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BAC Vertex VRC A-1012N Series, Operation & Maintenance Manual

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BAC Vertex VRC A-1012N Series Operation & Maintenance Manual Download Page 48

 

Vertex™ Evaporative

 Condenser Operation & Maintenance Manual 

–

 Fan Control                                                     

Page | 48 

9.  Fan Control 

 

EC Fan System Fan Control 

All EC fan motors are controlled simultaneously by a single 4-20mA analog signal where 4mA is 0% speed and 20mA is 100% 
speed. Control signals outside of this range will cause the unit to operate in emergency mode (approx. 40% fan speed). 

Sequence of Operation 

Fan Ramp Sequence 

Before start-up, ensure that the unit is energized and a control signal between 4 and 20mA is provided to terminals AIN and 
AGND. The fans will respond to an increasing speed signal, per 

Figure 19

: 

 

Figure 19. Ramp-up Sequence

 

1.

 

If the control signal is less than or equal to 3.2mA for more than 60 seconds: 

a.

 

The alarm light on the control panel will turn ON and an alarm signal will be enabled. 

b.

 

All fans will rotate at the emergency speed. 

2.

 

When the control signal reaches 4.6mA, the fans will initiate rotation. 

3.

 

Between 4.6mA and 20mA, the fans ramp up linearly and proportionally to the input speed signal. 

 

Summary of Contents for Vertex VRC A-1012N Series

Page 1: ...Vertex Evaporative Condenser OPERATION MAINTENANCE MANUAL ...

Page 2: ...cedure 12 Considerations for Initial Start Up 12 General 12 Cleaning 12 Inspection 12 Start Up 13 Extended Shutdown 15 Prolonged Outdoor Storage 16 Storage Preparation 16 Maintenance Requirements During Storage 18 Start Up Preparation After Prolonged Storage 18 4 Component Maintenance Procedures 19 Basin 19 Water Levels 19 Inspection Maintenance 20 EC Fan System 20 Electronically Commutated EC Fan...

Page 3: ...Control 33 Long Term Care of Stainless Steel 33 BAC s Manufacturing Process 33 Jobsite Considerations 33 Recommended Cleaning Procedure 33 System Cleaning 34 Coil Cleaning 34 Weld Byproduct Cleaning 34 6 Bleed Rate 35 7 Cold Weather Operation 36 Inspection Maintenance 36 Fan Section Icing Protection 36 Fan Control 37 Dry Operation 37 Basin Water and Internal Piping Freeze Protection 37 Basin Prote...

Page 4: ...an Ramp Sequence 48 VERTEX Fan Ramp down 49 EC Fan System Troubleshooting 49 Loss of Control Signal 49 Refrigeration System Controller Power Outages 49 Single Fan Communication Loss 49 All Fan Communication Loss 50 Power Outage 50 Single Fan Power Outage 50 Unit Power Outage 51 Fan Alarm Codes 51 BALTIDRIVE Power Train 53 Independent Fan Control Optional 53 Variable Frequency Drive Operation 54 Re...

Page 5: ...ndition of the unit 2 and check unit for unusual noise or vibration Inspect basin Flush water distribution system Inspect spray nozzles Clean basin strainer Clean water guards Drain basin and piping Check and adjust water level in basin Check operation of make up valve Inspect coil Check and adjust bleed rate Inspect unit finish Mechanical equipment system 1 Start Up Monthly Quarterly Annually Shu...

Page 6: ...ety and health authorities Before performing an adjustment or inspection of the VCOS make certain that all power has been disconnected and locked in the off position Moisture inside the switch can lead to switch failure Care must be taken when replacing the cover on the vibration switch to ensure that the proper watertight seal is obtained When the fan speed of the unit is to be changed from the f...

Page 7: ...ed solvents such as bleach or muriatic hydrochloric acid to clean stainless steel It is important to rinse the surface with warm water and wipe with a dry cloth after cleaning Mechanical and operational methods must be employed to protect these products against damage and or reduced effectiveness due to possible freeze up Please refer to BaltimoreAircoil com or contact your local BAC Representativ...

Page 8: ... from the make up water are left behind These dissolved solids may be either alkaline or acidic and as they are concentrated in the circulating water they can cause scaling or accelerated corrosion The extent of impurities in the air and water determines the frequency of most maintenance services and governs the extent of water treatment which can vary from a simple continuous bleed and biological...

