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Related Manuals for BAC HXV
Summary of Contents for BAC HXV
- Page 1 HXV Hybrid Cooler OPERATION & MAINTENANCE MANUAL...
- Page 2 Recommended Maintenance Intervals Inspect and clean as necessary: Start-Up Monthly Quarterly Annually Shutdown Inspect general condition of the unit and check unit for unusual noise or vibration Inspect cold water basin Flush water distribution system/Inspect spray nozzles Drain basin and piping Inspect the CIS combined inlet shields, fill and eliminators Inspect the CIS hail guards on top of the unit;...
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Page 3: Table Of Contents
Table of Contents OPERATION & MAINTENANCE » HXV HYBRID CLOSED CIRCUIT COOLING TOWER Warnings and Cautions PART 4 Bleed Rate Safety Precautions Bleed Rate Equipment Precautions General Maintenance Information PART 5 Cold Weather Operation Warranties Inspection and Maintenance Fan Section Icing Protection PART 1 Unit Operation &... -
Page 4: Safety Precautions
Safety Precautions DANGER • DANGER: Rotating equipment will cause severe personal injury or death to persons who come in contact. Do not perform any service, maintenance or inspection on or near the fans, motors, and drives, or inside the unit without first ensuring that the fans and pump motors are disconnected, locked out, and tagged out. -
Page 5: Equipment Precautions
• The basin heater is not designed to prevent icing during unit operation. • BAC units are typically installed immediately after shipment and many operate year round. However, if the unit is to be stored for a prolonged period of time either before or after installation, certain precautions should be observed, as outlined in “Prolonged Outdoor Storage”... - Page 6 Coil): Fluid In Coil Connection Air Inlet Louvers Access Door Spray Water Internal Access Ladder Pump Assembly and Platform Figure 1. HXV Hybrid Cooler Location of Water Level Float Switches, Basin Water Level Control and Basin Heater Cold Water Basin...
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Page 7: Operation
Storage Operation To optimize water and energy savings, the HXV Hybrid Cooler operates in two modes. In each mode, capacity is controlled by fan motor modulation, and all of the process fluid flows through the finned coil (dry coil) and then through the prime surface coil (wet coil). -
Page 8: Sequence Of Operation
Operating Modes • Adiabatic Mode (Balanced Water and Energy Savings): The spray water circulating pump distributes water over the fill surface. The fans draw air over the wetted fill where it is adiabatically pre-cooled resulting is a significantly lower air temperature and greatly increasing the rate of sensible heat transfer. -
Page 9: Start-Up Procedure
• Remove all dirt and debris from the fan guards. or death to persons who come in • If necessary or required by local code, disinfect the HXV towers in accordance with the most current versions of ASHRAE Standard 188: Legionellosis: Risk Management contact. - Page 10 • Lubricate the fan shaft bearings. At initial start-up, no bearing lubrication is required unless the unit has been idle for more than three months. Refer to page 17 for more details. NOTICE: Ensure the controls for • Apply a good quality, corrosion inhibiting the fan and pump motors are set grease, such as one of those recommended to allow a maximum of six on-off...
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Page 11: Extended Shutdown
• For storage prior to installation, coils should be charged with nitrogen at 15 psi in the factory. Dry coils are shipped from BAC charged with nitrogen. • Installed units that have been piped but not filled do not require additional precautions. - Page 12 Request the required voltage and transformer capacity from BAC. A third option is to use an auxiliary heat source and keep the winding warm by either convection or blowing warm air into the motor.
- Page 13 Maintenance Requirements Unit Operation and Storage • Rotate all fans and motors shafts monthly by hand. Hand-turning will ensure that the shafts and bearings rotate freely and will redistribute grease within the bearings. • Inspect the cold water basin monthly to ensure that the drain is open and remove any Prolonged Outdoor Storage leaves or debris that may have accumulated in the cold water basin.
