Marley NC fiberglass User Manual

NC® berglass cooling tower

INSTALLATION - OPERATION - MAINTENANCE

user manual

uk_Z0702489_D ISSUED 8/2018

READ AND UNDERSTAND THIS MANUAL PRIOR TO OPERATING OR SERVICING THIS PRODUCT.

contents

Note

This manual contains vital information for the proper installation and
operation of your cooling tower. Carefully read the manual before
installation or operation of the tower and follow all instructions.
Save this manual for future reference.

Page

Tower Shipment............................................................................................... 3

Receiving Tower .............................................................................................. 3

Tower Location ................................................................................................ 4

Tower Assembly .............................................................................................. 4

Motor Wiring .................................................................................................... 5

Mechanical Equipment .................................................................................. 6

Tower Startup .................................................................................................. 8

Tower Maintenance......................................................................................... 14

Water Quality and Blowdown ...................................................................... 14

Schedule of Tower Maintenance ................................................................. 16

Seasonal Shutdown Instructions ................................................................ 19

Prolonged Shutdown ..................................................................................... 19

Maintenance Schedule .................................................................................. 20

Additional Services ......................................................................................... 21

Troubleshooting ............................................................................................... 22

Warning

Caution

Note

The following defined terms are used throughout this manual to bring attention
to the presence of hazards of various risk levels, or to important information
concerning the life of the product.

Indicates presence of a hazard which can cause severe personal
injury, death or substantial property damage if ignored.

Indicates presence of a hazard which will or can cause personal
injury or property damage if ignored.

Indicates special instructions on installation, operation or maintenance
which are important but not related to personal injury hazards.

2

overview

This User Manual as well as those offered separately on motors, fans,
Geareducer, couplings, drive shafts, float valves, pumps, etc., are intended to
assure that this cooling tower serves you properly for the maximum possible
time. Since product warrantability may well depend upon your actions, please
read this User Manual thoroughly prior to operation.

This User Manual provides information regarding general cooling tower instal­lation and operation. Any deviation from, change or modification to, the User
Manual, the original design conditions or the original intended use of the
equipment may result in improper installation and/or operation of the tower.

Any such deviation, change or modification shall be the responsibility of
the party or parties making such deviation, change or modification. SPX
Cooling Technologies, Inc. expressly disclaims all liability for any such deviation,
change or modification. The equipment shall be warranted in accordance with
the applicable SPX Cooling Technologies Certification of Limited Warranty.

If you have questions about the operation and/or maintenance of this cool­ing tower, and you don’t find the answers in this manual, please contact your
Marley sales representative. When writing for information, or when ordering
parts, please include the serial number shown on the cooling tower nameplate.

Safety First

The location and orientation of the cooling tower can affect the safety of those
responsible for installing, operating or maintaining the tower. However, since
SPX Cooling Technologies does not determine the location or orientation of
the tower, we cannot be responsible for addressing those safety issues that
are affected by the tower’s location or orientation.

Tower Shipment

NC Fiberglass towers ship by truck unassembled. Responsibility for the
condition of the tower upon its arrival belongs to the shipper—as does the
coordination of multiple shipments, if required. Refer to the NC Fiberglass
Assembly Manual for instructions.

Receiving Tower

Prior to assembly, inspect the shipment for evidence of damage in transit. If
damage is apparent, note the freight bill accordingly. This will support your
future recovery claim.
Find and remove the installation instructions and bills of material. This informa­tion should be kept for future reference and maintenance purposes.

3

installation

Tower Location

Space available around the tower should be as generous as possible to pro­mote ease of maintenance—and to permit freedom of airflow into and through
the tower. If you have questions about the adequacy of the available space
and the intended configuration of the tower, please contact your Marley sales
representative for guidance.

Prepare a stable, level support foundation for the tower, utilizing weight, wind
load, and dimensional information appearing on appropriate Marley submittal
drawings. Supports must be level to insure proper operation of the tower.

Warning

Note

Caution

The cooling tower must be located at such distance and direction
to avoid the possibility of contaminated tower discharge air being
drawn into building fresh air intake ducts. The purchaser should ob­tain the services of a Licensed Professional Engineer or Registered
Architect to certify that the location of the tower is in compliance
with applicable air pollution, fire, and clean air codes.

Tower Assembly

Your Marley sales engineer is able to provide for the tower assembly by Marley’s
construction division or through a qualified subcontractor. Our subcontrac­tors provide safe, efficient assembly which complies with all requirements for
warranty protection of your tower by SPX Cooling Technologies. Refer to the
NC Fiberglass Assembly Manual for instructions.

Before assembly make sure that the tower orientation agrees with
your intended piping arrangement.

Except for horizontal components of top-mounted piping and as
prescribed on Marley drawings, do not support your pipe from the
tower or outlet connection—support it externally.