Page 9: ...d Platforms with Perimeter Handrails 5 Access Door with Safety Handle and Step 2 Drift Eliminators 6 Internal Walkway 3 BranchLok Removal System 7 Fan Cover 3A Feed Box Assembly 8 Water Guards 3B Spray Branch 9 Pump 3C Nozzles 10 Pump Riser Piping 4 Coil 11 Make Up Valve Assembly 12 Float Ball 13 Strainer Assembly 14 EC Direct Drive Fan System Assembly 15 Terminal Box Table 1 Vertex Evaporative Co...

Page 10: ...al Walkway B Fan Sheave 3 BranchLok Removal System 7 Partition Doors C Fan Sheave Bushing 3A Feed Box Assembly 8 Pump D Fan Bushing 3B Spray Branch 9 Pump Riser Piping E Axial Fan Assembly 3C Nozzles 10 Make Up Valve Assembly F Fan Shaft 4 Coil 11 Float Ball G Bearing Kit 12 Strainer Assembly H Mechanical Equipment Support 13 Air Intake Screens I Fan Cowl Assembly 14 Baltidrive Power Train J Motor...

Page 11: ...rtain essential and emergency repair part be maintained in your inventory to minimize any potential downtime Vertex Evaporative Condenser with EC Fan System Basic Recommended Spare Parts Parts to Consider if Extended Downtime is a Concern Basin Heater LWCO if equipped EC Direct Drive Fan System Assembly Door Gaskets Pump Make Up Valve Assembly Float Ball Spray Nozzles Suction Strainer Pump Seal Ki...

Page 12: ...in place Remove all dirt and debris from the fan guard s and combined inlet shields Inspect and clean all spray nozzles Clean all the mechanical components such as the fan and motor Remove accumulated dirt and debris from the water guards Flush the basin to remove any accumulated dirt and debris Remove clean and replace the basin strainer Inspection Conduct external inspection of the equipment Che...

Page 13: ...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 This equipment should never be operated without all fan screens access panels and access doors in place NOTICE BAC units are typically installed immediately after shipment and many operate year round Howe...

Page 14: ...sted to the correct water flow and pressure 2 25 psig at spray header connection NOTICE Spray system pressure greater than 10 0 psig may cause damage to the distribution system Check that the float operated make up valve is operating freely Closely monitor the water level and adjust as necessary during the first 24 hours of operation Inspect the nozzles and heat transfer section as described secti...

Page 15: ...race and insulate all exposed piping To minimize the risk of biological contamination during shutdown it is recommended the entire system be drained Clean all debris such as leaves and dirt from the interior and exterior of the unit including the combined inlet shields Clean and flush the basin with the basin strainer in place Leave the basin drain open so rain and melting snow will drain from the...

Page 16: ...if supplied at room temperature Tag belts appropriately for future identification During storage the coils should be charged with inert gas and capped Note that coils with steel connections are charged with 15 psig nitrogen at the factory prior to shipment If the condenser is removed from the system charge the coil with 15 psig of inert gas and cap the connections to reduce the risk of internal co...

Page 17: ...ns must also be taken to prevent insects from gaining access to the interior of the motor BALTIDRIVE Power Train BAC standard motors are designed for storage at ambient temperatures of 20ºF to 104ºF 28 9ºC to 40ºC Prolonged periods of exposure above or below these specified conditions could degrade components of the motor and cause malfunction or premature failure Motors should be removed and stor...

Page 18: ...al fans annually to ensure the blades are tight and there is no obvious corrosion between the hub and the fan blade Inspect the rust preventative coating on all motor external machined surfaces including shaft extensions monthly If necessary re coat the surfaces with RUST VETO Start Up Preparation After Prolonged Storage Keep in mind that start up procedures after long periods of storage are just ...

Page 19: ...the make up water supply pressure The make up valve controls the operating level which should be maintained at the levels shown in Table 3 Check the operating water level monthly and readjust the float when necessary to maintain the recommended operating level Model Number Operating Depth in Operating Height in Operating Volume gal Overflow Volume gal VRC xxxxA 1012N xx 9 15 43 254 479 VRC xxxxA 1...

Page 20: ...d bearings lubrication is not required With the fans running check for any unusual noises or vibrations Thoroughly inspect the fans for damaged or deteriorated fan blades and replace the fan system as required Electronically Commutated EC Fan Motors An EC motor has been designed to accept an AC power supply and use onboard electronics to operate similarly to a permanent magnet brushless DC motor A...