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Page 14: Detailed Component Maintenance Procedures
HXV HYBRID COOLER Detailed Component Maintenance Procedures Cold Water Basin The process fluid to be cooled is circulated inside the tubes of the unit’s heat exchanger. Heat flows from the process fluid through the coil to the spray water outside which is cascading over the tubes. -
Page 15: Fan
• Adjust the float to maintain the design operating level. See Table 2. Detailed Component Maintenance Procedures HXV units use axial fan(s). Thoroughly inspect the fan(s) for damaged or deteriorated fan Cold Water Basin blades and replace the fan(s) if necessary. Water Levels Inspection &... -
Page 16: Fan Drive System
Fan Drive System BALTIDRIVE Power Train and Independent Fan ® The BALTIDRIVE Power Train consists of a solid- ® backed, multi-groove, neoprene/polyester belt rated for cooling tower service, and corrosion resistant DANGER: Rotating equipment sheaves. These components provide high reliability will cause severe personal injury with low maintenance requirements. - Page 17 • Belt tension check: Detailed Component – Place a straight edge along the belt from sheave to sheave as shown in Figure 5a, or Maintenance use a tape measure as shown in Figure 5b, to measure belt deflection. Procedures – Apply a moderate force by hand (approximately 40 lbs/275 kPa) evenly across the width of the belt in the center of the span between the sheaves.
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Page 18: Fan Motors
Fan Motors HXV Hybrid Coolers use cooling tower inverter duty, premium efficient, totally enclosed, single-speed, single-winding, reversible ball bearing type motor(s). Inspection & Maintenance • Clean the outside of the motor at least quarterly to ensure proper motor cooling. • After prolonged shutdowns, check the motor insulation with an insulation tester NOTICE: Ensure the controls for prior to restarting the motor. -
Page 19: Fan Shaft Bearings
Extended lubrication lines are provided for convenience. Inspection & Maintenance • Lubricate the bearings with a manual grease gun or BAC’s optional Automatic Bearing Greaser. Do not use high-pressure grease guns because they may rupture the bearing seals. -
Page 20: Heat Transfer Section
Inspect the coil surface. Any corrosion, damage, or obstructions must be corrected. Fill & Drift Eliminators, Combined Inlet Shields, and CIS Hail Guards HXV Hybrid Coolers contain polyvinyl chloride (PVC) fill with integral drift eliminators, PVC combined inlet shields, and PVC drift eliminators located in the air path leaving the prime surface coil. -
Page 21: Water Distribution System
• Maintain the make-up water supply pressure between 15 psig and 50 psig for proper operation. BAC recommends a surge protector (provided by others) for pressures over 50 psig. • Set the initial basin water level by adjusting the wing nuts, so that the make-up valve is completely closed when the water level in the cold water basin is at the overflow connection. - Page 22 Optional Electric Water Level Control Package As an option, an electric water level control package is available in lieu of the mechanical make-up assembly. The package consists of a probe-type liquid level control assembly and a slow-closing solenoid valve. Stainless steel electrodes, factory-set at predetermined lengths, extend from an electrode holder into the cold water basin.
- Page 23 W WW.BALTIMOREAIR C OIL.C O M W WW.BALTIMOREAIR C OIL.C O M...
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Page 24: Corrosion Protection
To cosmetically touch up these areas with color matched paint use BAC Part #160133 3. The conversion factor used to available from your local BAC Representative. -
Page 25: Corrosion And Scale Control
Corrosion Protection Corrosion and Scale Control Water Treatment • To control corrosion and scale, maintain the water chemistry of the recirculating Corrosion and Scale Control water within the parameters listed in Table 3. The specific measures required vary Chemical Treatment from system to system and are dependent on the chemistry of the make-up water, the Requirements metallurgy of the piping and heat transfer devices exposed to the recirculating water,... -
Page 26: Chemical Treatment Requirements
• The chemicals must be compatible with the unit materials of construction as well as other materials used in the system (pipe, heat exchanger, etc.). • BAC discourages acid dosing as means of scale control except for open circuit cooling towers with remote sump applications or towers constructed from stainless steel. This should be done at a point in the system where total mixing and dilution occur before reaching the evaporative cooling equipment. -
Page 27: Long Term Care Of Stainless Steel
Steel BAC’s Manufacturing Process BAC takes precautions to prevent cross-contamination, processing galvanized and stainless steel parts separately. Also, stainless steel brushes are used to clean welds on stainless parts and care is taken to avoid scratching parts during processing. Organic cleaners are used to clean the finished product prior to shipping. -
Page 28: System Cleaning
