B08_-_Atch_1_-_DEVA_HVAC_Preventative_Maintenance__HVAC_Install_SOW.pdf

Statement of Work HVAC Park-Wide Preventive Maintenance

Death Valley National Park

Part 1: Scope/Background/Objective

1.1 Scope of Work

A. Perform preventative maintenance and repairs on HVAC systems, at various locations, throughout Death Valley National Park.

B. Perform installs of HVAC systems, (mini-split heat pumps & two 8-ton units) at specific locations outlined in the bid schedule and map from attachment B in Death Valley National Park

C. Provide callout service for HVAC emergencies and be on site within 24 hours of notification, during the period of performance.

D. This contract will be for a one (1) year from time of award.

1.2 Background

Park staff and visitors depend on functioning HVAC systems to provide a safe working and visiting environment. Summer daytime temperatures can reach 125° F while overnight temperatures often remain above 100° F. Working, living, and visiting Death Valley during these extreme temperatures, requires functioning and well-maintained HVAC systems. Death Valley experiences intense heat throughout the cooling season. Air conditioning failures, whether in Park housing or Park administrative buildings, interrupts living and working in the Park, can be life threatening, and need to be addressed expeditiously.

1.3 Objective

Ensure a safe and comfortable working, living, and visiting environment for Park staff and Park visitors by performing annual maintenance, repairs, and emergency response to Park HVAC systems.

Part 2: Contract Items

2.1 Equipment Summary

There are (107) air-conditioning units in Park housing and operation/administration buildings.

The AC units range in size from 2-ton mini split heat pump/conventional units to 16-ton commercial units. There is also (1) EVAPCO Closed Circuit Cooling Tower, model # ESWA 7723H, in operation at the Furnace Creek Visitor Center/Park Headquarters building.

2.2 Tasks & Supplies

1. Air conditioner preventive maintenance is required on a 3-year cycle; therefore, preventive maintenance will be addressed for up to sixty-five (65) residential and operation/administrative units annually. Preventive air conditioning maintenance may include, but not limited to, the following: cycle thermostat and inspect operation, refrigerant pressure test and re-charge as needed, replacement of components subject to wear or environmental deterioration, cleaning of compressor and fan housing, check for unusual noises and vibrations, replace filters.

2. Install fourteen (14) HVAC units, two for each residence listed, within the Cow Creek housing area with mini-split (heat pump) systems, including all appurtenances to make a complete operating system with a remote/wireless controller for each, mini-split systems. This will include the removal and haul off the old HVAC units. ;

3. Remove and recycle a 16-ton heat pump. Procure and install two (2) 8-ton heat pump units;

integrate controls and return to service at the Furnace Creek Visitors Center.

4. Provide cyclic maintenance to the EVAPCO cooling tower. The EVAPCO cooling tower provides closed loop chilled water to the various heat pumps spread out through the Visitor Center and Park Headquarters complex. Typical cooling tower systems requiring cyclic maintenance include, but are not limited to, the Fan System, the Recirculated Water System, and Cleaning of Stainless Steel. A complete checklist of cyclic maintenance required for the EVAPCO cooling tower can be found in Attachment A of the SOW.

5. Provide emergency service response to HVAC equipment failures, not to exceed sixteen (16).

Note that emergency callout service is a firm-fixed price. This is a not-to-exceed (NTE) firm fixed price line and not a cost reimbursement line. Parts/equipment to make the necessary repairs are not within scope of this requirement. Include:

Travel expense round trip from firm’s place of business to the Furnace Creek Visitor Center/Cow Creek Administrative Site. Travel expenses shall include labor hours, vehicle cost, fuel, meals, and all other costs associated with travel to/from Death Valley.

Overnight lodging for one night.

Additional crew labor hours (fully loaded).

Part 3: Additional Information

1. The HVAC units included in this contract are located in the Furnace Creek, Cow Creek, and Stovepipe Wells areas.

2. The Park will provide the contractor with a prioritized list of HVAC unit locations, manufacturer, and model numbers designated for annual inspection, as an attachment(s) to this Statement of Work.

3. Death Valley will provide Park staff as a point of contact (POC) and as an escort while performing work in the Park.

4. Contractor to provide replacement parts and material submittals to the assigned Park Contracting Officers Representative (COR) for Park approval.