Warning

4

For maintenance/safety purposes, SPX recommends a lockout
type disconnect switch for all mechanical equipment. In addition
to a disconnect switch, the motor should be wired to main power
supply through short circuit protection, and a magnetic starter with
overload protection.

installation

Motor Wiring

Wire motor leads as shown on the motor nameplate matching the supply voltage.
Do not deviate from the motor nameplate wiring.

Internal space heaters may be present, depending upon the motor manufac-

turer. For space heater operation and wiring refer to the Marley “Fan Motor”

User Manual Z0239042.

Either of following symbols may be shown on the motor nameplate –

Δ, Δ Δ

, Y, or YY. These symbols represent how the motor is constructed on the
inside and in no way have anything to do with a Delta or Wye electrical distribution
system serving the motor.

When using a starter:

• Set motor overload protection to 110% of motor nameplate amps. This
setting allows the fan motor to operate during cooler weather. During
cooler weather it is common for the motor to draw 6 to 10% higher than
nameplate amps. High amps are common during tower commissioning
when the tower is dry and the ambient air temperature is cool.

Note

Note

Note

Do not start the motor more than four to five times per hour. Short cy­cling the tower will cause fuses, breakers or O.L.s to operate and will
decrease motor life.

When using a two-speed starter:

• Motor rotation must be the same at slow speed and high speed.

• Single winding motor requires a starter with a shorting contactor.

• Two-winding motor requires a starter with out a shorting contactor.

• All two-speed starters must have a 20 second time delay relay when switch­ing from high speed to low speed.

Do not start the motor more than four to five times per hour (each low
speed start and each high speed start count as one start).

When using a VFD:

Before beginning, ensure that the motor is rated for “Inverter Duty” per
IEC 60 034 and 60 079.

• Set the VFD solid state overload protection to 119% of motor nameplate
amps and set “maximum current parameter” in the VFD to motor nameplate
amps. “Maximum current parameter” will reduce fan speed and limit amp

➠

5

installation

draw to nameplate amps during cold weather operation. If furnished
with a mechanical O.L. set this at 110% over motor nameplate amps.

• Motor rotation must be the same in both VFD mode and By-pass mode.

• If cable distance between the VFD and motor is greater than 31m a
DV/DT output filter is recommended to avoid damage to the motor.
31m distance is based on our field experience, the VFD manufacture
may state different distances and distance does vary depending on
the VFD manufacture.

• Program the VFD for variable torque output. Flux vector and constant
torque modes may damage the gearbox.

• Do not start and stop the motor using the safety switch at the motor.
If the drive is being commanded to run and the load side is cycled ON
and OFF with the safety switch this may damage the VFD.

Using a VFD in cooling applications has advantages over traditional single
or two speed motor control. A VFD can reduce the cost of electrical energy
being used and provide better temperature control. In addition, it reduces the
mechanical and electrical stress on the motor and mechanical equipment.
Electrical savings can be large during periods of low ambient temperature when
the cooling requirement can be satisfied at reduced speeds. To benefit from
these advantages, it is important that the drive be installed correctly.
Marley supplies VFD and VFD controls specifically designed for our cooling
products. If you have purchased a Marley VFD and/or controls package, please
follow the instructions in the User Manual for that system. Most VFD problems
can be avoided by purchasing the Marley drive system. If you are installing a
VFD other than the Marley drive, please refer to that drives installation manual.

Warning

Warning

6

Improper use of a VFD may cause damage to equipment or personal
injury. Failure to correctly install the VFD drive will automatically
void all warranties associated with the motor and any equipment
that is either electrically or mechanically (directly) attached to the
VFD drive system. The length of this warranty avoidance will be
contingent on properly installing the VFD system and repairing any
damage that may have occurred during its operation. SPX Cool­ing Technologies does not assume responsibility for any technical
support or damages for problems associate with non-Marley brand
VFD systems.

Changing the operational fan speed from the factory settings could
cause the fan to operate in an unstable region which may result in
damage to the equipment and possible injury.

installation

Mechanical Equipment

Warning

Always shut off electrical power to the tower fan motor prior to performing
any maintenance on the tower. Any electrical switches should be locked
out and tagged out to prevent others from turning the power back on.

1. If equipped, check oil level in accordance with the Geareducer User Manual
for the Geareducer. If oil is required, fill Geareducer to the proper level with
approved lubricant.

2. Spin the fan manually to assure that all fan blades properly clear the inside
of the fan cylinder. Observe the action of the sheaves and belts to be sure
that the motor is properly aligned with the fan sheave. See Belt Tensioning
and Sheave Alignment on page 16 and 17. If equipped with Geareducer
drive observe the action of the coupling (or drive shaft couplings) to be sure
the motor and Geareducer are properly aligned. If necessary correct align­ment (see Geareducer User Manual).

3. Momentarily energize (“bump”) the motor and observe rotation of the fan.
The fan should rotate in a counterclockwise direction when viewed from
below. If rotation is backwards, shut off the fan and reverse two of the three
primary leads supplying power to the motor.

