. When the fans are
cycled off, the water falling through the unit can draw air

16
Operation and Maintenance Instructions
flow into the fan section. During extremely low ambient
conditions, this moist air may condense and freeze on the
cold components of the drive system. When conditions
change and cooling is needed, any amount of ice that has
formed on the drive system can severely damage the fans
and fan shafts. Therefore, fans MUST be cycled during
low ambient operation to avoid long periods of idle
fan operation. Excessive cycling can damage the fan
motors. Limit the number of cycles to a maximum of
six per hour.
Two speed or pony motors offer a better method of
control. This additional step of capacity control will reduce
water temperature differentials and the amount of time
that the fans are off. This method of capacity control has
proven effective for applications where load variations are
excessive and cold weather conditions are moderate.
The use of a variable frequency drive provides the most
flexible method of capacity control for forced draft units.
The VFD control system allows the fans to run at nearly
an infinite range of speeds to match the unit capacity to
the system load. During periods of reduced load and low
ambient temperatures, the fans must maintain enough
speed to ensure positive air flow through the unit. This
positive air flow in the unit will prevent moist air from
migrating towards the cold fan drive components reducing
the potential for condensation to form and freeze on
them. The VFD control system should be implemented for
applications that experience fluctuating loads and severe
cold weather conditions.
Ice Management
When operating an evaporative cooling unit in extreme
ambient conditions, the formation of ice is inevitable. The key
to successful operation is to control or manage the amount
of ice that builds up in the unit. If extreme icing occurs, it
can lead to severe operational difficulties as well as potential
damage to the unit. Following these guidelines will minimize
the amount of ice that forms in the unit leading to better
operation during the cold weather season.
Induced Draft Units
When operating an induced draft unit during the cold
weather season, the control sequence must have a method
to manage the formation of ice in the unit. The simplest
method of managing the amount of ice buildup is by
cycling the fan motors off while keeping the pump on.
During these periods of idle fan operation, the warm water
that is absorbing the building load flows thru the coil to
help melt the ice that has formed in the coil, basin or louver
areas.
NOTE: Using this method during periods of high winds
can cause blow through, resulting in splash-out and ice
formation. To help prevent blow through and splash-out,
maintain a minimum 50% fan speed.
In more severe climates, the incorporation of a defrost
cycle can be used to mitigate and/or eliminate any
detrimental effects of ice in the unit. During the defrost
cycle, the fans are reversed at half speed while the
recirculating pump flows water through the unit’s water
distribution system. Operating the unit in reverse will melt
any ice or frost that may have formed in the unit or on the
air intake louvers. The defrost cycle requires the use of
two speed motors with reverse cycle starters or reversible
variable frequency drives. All motors supplied by EVAPCO
are capable of reverse operation.
The defrost cycle should be incorporated into the normal
control scheme of the cooler or condenser system.
The control system should allow for either a manual or
automatic method of controlling frequency and length of
time required to completely defrost the ice from the unit.
The frequency and length of the defrost cycle is dependent
on the control methods and ambient cold weather
conditions. Some applications will build ice quicker than
others which may require longer and more frequent defrost
periods. Frequent inspection of the unit will help “ne-
tune” the length and frequency of the defrost cycle.
Forced Draft Units
Defrost cycles are NOT recommended for forced draft
units, since allowing the leaving water temperature set
point to rise causes the fans to be off for very long periods
of time. This is not recommended for forced draft coolers
or condensers because of the potential for freezing the
fan drive components. Therefore, the defrost cycle is
an inappropriate method of ice management for forced
draft units. However, low speed fan operation or variable
frequency drives maintain a positive pressure in the
unit which helps prevent ice formation on the fan drive
components.
For more information on cold weather operation, please
download a copy of EVAPCO’s Engineering Bulletin 23 at
evapco.com
Troubleshooting:
see Bulletin 116-E, pages 31-33

17
Operation and Maintenance Instructions
PROCEDURE JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
1. Clean pan strainer – monthly or as needed
2. Clean and flush pan** – quarterly or as needed
3. Check bleed-off valve to make sure it is operative – monthly
4. Lubricate pump and pump motor according to manufacturer’s
instructions
5. Check operating level in pan and adjust float valve if neces-
sary – monthly
6. Check water distribution system and spray pattern – monthly
7. Check drift eliminators – quarterly
8. Check the fan blades for cracks, missing balancing weights,
and vibrations – quarterly
9. Check sheaves and bushings for corrosion. Scrape and coat
with ZRC - annually
10. Lubricate fan shaft bearings* – every 1000 hours of opera-
tion or every three months
11. Lubricate fan motor bearings – see mfg’s instructions. Typi-
cally for non-sealed bearings, every 2-3 years
12. Check belt tension and adjust – monthly
13. Inspect and grease sliding motor base - annually or as needed
14. Check fan screens, inlet louvers, fans and (dry) cooler coil.
Remove any dirt or debris – monthly
15. Inspect and clean protective nish – annually
- Galvanized: scrape and coat with ZRC
- Stainless: clean and polish with a stainless steel cleaner
16. Check water quality for biological contamination. Clean unit as
needed and contact a water treatment program** – regularly
17. Check coil surface for scale and/or corrosion - every 6 months
18. Inspect lubrication lines to bearings - quarterly
MAINTENANCE CHECKLIST