5. All contractor communication concerning the contract will be through the assigned Park CO and COR.

6. Must be licensed in the state of California for HVAC work.

Attachment A for LIFE

Operation and Maintenance Instructions

For EVAPCO Closed Circuit Coolers and Evaporative Condensers

Member of

International Institute of

Attachment A Ammonia Refrigeration www.iiar.org

† Mark owned by the Cooling Technology Institute

Table of Contents

3 Introduction

3 Safety Precautions

3 Terminology

4 Initial Storage and/or Idle Period Recommendations

5 International Building Code Provision

5 Initial and Seasonal Startup Checklist 6 General 6 Initial and Seasonal Startup 7 Recommended Maintenance Schedule 9 Seasonal Shutdown Checklist

10 Basic Closed Circuit Cooler/Condenser Sequence of Operation

11 Fan System 11 Fan Motor Bearings 11 Fan Shaft Ball Bearings 12 Fan Belt Adjustment 13 Fan Belt Adjustment – Induced Draft 14 Fan Belt Adjustment – Forced Draft 14 Gear Drives

14 Air Inlet 14 Coil Inlet 15 Fan System – Capacity Control 15 Fan Motor Cycling 15 Sequence of Operation for Fan Motor Cycling 15 Variable Frequency Drives

15 Sequence of Operations / Guidelines for Multi-fan Units with a VFD during Peak Load

16 Two-Speed Motors

16 Sequence of Operation for Two Fan Units with Two- Speed Motors during Peak Load

17 Recirculated Water System - Routine Maintenance 17 Suction Strainer in Cold Water Basin 18 Cold Water Basin 18 Operating Level of Water in Cold Water Basin 19 Water Makeup Valve

19 Pressurized Water Distribution Systems 20 Bleed-Off Valve 20 Pump (When Supplied)

21 Water Treatment and Water Chemistry 21 Bleed or Blowdown 21 Galvanized Steel – Passivation 22 Water Chemistry Parameters 22 Control of Biological Contamination 23 Gray Water and Reclaimed Water 23 Air Contamination

24 Cold Weather Operation 24 Unit Layout 24 Freeze Protection of Recirculating Water 26 Freeze Protection of Closed Circuit Cooler Coils 27 Unit Accessories

27 Cold Water Basin Heaters

27 Remote Sumps 27 Electric Water Level Control (EWLC) 27 Vibration Cutout Switches

27 Capacity Control Methods for Cold Weather Operation 27 Induced Draft Unit Capacity Control 28 Forced Draft Unit Capacity Control

28 Ice Management

28 Induced Draft Units 29 Forced Draft Units

30 Troubleshooting

33 Replacement Parts 33 Part Identification Drawings 34 ATC-E/ATWB/eco-ATWB 4’x6’ Wide Units 35 ATC-E/ATWB/eco-ATWB 4’x9’ & 4’x12’ Wide Units 36 ATC-E/ATWB/eco-ATC-A/eco-ATWB 7’ Wide Units 37 ATC-E/ATWB/eco-ATC-A/eco-ATWB 8’ & 8.5’

Wide Units 38 eco-ATC-H/eco-ATWB-H 8.5’ Wide Units

39 eco-ATWB-E 8.5’ Wide Units 40 ATC-E/ATWB/eco-ATC-A/eco-ATWB 10’ & 12’

Wide Units 41 eco-ATC-H/eco-ATWB-H 10’ & 12’ Wide Units 42 eco-ATWB-E 10’ & 12’ Wide Units 43 ESW4 8.5’ Wide Units

44 ESW4 12’ Wide Units 45 ESW4 14’ Wide Units 46 LSC-E/LSWE/eco-LSWE 4’ Wide Units 47 LSC-E/LSWE/eco-LSWE 5’ Wide Units 48 LSC-E/LSWE/eco-LSWE 8’ Wide Units

(Single Side Fans) 49 LSC-E/LSWE/eco-LSWE 10’ Wide Units

50 LRC/LRWB/eco-LRWB 3’ Wide Units

51 LRC/LRWB/eco-LRWB 5’ Wide Units 52 LRC/LRWB/eco-LRWB 8’ Wide Units 53 PMC-E/eco-PMC 5’ Wide Units 54 PMC-E/eco-PMC 10’ and 12’ Wide Units 55 PHC-E S 2.24m Wide-Single Side Air Inlet Units 56 PHC-E S 8.5’ Wide-Single Side Air Inlet Units