Caution

Note

If tower is equipped with a two-speed motor, check for proper rota­tion at both speeds. Check also to see that starter is equipped with a
20 second time delay which prevents direct switching from high
speed to low speed. If the fan is intended to be reversed for deicing
purposes, make sure that the starter is equipped with a two minute
time delay between changes of direction. These delays will prevent
abnormal stress from being applied to the mechanical equipment
and the electrical circuit components.

5. Run the motor and observe the operation of the mechanical equipment. Operation

should be stable.

6. If equipped with belt drive check the torque on the fan and motor sheave
after 10 to 60 hours of operation.

If the water supply system is not being operated—or if there is no
heat load on the system—motor amps read at this time may indicate
an apparent overload of as much as 10–20%. This is because of the
increased density of unheated air flowing through the fan. Deter­mination of an accurate motor load should await the application of
the design heat load.

7

operation

Tower Start-Up

Warning

Microorganisms including Legionella bacteria can exist in premise
plumbing including cooling towers. The development of an effective
water management plan (WM P) and implementation of maintenance
procedures are essential to prevent the presence, dissemination and
amplification of Legionella bacteria and other waterborne contami­nants throughout premise plumbing. Before operating the cooling
tower, the water management plan and maintenance procedures
must be in place and regularly practiced.

Water System:

1. Consult a knowledgeable water treatment professional to clean and
treat your new cooling tower prior to startup. Cooling towers must
be cleaned and disinfected regularly in accordance with local public
health services and recommendations.

2. Do NOT attempt any service unless the fan motor is locked out.

3. Remove any and all accumulated debris from tower. Pay particular at­tention to inside areas of cold water basin, entire hot water basin, and
hot water inlet. Make sure that cold water suction screens are clear
and properly installed.

4. For NC8401 thru NC8405 fill the water system to an approximate
depth of 178mm in the depressed section of the cold water basin. For
NC8407 thru NC8414 fill the water system to an approximate depth
of 203mm in the depressed section of the cold water basin. This is
the recommended operating water level. Adjust the float valve so that
it is essentially closed at that level. Continue filling the system until the
water reaches a level approximately 4mm below the lip of the overflow.

5. Start your pump(s). Observe system operation. Since the water system
external to the tower will have been filled only to the level achieved in
the cold water basin, a certain amount of “pump-down” of the basin
water level will occur before water completes the circuit and begins
to fall from the fill. The amount of initial pump-down may be insufficient
to cause the float valve to open. However, you can check its operation
by pressing down on the operating lever to which the stem of the float
valve is attached.

8

operation

6. Continue pump operation for about 15 minutes, after which it is rec­ommended that the water system be drained, flushed, and refilled in
order to clean the system.

7. While operating the pump(s) and prior to operating the cooling tower
fan, execute one of the two alternative biocidal treatment programs
described in the following:

• Resume treatment with the biocide which had been used prior to shut­down. Utilize the services of the water treatment supplier. Maintain the
maximum recommended biocide residual (for the specific biocide) for
a sufficient period of time (residual and time will vary with the biocide)
to bring the system under good biological control

or

• Treat the system with sodium hypochlorite to a level of 4 to 5 mg/L
free chlorine residual at a pH of 7.0 to 7.6. The chlorine residual must
be held at 4 to 5 mg/L for six hours, measurable with standard com­mercial water test kits.

If the cooling tower has been in operation and then shut down for a duration

of time and not drained, perform one of the two previous biocidal treatment
programs directly to the cooling water storage vessel (cooling tower sump,
drain down tank, etc.) without circulating stagnant water over the cooling
tower fill or operating the cooling tower fan.

After biocidal pretreatment has been successfully completed, cooling

water may be circulated over the tower fill with the fan off.

When biocidal treatment has been maintained at a satisfactory level for

at least six hours, the fan may be turned on and the system returned to
service. Resume the standard water treatment program, including biocidal
treatment.

9

operation

Range – °F =

Heat Load (Btu/hr)

GPM x 500

or — in SI units

Tower Operation

General:

The cold water temperature obtained from an operating cooling tower will vary
with the following influences:

1. Heat Load With the fan in full operation, if the heat load increases,
the cold water temperature will rise. If the heat load reduces, the cold
water temperature will reduce.

Note that the number of degrees (“range”) through which the tower

cools the water is established by the system heat load and the amount
of water being circulated, in accordance with the following formula:

Range – °C

The cooling tower establishes only the cold water temperature attain-

able under any operating circumstance.

2. Air Wet-Bulb Temperature Cold water temperature will also vary
with the wet-bulb temperature of the air entering the louvered faces of
the tower. Reduced wet-bulb temperatures will result in colder water
temperatures. However, the cold water temperature will not vary to the
same extent as the wet-bulb. For example, an 11°C reduction in wet­bulb may result in only an 8°C reduction in cold water temperature.

