BAC VCL Series Manual

VCL Evaporative Condensers
OPERATING AND MAINTENANCE INSTRUCTIONS
MVCLv19EN

Recommended maintenance and
monitoring programme
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.
Checks and adjustments Start-Up Weekly Monthly Quarterly Every 6
months
Annually Shutdown
Cold water basin & strainer X X
Operating level and make-up X X
Blow down X X
Sump heater package X X
Belt tension X X
Drive alignment X X
Locking collar X X
Rotation of fan(s) and pump(s) X
Motor voltage and current X X
Unusual noise and/or vibration X X
Inspections and monitoring Start-Up Weekly Monthly Quarterly Every 6
months
Annually Shutdown
General condition X X
Heat transfer section X X
Drift eliminators X X
Water distribution X X
Fan shaft X X
Fan motor X X
Spray water pump X X
Electric water level control package (optional) X X
TAB test (dip slides) X X
Circulating water quality X X
System overview X X
Record keeping as per event
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Lubrication Start-Up Weekly Monthly Quarterly Every 6
months
Annually Shutdown
Fan shaft bearings X X X
Motor bearings* X X
Adjustable motor base X X X
* only for motors with grease fittings with typical frame size > 200L (>30 KW)
Cleaning procedures Start-Up Weekly Monthly Quarterly Every 6
months
Annually Shutdown
Mechanical cleaning X X X
Disinfection** (X) (X) (X)
Drain basin and pump X
** depends on applied code of practice
Notes
1. Water treatment and auxiliary equipment integrated in the cooling system may require additions to the table
above. Contact suppliers for recommended actions and their required frequency.
2. Recommended service intervals are for typical installations. Different environmental conditions may dictate
more frequent servicing.
3. When operating in ambient temperatures below freezing, the unit should be inspected more frequently (see
Cold weather operations in the appropriate Operating and Maintenance Instructions).
4. For units with belt drive, tension on new belts must be readjusted after the first 24 hours of operation and
monthly thereafter.
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Table of contents
OPERATING AND MAINTENANCE INSTRUCTIONS
1 Construction Details 5
2 General information 6
Operating conditions 6
Connecting pipework 6
Safety precautions 7
Disposal requirements 8
Non-walking surfaces 8
Modifications by others 8
Warranty 9
3 Water Care 10
About water care 10
Biological control 13
Chemical treatment 13
Passivation 13
Overflow connection 14
4 Cold Weather Operations 15
About cold weather operation 15
Protection against sump water freezing 15
Capacity control 15
5 Maintenance Procedure 17
Checks and adjustments 17
Inspections and corrective actions 23
Lubrication 26
Cleaning procedures 27
6 Comprehensive Maintenance 29
About comprehensive maintenance 29
Prolonged outdoor stay 29
7 Further Assistance & Information 30
Assistance 30
More information 30
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1 Construction Details
1 Construction Details W W W . B A L T I M O R E A I R C O I L . E U
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CONSTRUCTION DETAILS
1. Casing
2. Water distribution section
3. High efficiency drift eliminators
4. Forward curved centrifugal fan
5. Fan shaft and bearing
6. Fan motor
10. Coil
11. Pump
12. Man size access door
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GENERAL INFORMATION
Operating conditions
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 ambient temperature range from -25°C to +40°C.
• Design pressure: 23 bar (std.) or 28 bar (option) according to PED
• Refrigerant inlet temperature: max. 120°C
• Refrigerant outlet temperature: min. - 20°C
• Suitable refrigerants: Natural refrigerants (R-717, R-1270), Halocarbon refrigerants, HFC`s.
Standard condenser coils are manufactured from black steel and hot dip galvanised after fabrication and may
contain certain contaminants, such as carbon, iron oxyde or welding particles. The interior condition of the coil,
including humid air must be considered, when using halocarbon (or HFC) refrigerants and sensitive system
components, such as electronic expansion devices or semi hermetic compressors. The installer must take the
necessary precautions on site to safeguard the operation of these components in conjunction with the condenser
coils.
Maximum spray pressure: 14 kPa (If pump(s) are installed by others, it is recommended to install a pressure gauge
at the inlet of the water distribution system.)
At ambient temperatures above 40°C ensure spray water pump remains running, even if condenser is idle. This
prevents unwanted discharge of refrigerant through safety valves (by others).
Stand-by pump arrangements for evaporative condensers require alternating operation of each pump at
least twice per week to avoid stagnant water conditions and bacteriological growth.
PURGE REQUIREMENTS
The installer of BAC condensers must ensure proper air purging of the system prior to operation.
Entrained air can obstruct free drainage of refrigerant and reduce condensing capacity, resulting in higher operating
pressures than designed.
All connections (installed by others) must be leak free and tested accordingly.
