Baltimore Aircoil Company equipment needs to be
properly installed, operated and maintained.
Documentation of the equipment used, including a
drawing, technical data sheet and this manual should be
kept on record. To achieve long, trouble-free and safe
operation, it is necessary to establish an operating plan
including a programme of regular inspection, monitoring
and maintenance. All inspections, maintenance and
monitoring actions should be recorded in a cooling system
logbook. The operating and maintenance instructions
published here can be used as a guide to achieve these
goals.
In addition to establishing the operating plan and the
cooling system logbook it is recommended to conduct a
cooling system risk analysis, preferably by an independent
third party.
For the cooling system, scale, corrosion and biological
control must be established and initiated when the system
is first filled with water and administered on a regular
basis thereafter in accordance with recognized Codes of
Practice, (such as EUROVENT 9 - 5/6, ACOP HSC L8, Guide
des bonnes pratiques, Legionella et tours
aéroréfrigérantes, etc.). Water sampling, test results and
corrective actions should be recorded in the cooling
system logbook.
For more specific recommendations on keeping your
cooling system efficient and safe, contact your local BAC
Balticare service provider or representative. Name, e-mail
and phone number can be found on the website
www.BACservice.eu.
Table of Contents page
Construction Details 2
General Information 3
Water Care 4
Cold Weather Operations 5
Maintenance Procedures 6
Comprehensive Maintenance 13
Further Assistance & Information 14
2
CONSTRUCTION DETAILS
TYPICAL CROSS SECTION
- Water Distribution System
- Eliminators (not shown)
- Fill
- Cold Water Basin
- Strainer
- Drain
- Overflow
- Make-up Assembly & Quick Fill
- Louvres
- Fan Shaft (not shown)
- Fan (not shown)
- Drive Train (not shown)
- Motor Base (not shown)
- Motor
- Access door (not shown)
Note: Models RCT-2118 and RCT-2129 are direct drive and do not have drive
train.
RCT Cooling Towers
GENERAL INFORMATION
3
BAC cooling equipment is designed for the operating conditions
specified below, which must not be exceeded during operation.
Wind Load: For safe operation of unshielded equipment exposed to
wind speeds above 120 km/h installed at a height above 30 m from
the ground contact your local BAC-Balticare representative.
Seismic Risk: For safe operation of equipment installed in moderate
and high hazard area’s contact your local BAC Balticare
representative.
Standard electrical motors are suitable for an ambiant temperature
range from -25°C to +40°C.
COOLING TOWERS
Maximum inlet pressure : 0.5 bar
Water inlet temperature : max. 55°C (std. fill) or 65°C (high
temperature option)
Water outlet temperature : min. 5°C
For circulating water quality compatible with construction materials
refer to section ‘WATER CARE’ on page 4.
Note: Actual spray pressure is indicated on technical data sheet supplied with
order acknowledgement.
All piping external to BAC cooling equipment must be supported
separately. In case the equipment is installed on vibration rails or
springs, the piping must contain compensators to eliminate
vibrations carried through the external pipework.
All electrical, mechanical and rotating machinery constitute a
potential hazard, particularly for those not familiar with its design,
construction and operation. Accordingly, adequate safeguards
(including use of protective enclosures where necessary) should be
taken with this equipment both to safeguard the public (including
minors) from injury and to prevent damage to the equipment, its
associated system and the premises.
If there is doubt about safe and proper rigging, installation,
operation or maintenance procedures, contact the equipment
manufacturer or his representative for advise.
When working on operating equipment, be aware that some parts
may have an elevated temperature. Any operations on elevated
level have to be executed with extra care to prevent accidents.
!
Do not cover units with PVC eliminators or fill with a plastic
tarpaulin. Temperature increase due to sun radiation could
deform the fill or eliminators
AUTHORIZED PERSONNEL
The operation, maintenance and repair of this equipment should be
undertaken only by personnel authorized and qualified to do so. All
such personnel should be thoroughly familiar with the equipment,
the associated systems and controls and the procedures set forth in
this and other relevant manuals. Proper care, procedures and tools
must be used in handling, lifting, installing, operating and repairing
this equipment to prevent personal injury and/or property damage.
MECHANICAL SAFETY
Mechanical safety of the equipment is in accordance with the
requirements of the EU machinery directive. Depending upon site
conditions it also may be necessary to install items such as bottom
screens, ladders, safety cages, stairways, access platforms,
handrails and toe boards for the safety and convenience of the
authorized service and maintenance personnel. At no time this
equipment should be operated without all fan screens, access
panels and access doors in place.
When the equipment is operated with a variable fan speed control
device, steps must be taken to avoid operating at or near to the
fan’s «critical speed». For more information consult your local BAC
Balticare representative.