3. Water Flow Rate Increasing the water flow rate (m3/hr) will cause a
slight elevation in cold water temperature, while reducing the water flow
rate will cause the cold water temperature to lower slightly. However,
at a given heat load (see formula above), m3/hr reductions also cause
an increase in the incoming hot water temperature. Use care to prevent
the hot water from exceeding 46°C, in order to prevent damage to the
tower components.

4. Airflow Rate Reducing airflow through the tower causes the cold
water temperature to rise. This is the approved method by which to
control leaving water temperature.

=

Heat Load (kW)

Water Flow (m3/hr) x 1.162

10

If your tower is equipped with a single-speed motor, the motor may

be shut off when the water temperature becomes too cold. This will
cause the water temperature to rise. When the water temperature then
becomes too warm for your process, the motor can be restarted.

operation

Fan Cycling Limits:

Note

Note

Considering the normal fan and motor sizes utilized on NC towers,
anticipate that approximately 4 to 5 starts per hour are allowable.

If your tower is equipped with a two-speed motor, greater opportunity

for temperature control is afforded you. When the water temperature
becomes too cold, switching the fan to half-speed will cause the cold
water temperature to rise—stabilizing at a temperature a few degrees
higher than before. With a further reduction in water temperature, the
fan may be cycled alternately from half-speed to off.

Do not start the motor more than four to five times per hour (each
low speed start and each high speed start count as one start).

If your tower consists of two or more cells, cycling of motors may be

shared between cells, increasing your steps of operation accordingly.
For greater insight on cold water temperature control, please read

Marley Technical Report H-001 , “Cooling Tower Energy and its
Management” available from your Marley sales representative or you

can download a copy from Marley’s website at spxcooling.com.

Note

Freezing Weather Operation

During operation in subfreezing weather, the opportunity exists for ice to form
in the colder regions of the tower. Your primary concern is to prevent the
formation of destructive ice on the cooling tower fill. Your understanding of
cold weather operation will be enhanced if you read Marley Technical Report
H-003 , “Operating Cooling Towers in Freezing Weather,” augmented by
the following guidelines. Available for download at spxcooling.com.

Slushy, transitory ice forms routinely in the colder regions of the fill
of low temperature towers, and is visible through the tower louvers.
Such ice normally has no adverse effect on tower operation, but
its appearance should be a signal to the operator to undertake ice
control procedures.

It is the operator's responsibility to prevent the formation of destruc­tive (hard) ice on the cooling tower fill. Certain guidelines should
be followed:

➠

11

operation

1.

Do not allow the tower’s leaving water temperature to drop
below a minimum allowable level (2.5° to 5°C) established as
follows:

During the coldest days of the first season of operation, observe whether

any ice is forming on the louver face, particularly near the bottom of the
louver face. If hard ice is present on the louvers, an appropriate eleva­tion in the allowable cold water temperature is mandatory. If the coldest
possible water is beneficial to your process, ice of a mushy consistency
can be tolerated—but routine periodic observation is advisable.

If the minimum allowable cold water temperature is established at or

near maximum heat load, it should be safe for all operating conditions.
However, if established at reduced load, increased heat loads may

reintroduce the potential for icing.

Having established the minimum allowable cold water temperature,

maintaining that temperature can be accomplished by fan manipulation,
as outlined in Item 4 under Tower Operation on page 10. However,

in towers of more than one cell, the limiting temperature established

applies to the water temperature of the cell or cells operating at the

highest fan speed—not necessarily the net cold water temperature

produced by the entire tower.

2. As cold air enters the louvers, it causes the falling water to be drawn
inward toward the center of the tower. Thus, under fan operation,
the louvers and lower periphery of the tower structure remain partly
dry, seeing only random splashing from within the tower—plus normal
atmospheric moisture from the entering air. Such lightly wetted areas
are most subject to freezing.

Although ice is unlikely to cause structural damage to the fill, it may

build up sufficiently to restrict the free flow of air through the louvers.
This will have the effect of reducing the tower’s thermal performance
efficiency. When excessive ice forms on the louvers, stop the fan for
a few minutes. With the fan off, the increase in the water temperature
and the action of the cascading water will reduce the ice buildup on
the louvers.

12

operation

Intermittent Freezing Weather Operation:

If periods of shutdown (nights, weekends, etc.) occur during freezing weather,
measures must be taken to prevent the water in the cold water basin—and all
exposed pipework—from freezing. Several methods are used to combat this.
Consult your Marley sales representative for more information.

Caution

Unless some means of freeze prevention is incorporated into your
system, the tower basin and exposed pipework should be drained
at the beginning of each wintertime shutdown period.

It is recommended that you discuss your freeze prevention options with your
local Marley sales representative.