Page 21: ...ting the blade by hand and then by moving the blade tip forward and back There should be no play or slippage o Inspect each blade for excessive scale build up that could cause vibration o Check each blade for any cracks If cracks are found the fan motor should be locked out until the fan is replaced Contact your local BAC Representative for assistance Tip Clearance Check the clearance between the ...

Page 22: ... belt from sheave to sheave as shown in Figure 5 or use a tape measure as shown in Figure 6 to measure belt deflection o 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 o There is adequate belt tension if the belt deflects between 1 4 and 3 8 as shown in Figure 5 and Figure 6 Figure 5 Belt Tension with a ...

Page 23: ...bute the tension throughout the belt Figure 7 Motor Adjusting Screw Drive alignment check and adjustment o Place a straight edge across the driver and the driven sheaves as shown in Figure 8 o The straight edge should contact all four points as shown in Figure 8 indicating that the drives are properly aligned o There should be no more than 1 16 deviation from the four points of contact o In case o...

Page 24: ...aintenance For all units ordered with the BALTIDRIVE Power Train two pillow block ball bearings support the fan shaft and are provided with extended lube lines as standard on the Vertex Evaporative Condenser Each bearing is equipped with a lubrication fitting and a locking collar to keep out moisture Only lubricate the bearings with a manual grease gun or BAC s optional Automatic Bearing Greaser D...

Page 25: ...the seal on the underside of the bearing o Seasonal Start Up Purge the bearings with new grease prior to start up o Operation Purge the bearings with new grease every three months while in operation o Extended Shutdown Purge the bearings with new grease prior to any prolonged storage or downtime Locking Collars Each eccentric locking collar should be checked quarterly to ensure that the inner bear...

Page 26: ...em Water is distributed through a corrosion resistant polyvinyl chloride PVC spray distribution system The drift eliminators are made of PVC which requires no protection against rot decay rust or biological attack The inspection procedure is as follows Shut off the fan and lock out and tag out the fan and pump motors Remove drift eliminators to allow a clear view of the spray distribution system a...

Page 27: ...g the float and all thread rod using the wing nuts provided Inspect the make up valve assembly monthly and adjust if necessary Inspect the valve annually for leakage Replace the valve seat if necessary Maintain the make up water supply pressure between 15 psig and 50 psig for proper operation BAC recommends a pressure regulator valve provided by others for pressures over 50 psig Set the initial ba...

Page 28: ...assembly and a slow closing solenoid valve Stainless steel electrodes factory set at predetermined lengths extend from an electrode holder into the basin For more information refer to the Electric Water Level Control Operation Maintenance Manual available at BaltimoreAircoil com Clean the stainless steel electrodes periodically to prevent accumulations of scale corrosion sludge or biological growt...

Page 29: ...nts protected with the thermosetting hybrid polymer can be scratched scraped or blemished To touch up these areas use a repair kit BAC Part 160133 available from your local BAC Representative Stainless Steel Components Inspect stainless steel components for signs of blemishes or corrosion See section Long Term Care of Stainless Steel on Page 33 for cleaning and care instructions TriArmor Corrosion...

Page 30: ...er water treatment program administered under the supervision of a competent water treatment specialist is an essential part of routine maintenance to ensure the safe operation and longevity of evaporative cooling equipment as well as other system components In evaporative cooling products cooling is accomplished by evaporating a small portion of the recirculating water as it flows through the uni...

Page 31: ...tion Different combinations of materials may be used on the same unit 6 Water chemistry will change with operating temperatures The recommended guidelines listed in Table 5 refers to water temperature at 95 F 7 EVERTOUGH Construction units have a TriArmor Corrosion Protection System basin 8 Galvanized steel units require passivation in order to prevent white rust refer to Passivation 9 The convers...

Page 32: ...ctly into the unit s basin or water distribution system as this can severely damage areas directly contacted When chlorine is added to the system free residual chlorine should not exceed 1 ppm except as noted in Start Up Procedure on Page 12 and Extended Shutdown on Page 15 Exceeding this limit may accelerate corrosion Passivation NOTE Stainless steel basins and basins protected by the TriArmor Co...

