Amcot ST Series Troubleshooting guide

OPERATIONS AND MAINTENANCE
INSTRUCTIONS
ST SERIES COOLING TOWERS
AMCOT COOLING TOWER CORPORATION
1-800-444-8693
WWW.AMCOT.COM
[email protected]OM
LAST REVISED: 04/18
DOCUMENT: STOM0418

AMCOT ST SERIES FIBERGLASS COOLING TOWER
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TABLE OF CONTENTS
SECTIONS PAGES
Introduction 3
Safety Precautions 4
Inspect Your Shipment 5
General Overview
Principle of Operation 5
Tower Construction 6-8
General Operating Precautions 9
Startup
Inspection Checklist 10
Startup Procedures 11
Preventative Maintenance Checklists
Monthly 12
Quarterly, Semi-Annual 13
Annual 14
General Maintenance
Water Distribution System
Sprinkler Arm Assemblies 15-18
Spray Head Assemblies 19-22
Fill Media & Water Basin 23
Inlet Louvers & Anti-Splash Louvers 24
Pipe Connections/Float Valve Assembly 25-28
Water Inlet Pressure 29
Ladders & Fan Guards 30
Fan Assembly 30-34
Motors 35-37
V-Belt Reducer 38-43
Seasonal / Prolonged Shutdown 44
Water Treatment 45-46
Troubleshooting 47

AMCOT ST SERIES FIBERGLASS COOLING TOWER
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INTRODUCTION
We would like to first say thank you for your business and purchase of an Amcot ST Series, open loop,
counter flow, water cooling tower. Amcot strives to provide all of our clients with the highest level of
customer service and quality products. Amcot’s ST series cooling towers when operated and maintained
properly will provide your facility with years of reliable service.
This operations and maintenance manual is designed to provide a wide range of recommendations and
instructions on how to properly operate and maintain your cooling tower. It is important to remember
that ALL cooling towers, regardless of manufacturer, face very harsh environments and it is imperative
that proper maintenance is performed regularly in order to ensure a long service life.
Don’t forget about your cooling tower!
Most cooling towers are located in a remote area of your facility, either on a roof, or outside and away
from most other equipment. It is easy for maintenance staff and personnel to forget about them or not
perform regular maintenance as a result. Unfortunately if this occurs, what could have been a relatively
quick and inexpensive repair, could become a major ordeal for your facility. It is important to remember
that your cooling tower is just one component in an overall system, but is a very critical as it helps
maintain optimal operating temperatures for all of the other equipment.
This manual will cover basic operation of your tower, general recommendations for water quality,
shutdown/startup checklists, and more!
If at any time you have questions, please contact your distributor, installing contractor or Amcot
representative for immediate assistance. It is always helpful to have your model number and serial
number which can be located on the unit’s equipment tag. A duplicate tag for your tower was included
in your shipment. This extra label can be placed below for quick reference.
YOUR TOWER WILL SHIP WITH ONE (1) EXTRA EQUIPMENT TAG.
PLACE THE EXTRA TAG HERE FOR QUICK REFERENCE.

AMCOT ST SERIES FIBERGLASS COOLING TOWER
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SAFETY PRECAUTIONS
It is important that only qualified technicians, licensed contractors, or licensed electricians perform
installation related services of your cooling tower in order to make sure the unit is properly installed and
in compliance with local building codes. Amcot is not responsible for any failures or damages to the
cooling tower or it’s components in the event the unit is not properly installed.
Also, to prevent personal injury or property damage it is important that the cooling tower is operated in
a proper manner with all safety guards in place at all times.
WARNING: Cooling Towers should be installed with proper disconnect switches which are located
within visible sight of the unit and have lock out capabilities. They must be properly sized if those
disconnects are fused or include breakers. All electrical components must be installed in strict
accordance to your local building codes.
WARNING: All electrical equipment should be disconnected and locked out prior to disassembling,
entering, or working on the cooling tower.
WARNING: Most cooling towers utilize chemical treatment systems designed to help against the
accumulation of scale, biological growth, along with bacteria and Legionella, all of which can be
harmful if inhaled or ingested. While in most circumstances the air exhaust will not pose harm to
individuals, it is strongly recommended that workers wear proper PPE equipment when working on or
near the cooling tower.
WARNING: The cooling tower must always be operated with fan guard(s), louvers, and casing panels
in place and secured. Failure to do so may cause personal injury, property damage, or both.
WARNING: Some vibration during operation is normal for most cooling towers. Preassembled towers
are quality checked for loose fasteners and proper fan pitch, however during transit it is possible that
fasteners may become loose. In the event you experience significant vibration occurring, immediately
shut off the unit and check all fasteners and verify pitch and blade angle per the instructions in this
manual before turning back on. If vibrations persist, contact your installing contractor,
representative, or Amcot directly. Running the tower with excessive vibration can lead to significant
equipment damage and even possibly cause personal injury or property damage.