13

maintenance

Water Treatment and Blowdown

Maintaining Water Quality:

The materials used in an NC Fiberglass tower are selected to offer long,
corrosion-free service in a “normal” cooling tower environment, defined
as follows:

• Circulating water with a pH between 6.5 and 8; a chloride content
(as NaCl) below 500 mg/L; a sulfate content (SO4) below 250 mg/L;
total alkalinity below 500 mg/L; calcium hardness (as CaCO3) above
50 mg/L.

• Chlorine (if used) shall be added intermittently, with a free residual not
to exceed 1 mg/L – maintained for short periods. Excessive chlorine
levels may deteriorate sealants and other materials of construction.

• An atmosphere surrounding the tower no worse than “moderate indus­trial,” where rainfall and fog are no more than slightly acid, and they do
not contain significant chlorides or hydrogen sulfide (H2S).

Note

Unless you purchased an NC Fiberglass tower with stainless steel
structure, the structure of your tower consists primarily of galvanized
steel, therefore your water treatment program must be compatible
with zinc. In working with your water treatment supplier, it is impor­tant that you recognize the potential effects on zinc of the specific
treatment program you choose.

Blowdown:

A cooling tower cools water by continuously causing a portion of it to evaporate.
Although the water lost by evaporation is replenished by the makeup system, it
exits the tower as pure water—leaving behind its burden of dissolved solids to
concentrate in the remaining water. Given no means of control, this increasing
concentration of contaminants can reach a very high level.
In order to achieve water quality which is acceptable to the cooling tower (as
well as the remainder of your circulating water system), the selected water
treatment company must work from a relatively constant level of concentra­tions. This stabilization of contaminant concentrations is usually accomplished
by blowdown, which is the constant discharge of a portion of the circulating
water to waste. As a rule, acceptable levels on which to base a treatment
schedule will be in the range of 2-4 concentrations. The following table gives
approximate rates of blowdown (percent of total water flow rate constantly
wasted) to achieve those concentrations at various cooling ranges.*

14

maintenance

.6

.4

.2

.0

.8

Note

egnaRgnilooC

3°C 7.83.52.81.11.80

6°C

8°C 3.2 81.187.85.83.82

11°C 1.3 85.1 50.187.15.83

14°C 9.3 89.1 23.189.46.84

* Range = Difference between hot water temperature coming to tower and cold water

temperature leaving tower.

X5.1 X0.2 X5.2 X0.3 X0.4 X0.5 X0.6

5.187.15.83.52.81

snoitartnecnoCforebmuN

0.

1.

2.

3.

3.

.etarretawgnitalucricehtfo%20.0fotfirdnodesaberasreilpitluM

EXAMPLE: 159.1 m3/hr circulating rate, 10°C cooling range. To main-
tain 4 concentrations, the required blowdown is 0.458% or .00458 times

159.1 m3/hr, which is 0.7 m3/hr.
If tower is operated at 4 concentrations, circulating water will contain four
times as much dissolved solid as the makeup water, assuming none of the
solids form scale or are otherwise removed from the system.

When water treatment chemicals are added, they should not be in­troduced into the circulating water system via the cold water basin
of the cooling tower. Water velocities are lowest at that point, which
results in inadequate mixing.

Warning

Cooling Tower Inspection and Maintenance

Microorganisms including Legionella bacteria can exist in premise
plumbing including cooling towers. The development of an effective
water management plan (WM P) and implementation of maintenance
procedures are essential to prevent the presence, dissemination and
amplification of Legionella bacteria and other waterborne contami­nants throughout premise plumbing. Before operating the cooling
tower, the water management plan and maintenance procedures
must be in place and regularly practiced.

In addition, the following steps are recommended:

Do NOT attempt any service unless the fan motor is locked out.

• Consult a knowledgeable water treatment professional to clean and
treat your cooling tower. See Tower Startup section of this manual.

• Cooling towers must be cleaned and disinfected regularly in accordance
with local public health services and recommendations.

15

maintenance

• Workers performing decontamination procedures must wear personal
protective equipment (PPE) as directed by their facility safety officer.

• Cooling towers must be visually inspected regularly to assess signs of
bacterial growth, appearance of debris and scale on drift eliminators
and general operating conditions.

• Replace worn or damaged components.

To minimize the presence of waterborne microorganisms, including

Legionella, follow the water management plan for your facility, perform

regularly scheduled cooling tower inspections and maintenance, and enlist

the services of water treatment professionals.

For additional technical support, contact your Marley sales represen-

tative. For help identifying the sales representative in your area, visit

spxcooling.com/replocator.

Schedule of Tower Maintenance:

Included with this instruction packet are separate User Manuals on each major
operating component of the tower, and it is recommended that you read them
thoroughly. Where discrepancies may exist, the separate User Manuals will
take precedence.

Warning

The following is recommended as a minimum routine of scheduled maintenance:

Always shut off electrical power to the tower fan motor prior to
performing any inspections that may involve physical contact with
the mechanical or electrical equipment in or on the tower. Lock out
and tag out any electrical switches to prevent others from turning
the power back on. Service personnel must wear proper personal
protective clothing and equipment.

