Marley Aquatower 490A User manual

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/Marley Aquatower®Cooling Tower /
User Manual 01-1248D

3
Warning
Caution
Contents
Tower Installation.................................................................................... 4
Piping to Tower....................................................................................... 5
Mechanical Equipment Installation ........................................................ 6
Motor Wiring........................................................................................... 9
Starting and Operating Instructions ..................................................... 12
Maintenance Instructions ..................................................................... 14
Cooling Tower Cleaning ....................................................................... 16
Blowdown............................................................................................. 17
Seasonal Shutdown Instructions.......................................................... 18
Troubleshooting.................................................................................... 19
Wiring Diagrams ................................................................................... 20
Parts List .............................................................................................. 23
The following defined terms are used throughout this manual to bring at-
tention 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.
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.
Note

4
Installation
Receiving Inspection
The motor and miscellaneous parts ship with the tower. Check motor
nameplate to be sure that power supply and motor have the same char-
acteristics. Inspect the entire shipment for any damage that may have
occurred in transit.
Tower Location
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 appli-
cable air pollution, fire, and clean air codes.
Locate so prevailing wind will blow into the louvered face, and direct fan
discharge away from building surfaces. Locate so there is free air flow to
and from the tower. Allow clearance on all sides for maintenance.
Indoor Installation
Use a duct from the tower air discharge to the outside. You may also want
to install an inlet air duct. Do not allow the total pressure loss through
ducts to exceed 0.10 inches H2O. To minimize pressure losses:
• Use 20% oversize ducts.
• Avoid sharp turns or abrupt changes in size.
• Keep duct length to a minimum.
• Screened or louvered openings should have a net free area at least
20% greater than the tower discharge opening area.
Attach ducts to the tower using flexible connections, and support ducts
independently from the tower. Provide access openings for servicing the
mechanical equipment if air discharge ducts are installed. If the duct dis-
charges into the prevailing wind, you may need to install a windbreak or an
elbow to serve as a deflector. Ducts installed on towers with year-round
usage should be water tight and insulated to prevent condensation.
Warning
➠

5
Installation
Tower Installation
Install tower in a level position on a stable foundation. Anchor tower to
the foundation through holes at base of tower, using four 3⁄8" diameter
bolts (not supplied). Remove strapping and brackets from the louver
face on Models 4940, 4950, and 4960 and reinstall the bolts to the cold
water basin.
Piping to Tower (Summer–Only Operation)
1. Use large enough piping to minimize friction loss.
2. Connect float valve to makeup water supply. Install the threaded valve
stem and float located in the loose parts package.
3. Install a valved blowdown line at some point in the system, preferably
in the hot water line near the top of the tower, so that water will flow
through the line whenever the pump is operating. (Blowdown is the
continuous removal of a small amount of water during operation to
retard scale and corrosion.)
Cooling
Tower
with
Bottom
Outlet
Heat
Load
Indoor
Storage 
Tank
Pump
Make-Up
Line
Inlet
Gravity Line
from Outlet
Overflow and
Drain to Sewer
Figure 1

6
Installation
SUPPORT BRACKET
(WITH ADJUSTMENT SLOTS)
1/4" TAP SCREW
Piping to Tower (Year–Round Operation)
1. If your tower must operate during freezing weather, it is recommended
that the tower be installed for gravity flow operation. See Figure 1.
2. Provide an indoor open type storage tank with a capacity that will
contain all water that will drain into the tank from the system during
shutdown.
3. Connect tower outlet to storage tank. Bottom outlet option should
be used for gravity flow.
4. Install makeup water, bleed-off, overflow and drain lines on tank.
5. Insulate and heat water lines exposed to freezing temperatures.
Mechanical Equipment Installation
Aquatowerswith factory-installedcontrols ship with themotor,sheave,
belt, and belt guard factory-installed. Remove shipping stiffener plate
and hardware at the adjustable end of the motor support plate and
proceed to Motor Electrical Connections.
Motor, Sheave, and V-Belt Installation
1. Check the motor nameplate to be sure its voltage, phase and frequency
ratings are the same as the power supply.
Note
Motor Frame Fastener Size
56–143T–145T 5/16"
182T thru 215T 3/8"
Figure 2
➠