ELECTRICAL SAFETY
Each fan and pump motor associated with this equipment should be
installed with a lockable disconnect switch located within the sight
of the equipment. No service work should be performed on or near
the fans, motors, drives or inside the equipment unless fan and
pump motors, heaters etc. are electrically isolated.
LOCATION
All cooling equipment should be located as far away as possible
from occupied areas, open windows or air intakes to buildings.
LOCAL REGULATIONS
Installation and operation of cooling equipment may be subject of
local regulations, such as establishment of risk analysis. Ensure
regulatory requirements are consistently met.
Operating Conditions
Connecting Pipework
Safety Precautions
4
WATER CARE
In all cooling equipment, operating in evaporative mode, the cooling
is accomplished by evaporating a small portion of the re-circulating
water as it flows through the equipment. When this water
evaporates, the impurities originally present in the water remain.
Unless a small amount of water is drained from the system, known
as blow down, the concentration of dissolved solids will increase
rapidly and lead to scale formation or corrosion or both. Also, since
water is being lost from the system through evaporation and blow
down, this water needs to be replenished.
The total amount of replenishment, known as make-up, is defined
as:
Make-up = evaporation loss + blow down
In addition to the impurities present in the make-up water, any
airborne impurities or biological matter are carried into the
equipment and drawn into the re-circulating water. Over and above
the necessity to blow down a small quantity of water, a water
treatment programme specifically designed to address scale,
corrosion and biological control should be initiated when the system
is first installed and maintained on a continuous base thereafter.
Moreover there must be an ongoing programme of monitoring in
place to ensure the water treatment system is maintaining the
water quality within the control guidelines.
Check and adjustments of blow down depends on the blow down
device actual in use.
To prevent excessive build-up of impurities in the circulating water, a
small amount of water must be « bled » from the system at a rate to
be determined by the water treatment regime. The amount of blow
down is determined by the design cycles of concentration for the
system. These cycles of concentration depend on the quality of the
make-up water and the design guidelines for the quality of the
recirculating water given below.
Make-up water to the evaporative unit should have minimum 30
ppm hardness as CaCO3.
Where use of a softener is necessary to achieve this, the supply to
the evaporative unit should not be totally softened, but blended with
the incoming unsoftened water to achieve the minimum hardness
between 30 and 70 ppm as Ca CO3.
Maintaining a minimum hardness in the make-up water offsets the
corrosive properties of totally softened water and reduces the
reliance on corrosion inhibitors to protect the system.
Note: (*)Higher concentration of sulphates is allowed, provided the sum of
chlorides + sulphates paramteters does not exceed 1500 mg/l for Pultruded
composite.
Cycles of concentration are the ratio of the dissolved solids
concentration in the circulating water compared to the dissolved
solids concentration in the make-up water. The blow down rate can
be calculated as follows :
Blow down = Evaporation loss / Cycles of concentration - 1
The evaporation loss is not only function of the heat load but also
depends on climatic conditions, the type of equipment used and the
method of capacity control, which is applied. The evaporation loss at
summer conditions is approximately 0.431 l/ 1000 kJ heat
rejection. This number should be used for blow down valve sizing
only and not for the calculation of annual water consumption.
The growth of algae, slimes and other micro-organisms, if
uncontrolled, will reduce system efficiency and may contribute to
the growth of potentially harmful micro-organisms, such as
Legionella, in the recirculating water system.
Accordingly a treatment programme specifically designed to
address biological control should be initiated when the system is
first filled with water and administered on a regular base thereafter
in accordance with any regulations (national, regional) that may
exist or in accordance with accepted codes of good practice, such as
EUROVENT 9-5/6, VDMA Detailsheet 24649 etc.
It is strongly recommended to monitor the bacteriological
contamination of the recirculating water on a regular base (for
example, TAB test with dip slides on a weekly base) and record all
results. Water treatment should meet the following requirements:
- The chemicals must be compatible with the materials of
construction used in the cooling system.
- Chemicals should be fed into the re-circulated water to avoid
localised high concentrations, which may cause corrosion.
Chemicals are normally fed into the pump discharge line. Batch
feeding of chemicals does not afford adequate control of water
quality and is not recommended.
It is strongly recommended to check the key parameters of the
circulating water quality on a monthly base. See Table: Circulated
Water Quality Guidelines. All test results need be recorded.
When new systems are first commissioned, special measures
should be taken to ensure that galvanized steel surfaces are
properly passivated to provide maximum protection from corrosion.