16

maintenance

SHEAVE

STRAIGHT EDGE

SHEAVE

THREADED ROD

FAN SHAFT

Belt Tensioning:

The belts are adjusted by tensioning bolts which adjust the motor base. Check
tension frequently during the first 24-48 hours of run-in operation. To properly
adjust the belt tension, position the fan motor so that moderate pressure on
the belt midway between the sheaves will produce a 13mm deflection. Over­tensioning shortens belt and bearing life. Keep belts free from foreign material
which may cause slipping. Never apply belt dressing as this will damage the
belt and cause early failure. A Dodge® V-Belt Tension Tester or similar device is
an alternate method for tensioning V-belts. Check with you local belt supplier.

Sheave Alignment:

• The motor sheave is to be positioned as close as possible to the motor
in order to minimize torque on the motor bushings.

• The motor and fan sheaves may have grooves that are not used. The bot­tom surface of the motor and fan sheaves must be aligned within 3mm of
each other and level within ½° (3mm in 300mm) in order to not adversely
affect belt and sheave life.

• Alignment can be achieved by placing a straight edge across the top of
the sheaves making sure that it is level and measuring down to the bottom
surface of both sheaves at four points.

• The belts are to be located in the inboard set of grooves closest to the
bearing.

➠

17

maintenance

Weekly Visually inspect the cooling tower to assess general operating condi­tions and for signs of microbial growth and appearance of debris, scale and
corrosion. Consult a knowledgeable water treatment professional to maintain
cooling tower hygiene.
Observe, touch, and listen to the tower. Become accustomed to its normal
appearance, sound, and level of vibration. Abnormal aspects relating to the
rotating equipment should be considered reason to shut down the tower until
the problem can be located and corrected. Observe operation of the motor, fan
shaft bearing and fan. Become familiar with the normal operating temperature
of the motor, as well as the sight and sound of all components as a whole.
Monthly (Inspect louvers, drift eliminators and basin trash screens and
remove any debris or scale which may have accumulated. Replace any dam­aged or worn out components. Use of high-pressure water may damage the
eliminator and louver material.
Observe operation of the float valve. Depress the operating lever to make
sure that the valve is operating freely. Inspect the suction screen for plugging.
Remove any debris that may have accumulated.

Note

Check for any buildup of silt on the floor of the cold water basin. Mentally note
the amount, if any, so future inspections will enable you to determine the rate
at which it is forming.

Every 3 months Lubricate fan shaft bearings. While rotating equipment by

hand, grease the bearings with lithium based grease until a bead forms

around the seals. Mobil SHC 460 grease is recommended.

Semi-Annually If equipped, check the belt tension and condition.
If equipped, check Geareducer oil level. Shut down the unit and allow 5 min­utes for the oil level to stabilize. Add oil if required.

If equipped, Geareducer models used on NC Fiberglass cooling
towers are designed for 5-year oil change intervals. To maintain five­year change intervals, use only oil designed specifically for these
Geareducers. If, after five years, turbine-type mineral oil is used, the
oil must be changed semiannually. Refer to the Geareducer Manual
for oil recommendations and further instructions.

Annually Lubricate motor according to the manufacturer’s instructions. Fan

motors with sealed bearings do not require lubrication maintenance.

Check to see that all bolts are tight in the fan and mechanical equipment region,
including the fan guard. Refer to component User Manuals for torque values.
Inspect the tower thoroughly, making maximum use of instructions given in the

18

maintenance

separate service manuals. Check structural bolted connections and tighten as
required. Make preventive maintenance repairs as necessary.

Every 5 Years: If equipped, change Geareducer oil. Refer to the Geareducer
User Manual for instructions.

Seasonal Shutdown Instructions

When the system is to be shut down for an extended period of time, it is recom­mended that the entire system (cooling tower, system piping, heat exchangers,
etc.) be drained. Leave the basin drain open.

During shutdown, follow recommendations in the Cooling Tower Inspec­tion and Maintenance section of this manual before attempting repairs.

Pay particular attention to mechanical equipment supports and driveshafts.

Tower Framework Check structural bolted connections and tighten as
required.

Caution

Fan Check fan assembly bolting and tighten as required. Use torque settings
prescribed on the fan nameplate. Refer to fan user manual.

Fan Motor Clean and lubricate motor (if required) at close of each operating
season. (Refer to motor manufacturer’s recommendations). Does not apply to
motors with sealed bearings. Check motor anchor bolts and tighten as required.

Do not start motor before determining that there will be no interfer­ence with free rotation of the fan drive.

The motor should be operated for three hours at least once a month. This
serves to dry out windings and lubricate bearing surfaces. Refer to Marley

“Fan Motor” User Manual Z0239042 for additional information.