18
Operation and Maintenance Instructions
OPTIONAL ACCESSORIES JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
1. Gear Reducer – Check oil level with unit stopped - 24 hours
after start-up & monthly
2. Gear Reducer/Piping – Do visual inspection for oil leaks, audi-
tory inspection for unusual noises and vibrations - monthly
3. Gear Reducer – Replace oil - semi-annually
4. Oil Pump – Do visual inspection for leaks and proper wiring -
monthly
5. Gear Reducer/Coupling – Check alignment of the system -
24 hours after start-up & monthly
6. Coupling/Shaft – Inspect flex elements and hardware for tight-
ness, proper torque & crack/deterioration - monthly
7. Heater Controller – Inspect controller and clean probe ends -
quarterly
8. Heater – Inspect junction box for loose wiring and moisture –
one month after start-up and semi-annually
9. Heater – Inspect elements for scale build-up – quarterly
10. Electronic Water Level Controller – Inspect junction box for
loose wiring and moisture – semi-annually
11. Electronic Water Level Controller – Clean probe ends of scale
build-up – quarterly
12. Electronic Water Level Controller – Clean inside the standpipe
– annually
13. Solenoid Make-up Valve – Inspect and clean valve of debris –
as needed
14. Vibration Switch (mechanical) – Inspect enclosure for loose
wiring and moisture – one month after start-up and monthly
15. Vibration Switch – Adjust the sensitivity - during start-up and
annually
16. Sump Sweeper Piping – Inspect and clean piping of debris –
semi-annually
17. Clean Dry Coil(s) – semi-annually
18. Water Level Indicator – Inspect and clean - annually
19. SUN Solar Panels – Inspect for damage and clean with hose
and soft brush - semiannually
DURING IDLE PERIODS
1. Two or more days: energize motor space heaters or run mo-
tor for 10 min twice daily
2. Few Weeks: Run gear reducer for 5 minutes - weekly
3. Several Weeks: Completely ll gear reducer with oil. Drain to
normal level prior to running. - once
4. One Month or longer: Rotate motor shaft/fan 10 turns - monthly
5. One Month or longer: Megger test motor windings -
semi-annually
* See maintenance manual for start-up instructions and lubrication recommendations.
** Cooling Towers must be cleaned on a regular basis to prevent the growth of bacteria including Legionella Pneumophila.

19
Operation and Maintenance Instructions
Seasonal Shutdown Checklist
When the system is to be shut down for an extended period of
time, the following services should be performed.
1. The evaporative cooling unit cold water basin should
be drained
2. The cold water basin should be flushed and cleaned
with the suction strainer screens in place.
3. The suction strainer screens should be cleaned and
re-installed.
4. The cold water basin drain should be left open.
5. The fan shaft bearings and motor base adjusting
screws should be lubricated. This should also be
performed if the unit is going to sit idle prior to initial
start-up.
6. The makeup water supply, overflow and drain lines,
as well as the recirculating pump and pump piping
up to the overflow level must be heat traced and
insulated to account for any residual water.
7. The finish of the unit should be inspected. Clean and
refinish as required.
8. The fan, motor and pump bearings need to be
turned at least once a month by hand. This can be
accomplished by making sure the unit’s disconnect
is tagged and locked out, and grasping the fan
assembly, rotating it several turns.
9. Energize fan motor space heaters.
10. Closed Circuit Coolers only - If the recommended
minimum fluid flows through the heat transfer
coil cannot be maintained, and an anti-freeze
solution is not in the coil, the coil must be drained
immediately whenever the system pumps are shut
down or flow stops during freezing conditions. This
is accomplished by having automatic drain valves
and air vents in the piping to and from the cooler.
Care must be taken to ensure that the piping is
adequately insulated and sized to allow the water to
flow quickly from the coil. This method of protection
should be used only in emergency situations and
is neither a practical nor recommended method of
freeze protection. Coils should not be drained for an
extended period of time, as internal corrosion may
occur. See Cold Weather Operation section of this
document for more details.
See fan and pump manufacturer maintenance and long
term storage instructions for more detailed instructions.

©2013 EVAPCO Europe Bulletin 116R-E Metric 0322
Operation and Maintenance Instructions
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