AMCOT ST SERIES FIBERGLASS COOLING TOWER
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INSPECT YOUR SHIPMENT
Amcot makes every attempt to ensure your tower was properly packaged and secured for transit to
your location. Unfortunately shipping damage can occur. It is the receiving party’s responsibility to
INSPECT the tower BEFORE you sign the bill of lading. IF damage is noticed, you should reject the
delivery, take pictures, and immediately contact your contractor, representative or Amcot.
PLEASE NOTE IF YOU SIGN THE BILL OF LADING FROM THE CARRIER AND DO NOT INDICATE DAMAGES,
AMCOT WILL BE UNABLE TO FILE ANY FREIGHT CLAIMS ON YOUR BEHALF.
YOU, THE RECEIVER, WILL BE REQUIRED TO FILE SUCH CLAIMS.
SEE AMCOT TERMS AND CONDITIONS FOR ADDITIONAL INFORMATION.
GENERAL OVERVIEW
PRINCIPLE OF OPERATION
The Amcot ST Series cooling tower is an open loop counter flow type of unit designed to remove excess
heat from a water cooled system or application so that the equipment generating this heat can
continuously operate within a specific temperature range.
Cooling towers are designed to remove system generated heat through evaporation. This evaporation
occurs as a result of hot water being pumped into the tower, up a center standpipe to a rotating
sprinkler system which distributes the water across a heat transfer media (fill media). At the same time,
the fan pulls outside air into the unit through the air inlet louvers located around the bottom of the
tower. The heat is transferred from the water to the incoming air as the two come into contact within
the heat transfer media. The cold water which results from the heat transfer process is collected in the
cooling tower’s cold water basin and then is
pumped by an external water pump (sold
separately) back to your system where the
process is repeated. The warm humid air exits
the tower into the atmosphere. The diagram to
the right illustrates the heat transfer process that
occurs during normal operation.
While this illustration is for a general
understanding of how your tower works, there
are many details not shown. This brief
explanation is a simplified method of how your
cooling tower functions. Each installation and
project is different. Amcot can provide support
for your cooling tower and the components
supplied with the tower. For overall system
design questions you should contact the
contractor or engineer who did the initial design.

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GENERAL OVERVIEW
TOWER CONSTRUCTION
Casing and Cold Water Basin
The Amcot ST Series Cooling Tower is constructed of heavy duty UV resistant fiber reinforced polyester,
also known as fiberglass or FRP. The FRP exterior includes the upper casing panels and the cold water
basin. Fiberglass is a mixture of polyester resin material and fiber matting formed by layering the fiber
cloth and resin to create a finished product that is very strong, durable, resistant to cracking, non-
corrosive, and provides superior protection against chemical attack. The polyester resin incorporates a
UV inhibitor additive which protects against decay or deterioration from ultraviolet light which is a
natural occurrence.
The Amcot ST Series cold water basin utilizes a sloped basin designed to facilitate proper water flow to
the outlet pipe connection and promote positive head pressure for your circulating pump. The sloped
basin also allows for complete water drainage to occur during maintenance, cleaning, or seasonal
shutdown. The cold water basins incorporate your inlet/outlet connections which are the main supply
and return lines, a float valve assembly for water makeup, a drain connection for removing water from
the system, and an overflow connection to prevent the basin from overflowing should the float valve
not be properly installed or becomes inoperable. Your outlet connection is supplied with a removable
suction strainer which helps prevent large debris from entering your piping system.
The FRP Components are coated in a UV resistant gel coat so the tower will have a glossy sheen to the
exterior surfaces. Over time it is normal for this sheen to dull as the tower ages
Structural Framework
On Amcot models ST-H-3 to ST-175 the mounting legs of the tower are integrated into the cold water
basin to help simplify installation and construction.
For Amcot models ST-200 and greater the mounting framework of the tower is designed from Hot
Dipped Galvanized Steel (HDGS) or Stainless Steel 304 (Optional) framing which provides reinforcement
and support for the larger overall structure of these models.
WARNING: Your cooling tower MUST be supported in accordance with our recommended
support drawings and also comply with local building code requirements. Failure to properly support
the cooling tower can result on property damage, equipment failure, or personal injury. If your tower
is not properly supported, your warranty will be void in accordance with Amcot Terms and Conditions.
Your tower must be properly supported by anchoring it to a concrete pad, piers, or columns or to a steel
I-beam frame (not supplied by Amcot) that is designed to handle the operating weight and load of the
tower.