57 PHC-S 10’ and 12’ Wide-Single Side Air Inlet Units 58 PHC-D 12’ and 14’ Wide-Two Sided Air Inlet Units

59 - 61 Notes

Introduction

Safety Precautions

Terminology

Congratulations on the purchase of your EVAPCO evaporative cooling unit! EVAPCO equipment is constructed of the highest quality materials and designed to provide years of reliable service when properly maintained.

Thoroughly clean road salt, dirt and debris from unit immediately after delivery. Residue left on product surfaces can cause damage that is not covered by any warranty.

Evaporative cooling equipment is often remotely located and periodic maintenance checks are often overlooked. It is important to establish a regular maintenance program and be sure that the program is followed. This bulletin should be used as a guide to establish a program. A clean and properly serviced unit will provide a long service life and operate at peak efficiency.

This bulletin includes recommended maintenance services for unit start up, unit operation and unit shutdown and the frequency of each.

Please note: the recommendations of frequency of service are minimums. Services should be performed more often when operating conditions necessitate.

Become familiar with your evaporative cooling equipment. Refer to the isometric drawings located on pages 34-57 for information on the arrangement of components in your equipment.

If you should require any additional information about the operation or maintenance of this equipment, contact your local EVAPCO representative. You may also visit www.evapco.com for more information.

Qualified personnel should use proper care, procedures and tools when operating, maintaining or repairing this equipment in order to prevent personal injury and/or property damage. The warnings listed below are to be used as guidelines only.

This equipment should never be operated without fan screens and access doors properly secured and in place.

A lockable disconnect switch should be located within sight of the unit for each fan motor associated with this equipment. Before performing any type of service or inspection of the unit make certain that all power has been disconnected and locked in the “OFF” position.

The top horizontal surface of any unit is not intended to be used as a working platform. No routine service work is required from this area.

Building water systems receive potable and non-potable water from either a public or private entity for their water supply.

This water supply for the building water system can contain various waterborne pathogens, including Legionella bacteria, which can cause or contribute to various illnesses if aspirated, ingested or inhaled. Since evaporative cooling equipment uses the same building water, there is some potential that these pathogens might propagate in the equipment. Therefore, careful consideration should be undertaken with respect to equipment location and the implementation of effective water management, inspection and cleaning protocols. (See Control of Biological Contaminants in these Operation and Maintenance Instructions.)

Throughout this manual, the terms “Induced Draft” and “Forced Draft” are used. Below is a list of EVAPCO closed circuit cooler and condenser products offerings and associated terminology.

Induced Draft equipment includes the following EVAPCO product models:

ESW4 - Closed Circuit Cooler

Initial Storage and/or Idle Period Recommendations

AT Product Lines

• ATWB - Closed Circuit Cooler

• ATC-E - Evaporative Condenser

• eco-ATWB - Closed Circuit Cooler

• eco-ATWB-E - Wet/Dry Closed Circuit Cooler

• eco-ATWB-H - Wet/Dry Closed Circuit Cooler

• eco-ATC-A - Wet/Dry Evaporative Condenser

• eco-ATC-H Wet/Dry Evaporative Condenser

PHC-E - Parallel Hybrid Evaporative Condenser

Forced Draft equipment includes the following EVAPCO product models:

LR Product Lines

• LRWB - Closed Circuit Cooler

• LRC - Evaporative Condenser

• eco-LRWB - Wet/Dry Closed Circuit Cooler

LS Product Lines

• LSWE - Closed Circuit Cooler

• LSC-E - Evaporative Condenser

• eco-LSWE - Wet/Dry Closed Circuit Cooler

PM Product lines

• PMC-E - Evaporative Condenser

• PMC-Q - Evaporative Condenser

• eco-PMC - Wet/Dry Evaporative Condenser

If the unit will sit for idle periods of time it is recommended that the following be performed in addition to all component manufacturers recommended maintenance instructions.