Passivation is the formation of a protective, passive, oxide layer on
galvanized steel surfaces. To ensure that galvanized steel surfaces
are passivated, the pH of circulating water should be kept between
7.0 and 8.2 and calcium hardness between 100 and 300 ppm (as
CaCO3) for four to eight weeks after start-up, or until new zinc
surfaces turn dull grey in colour. If white deposits form on
galvanized steel surfaces after the pH is returned to normal service
levels, it may be necessary to repeat the passivation process.
Note: Stainless steel units and units protected by the BALTIBOND® hybrid
coating, without galvanized coil, do not require passivation.
In case you can’t keep the pH below 8.2, a secondary approach is to
conduct a chemical passivation using inorganic phosphate or filmforming passivation agents. Consult your water treatment specialist
for specific recommendation
About Water Care
Pultruded Composite
pH 6.5 to 9.5
pH during initial passivation Not Applicable
Total hardness as (CaCO3) 750 mg/l
Total alkalinity as (CaCO3) 600 mg/l max.
Total Dissolved Solids 2500 mg/l max.
Conductivity 4000 µS/cm
Chlorides 750 mg/l max.
Sulfates() 750 mg/l max.()
Total suspended solids 25 mg/l max.
Chlorination (as free chlorine): continuous
2 mg / l max.
Chlorination (as free chlorine): batch
dosing for cleaning & disinfection
5-15 mg/l max. for 6 hours max.
25 mg/l max. for 2 hours max.
50 mg/l max. for 1 hour max.
Table 1: Circulated Water Quality Guidelines for Pultruded Composite
Biological Control
Chemical Treatment
Passivation
COLD WEATHER OPERATIONS
5
BAC equipment can be operated in subfreezing ambient conditions
provided the proper measures are taken :
- Protection against sump water freezing, when the system is idle.
- Capacity control to prevent ice formation during operation.
Listed below are general guidelines, which should be followed to
minimise the possibility of freeze-up. As these guidelines may not
include all aspects of the anticipated operation scheme, system
designer and operator must thoroughly review the system, location
of the equipment, controls and accessories to ensure reliable
operation at all times.
To prevent sump water from freezing, either sump heaters or a
remote sump located in a heated indoor area must be installed. For
a seasonal shut down during the cold weather period, it is
recommended to drain the sump.
Thermostats for electrical sump heaters for this equipment are set
to maintain a sump water temperature of 4°C.
In addition to protecting the sump water, all exposed water piping, in
particular make-up water lines should be heat traced and insulated.
It is necessary to prevent the recirculating water from approaching
freezing conditions when the system is operating under load. The
most « critical » situation occurs, if operation at subfreezing
conditions coincides with light load conditions. The key to protecting
the recirculating water is capacity control by adjustment of airflow
to maintain the temperature of the recirculating water minimal
above freezing point. As a rule of thumb this minimum temperature
is 5°C, but there are applications, where even lower temperatures
can be accepted. (Contact your local BAC Balticare representative
for advice.)
Whenever two speed motors are used for capacity control, a time
delay of at least 15 seconds is required when switching form high to
low speed. Sudden switch over might damage the drive system or
the motor.
Note: When operating with VFD drives above nominal frequency be aware of
the potential risk for motor overload or mechanical damages.
Note: It is recommended to provide sinus filters on the VFD to prevent bearing
damage on fan motors.
!
Please refer to fan motor nameplate data when
programming a VFD.
The purpose of a Low Level Cut out Switch is to protect the pump
from running dry in case of make-up failure or extreme water loss.
The status of the alarm can be checked prior to pump start-up, but
should not be considered during the first minute after start-up, since
activation of the pump can cause a water level drop, that might
trigger the alarm. Normal make-up will stabilize the water level after
a short period of time.
About Cold Weather Operation
Protection Against Sump Water Freezing
Capacity Control
6
MAINTENANCE PROCEDURES
COLD WATER BASIN AND BASIN STRAINERS
The cold water basin should be inspected regularly. Any debris
which may have accumulated in the basin or on the strainers should
be removed. Quarterly, or more often if necessary, the entire cold
water basin should be drained, cleaned and flushed with fresh water
to remove the silt and sediment which normally collects in the basin
and under the wet deck surface during operation.
When flushing the basin, the strainers should be left in place to
prevent the sediment from re-entering the unit system. After the
basin has been flushed, the strainers should be removed, cleaned,
and replaced before refilling the basin with fresh water.
!
DO NOT USE ACID TO CLEAN THE STRAINERS
Remote Basin
The water level in the basin of equipment designed for remote basin
operation is a function of the circulating water flow rate; water
outlet connection size, quantity and location, and outlet piping size
and configuration. The remote basin unit is supplied without a water
make-up assembly or a strainer and the basin operating level during
remote basin operation is not adjustable.
OPERATING LEVEL AND MAKE-UP
As the water circulating through the tower is cooled, it collects in the
cold water basin and passes through the strainers into the system.