7
2. Make sure the fan is tightly secured to the bearing housing shaft and
that it rotates freely. Make sure the bearing housing is secured to its
support.
3. Attach motor to motor base with four bolts, flat washers, lock wash-
ers and nuts provided, see Figure 2. You may want to loosen the
adjusting bolts and raise the motor base so you can reach under the
motor base to tighten the motor hold-down bolts.
4. Apply a rust preventive coating to the motor shaft to prevent shaft
corrosion and to ease sheave installation and removal.
5. Install motor sheave and align it with fan sheave. Motor support
brackets are slotted to assist in alignment. See Figure 2. A plumb
line will be helpful in aligning sheaves. See Figure 3.
6. Remove the fan guard and fan cylinder splice plate (Series 4900 only)
at the top of the fan cylinder. Install the belt over the fan by passing
the belt over the fan and rotating the fan blades past the belt. Install
the belt onto the sheaves.
Figure 3
Installation
PLUMB LINE
SHEAVES MUST BE PARALLEL TO
EACH OTHER AND IN THE SAME
PLANE OF OPERATION FAN SHEAVE
MOTOR SHEAVE

8
Installation
7. Use the adjusting bolts on the motor support to adjust belt tension. A
correctly tensioned belt does not slip when the fan is running—and the
“tight” side is straight between sheaves. The “slack” side will have a
slight bow. If possible, use a commercially available tension measuring
device. Avoid over-tensioning. Too much tension reduces bearing
and belt life. Check the tension on new belts after 8 to 12 hours of
operation.
8. Install the belt guard as shown in Figure 2.
9. Install fan cylinder splice plate and fan guard.
10. Check bearing housing oil cup level. Fill to the proper level with SAE
30 (ISO 100) weight oil.

9
Installation
Motor Wiring
Wire motor leads as shown on the motor nameplate matching the supply
voltage. Do not deviate from the motor nameplate wiring.
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.
• Do not start the motor more than six 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 six 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 NEMA MG-1, part 31.
• 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 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.
Note

10
Installation
• If cable distance between the VFD and motor is greater than 100
feet a DV/DT output filter is recommended to avoid damage to the
motor. 100 feet 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 en-
ergy 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.
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.
Warning
Warning

11
Motor Electrical Connections
If Aquatower is equipped with Marley Control System, refer to Control
System Manual for wiring instructions.
Connect motor to power supply in accordance with the National Electric
Code and local requirements. Failure to wire the motor correctly will void
its warranty. Overload protection for motors must be part of the control
system. Figure 4 shows one possible control scheme. Other various wir-
ing diagrams appear on pages 20 thru 22.
Installation
L1
L2
L3
MMM
STOP START
M
M
OL
2-WIRE CONTROL (IF USED)
NOTE: L3 IS USED ON 3-PHASE MOTOR ONLY.
MOTOR
Figure 4
Note

12
Operation
Starting and Operating Instructions
Among other sources, outbreaks of Legionnaires’ Disease have
reportedly been traced to cooling towers. Maintenance and water
treatment procedures that prevent amplification and dissemination
of Legionella and other airborne bacteria should be formulated and
implemented BEFORE systems are operated and continued regularly
thereafter to avoid the risk of sickness or death.
1. New installations should be cleaned and treated with biocides by a
water treatment expert before startup.
2. Clean all debris, such as leaves and dirt from the cooling tower fill and
basin.
3. Fill the circulating system with water. The cold water basin should be
filled with water until level is at the rim of the overflow.
The water conditions during the initial tower operation are crucial in
preventing premature corrosion of galvanized steel (white rust). For
at least the first eight weeks of operation, pH should be controlled
between 6.5 and 8.0 with hardness and alkalinity levels between 100
and 300 ppm (expressed as CaCO3).
If tower is equipped with a standard side-suction connection, vent
any accumulated air from the top of the suction hood by removing
one or both tap screws provided at that location. Replace these tap
screws when venting is complete.
4. Start your pump(s). Observe system operation. Since the water system
external to the tower will have been filled only to the level in the cold water
basin, some “pump-down” of the basin water level willoccur before wa-
ter completes the circuit and begins to fall from the fill. The initial pump-
down may not be enough to cause the float valve to open. However, you
can check its operation by pressing down on the operating lever. Adjust
the float valve during tower operation with heat load to maintain 4" water
depth in the depressed section of the basin on Models 490A through
493B. Maintain 51⁄2" water depth on Models 494A through 496B.
Hot water temperatures exceeding 125°F could damage PVC fill.
Note
Note
➠
Warning

13
5. Make sure blowdown line is discharging water.
6. Depth ofwaterinhotwaterbasinshouldbeuniform. Ifthe basinoverflows,
reduce the flow rate. Do not pump more water than design capacity.
7. Continue pump operation for about 15 minutes, after which it is rec-
ommended that the water system be drained, flushed, and refilled.
8. While operating the condensing water pump(s) and prior to operat-
ing 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. Main-
tain 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
(ppm) free chlorine residual at a pH of 7.0 to 7.6. The chlorine re-
sidual must be held at 4 to 5 mg/L (ppm) 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 circulat-
ing 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. Check fan for free rotation and check oil level in bearing housing as
required (see maintenance instructions). Start motor and check di-
rection of rotation. Fan must rotate clockwise when viewed from the
fan discharge side. If the rotation is incorrect, change any two of the
three motor leads.
Do not allow the total motor acceleration time to exceed 30 seconds
per hour.
Operation
Note