• The fan/motor/pump bearings and motor bearings need to be turned by hand at least once a month. This can be accomplished by tagging and locking out the unit’s disconnect, grasping the fan assembly (or removing the pump motor fan guard), and rotating it several turns.

• If unit sits longer than a few weeks, run gear reducer (if equipped) for 5 minutes weekly.

• If unit sits longer than 3 weeks, completely fill gear reducer with oil. Drain to normal level prior to running.

• If unit sits longer than one month, insulation test motor windings semi-annually.

• If fan motor sits idle for at least 24 hours while the spray pumps are energized distributing water over the coil, motor space heaters (if equipped) should be energized. Alternatively, fan motors may be energized for 10 minutes, twice daily, to drive any moisture condensation out of the motor windings.

• If coil sits longer than one month, nitrogen charge the coil.

• Energize fan motors space heaters.

Initial and Seasonal Startup Checklist

The International Building Code (IBC) is a comprehensive set of regulations addressing the structural design and installation requirements for building systems – including HVAC and industrial refrigeration equipment. The code provisions require that evaporative cooling equipment and all other components permanently installed on a structure must meet the same seismic design criteria as the building.

All items attached to EVAPCO closed circuit coolers or evaporative condensers must be independently reviewed and isolated to meet applicable wind and seismic loads. This includes piping, ductwork, conduit, and electrical connections. These items must be flexibly attached to the EVAPCO unit so as not to transmit additional loads to the equipment as a result of seismic or wind forces.

General

1. Verify that the overall installation reflects the requirements of the installation guidelines found in EVAPCO Bulletin 311 – Equipment Layout Manual available at www.evapco.com.

2. Fan motor space heaters: To prevent any moisture buildup in the windings and bearings, space heaters are provided as standard on every fan motor. These should be wired prior to operation.

3. For multi-speed fan motors, verify that 30 second or greater time delays are provided for speed changes when switching from high to low speed. Also check to see if interlocks are provided to prevent simultaneously energizing high and low speed, and confirm both speeds operate in the same direction.

4. Verify all safety interlocks work properly.

5. For units operating with a variable frequency drive, make certain that minimum speed requirements have been set.

Check with VFD manufacturer for recommended minimum speeds. See “Fan System - Capacity Control” section for more information, and recommendations on locking out resonance frequencies.

6. Verify that a water treatment plan has been implemented including passivation of galvanized steel units. See “Water Treatment and Water Chemistry” section for more details.

7. If the unit is going to sit idle for an extended period of time, follow all manufacturers’ fan motor and pump instructions for long-term storage. Plastic sheets or tarps should never be used to protect a unit during storage. This practice can trap heat inside the unit, and could potentially cause damage to plastic components. See your local EVAPCO representative for additional information on unit storage.

BEFORE BEGINNING ANY MAINTENANCE, BE CERTAIN THAT THE POWER IS TURNED OFF

AND THE UNIT IS PROPERLY LOCKED AND TAGGED OUT!

Initial and Seasonal Startup

1. Clean and remove any debris, such as leaves and dirt from the air inlets.

2. Flush the cold water basin (with the strainer screens in place) to remove any sediment or dirt.

3. Remove the strainer screen, clean and reinstall.

4. Check mechanical float valve to see if it operates freely.

5. Inspect water distribution system nozzles and clean as required. Check for proper orientation.

(This is not required at initial startup. The nozzles are clean and set at the factory).

6. Check to ensure drift eliminators are securely in place and in the proper orientation.

International Building Code Provisions

Initial and Seasonal Startup Checklist (Continued)

7. Adjust fan belt tension as required. See “Fan Belt Adjustment” section.

8. Lubricate fan shaft bearings prior to seasonal startup.

9. Turn the fan(s) and pumps by hand to insure it turns freely without obstructions.

10. Visually inspect the fan blades. Blade clearance should be approximately 3/8” (1/4” minimum) from tip of blade to the fan cowl. The fan blades should be securely tightened to the fan hub.

11. If any stagnant water remains in the system including “dead legs” in the piping, the unit must be disinfected prior to the fans being energized. Please refer to ASHRAE Guideline 12 and CTI Guideline WTP-148 for more information.

12. Manually fill the cold water basin up to the overflow connection.

13. For closed circuit coolers, fill the heat exchanger coil with the specified fluid and “burp” air from the system before pressurizing, using vents on coil inlets. Do not do this for evaporative condensers.