The operating water level is controlled by the make-up valve and
should be maintained at an operating water level of 140 mm below
ledge on which louvres rest.
The operating water level in the cold water basin will vary somewhat
with system thermal load (evaporation rate), the bleed rate
employed and the make-up water supply pressure. Because the
typical winter load is less than the summer load, the winter
evaporation rate is frequently less than the summer evaporation
rate. With this reduced evaporation rate in winter, the water level in
the cold water basin will increase unless the float is readjusted. The
operating water level should be checked monthly and float readjusted as necessary to maintain the recommended operating
level.
A float operated water make-up assembly is furnished as standard
equipment on cooling towers. It is located inside the unit within easy
reach from the access door.
The standard make-up assembly (see figure below) consists of a
make-up valve connected to a float arm assembly and actuated by a
large diameter plastic float. The float is mounted on an all-thread
rod which is held in place by wing nuts. The operating water level in
the cold water basin can be adjusted by repositioning the float and
all-thread rod using the wing nuts provided.
The make-up assembly should be inspected monthly and adjusted
as necessary. The valve itself should be inspected annually for
leakage and the valve seat replaced if necessary. The make-up
water supply pressure should be maintained between 100 and 450
kPa for proper operation of the valve.
To make the initial basin water level setting, fill the sump with water
until 2 cm above the operating level. Adjust the wing nuts of the
float ball so that the make-up valve is completely closed. Before
starting the unit for the first time, fill the sump until 1 cm below
overflow level (push float ball under). Under normal load conditions
this setting should produce the correct operating level. At low load
conditions the operating level will rise and needs to be adjusted. The
unit basin should be closely monitored and water level adjusted as
necessary during the first 24 hours of operation.
- Float Ball
- All Threaded rod
- Wing Nuts
- Float Arm Assembly
- Float Valve
BLOW DOWN
In case of a continuous blow down with a metering valve in the
bleed line, ensure that the valve is unobstructed and that blow down
water can drain freely. Measure the blow down flow rate by
recording the time needed to fill a given volume.
For automatic blow down using conductivity control, ensure that the
conductivity probe is clean and that the blow down solenoid valve is
operational. Unless you have a specific adjustment procedure, your
water treatment company should check and adjust set points.
Checks and Adjustments
Figure 1: Basin Strainer
Figure 2: Mechanical Float Assembly
Figure 3: Water Make-up Valve Assembly
MAINTENANCE PROCEDURES
7
SUMP HEATER PACKAGE
Sump heaters must only operate in the winter to prevent the sump
water from freezing, when the water pump(s) and the fan(s) are shut
off. Under no circumstances should sump heaters operate at other
times as they could potentially heat the water to temperature levels,
which are favourable to bacteriological growth. Ensure every six
months the heater thermostat is properly set and clean. Also ensure
that control and safety devices, such as low level cut out switches,
are operational, clean and properly incorporated into the control
circuit.
!
SUMP HEATERS CAN BE HOT.
BELT TENSIONING
Belt tensioning can be checked as follows:
- Shut off fan(s).
- Rotate the fan sheave half a turn to evenly distribute the tension
in the belt before measuring.
- Check belt tension by verifying both following conditions:
the deflection amounts 10 mm/m free belt length (see figure
below)
the deflection force required is between the minimum and
maximum values given in the table below.
- Fan Sheave
- Belt
- Motor Sheave
- 10 mm/m Deflection = Proper Belt Tension
- Straight Edge
New belts have to be re-tensioned after 24 hours operation.
If Belt tensioning is required, please proceed as follows:
- Loosen the lock nuts on the Motor Base Adjusting Screws.
- Turn the Motor Base Adjusting Screws clockwise to tension the
belt, or counter-clockwise to relieve belt tension. During
adjustment of belt tension the drives should be rotated several
times by hand to evenly distribute the tension throughout the
belt.
- When the belt is properly tensioned, retighten the locking nuts
on the Motor Base Adjusting Screws.
Note: There should be no “chirp” or “squeal” when the fan motor is started.
DRIVE ALIGNMENT
Proper drive alignment ensures maximum belt life. Alignment is
checked for standard drives after correct belt tensioning by placing
a straightedge across both sheaves as shown in the Figure below.
When the drives are properly aligned the gap measured between
straightedge and sheave does not exceed 0,5 mm per 100 mm of
fan sheave diameter.
- Motor Sheave
- Fan Sheave
- Points of Contact
LOCKING COLLAR
The excentric locking collar of the bearing at the drive end ensures
that the inner bearing race is secured to the fan shaft. Locking
collars can be set using the following procedure. (See Figure below)
- Stop fan(s) and remove side access panel(s).