Page 33: ...ss steel The chromium in the steel reacts with the oxygen in the air to form a chromium oxide surface layer also called the passivation layer that provides the corrosion resistance in stainless 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 stai...

Page 34: ...cotch Brite products may be used where aesthetic considerations are not important followed by solvent cleaning with organic solvents as described above It is important to rinse the surface with warm water and wipe with a dry cloth after 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 e...

Page 35: ...cally cycles of concentration equal the ratio of the concentration of dissolved solids for example chlorides sulfates etc in the recirculating water to the concentration of the same material in the make up water In order to optimize heat transfer efficiency and maximize equipment life bleed or blowdown a small amount of recirculating water from the system This controls the cycles of concentration ...

Page 36: ...o over pumping clogged strainers or make up valve malfunction Some unit icing can be expected in very cold weather Usually this will not affect the operation of the unit Resolve any icing conditions that may damage the unit or the supports impair the system performance or create a safety hazard Fan Section Icing Protection There are three basic operational methods which can be used to provide the ...

Page 37: ...ion For dry operation switch points and recommendations contact your local BAC representative Basin Water and Internal Piping Freeze Protection Basin Protection It is important to protect the basin and internal piping The basin water could freeze when the unit is shutdown and exposed to subfreezing ambient temperatures Remote Sump The ideal method of protection is a remote sump located in a heated...

Page 38: ...g circuits is job specific Minimum Operation When utilizing an auxiliary cooling circuit with water as the cooling media the system must be operated to meet minimum flow and temperature requirements Maintain a minimum heat load so that the temperature of the fluid leaving the coil is not less than 50 F 10 C To maintain the leaving fluid temperature at 50 F 10 C when the process load is extremely l...

Page 39: ...closure that is suitable for outdoor use Annually inspect the basin heater prior to the risk of reaching freezing operating conditions Figure 11 Basin Heater Operation Ensure that the heating element is completely submerged before energizing the main disconnect For installations that have a BAC Controls Enclosure please consult the submittal packet provided with the unit and contact your local BAC...

Page 40: ...ation NOTICE For the stand alone BAC heater control panel do not operate the system unattended or for extended periods of time during test mode resistor across terminals T1 and T2 Operation in water temperatures above 45 F 7 2 C could damage the unit NOTICE For the stand alone BAC heater control panel do not operate the system unattended or for extended periods of time with terminals G1 G2 jumpere...

Page 41: ...jumper wire across terminals G1 and G2 on the combination temperature low level control circuit board Install the heater control panel cover Energize the system and listen for the contactor closing Operate the system until the ice is melted around the probe After operation de energize the circuit disconnect the heater control panel and tag out the circuit Remove the jumper check all connections re...

Page 42: ... start and stop the fan motor s two more times to ensure that the VCOS is properly set Mechanical Vibration Cutout Switch Optional Set Point Adjustment When Installed 1 For safety turn off then lock and tag out the electrical supply to the fan motor s 2 Turn adjustment screw counterclockwise 1 8 turn at a time until you hear the control trip 3 Once tripped rotate adjustment screw turn clockwise Pu...

Page 43: ...int so that any vibration will cause a trip condition The light will come on immediately and the trip will occur after the duration of the time delay proving the complete system is operational If test position is maintained for less than the duration of the time delay the trip will not occur thus permitting the system test without shutdown Calibration A light adjacent to the set point control come...

Page 44: ...ex Evaporative Condenser Operation Maintenance Manual Operation Considerations for Accessories Page 44 Redundant Pump System Optional Figure 14 Discharge and Suction Valves Figure 15 Bleed and Bypass Valves ...

Page 45: ... discharge valve that should be open during normal operation 3 Start the pump that will be in operation Pump Removal 1 Shut down lock out and tag out power to the pump motor for the pump that will be removed 2 Close the bypass valve for the pump that will be removed 3 Close the suction valve and the discharge valve to isolate the pump that will be removed 4 Loosen and remove the flange hardware an...

Page 46: ...ve Condenser Operation Maintenance Manual Operation Considerations for Accessories Page 46 Figure 16 Pump Volute Flanges Figure 17 Long Term Pump Removal Flange Hardware Install Blind Flanges Tee Bypass Lines Together ...