AMCOT ST SERIES FIBERGLASS COOLING TOWER
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GENERAL OVERVIEW
TOWER CONSTRUCTION
Motor Support Frame and Fan Guards
The Amcot ST Series cooling towers are provided with Hot Dipped Galvanized Steel (HDGS) or Stainless
Steel 304 (Optional) OSHA compliant removable fan guards and heavy duty welded motor support
frames which are designed to properly support and distribute the weight and forces being generated by
the mechanical assembly.
NEVER OPERATE YOUR COOLING TOWER WITHOUT FAN GUARDS INSTALLED!
Air inlet Louvers
The air inlet louvers of the ST Series cooling tower is a PVC mesh screen which is designed to prevent
debris and wildlife from entering the cooling tower. The air inlet louvers are designed so that they can
be removed for cleaning or replacing. Removing the louver sections also permits access to the inside of
the cold water basin.
Heat Transfer Media (Fill Media)
The ST Series cooling tower utilizes a heat transfer media known as “Fill Media”. Fill media is an
embossed PVC sheet material which is glued together to form a series of channels known as flutes.
These flutes help spread out the water as it flows across the material. By spreading out the water, the
fill media increases the water surface area that becomes exposed to the air flow. This in turn increases
the amount of heat that can be removed from the system.
Your fill media is capable of withstanding continuous operating hot water temperatures of 115°F and is
impervious to rot, decay, rust, and biological attack. The fill media is installed in preassembled packs or
blocks.
It is important that proper water treatment be maintained by utilizing a local water treatment specialist
in your area. Failure to maintain proper water treatment can cause the fill media to become clogged or
fouled up over time, which will decrease your unit’s overall capacity and ultimately result in an increase
to your cold water temperature. If using a chemical water treatment system you should incorporate a
biocide as a component of that treatment program to eliminate biological growth.
Water Distribution System
Your cooling tower is designed with a rotating spray system that is driven by incoming water pressure.
Water enters the tower from the inlet pipe connection (located on the cold water basin side wall) and is
pumped through a center stand pipe to the sprinkler head which directs water to a series of spray arms.
The spray arms have a series of holes that allow the incoming hot water to be distributed onto the fill
media. This assembly rotates in a clockwise fashion ensuring that water is evenly distributed to all areas
of the fill media.

AMCOT ST SERIES FIBERGLASS COOLING TOWER
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GENERAL OVERVIEW
TOWER CONSTRUCTION
Fan Blade Assembly
For ST Series models ST-3 thru ST-30 the fan assemblies are fixed pitch type, constructed from nylon.
The pitch angles are preset by the factory to ensure proper operation and maximum allowable air flow is
being generated while maintaining proper motor amp draw.
For models ST-40 and ST-50 the fan assemblies remain fixed pitch, but the fan blades are constructed
from aluminum alloy while the hub is nylon.
For ST-60 through ST-1500 fans are adjustable pitch type and constructed from light weight corrosion
resistant aluminum alloy. Blades are secured to the fan hub through a serious of stainless steel U-bolts.
Adjustable pitch fans do allow for some minor adjustment on the customer’s part when it comes to air
flow through the unit, however it is not recommended that you make these adjustments unless you are
a licensed professional.
WARNING: Failure to properly balance fan assemblies can cause equipment failure, excessive
vibrations, and personal injury in the event of a failure. It is critical that fans be balanced prior to
startup by the installing technician even on towers that shipped preassembled!
Fan Motors & Reducers
Amcot ST Series models ST-H-5 thru ST-200 are supplied with direct drive motors which means that the
mechanical assembly simply consists of a motor and fan assembly. For these units, there are no
bearings to grease or belts to adjust.
On models ST-225 thru ST-1500 the mechanical assembly incorporates a housed belt reducer which
regulates the output speed on the fan assembly to ensure proper air flow is maintained while
minimizing sound generation. The reducer assembly is fully housed in an epoxy coated steel case with
removable side walls for accessing the internal components and for adjusting belt tension. For
adjustment and maintenance please see the appropriate section of this manual for more information.
Motors on the Amcot towers are designed to meet NEMA energy requirements and are UL/CSA
approved and are IP55 compliant. On models ST-30 thru ST-1500 the motors can be operated on
variable frequency drives (supplied separately) in order to maximize energy savings. In addition, all
motors can be operated on standard on/off type of temperature controllers (sold separately).
Models ST-H-5 thru ST-H-20 utilize single phase 110/220v dual voltage motors which can accommodate
either service power. ST-H-20 also has the ability to be supplied with a three phase 208-230/460v multi-
voltage motor. ST-30 thru ST-1500 are supplied in 3 phase 208-230/460v motors as a standard. For
special motor voltage requirements, Amcot can provide such motors which would be special order and
have extended lead times.