- Loosen the set screw.
- Using a drift pin centerpunch, tap the collar (in the hole provided)
tangentially in the direction of rotation while holding the shaft.
- Retighten the screw.
- Install access panel(s) and start fan(s).
- Locking Collar
- Lubrication Fitting
- Extended Lubrication Line
ROTATION OF FAN(S) AND PUMP(S)
Fans must rotate without obstruction and both fans and pumps
must rotate in the correct direction, which is indicated by arrows on
the equipment. Check proper functioning as follows:
- Stop fan(s) and pump(s).
- Turn the fan by hand to ensure rotation without obstruction.
Remove obstruction, if present.
- Start the pump(s) and check for the proper rotation as indicated
by the arrow on the pump cover. If rotation is wrong, stop pump
and correct electrical wiring.
- Start the fan(s) and check for proper rotation as indicated by the
arrow on the fan housing. If rotation is wrong stop fan(s) and
correct fan motor wiring.
Belt Profile Diameter (mm)
Motor Sheave
Deflection Force (kg)
Min. Max.
B 100 through 118
125 through 140
150 through 170
180
1.5
1.5
2.0
2.5
2.0
2.5
2.5
3.0
Table 2: Belt Tension Forces
Figure 4: Fan Belt Check and Adjustment
Figure 5: Checking sheave alignment
Figure 6: Locking Collar Assembly
8
MAINTENANCE PROCEDURES
MOTOR VOLTAGE AND CURRENT
Check the voltage and the current of all three legs of the motors.
The current should not exceed the nameplate rating. After
prolonged shutdown the motor insulation should be checked with a
megger insulation tester prior to restarting.
- Insulation resistance test – minimum value should be 1 Mega
Ohm (1.000.000 Ohms).
- Thermistors, if fitted, should be checked for continuity with a
multi-meter but never megger-tested.
- Ensure supply voltage and frequency correspond to the motor
nameplate rating.
- Ensure shaft turns freely.
- Wire the motor in accordance with the wiring diagram as shown
on the motor nameplate and/or in the motor terminal box.
- Turn on unit and check amp draw does not exceed nameplate
rating.
Note: If motor is stored, it should be in a clean, dry place & have the shaft
rotated occasionally. Storage areas should not be subject to vibration.
!
Rapid on-off cycling can cause the fan motor to overheat.
It is recommended that controls be set to allow a maximum of 6 on/
off cycles per hour. When two speed motors are used, the motor
starter should include a 15 seconds time delay when switching from
high to low speed.
DRIVE TRAIN
- Fan Sheave
- Belt
- Motor Sheave
The DRIVE TRAIN consists of a specially designed belt, a fan sheave
and a motor sheave. The high efficiency belt provides the premium
quality necessary for evaporative cooling equipment service.
Together these components provide a highly reliable system with
low maintenance requirements. The DRIVE TRAIN should be
inspected periodically to check the belt tension, condition of the
sheaves and belt, and when necessary adjust the tension. The
recommended service intervals are specified elsewhere.
Initial Start-up: If the equipment was supplied in assembled major
sections, no servicing is required prior to initial unit start-up since
the drive has been tensioned and aligned at the factory. If
equipment was supplied completely knocked-down (KD) then check
drive alignment & belt tensioning as per procedures outlined above.
Seasonal Start-Up: Readjust the tension on the belt. Check
condition of sheaves.
Operation: After initial unit start-up or the installation of a new belt,
the tension must be readjusted after the first 24 hours of operation.
Thereafter the condition of the belt should be checked monthly and
the tension adjusted as necessary, but at least once every 3
months.
!
No service work should be performed on the drive train without
first ensuring the fan and pump motors have been isolated,
tagged and locked in the off position.
UNUSUAL NOISE AND VIBRATIONS
Unusual noise and/or vibration are the result of malfunctioning of
mechanical components or operational problems (unwanted ice
formation). If this occurs, a thoroughful inspection of the entire unit
followed by immediate corrective action is needed. If required,
consult your local BAC Balticare representative for assistance.
GENERAL CONDITION OF THE EQUIPMENT
The inspection should focus on following areas:
- damage of corrosion protection
- signs of scale formation or corrosion
- accumulation of dirt an debris
- presence of biofilms
If there is evidence of scale formation (more than 0.1 mm) or
corrosion, water treatment regime must be checked and adjusted
by the supplier.
Any dirt and debris need be removed following the CLEANING
PROCEDURE described in this manual (see page 12).
If there is evidence of biofilms, the system, including piping, should
be drained, flushed and cleaned of slimes and other organic
contamination. Refill system with water and apply biocide shock
treatment. Check pH value and functionality of ongoing biocide
treatment.
