Marley Aquatower 492A, Aquatower492B, Aquatower490B, Aquatower 493A, Aquatower493B User Manual
...
>ViÊNÊ>ÊÀÞÊ}ÊNÊ>ÀiÞ
}Ê/iV}iÃ
Marley Aquatower® Cooling Tower
/
/
User Manual 01-1248D
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.
Warning
Caution
Note
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.
3
Warning
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.
➠
4
Installation
Cooling
Tower
with
Bottom
Outlet
Heat
Load
Indoor
Storage
Tank
Pump
Make-Up
Line
Inlet
Gravity Line
from Outlet
Overflow and
Drain to Sewer
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.)
Figure 1
5
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
Note
Motor Frame Fastener Size
56–143T–145T 5/16"
182T thru 215T 3/8"
Aquatowers with factory-installed controls ship with the motor, 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.
➠
Figure 2
6
Installation
PLUMB LINE
SHEAVES MUST BE PARALLEL TO
EACH OTHER AND IN THE SAME
PLANE OF OPERATION
FAN SHEAVE
MOTOR SHEAVE
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.
Figure 3
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.
7
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.
8
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:
Note
• 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.
9
Loading...