NOTE: Closed circuit coolers should only be used on sealed, pressurized systems. Continual aeration of the water in an open system can cause corrosion inside the tubes of the cooler leading to premature failure.

For closed circuit coolers with optional controls, see controls O&M for proper startup procedure.

After the unit has been energized, check the following:

1. Adjust mechanical float valve as required to the proper water level.

2. Unit basin should be filled to the proper operating level. See “Recirculating Water System Operating Levels” section for more details.

3. Verify fan(s) is rotating in proper direction.

4. Start the spray water pump(s) and check for proper rotation as indicated by the arrow on the front cover.

5. Measure voltage and current on all three power leads of pump and fan motor. The current should not exceed the motor nameplate full load amp rating taking the service factor into account.

6. Consult your qualified water treatment company to fine tune the minimum bleed necessary, see “Water Treatment and Water Chemistry” section.

7. See fan and pump motor manufacturer maintenance and long-term storage instructions for more detailed information.

The motors should be lubricated and serviced in accordance with manufacturer’s instructions.

8. All new evaporative cooling equipment and associated piping should be precleaned and flushed to remove grease, oil, dirt, debris, and other suspended solids prior to operation. Any precleaning chemistry should be compatible with the cooling equipment’s materials of construction. Alkaline formulations should be avoided for systems which include galvanized materials of construction.

Closed hydronic systems connected to either a closed circuit cooler or dry cooler should be precleaned and flushed to remove debris, grease, flash rust, oil, and other suspended solids prior to operation. EVAPCO recommends the use of inhibitor chemistry or inhibited glycol to minimize corrosion and scale during normal operation. EVAPCO recommends a minimum of 25% inhibited glycol to minimize corrosion.

Recommended Maintenance Schedule

PROCEDURE FREQUENCY

1. Clean pan strainer Monthly or as needed

2. Clean and flush pan** Quarterly or as needed

3. Check bleed-off valve to make sure it is operative Monthly

4. Check operating level in pan and adjust float valve if necessary Monthly

5. Check water distribution system and spray pattern Monthly

6. Check drift eliminators Quarterly

7. Check the fan blades for cracks, missing balancing weights loose weight port caps and open drain holes (Super Low Sound Fans) and vibrations

Quarterly

8. Check sheaves, bushings, fan shafts and fan hubs for corrosion.

Scrape and coat with ZRC

Annually

9. Inspect lubrication lines to bearings Quarterly

10. Lubricate fan shaft bearings* Every 1000 hours of operation (or every three months)

11. Check belt tension and adjust Monthly

12. Sliding motor base – Inspect and grease Annually or as needed

13. Check fan screens, inlet louvers and fans. Remove any dirt or debris Monthly or as needed

14. Inspect and clean protective finish

- Galvanized: scrape and coat with ZRC

- Stainless: clean and polish with a stainless steel cleaner.

Annually

15. Check water quality for biological contamination.

Clean unit as needed and contact a water treatment company for recommended water treatment program**

Regularly

OPTIONAL ACCESSORIES:

1. Gear Reducer – Check oil level with unit stopped 24 hours after startup & monthly

2. Gear Reducer/Piping – Do visual inspection for oil leaks, auditory inspection for unusual noises and vibrations

Monthly

3. Gear Reducer – Replace oil Semiannually

4. Oil Pump – Do visual inspection for leaks and proper wiring Monthly

5. Gear Reducer/Coupling – Check alignment of the system 24 hours after startup & monthly

6. Coupling/Shaft – Inspect flex elements and hardware for tightness, proper torque & crack/deterioration

Monthly

7. Heater Controller – Inspect controller and clean probe ends Quarterly

8. Heater – Inspect junction box for loose wiring and moisture One month after startup and semiannually

* See maintenance manual for startup instructions and lubrication recommendations.