At start of new operating season, make sure bearings are adequately lubricated
before returning motor to service. Does not apply to motors with sealed bearings.

Prolonged Shutdown:

If shutdown period is longer than seasonal, contact your Marley sales repre­sentative for additional information.

19

maintenance schedule

Maintenance Service Monthly Semi-annually Seasonal Startup or Annually

Inspect General Condition and Operation

Observe Operation of:

Mechanical–motor, fan and drive mechanism

Makeup valve (if equipped)

Inspect for unusual noise or vibration

Inspect and Clean:

Air inlet

PVC drift eliminators

Distribution basin, nozzles and collection basin

Fan motor exterior

Check:

Collection water basin level

Blowdown–adjust as required

Geareducer Drive (if equipped):

Check for loose fasteners including oil drain plug

Check for / repair oil leaks

Check oil level

Change oil

Make sure vent is open

Check driveshaft or coupling alignment

Check for loose driveshaft or coupling fasteners

Check driveshaft or coupling bushings or flex element for unusual wear

Lube lines (if equipped):

Check for oil leaks in hoses or fittings

Belt drive (if equipped):

Fan shaft bearing lubrication (every 3 mo.) every 3 months every 3 months

Check and tighten support fasteners

Check shaft, sheave and belt alignment

Check belt tension and condition

Check sheave bushing fastener torque

Fan:

Check and tighten blade and hub fasteners

Check fan blade pitch and tip clearance

Inspect and touch up fan hub

Motor:

Lubricate (as required)

Check mounting bolts for tightness

Operate at least 3 hours a month 3 hours a month 3 hours a month

Inspect and touch up all metal surfaces

Structure, Bearing Housing, Sheaves, Coupling Flange:

Inspect/tighten all fasteners

Inspect and touch up all metal surfaces

x x

x x

x x

x x

x x

x x

x x

x x

x x

x x

x x

x x

R

x x

x x

x R x

x x

R

x

x

x x

x

x

x

x

x

x

x

x

x

x

R — Refer to Component User Manual

Note: It is recommended at least weekly, that the general operation and condition be observed. Pay attention to

any changes in sound or vibration that may signify a need for closer inspection.

20

maintenance

Additional Services

Our interest in your NC Fiberglass cooling tower does not end with the sale.
We want to make sure that you gain the maximum possible benefit from its
purchase.

Therefore, the following services are available which are intended to assure
the maximum possible service life under your operating conditions, tailor the
operating characteristics to your specific needs, and maintain consistent op­timum thermal performance capability. They are available by contacting your
Marley sales representative.

Replacement Parts:

With the exception of the motor, every component of your tower is designed
and manufactured by SPX Cooling Technologies. We do this because com­mercially available components have not proved capable of withstanding the
harsh environment of a cooling tower — nor do they contribute their share to
the thermal capability and operating characteristics intended.
A complete stock of all parts and components is maintained at one or more
of the various Marley plants. In cases of emergency, they can normally be
shipped within 24 hours — by air freight, if necessary. However, you would
obviously benefit from anticipating your need in advance, thus avoiding the
cost of special handling.
Be sure to mention your tower serial number (from the tower nameplate) when
ordering parts.

Periodic Maintenance:

You may wish to contract with SPX for regularly scheduled visits — for the
purpose of inspecting and reporting your tower’s condition — to make recom­mendations intended to prevent emergencies — and to perform maintenance
considered outside the norm.
This service is not intended to replace the important function performed by
your maintenance staff. Their attention assures the tower’s routine operating
performance, and is invaluable. However, we recognizes that the unusual
manner in which a cooling tower performs its function — as well as the unique
forces which act upon it — may be considerations which occasionally require
the services of an expert technician.

21

troubleshooting

Trouble Cause Remedy

Check power at starter. Correct any bad connections between the
control apparatus and the motor.

Motor will not start

Unusual motor noise

Motor runs hot

Power not available at motor
terminals

Wrong connections Check motor and control connections against wiring diagrams.

Low voltage

Open circuit in motor winding Check stator windings for open circuits.

Fan drive stuck

Rotor defective Look for broken bars or rings.

Motor running single-phase

Motor leads connected incorrectly Check motor connections against wiring diagram on motor.

Bad bearings Check lubrication. Replace bad bearings.

Electrical unbalance Check voltages and currents of all three lines. Correct if required.

Air gap not uniform Check and correct bracket fits or bearing.

Rotor unbalance Rebalance.

Cooling fan hitting end bell-guard Reinstall or replace fan

Wrong voltage or unbalanced
voltage

Overload

Wrong motor RPM

Bearings over greased

Wrong lubrication in bearings Change to proper lubricant. See motor manufacturer’s instructions.

One phase open

Poor ventilation

Winding fault Check with Ohmmeter.

Bent motor shaft Straighten or replace shaft.

Insufficient grease

Too frequent starting or speed
changes

Deterioration of grease or foreign
material in grease

Bearings damaged Replace bearings.