AMCOT ST SERIES FIBERGLASS COOLING TOWER
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GENERAL OVERVIEW
GENERAL OPERATING PRECAUTIONS
PERFORMANCE
Since the volume of water has a direct impact on cooling tower performance, be sure that the water
flow rate is constantly maintained during operation. Fluctuations in water flow will directly impact
cooling tower performance. Low flow rates can cause excessive scale and algae growth. Scale and algae
accumulation can be minimized by incorporating a water treatment program (chemical or non-chemical
types). It is best to contact the installing contractor or local representative for further assistance in
these matters.
WATER LEVEL
Proper water level in the cold water basin should be maintained at all times. The recommended water
level is 2-3 inches below the overflow. If the water level in the basin becomes too low this can allow air
to enter your piping and cause pump cavitation. Closely monitor your float valve assembly or electronic
level controller and ensure a proper water level is maintained.
NOISE/VIBRATION
Pay close attention to general operating conditions of your tower such as noise, vibrations, water
temperature, and motor voltage. Sudden changes in any of these items can be an indicator that a
problem has begun to develop and ultimately failure if you do not address the problem in a timely
manner. Sudden increases in vibration can mean a fan assembly is cracked or out of balance or
structural brackets may be compromised. Sudden shifts in voltages or amp draws can mean that
reducer belts need to be adjusted or motor bearings could be failing or something is wrong with the
power supply connected to the motor.
REPLACEMENT PARTS
Amcot stocks most parts for ST Series cooling towers in our Ontario, California facility. Amcot
replacement parts are available through major HVAC wholesalers and distributors along with other
authorized equipment distributors.
Only the use of original Amcot components is recommended. Using third party components that are not
original factory parts will void your tower’s warranty and could have significant impact on the towers
rated capacity or performance.
If you are unsure of who your local supplier is, please call Amcot at 1-800-444-8693 and we will be more
than happy to assist you with finding an authorized dealer.

AMCOT ST SERIES FIBERGLASS COOLING TOWER
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STARTUP INSPECTION
Once your cooling tower has been properly installed by licensed professionals, proper startup of the unit
should occur. Below is a checklist of items to verify prior to performing initial startup of your unit and
after seasonal shutdowns.
GENERAL PROCEDURES
REMEMBER TO ALWAYS SHUT DOWN AND PERFORM LOCKOUT/TAG-OUT PROCEDURES
PRIOR TO SERVICING OR ACCESSING YOUR EQUIPMENT!
Unit should be installed level and on proper footings or foundations made from concrete or
steel.
oUneven foundations can impact equipment service life and void your warranty.
Units should be secured and fastened according to the unit’s foundation drawing.
oFailure to properly secure the unit can cause equipment damage and void your
warranty.
Circulating water pump suction connection must be below the outlet connection to the cooling
tower.
oFailure to properly install your pump will cause damage to not only the pump’s
components but also can impact your overall system design.
All piping should be properly supported. The cooling tower is not designed to be or act as a pipe
support.
oFailure to properly secure piping can cause physical damage to the cooling tower and
void your warranty.
Inlet and Outlet connections should incorporate flex connections at the point of connection to
help isolate vibration from the tower or the pump.
All piping connections should have operable valves for proper water balancing and tower
isolation and servicing.
Ensure your disconnect switch is properly installed and working.
Any safety interlocks should be tested.
When operating ST Series towers on inverter drives or Variable Frequency Drives, make sure the
minimum speed requirements have been programmed.
oStandard Fan Motors on the ST Series can be operated on variable frequency drives with
an operating range of 20-60 hertz.
Verify all valves, sensors, gauges, or other accessories are working properly.
Amcot recommends a local water treatment specialist provide you with a water treatment
program that is suitable for your local conditions.
oFailure to implement and maintain a water treatment plan may void your tower
warranty as this is the responsibility of the owner to maintain such plans.
Make sure all electrical connections are secure.
Check inside your tower and remove any debris.
Check under or around your tower for any signs of water leaks.