Page 47: ...ount See Figure 18 2 Attach the flange hardware and gaskets to the suction and discharge flanges of the pump volute See Figure 16 3 After the new pump and new gaskets are installed and all connections are properly fastened open the bypass valve for the new pump 4 Open the suction valve for the new pump 5 If the newly installed pump is to be operated refer to the instructions for pump switch over F...

Page 48: ... start up ensure that the unit is energized and a control signal between 4 and 20mA is provided to terminals AIN and AGND The fans will respond to an increasing speed signal per Figure 19 Figure 19 Ramp up Sequence 1 If the control signal is less than or equal to 3 2mA for more than 60 seconds a The alarm light on the control panel will turn ON and an alarm signal will be enabled b All fans will r...

Page 49: ...at the emergency speed b An alarm light on the control panel will turn on and an alarm signal will be enabled Single Fan Communication Loss 1 If the signal is restored within 60 seconds a The affected fan will run at the last known control signal as long as the signal returns in less than 60 seconds b The remaining fans will run according to the control signal 2 If the signal is not restored withi...

Page 50: ...have power and that the communication signal is restored b Turn on the override switch on the control panel and an amber light will turn on c All fans will start to operate based on the control signal 4 To turn off the override light the unit must be restarted with a valid control signal present Power Outage Single Fan Power Outage 1 If power is restored within 60 seconds and an uninterrupted cont...

Page 51: ...ithin 60 seconds of power restoration i The unit will operate based on the control signal b If the control signal is not restored within 60 seconds of power restoration i The alarm light on the control panel will turn ON and an alarm signal will be enabled ii After power is restored all fans will rotate at the emergency speed 2 Troubleshooting the Issue a Make sure that a valid control signal and ...

Page 52: ...n blades are physically blocked Inspect fan housing for blockage 6x Power module failure Controller circuitry has a short to ground or motor winding is damaged Verify wiring to motor 7x DC undervoltage DC link voltage is lower than limit Verify wiring to motor 8x DC overvoltage DC link voltage is higher than limit Verify wiring to motor 9x Cooling down power module Motor is attempting to cool down...

Page 53: ...g s o Check the fan blades for looseness first by twisting the blade by hand and then by moving the blade tip forward and back There should be no play or slippage o Inspect each blade for excessive scale build up that could cause vibration o Check each blade for any cracks If cracks are found the fan motor should be locked out until the fan is replaced Contact your local BAC Representative for ass...

Page 54: ...stages to reduce staging current o Staging Down Turn off the fan motor No need for delays Variable Frequency Drive Operation Applications utilizing variable frequency drives VFDs for fan motor control must use inverter duty motors built in compliance with NEMA standard MG 1 Part 31 Operation of the unit at a speed which resonates with components of the drive system or support structure may result ...

Page 55: ...to the motor circuit is locked out Attach the accelerometer provided by others onto the box beam as shown in Figure 22 The accelerometer should be placed on the top of the bearing support channel near the fan side bearing as shown Figure 22 Accelerometer Location Belt Drive Connect the signal wire from the accelerometer provided by others to the vibration analyzer provided by others Be sure to rou...

Page 56: ...ed Continue to slowly increase the speed while monitoring the vibration level If this is a resonance then the value should peak and eventually decrease to a level that is below 0 35 ips as the speed is increased After the vibration level has peaked and continues to fall record the speed where the value equals 0 35 ips as the upper end of the lockout range Using this data a baseline for vibration h...

Page 57: ...ssory to layout and mark the hole pattern on the exterior of the basin 2 Drill a pilot hole from the outside of the basin to the inside of the basin 3 On the inside of the basin a For connections 3 or less score the TriArmor Corrosion Protection System with a hole saw as shown in Figure 23 b For connections 3 or greater proceed to step 4 Figure 23 Scored TriArmor Corrosion Protection System Suppli...

Page 58: ...ting saw or a Sawzall for larger connections 3 or greater Figure 24 Removal Material 5 Position the BAC supplied stainless steel backing ring gasket to the inside of the basin 6 Position the flange to the outside of the basin 7 Bolt the flange and the stainless steel backing plate together using stainless steel bolts 8 Seal any exposed galvanized steel of the connection inside the basin with Vulke...

Page 59: ...Vertex Evaporative Condenser OPERATION MAINTENANCE MANUAL BaltimoreAircoil com 2022 Baltimore Aircoil Company 7600 Dorsey Run Road Jessup MD 20794 410 799 6200 RGOMVRCA01_R3 0 ...

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