The RCT Cooling Towers are constructed of corrosion resistant
materials. The wet deck surface is made of en inert synthetic
material that requires no protection against rot, decay, rust or
biological attack. Other materials used in construction of the
equipment, that are listed below, should be inspected regularly.
Stainless Steel Components
Stainless steel components should be inspected for sighs of
blemishes or corrosion and cleaned with stainless steel wool as
necessary. If more extensive corrosion is prevalent, contact you local
BAC-Balticare Representative.
Fibreglass Re-Inforced Polyester (FRP) Components
FRP components should be inspected for accumulation of dirt and
cleaned with soap and water as necessary. Also FRP components
should be inspected for any penetration of gelcoat or veil. Such
penetrations should be repaired immediately.
Figure 7: Drive Train
Inspections and Corrective Actions
MAINTENANCE PROCEDURES
9
HEAT TRANSFER SECTION
The fill should be inspected and cleaned at least quarterly or more
regularly if required by local authorities.
The inspection procedure is as follows:
- Shut off fan(s) and pump(s).
- Remove the access panel.
- Inspect the wet deck surface for
- obstructions
- damages
- corrosion
- fouling.
Remove any obstructions from heat transfer section(s).
Any damages or corroded areas need to be repaired. Call your local
BAC Balticare representative for assistance.
Minor fouling can usually be removed chemically or by temporary
changes to the water treatment programme. Contact your water
treatment supplier for advice. Major fouling requires cleaning and
flushing according to the CLEANING PROCEDURES (See page 12).
Regular checking of the total aerobic bacteria count (TAB) and
maintaining it within acceptable levels are the key to prevent
fouling.
Note: When working on fill section or above fill section, fill bundle edges
should be protected from damage by service personnel, tools or debris by
placing a temporary cover of plywood, or other suitable material, over the top
of the fill bundles.
DRIFT ELIMINATORS
The inspection procedure is as follows :
- With fan(s) and pump(s) running visually check for areas with
excessive drift loss.
- Shut off fan(s) and pump(s) and visually check eliminators for
- obstructions
- damages
- cleanliness
- proper fit
- If any of the above problems have been observed, stop fan(s)
and pump(s) and remove eliminators.
- Clean eliminators from debris and foreign matter. Remove dirt
and obstructions. Replace damaged or ineffective eliminators.
- Install eliminators and ensure they fit tightly with no gaps.
WATER DISTRIBUTION
The inspection procedure is as follows :
- Shut off the fan(s), but leave the pump(s) running.
- Check and adjust spray pressure, if required.
- Remove the eliminators.
- Check to see if the nozzles are producing the spray pattern
shown in figure(s) below
- Clean water distribution from dirt and debris. Ensure spray
branches and nozzles are in place and clean. Replace damaged
or missing nozzles.
- Install eliminators and ensure they fit tightly with no gaps.
- Start fan(s) and pump(s).
COMBINED INLET SHIELDS
Combined inlet shields are installed at the air inlet side. These will
prevent UV light from shining into the sump water and will eliminate
the suction of large airborne impurities and debris. In addition, they
will prevent water from splashing out of the air intake side of the
unit during fan cycling.
Figure 8: Removable Fill
Figure 9: Removable Drift Eliminators
Figure 10: Nozzle Spray Distribution Type Cooling Tower
Figure 11: Removable Spray System
10
MAINTENANCE PROCEDURES
Inspect regularly and remove foreign objects that might impair air
passage. Replace broken and missing parts when necessary. Failure
to replace broken shields will result in water loss due to splash out.
You can remove the Combined Inlet Shields by simple loosening a
single bolt on both ends of the air intake side. This allows simple
removal of the combined inlet shields in small and easy to handle
sections allowing full access to the sump section for maintenance.
.
Figure 12: Remove Combined Inlet Shields
FAN SHAFT
The fan shaft is fabricated from stainless steel. The exposed areas
of the fan shaft are coated with a soft seal for added corrosion
protection. It is recommended that the coating be inspected for
continuity quarterly or at least every 6 months. Any signs of surface
corrosion must be treated. This involves:
- Removal of the protective coating with a suitable cleaning
medium
- The removal of any surface corrosion with emery cloth
- The re-coating of the shaft with soft seal.
AXIAL FAN
Due to its size and speed, the axial fan has great potential for injury
and destruction if damaged. Inspect closely, and as required,
replace damaged or deteriorating fan blades. Inspection should
include the fan, fan cylinder and fan guard, and these should be
inspected for
- Fan blade tip clearance
- Pitch angle
- Bolt torque
- Excessive vibration
- Deterioration of fan assembly
Correct or adjust if necessary.
Note: Before any disassembly, fan blades and hub should be match marked
to ensure proper blade pitch angle when reassembled.