• If the iron chips are not removed with the Scotch-Brite™ Products, electro-chemical cleaning may be required. BAC uses commercially available equipment for electro-chemical cleaning in the field. System Cleaning System Cleaning With proper precautions, prior to start-up circulate an alkaline solution which can be used NOTE: Contact your local water to clean condenser or process water systems through a closed circuit cooling tower. -
Page 29: Part 4 Bleed Rate
HXV HYBRID COOLER Bleed Rate In evaporative cooling, evaporation of a small portion of the recirculating spray water as it flows through the equipment causes the cooling effect. As this water evaporates, NOTE: A proper water treatment the impurities originally present remain in the recirculating water. The concentration of program, administered under the the dissolved solids increases over time and can reach unacceptable levels. -
Page 30: Bleed Rate
NOTE: Evaporation is proportional to the load and will vary seasonally. E = Q * R * 0.001 = 800 * 10 * 0.001 = 8 USGPM BAC recommends the use of a conductivity meter to maximize = 250 ppm = 5.55 water conservation. -
Page 31: Cold Weather Operation
50°F (10°C) for HXV units with water (non-glycol) as the heat transfer liquid and 45°F (7.2°C) for HXV units with glycol as the heat transfer liquid. Coils will freeze in ambient temperatures of 32°F or lower without a heat load. Use of glycol is W WW.BALTIMOREAIR C OIL.C O M... -
Page 32: Basin Water And Internal Piping Freeze Protection
The HXV Hybrid Cooler provides high switch points for dry operation. One method to prevent icing is dry operation. Dry operation of the HXV unit protects fans from ice formation due to mist and splash from the cold water basin. The water in the cold water basin must be drained for dry operation in freezing ambient conditions. -
Page 33: Coil Freeze Protection
Further protection against coil freeze-up is possible with the installation of an alarm to alert personnel when the temperature of the fluid leaving the prime surface coil (wet coil) falls below 50°F (10°C). Contact your local BAC Representative for guidelines on the installation of an emergency coil drain system. -
Page 34: Operation Considerations For Accessories
For NOTICE: The basin heater is not installations that have a BAC Controls Enclosure, please consult the submittal packet designed to prevent icing during provided with the unit and contact BAC for support. -
Page 35: Cis Hail Guards
NOTE: Figure 8 is superseded by anydrawing supplied with the panel by the manufacturer. Figure 9. Example Wiring Diagram for Stand Alone BAC Heater Control Panel (Refer to Submittal Drawing for Specific Wiring Diagram) CIS Hail Guards NOTICE: Do not allow CIS sections to drag across coil fins, damage to CIS hail guards are provided to protect the dry coil from hail damage. -
Page 36: Vibration Cutout Switch
Operation Considerations for Accessories Testing: • De-energize, lock out and tag out power to the fan motors before entering the HXV unit to Basin Heater reset, test, or calibrate the VCOS. Operation • Carefully remove the cover from the VCOS housing. -
Page 37: Mechanical Vibration Cutout Switch
Mechanical Vibration Cutout Switch Considerations for Accessories The Mechanical Vibration Cutout Switch and the Optional Electronic Vibration Cutout Switch Stand Alone BAC Heater should be tested and field adjusted at start-up and yearly thereafter. Control Panel Operation Mechanical Vibration Cutout Switch (Standard) -
Page 38: Fan Control
HXV HYBRID COOLER Fan Control Independent Fan Control BAC recommends controlling all fans together. However, follow the instructions below if independent fan control is performed. NOTE: With evaporative cooling, a In an operating induced draft unit with independent fan capabilities and no partitions, 15 second fan motor delay will not idle fans tend to windmill in the reverse direction. -
Page 39: Resonant Speed
Fan Control Resonant Speed Independent Fan Control Variable Frequency Drive Operation Resonant Speed Identification Procedure Resonant Speed There are several characteristic frequencies at which vibration levels may resonate with unit structural components. These include fan speed, motor speed, bearing frequency, and blade pass frequency. - Page 40 • As stated previously, when adjusting the VFD speed, proceed slowly while monitoring the vibration levels. If the vibration value approaches 0.35 ips (0-peak), slowly “zero in” on the speed where the value equals 0.35 ips, and record the speed at which this occurs as the lower end of the lockout range.
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Page 41: Part 8 Installation Instructions For Field Connections
® Table 7. Supplies for Installing Field Connections 1. Use the BAC template provided with the accessory to layout and mark the hole pattern on the exterior of the cold water basin. 2. Drill a pilot hole from the outside of the cold water basin to the inside of the cold water basin. -
Page 42: W W W . B A L T I M O R E A I R C O I L . C O M
COOLING TOWERS CLOSED CIRCUIT COOLING TOWERS ICE THERMAL STORAGE EVAPORATIVE CONDENSERS HYBRID PRODUCTS PARTS & SERVICES w w w . B a l t i m o r e A i r c o i l . c o m 7600 Dorsey Run Road, Jessup, MD 20794 ›...