To verify absence of non condensables in the refrigeration system, follow the instructions in the BAC Application
Handbook – EU Edition (https://www.baltimoreaircoil.eu/downloads/pdf-Application-Handbook-EU-Edition),
Section "Condenser Engineering Guidelines".
Connecting pipework
All piping external to BAC cooling equipment must be supported separately.
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In case the equipment is installed on vibration rails or springs, the piping must contain compensators to eliminate
vibrations carried through the external pipework.
The equipment outlet piping must be installed under the operating level of the equipment to prevent air suction and
pump cavitation.
Suction pipe sizing should be done according to good practice, which may for larger flows require larger pipe
diameters than the outlet connection. In such cases adapter pieces need to be installed.
Safety precautions
All electrical, mechanical and rotating machinery constitutes 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 advice.
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.
CAUTION
Do not cover units with PVC eliminators with a plastic tarpaulin. Temperature increase due to sun
radiation could deform the 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, personal protective
equipment, procedures and tools must be used in handling, lifting, installing, operating, maintaining and repairing
this equipment to prevent personal injury and/or property damage. Personnel must use personal protective
equipment where necessary (gloves, ear plugs, etc...)
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.
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ELECTRICAL SAFETY
All electrical components associated with this equipment should be installed with a lockable disconnect switch
located within sight of the equipment.
In the event of multiple components, these can be installed after a single disconnect switch but multiple switches
or a combination thereof are also allowed.
No service work should be performed on or near electrical components unless adequate safety measures are
taken. These include, but are not limited to the following:
• Isolate the component electrically
• Lock the isolation switch in order to prevent unintentional restart
• Measure that no electrical voltage is present anymore
• If parts of the installation remain energized, make sure to properly demarcate these in order to avoid confusion
Fan motor terminals and connections may have residual voltage after unit shut-down. Wait five minutes after
disconnecting the voltage at all poles before opening the fan motor terminal box.
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 to local regulations, such as establishment of risk
analysis. Ensure regulatory requirements are consistently met.
Disposal requirements
Dismantling of the unit and treatment of refrigerants (if applicable), oil and other parts must be done with respect to
the environment whilst protecting workers from potential risks related to exposure to harmful substances.
National and regional legislation for material disposal and protection of workers should be taken into account with
regard to:
• Appropriate handling of construction and maintenance materials when dismantling the unit. In particular when
dealing with materials that contain harmful substances, such as asbestos or carcinogenic substances.
• Appropriate disposal of the construction and maintenance materials and components such as steel, plastics,
refrigerants and waste water according to local and national requirements for waste management, recycling
and disposal.
Non-walking surfaces
Access to and maintenance of any component needs to be performed in accordance with all local applicable laws
and regulations. If the proper and required access means are not present, temporary structures need to be
foreseen. Under no circumstance can one use parts of the unit, that are not designed as an access mean, unless
measures can be taken to mitigate any risks that might occur from doing so.
Modifications by others
Whenever modifications or changes are made by others to the BAC equipment without written permission of BAC,
the party who has done the modification becomes responsible for all consequences of this change and BAC
declines all liability for the product.
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Warranty
BAC will guarantee all products to be free from manufactured defects in materials and workmanship for a period of
24 months from the date of shipment. In the event of any such defect, BAC will repair or provide a replacement.
For more details, please refer to the Limitation of Warranties applicable to and in effect at the time of the
sale/purchase of these products. You can find these terms and conditions on the reverse side of your order
acknowledgement form and your invoice.
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WATER CARE
About 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 CaCO3.
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.
To control corrosion and scale, the water chemistry of the circulated water has to be kept within the water quality
guidelines of the specific materials of construction used, as listed in the following table(s).
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3 Water Care
3 Water Care

Baltibond®Hybrid Coating and SST304L
pH 6.5 to 9.2
pH during initial passivation Below 8.2
(for units with HDG coil only)
Total hardness (as CaCO3) 50 to 750 mg/l
Total alkalinity (as CaCO3) 600 mg/l max.
Total dissolved solids 2050 mg/l max.
Conductivity 3300 µS/cm
Chlorides 300 mg/l max.
Sulfates* 350 mg/l max.*
Total suspended solids 25 mg/l max.
Chlorination (as free chlorine / halogen): continuous 1.5 mg/l max.
Chlorination (as free chlorine / halogen): 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.
Circulated water quality guidelines for Baltibond®Hybrid Coating
*Note: Higher concentration of sulfates is allowed, provided the sum of chlorides + sulfates parameters does not exceed 650 mg/l for
Baltibond/SST304L.
Baltiplus protection
pH 6.5 to 9.0
pH during initial passivation Below 8.2
Total hardness (as CaCO3) 50 to 600 mg/l
Total alkalinity (as CaCO3) 500 mg/l max.