!
No service work should be performed on or near the fans,
motors, and drives or inside the unit without first ensuring the fan
and pump motors have been isolated, tagged and locked in the
off position.
FAN MOTOR
The standard fan motor for this line of units is a TEFC (Totally
Enclosed Fan Cooled) motor. The motor with frame size smaller or
equal than 200L has permanently lubricated ball bearings and
special moisture protection on the bearings, shaft and windings.
The only servicing required during operation is to clean the outside
surface of the motor at least quarterly to ensure proper motor
cooling. After prolonged shutdowns, the motor insulation should be
checked with a “megger” insulation tester before restarting the
motor.
Do not wash down the motor unless it is IP66 rated. On a quarterly
or six monthly basis check:
- electric connections
- motor protection devices
- check amp draw
- motor bearings for noise/overheating
- motor holding bolts
- external surface of motor for corrosion
If the motor is equipped with space heaters, these must be
activated when the motor is idle in order to prevent condensation
inside the motor.
!
Do no run/start the fan motor(s) when there is no heat load.
ELECTRIC WATER LEVEL CONTROL PACKAGE
(OPTIONAL)
The electric water level control package (optional) maintains a
constant water level in the cold water sump independent of cooling
load changes and water supply pressure variations. Ensure every six
months that all components (valve, float switches) are operational
and clean.
!
When disassembling the float switch for cleaning, make sure to
reassemble it in exactly the same position, otherwise it will not
function correctly.
ACCESS DOOR
The large access door is easily removed to provide complete access
to drift eliminators, spray system and fill.
Figure 13: Axial Fan on Direct Drive Unit
MAINTENANCE PROCEDURES
11
!
The access door should not be removed without first ensuring the
fan and pump motors have been isolated, tagged and locked in
the off position.
To remove the door, take out the louvres from door side. Loosen and
remove the knobs that hold the door in place. Larger units are
provided with convenient anchor points to assist in removing the
door and securing the door to the unit when removed.
FAN SHAFT BEARINGS
The fan shaft is supported by two pillow block ball bearings (see
Figure below), each equipped with a lubrication fitting and a slinger/
locking collar to keep out moisture.
Under normal operating conditions the bearings should be greased
every 1000 operating hours or at least every three months. The
bearings should be lubricated with one of the following water
resistant inhibited greases, which are good for ambient
temperature ranging from - 20°C to 120 °C.
- Bearing with Locking collar
- Lubrication Fitting
- Extended Lubrication Line
- Bearing with Locking collar
- Lube Fitting
Note: For grease products see Table below
MOTOR BEARINGS
Motors with frame size >200L (>30 kW) have grease fittings
- grease intervals : twice a year unless otherwise shown on the
nameplate of the motor
- grease products : see below
The bearings should be lubricated only with a hand grease gun. Do
not use high-pressure grease guns, since they may rupture the
bearing seals. When lubricating, purge the old grease from the
bearing by gradually adding grease until a bead of new grease
appears at the seal.
GREASE PRODUCTS
ADJUSTABLE MOTOR BASE
The motor base adjusting screw (see figure below) should be coated
every six months using a good quality corrosion inhibiting grease,
such as one of those recommended for lubricating the fan shaft
bearings.
- Motor Base locking nuts (both sides)
- Adjusting Screw
Lubrication
Figure 14: Access Door Anchor Points.
Figure 15: Ball Bearing
Shell Alvania grease RL3 -20°C to +120°C
Texaco Multifak Premium 3 -30°C to +140°C
Klüber Isoflex LDS Special A -50°C to +120°C
Mobil Mobilith SHC 100 -40°C to +175°C
Total Fina Elf Multis 3 -20°C to +120°C
Table 3: Grease Products
Figure 16: Ball Bearing
Figure 17: Adjustable Motor Base
12
MAINTENANCE PROCEDURES
MECHANICAL CLEANING
Keeping your evaporative cooling equipment (and the associated
system) clean will maintain its efficiency and help to prevent
uncontrolled bacteriological growth. The recommended cleaning
procedures are described below :
- Disconnect fan and pump motor(s) and shut off make-up supply.
- Remove screens, eliminators, access panels and doors and
drain system. Do not remove sump strainer.
- Clean debris from exterior and fan(s) with soft brush, if
necessary use water and soap.
- Clean interior with (soap) water and soft brush, if necessary use
high pressure water jet.
- Remove any debris from water distribution system and clean any
nozzles if clogged. If necessary nozzle and grommet may be
removed for cleaning.
- Remove debris from heat transfer section (coil/fill) . Do not use
steam or high pressure water to clean cooling tower wet deck
surface.
- Flush with clean water and drain to remove accumulated dirt.