Check starter contacts and control circuit. Reset overloads, close
contacts, reset tripped switches or replace failed control switches.

If power is not on all leads at starter, make sure overload and short
circuit devices are in proper condition.

Check nameplate voltage against power supply. Check voltage at
motor terminals.

Disconnect motor from load and check motor and Geareducer for
cause of problem.

Stop motor and attempt to start it. Motor will not start if single phased.
Check wiring, controls and motor.

Check voltage and current of all three lines against nameplate values.

Check fan blade pitch. See Fan User Manual. Check for drag in fan
drivetrain as from damaged bearings.

Check nameplate against power supply. Check RPM of motor and gear
ratio.

Remove grease reliefs. Run motor up to speed to purge excessive
grease. Does not apply to motors with sealed bearings.

Stop motor and attempt to start it. Motor will not start if single phased.
Check wiring controls and motor

Clean motor and check ventilation openings. Allow ample ventilation
around motor.

Remove plugs and regrease bearings. Does not apply to motors with
sealed bearings.

Limit cumulative acceleration time to a total of 30 seconds per hour.
Set on/off or speed change set-points farther apart. Consider installing
a Marley VFD for fine temperature control.

Flush bearings and relubricate. Does not apply to motors with sealed
bearings.

22

troubleshooting

Trouble Cause Remedy

Voltage too low at motor

Motor does not come up to
speed

Wrong motor rotation Wrong sequence of phases Switch any two of the three motor leads.

Geareducer noise

Unusual fan drive vibration

Fan noise

Scale or foreign substance in
circulating water system

Cold-water temperature too
warm
(see “Tower Operation”)

Excessive drift exiting tower

terminals because of line drop

Broken rotor bars

Geareducer bearings

Gears

Loose bolts and cap screws

Unbalanced driveshaft or worn
couplings

Fan

Worn Geareducer bearings Check fan and pinion shaft endplay. Replace bearings as necessary.

Unbalanced motor

Bent Geareducer shaft Check fan and pinion shaft with dial indicator. Replace if necessary.

Blade rubbing inside of fan
cylinder

Loose bolts in blade clamps Check and tighten if necessary

Insufficient blowdown See “Water Treatment” section of this manual.

Water treatment deficiency

Entering wet-bulb temperature
is above design

Design wet-bulb temperature
was too low

Actual process load greater
than design

Overpumping Reduce water flow over tower to design conditions.

Tower starved for air

Distribution basins overflowing

Faulty drift elimination

Check transformer and setting of taps. Use higher voltage on
transformer terminals or reduce loads. Increase wire size or reduce
inertia.

Look for cracks near the rings. A new rotor may be required. Have
motor service person check motor.

If new, see if noise disappears after one week of operation. Drain, flush
and refill Geareducer oil. See Geareducer User Manual. If still noisy,
replace.

Correct tooth engagement. Replace badly worn gears. Replace gears
with broken or damaged teeth

Tighten all bolts and cap screws on all mechanical equipment and
supports.

Make sure motor and Geareducer shafts are in proper alignment and
“match marks” properly matched. Repair or replace worn couplings.
Rebalance driveshaft by adding of removing weights from balancing
cap screws. See Driveshaft User Manual.

Make certain all blades are as far from center of fan as safety devices
permit. All blades must be pitched the same. See Fan User Manual.
Clean off deposit build-up on blades

Disconnect load and operate motor. If motor still vibrates, rebalance
motor.

Adjust cylinder to provide blade tip clearance.

Consult competent water treating specialist. See “Water Treatment”
section of this manual.

Check to see if local heat sources are affecting tower. See if
surrounding structures are causing recirculation of tower discharge air.
Discuss remedy with Marley representative.

May have to increase tower size. Discuss remedy with Marley
representative.

May have to increase tower size. Discuss remedy with Marley
representative.

Check motor current and voltage to be sure of correct contract power.
Repitch fan blades if necessary. Clean louvers, fill and eliminators.
Check to see if nearby structure or enclosing walls are obstructing
normal airflow to tower. Discuss remedy with Marley representative.

Reduce water flow rate over tower to design conditions. Be sure hot
water basin nozzles are in place and not plugged.

Check to see that integral fill, louvers and eliminators are clean, free
of debris and installed correctly. If drift eliminators are separate from
fill, make sure they are correctly installed in place. Clear if necessary.
Replace damaged or worn out components.

23

NC Fiberglass

USER MANUAL

SPX COOLING TECHNOLOGIES UK LTD

3 KNIGHTSBRIDGE PARK

WORCESTER WR4 9FA UK

44 1905 750 270 | [e-mail]

spxcooling.com

uk_Z0702489_D | ISSUED 8/2018

© 2009-2018 SPX COOLING TECHNOLOGIES, INC | ALL RIGHTS RESERVED

In the interest of technological progress, all products are subject to design

and/or material change without notice.