Total dissolved solids 1500 mg/l max.
Conductivity 2400 µS/cm
Chlorides 250 mg/l max.
Sulfates* 250 mg/l max.*
Total suspended solids 25 mg/l max.
Chlorination (as free chlorine / halogen): continuous 1 mg/l max.
Chlorination (as free chlorine / halogan): 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.
Circulated water quality guidelines for Baltiplus protection
*Note: Higher concentration of sulfates is allowed provided the sum of chlorides + sulfates parameters does not exceed 500 mg/l for Baltiplus
protection.
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3 Water Care
3 Water Care

SST304L
SST316L with HDG coil
SST316L
(with SST316L coil)
pH 6.5 to 9.2 6.5 to 9.5
pH during initial passivation Below 8.2
(for units with HDG coil only)
Not applicable
Total hardness (as CaCO3) 50 to 750 mg/l 50 to 750 mg/l
Total alkalinity (as CaCO3) 600 mg/l max. 600 mg/l max.
Total dissolved solids 2050 mg/l max. 2500 mg/l max.
Conductivity 3300 µS/cm 4000 µS/cm
Chlorides 300 mg/l max. 750 mg/l max.
Sulfates* 350 mg/l max.* 750 mg/l max.*
Total suspended solids 25 mg/l max. 25 mg/l max.
Chlorination (as free
chlorine/halogen): continuous
1,5 mg/l max. 2 mg/l max.
Chlorination (as free
chlorine/halogen): 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.
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.
Circulated water quality guidelines for Stainless Steel
*Note: Higher concentration of sulphates is allowed provided the sum of chlorides + sulphates parameters does not exceed 650 mg/l for
SST304L and 1500 mg/l for SST316L.
For Ozone water treatment application:
• Stainless steel 316L execution is required.
• Ozone levels are to be maintained to 0.2 ppm ± 0.1 ppm for at least 90% of the time, with absolute maximum
peaks of 0.5 ppm
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.
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Biological control
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.
Also during shutdown periods it is recommended to continue the water treatment programme. Alternatively, the
basin and pump should be drained.
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.
Certain products used for water treatment, particular some dispersant and bio-dispersant additives, might change
the properties of the water (such as the surface tension), which can cause excessive drift loss (water passing
through the eliminators). In such case we recommend to review the water treatment (product type, dosage) with
your water treatment expert.
In case of doubt, a short test can be performed, after cleaning & disinfection, using fresh water without addition of
the concerned chemical (within the limits of the local legislation).
Chemical treatment
1. Water treatment chemicals or non-chemical systems need to be compatible with the materials of construction
used in the cooling system including the evaporative cooling equipment itself.
2. In case of chemical water treatment, chemicals should be added to the recirculating water by an automatic
feed system. This will prevent localised high concentrations of chemicals, which may cause corrosion.
Preferably the water treatment chemicals should be fed into the cooling system at the discharge of the
recirculation pump. The chemicals should not be fed in concentrated form, nor batch fed directly into the cold
water sump of the evaporative cooling equipment.
3. BAC specifically discourages acid dosing as mean of scale control (unless under certain strict circumstances
for open circuit cooling towers with very large system volume and remote sump, or constructed from stainless
steel).
4. A competent water treatment company should be consulted for the specific water treatment programme to be
applied. Next to the supply of dosing and control equipment and chemicals, the programme should include
regular monthly monitoring of the circulating and make up water quality.
5. If it is proposed to operate a treatment programme outside the BAC Water Quality Control Guidelines, the BAC
factory warranty may be invalidated if the water quality is persistently outside the Control Guidelines, unless
specific prior written BAC approval. (Some parameters may be exceeded under certain strict circumstances.)
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 to be recorded.
Passivation
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.
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3 Water Care
3 Water Care

Full stainless steel units and units protected by the Baltibond®hybrid coating do not require passivation.
An exception to this are units with a galvanized steel coil bundle which do still require the proper
passivation procedure as described here in this section.
In case you can't keep the pH below 8.2, a secondary approach is to conduct a chemical passivation using
inorganic phosphate or film-forming passivation agents. Consult your water treatment specialist for specific
recommendation.
Overflow connection
A slight loss of water through the overflow on forced draft units is normal when the fans are in operation, since the
unit is in overpressure and some saturated air will be blown out to the unit, carrying several droplets of water.
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4 Cold Weather Operations
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COLD WEATHER OPERATIONS
About cold weather operation
BAC cooling equipment can be operated in sub freezing ambient conditions provided the proper measures are
taken. Listed below are general guidelines which should be followed to minimize the possibility of coil 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.
Protection against sump water freezing
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 and
pump.