- Remove, clean and replace sump strainer(s).
- Clean debris from screens and eliminators with water jet and
install.
10.Remove debris from access doors and panels with soft brush
and (soap) water and install.
11.Close drain and open make-up supply. Fill system to overflow
level with clean water.
DISINFECTION
Disinfection of your cooling system may be needed in case of high
concentration of aerobic bacteria and/or Legionella. Disinfection is
also recommended for evaporative cooling systems with known or
suspected high bacteriological levels, prior to a cleaning procedure.
Some local or national guidance also recommends disinfection
prior to initial start up, after a prolonged shut down, after routine
cleaning operations or when significant alterations have been made
to the cooling system.
Disinfection must be carried out in accordance with a proper
procedure and take into account the safety of the cleaning and
disinfection staff.
Typically disinfection is achieved using a sodium hyperchloride
solution to maintain a residual value of 5 - 15 mg/l of free chlorine
and circulate this around the system for up to 6 hours. Higher
chlorine levels for a shorter period are possible, but require a higher
level of corrosion protection than galvanized steel only. Consult your
BAC Balticare representative for further information.
Excessive levels of chlorine must be avoided as this quickly can lead
to corrosion and damage to your system.
Chlorinated water should be de-chlorinated before draining and
after disinfection the system must be thoroughly flushed through
with clean water.
Note: A proper regularly monitored biocide programme reduces the need for
cleaning and disinfection actions significantly.
Cleaning Procedures
COMPREHENSIVE MAINTENANCE
13
In order to ensure maximum efficiency and minimum downtime of
your evaporative cooling system, it is recommended to establish
and execute a programme of preventive maintenance. Your local
BAC Balticare representative will assist you in establishing and
implementing such programme. The preventive maintenance
programme must not only avoid that excessive downtime occurs
under unforeseen and unwanted conditions, but must also ensure
that factory authorized replacement parts are used, which are
designed to fit and for their purpose carry the full factory warranty.
To order factory authorized parts, contact your local BAC Balticare
representative. Be sure you include the unit serial number when
ordering any parts.
To facilitate servicing of the equipment, it is suggested that the
following parts be carried on hand :
- Make-up float ball (if applicable)
- Valve seal for water make-up valve
- Fan shaft bearings
- Spray nozzles and grommets
- Spray distribution branch grommets
- Set of belts
Insist on factory authorised parts to avoid loss of efficiency or an
operational risk, which may occur if non-authorised parts are used.
Should the unit(s) be stored outside prior to installation and/or
start-up for approximately one month or longer, or stored in severe
climates, it is imperative that certain actions be performed by the
installing contractor in order to maintain the unit in “as shipped”
condition. These actions include but are not limited to:
- Rotate the fan(s) once per month, at least 10 revolutions.
- Rotate the motor shaft once per month, at least 10
revolutions
- Add desiccants to control panel interiors.
- Wrap motor in non-plastic protective material.
- Ensure hot water basins are covered.
- Keep drains open on the cold water basins.
- Remove and stor fan belts and access door gaskets.
- Ensure unit(s) is stored on level ground.
- For coil products N2 is recommended to prevent internal
corrosion.
- Purge old bearing grease by new grease at start of storage
period and repeat before start-up.
- Protect all black steel components with RUST VETO or
equivalent corrosion protective material.
For complete instructions, please contact your local BAC-Balticare
Representative
About Comprehensive Maintenance
Prolonged Outdoor Storage
14
FURTHER ASSISTANCE & INFORMATION
BAC has established a specialized independent total care company
called Balticare . The BAC Balticare offering involves all elements
required to ensure a safe and efficient operation of your evaporative
cooling products. From a full range of risk assessment to selective
water treatment, training, testing, record keeping and annual
system overview. For more details, contact BAC Balticare at
www.balticare.com or you can also contact your local BAC
representative for further information and specific assistance at
www.BaltimoreAircoil.eu.
REFERENCE LITERATURE
- Eurovent 9-5 (6) Recommended Code of Practice to keep your
Cooling System efficient and safe. Eurovent/Cecomaf, 2002,
30p.
- Guide des Bonnes Pratiques, Legionella et Tours
Aéroréfrigérantes. Ministères de l’Emploi et de la Solidarité,
Ministère de l’Economie des Finances et de l’Industrie,
Ministère de l’Environnement, Juin 2001, 54p.
- Voorkom Legionellose. Minsterie van de Vlaamse
Gemeenschap. December 2002, 77p.
- Legionnaires’ Disease. The Control of Legionella Bacteria in
Water Systems. Health & Safety Commission. 2000, 62p.
- Hygienische Anforderungen an raumlufttechnische Anlagen.
VDI 6022.