14
Maintenance
Warning
Maintenance Instructions
Always make certain that mechanical equipment is inoperable during
periods of maintenance—or during any situation of possible endan-
germent to personnel. If your electrical system contains a disconnect
switch, lock it out until the period of exposure to injury is over.
The top of the tower is not a working surface. Do not stand, sit or
walk on top of the tower. Use an appropriate ladder adjacent to the
tower whenever you perform any maintenance activity on the tower’s
upper surfaces.
This product is constructed using cold-formed sheet metal. Use
protective clothing, gloves and shoes as appropriate for protection
against edges of thin gage material.
Motor
Lubricate the motor according to the motor manufacturer’s supplied in-
structions. Remove any oil, dust or scale deposits from the motor which
can cause excessive insulation temperatures.
Refer to Electric Motors on Cooling Towers, Manual 92-1475, for additional
maintenance and lubrication information.
Fan Shaft Bearing Housing
Check bearing housing oil cup level. Fill to the proper level with SAE 30
(ISO 100) weight oil.
Belt Tension
Check belt tension every two to three weeks during peak operating sea-
son.
Makeup Float Valve
Check float valve periodically for proper operation and proper water
level.
Basin and Suction Screen
Drain and clean cold water basin and suction screen periodically.
Blowdown
Check the blowdown for continuous water discharge during operation.

15
Maintenance Schedule
Maintenance Service Monthly Semi-annually Seasonal Startup or Annually
Inspect General Condition and Operation x x
Observe Operation of:
Mechanical–motor, fan and drive mechanism x x
Makeup valve (if equipped) x x
Inspect for unusual noise or vibration x x
Inspect and Clean:
Air inlet x x
PVC drift eliminators x x
Distribution basin, nozzles and collection basin x x
Fan motor exterior x x
Check:
Collection water basin level x x
Blowdown–adjust as required x x
Belt drive:
Fan shaft bearing lubrication (every 3 mo.) every 3 months every 3 months
Check and tighten support fasteners x
Check shaft, sheave and belt alignment x
Check belt tension and condition x x
Check sheave bushing fastener torque x
Fan:
Check and tighten blade and hub fasteners x
Check fan blade pitch and tip clearance x
Check fan cylinder for loose fasteners x
Motor:
Lubricate (grease as required) R
Check mounting bolts for tightness x
Operate at least 3 hours a month 3 hours a month 3 hours a month
Basin Heater (if equipped):
Check for proper operation of temp/low water level sensor x
Inspect/clean buildup of contaminant from sensor x x
Structure:
Inspect/tighten all fasteners x x
Inspect and touch up all metal surfaces 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.

16
Maintenance
Cooling Tower Cleaning
Any evaporative-type cooling tower must be thoroughly cleaned on
a regular basis to minimize the growth of bacteria, including Legio-
nella Pneumophila, to avoid the risk of sickness or death. Service
personnel must wear proper personal protective equipment during
decontamination. Do NOT attempt any service unless the fan motor
is locked out.
Operators of evaporative cooling equipment, such as water cooling tow-
ers, should follow maintenance programs which will reduce to an abso-
lute minimum the opportunity for bacteriological contamination. Public
Health Service officials have recommended that “good housekeeping”
procedures be followed, such as: regular inspections for concentrations
of dirt, scale, and algae; periodic flushing and cleaning; and the following
of a complete water treatment program including biocidal treatment. See
Starting and Operating Instructions on page 12.
A visual inspection should take place at least once a week during the
operating season. Inspect for bacterial growth and general operation
conditions. Bacterial growth should be reported to your water treatment
expert for immediate attention. At a minimum, cooling towers should be
cleaned and disinfected with biocides twice a year. Systems with biofoul-
ing or positive cultures of legionella may require additional cleaning.
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. The louvers, drift eliminators and easily accessible
fill surfaces should be flushed by use of a moderate-pressure water nozzle,
being careful not to cause physical damage. Use of high-pressure water
may damage the eliminator and louver material. A reliable water treatment
program should be installed and maintained. Filtration devices may be
employed to reduce the suspended solids concentrations, thus increasing
the effectiveness of the water treatment program.
Warning