Drainage of the sump and pump will also be needed if dry operation is anticipated, even if sump heaters are
installed. These heaters will NOT prevent sump water from freezing during dry operation at sub freezing ambient
conditions. Remote sump installations are best suited for a flexible switch from wet to dry operation, as the sump
water is protected at all times. For dry operation applications, ensure that make-up water line is shut off and make-
up valve completely drained.
Thermostats for electrical sump heaters for this equipment are set to maintain a sump water temperature of 4°C.
CAUTION
Switch off heaters when the sump is drained.
Capacity control
In addition to protecting the sump water, all exposed water piping, in particular make-up water lines should be heat
traced and insulated.
Spray pumps also need to be heat traced and insulated from pump suction to the overflow level, if they can be
exposed to sub-freezing ambient conditions.
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 air flow 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.)
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The desired method to match the cooling capacity to load and weather conditions is to adjust the air flow by the
use of modulating controls (variable speed drives).
Alternatively, multi speed fan motors or fan cycling can be applied, but fans operating on a common heat exchange
section should always be operated simultaneously.
It is not recommended to cycle the spray pump as a means of controlling the unit capacity.
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.
When operating with VFD drives above nominal frequency be aware of the potential risk for motor overload
or mechanical damages.
It is recommended to provide sinus filters on the VFD to prevent bearing damage on fan motors.
CAUTION
Refer to fan motor nameplate data when programming a VFD.
Spray pumps should be switched off when the fan(s) are idle. Operation with pump but without fan(s) does not
provide cooling capacity of any significance but could lead to occasional water splash out at the air intake. For this
reason this operation mode should be avoided. Spray pump should be switched off with a time delay of maximum
30 seconds after switching off the fan(s) and should be activated maximum 30 seconds prior to the anticipated
start of the fan(s).
The purpose of a low level cut out switch for pump protection 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.
In case the low level alarm signals, that there is no longer enough water in the cold water sump to guarantee a
proper operation, the pump should be stopped (after a time delay of 60 seconds) and only manually restarted after it
has been verified that the water in the sump is at or near the overflow level.
In case the low level pump alarm is used to stop the pump, appropriate control logic should be incorporated
to prevent hunting of the pump motor. Once the spray pump is stopped, the water in suspension will drain
back to the tank and raise the water-level above the alarm level, which will reset the alarm immediately. A manual
reset of the alarm after solving the root cause of the low level alarm is recommended. Frequent start/stop or
hunting will damage the motor.
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5 Maintenance Procedure
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MAINTENANCE PROCEDURE
Checks and adjustments
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 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.
CAUTION
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 and the basin operating level during remote basin
operation is not adjustable.
OPERATING LEVEL AND MAKE-UP
Before initial start up the straps, that prevent the float ball from moving during transport, as well as the protective
bag around this ball, need to be removed.
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Fixation and wrapping of float ball
Operating height is the water level above sump bottom during operation.
Operating water level
1. Operating height
2. Overflow
3. Pan bottom
Operating heights for the evaporative cooling equipment are indicated in the tables below:
Model Operating height
(measured from pan bottom)
(mm)
VCL 140
To check the operating level, proceed as follows:
1. Shut off fan(s) but keep pump(s) running.
2. Remove circular access door next to make-up connection.
3. Measure height from sump bottom to water level and compare with face value from table.
4. Check valve for leakage and replace valve, if necessary.
5. Check that float arm can move freely and that float ball floats and closes valve.
6. Ensure that make-up water supply is adequate.
This procedure does not apply for
• equipment equipped with electrical water level control
• remote sump applications
If a float operated water make-up is used, initial setting and regular adjustments are needed.
The float controlling the make-up valve is mounted on a threaded rod, held in place by wing nuts. (see figure below)
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Water make-up valve assembly
1. Float ball
2. Float arm assembly
3. Float valve
CAUTION
Supply pressure for mechanical make-up valves should be between 1 and 3,5 bar.
To make the initial basin water level setting, fill the sump with water until 2 cm above 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 till 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.
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.
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.
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5 Maintenance Procedure
5 Maintenance Procedure

CAUTION
Sump heaters can be hot.
BELT TENSIONING
Belt tensioning can be adjusted by changing the position of the fan motor(s) by rotating the motor base adjustment
screw, which extends through the bottom frame angle.
Check belt tension as follows:
1. Shut off fan(s).
2. Rotate the fan sheave half a turn to evenly distribute the tension in the belt before measuring.
3. 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.
CAUTION
Fan has to be blocked while replacing belts.
Fan belt check and adjustment
1. Fan sheave
2. Belt
3. Motor sheave
4. 10 mm/m deflection = proper belt tension
5. Straight edge
CAUTION
Over-tensioning of belts can lead to component damage.
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