17
Blowdown
A cooling tower cools water by continuously causing a portion of it to evapo-
rate. Although the water lost by evaporation is replenished by the makeup
system, itexitsthe tower aspure water—leaving behindits burden ofdissolved
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 concentra-
tions. This stabilization of contaminant concentrations is usually accom-
plished 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 are intherangeof2–4 concentrations. Thefollowing table
gives approximate blowdownrates(percentof totalwater flowrateconstantly
wasted) to achieve those concentrations at various cooling ranges*:
Maintenance
Note
Blowdown Rate
Cooling Two Four
Range (°F) Concentrations Concentrations
10 0.7% 0.17%
15 1.1% 0.30%
20 1.5% 0.43%
* Range is the difference between hot water temperature entering the tower and
cold water temperature leaving the tower.
When water treatment chemicals are added, they should not be in-
troduced 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 and may damage the cooling tower.
Intermittent Wintertime 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, including Marley automatic basin heater system.
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.
If tower basin is drained, verify that all basin heaters have been shut
off either by automatic cutoff or disconnect switch.
Caution
Warning

18
Maintenance
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, clean the tower and make any necessary repairs. Apply
protective coating as required to all metal parts. Pay particular attention
to bearing housing supports.
Bearing Housing
• At shutdown, check the oil level in the oil cup.
• At start of new operating season, operate until the oil is warm—drain
and refill. Use SAE 30 (ISO 100) weight oil.
• Bearing housing must be refilled at the point where the oil line from
the oil reservoir cup connects to the bearing housing. Attach oil line
and fill line and oil cup. Fan guard will have to be removed to change
oil. Each month check the oil level at the oil cup.
Electric Motor
Clean and lubricate motor at close of each operating season. Refer to
motor manufacturer’s recommendations.
Do not start motor before determining that there will be no interfer-
ence with free rotation of the fan drive.
The motor should be run for three hours at least once a month to dry out
windings and relubricate bearing surfaces. Refer to Electric Motors on
Cooling Towers, Manual 92-1475.
At start of new operating season, make sure bearings are adequately
lubricated before returning motor to service.
Prolonged Shutdown
If shutdown period is longer than seasonal, contact your Marley Sales
Representative for additional information.
Whenever you order parts or correspond with us about your tower,
please include the tower serial number located on the tower's name
plate.
Note
Warning

19
Troubleshooting
Remedy
Stop motor and attempt to start it. Motor will not start if single-
phased. Check wiring, controls and motor.
Check motor connections against wiring diagram on motor.
Check lubrication. Replace bad bearings.
Check voltage and currents of all three lines. Correct if required.
Rebalance.
Check voltage and current of all three lines against nameplate
values.
Check nameplate RPM of motor and sheave ratio against parts
list. Measure RPM.
Remove grease reliefs. Run motor up to speed to purge excessive
grease.
Change to proper lubricant. See motor manufacturer’s instructions.
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 ventila-
tion around motor.
Check with Ohmmeter.
Straighten or replace shaft.
Remove plugs and regrease bearings.
Limit cumulative starting time to a total of 30 seconds each hour.
Flush bearings and relubricate.
Replace bearings.
Tighten all bolts and cap screws on all mechanical equipment and
supports.
Replace bearings.
Replace shaft.
Make sure fan and motor are straight and properly aligned.
Check belt for proper tension.
Disconnect load. Remove sheave, tape key in keyway and
operate motor. If motor still vibrates, rebalance motor.
Trouble
Unusual motor noise
Motor runs hot
Unusual fan drive
vibration
Cause
Motor running single-phase
Motor leads connected incorrectly
Bad bearings
Electrical unbalance
Rotor unbalance
Motor overload, wrong voltage or
unbalanced voltage
Wrong fan RPM
Bearings overgreased
Wrong lubricant in bearings
One phase open
Poor ventilation
Winding fault
Bent motor shaft
Insufficient grease
Too frequent starting
Deterioration of or foreign material
in grease
Bearings damaged
Loose bolts and cap screws
Worn fan shaft bearings
Bent shaft
Misalignment
Loose or stretched belt
Unbalanced motor

20
Wiring Diagrams
T1-L1
T2
T3
T4
T8
T5-L2
Capacitor Start Single Phase Motors,
Reversible, Double Voltage
Without Thermal Overload (Integral HP)
High Voltage
1. Connect T1 and L1 and insulate.
2. Connect T2, T3 and T8 and insulate.
3. Connect T4, T5 and L2 and insulate.
Low Voltage
1. Connect T2, T3, T8 and L1 and insulate.
2. Connect T2, T4, T5 and L2 and insulate.
With Thermal Overload (Fractional HP)
High Voltage
1. Insulate P2.
2. Connect T2, T3 and L8 and insulate.
3. Connect T4, T5 and L2 and insulate.
4. Connect P1 and L1 and insulate.
P1-L1
T2
T3
T4
T8
T5-L2
T2
➠