** Cooling towers must be cleaned on a regular basis to prevent the growth of bacteria including Legionella Pneumophila.

Recommended Maintenance Schedule (Continued)

OPTIONAL ACCESSORIES:

9. Heater – Inspect elements for scale buildup Quarterly

10. Electronic Water Level Controller – Inspect junction box for loose wiring and moisture

Semiannually

11. Electronic Water Level Controller – Clean probe ends of scale buildup

Quarterly or as needed

12. Electronic Water Level Controller – Clean inside the standpipe Annually

13. Solenoid Makeup Valve – Inspect and clean valve and strainer of debris

As needed

14. Vibration Switch (mechanical) – Inspect enclosure for loose wiring and moisture

One month after startup and monthly

15. Vibration Switch – Adjust the sensitivity During startup and annually

16. Sump Sweeper Piping – Inspect and clean piping of debris Semiannually

17. Water Level Indicator – Inspect and clean Annually

DURING IDLE PERIODS:

IDLE PERIOD RECOMMENDED ACTION FREQUENCY

Two or More Days Energize motor space heaters - or run motors for 10 minutes Twice daily

A Few Weeks Run gear reducer for 5 minutes Weekly

Several Weeks Completely fill gear reducer with oil. Drain to normal level prior to running.

Once

One Month or Longer

Rotate motor shaft/fan 10 turns Biweekly

Megger test motor windings Semiannually

Seasonal Shutdown Checklist

When the system is to be shut down for an extended period of time, the following services should be performed.

1. The evaporative cooling unit cold water basin should be drained.

2. The cold water basin should be flushed and cleaned with the suction strainer screens in place.

3. The suction strainer screens should be cleaned and reinstalled.

4. The cold water basin drain should be left open.

5. The fan shaft bearings and motor base adjusting screws should be lubricated. This should also be performed if the unit is going to sit idle prior to initial startup.

6. The makeup water supply, overflow and drain lines, as well as the recirculating pump and pump piping up to the overflow level must be heat traced and insulated to account for any residual water.

7. The finish of the unit should be inspected. Clean and refinish as required.

8. The fan, motor, and pump bearings need to be turned at least once a month by hand. This can be accomplished by making sure the unit’s disconnect is tagged and locked out, and grasping the fan assembly, rotating it several turns.

9. Energize fan motor space heaters.

10. CLOSED CIRCUIT COOLERS ONLY - If the recommended minimum fluid flows through the heat transfer coil cannot be maintained, and an antifreeze solution is not in the coil, the coil must be drained immediately whenever the system pumps are shut down or flow stops during freezing conditions. This is accomplished by having automatic drain valves and air vents in the piping to and from the cooler. Care must be taken to ensure that the piping is adequately insulated and sized to allow the water to flow quickly from the coil. This method of protection should be used only in emergency situations and is neither a practical nor recommended method of freeze protection. Coils should not be drained for an extended period of time, as internal corrosion may occur. See the “Cold Weather Operation” section of this document for more details.

See fan and pump manufacturer maintenance and long-term storage instructions for more detailed instructions.

System Off / No Load The system pumps and fans are off. If the basin is full of water a minimum basin water temperature of 40ºF must be maintained to prevent freezing. This can be accomplished with the use of optional basin heaters. See the “Cold Weather Operation” section of this bulletin for more details on cold weather operation and maintenance.

System/Condensing Temperature Rises The recirculation pump turns on. The unit will provide approximately 10% cooling capacity with only the pump running. If the unit has positive closure dampers they should be fully opened before the pumps turn on.

If the system temperature continues to rise, the unit fan is cycled on. For a variable speed controller, the fans are turned on to minimum speed. See the “Fan System – Capacity Control” section of this bulletin for more details on fan speed control options. If the system temperature continues to rise, then the fan speed is increased as required, up to full speed.

NOTE: During subfreezing weather the minimum recommended speed for variable speed controllers is 50%. ALL FANS IN OPERATING CELLS OF MULTIPLE CELL UNITS MUST BE CONTROLLED TOGETHER TO PREVENT ICING ON THE FANS.

System/Condensing Temperature Stabilizes Control the leaving fluid temperature (closed circuit coolers) or condensing temperature (evaporative condensers) by modulating the fan speeds with variable speed drives or by cycling fans on and off with single or two-speed drives.

System/Condensing Temperature Drops Decrease the fan speed, as required.

System Off / No Load The system pump turns off. The starter interlock will energize any optional basin heaters in cold weather.

The recirculation pump should not be used as a means of capacity control, and should not be cycled frequently. Excessive cycling can lead to scale buildup, and reduce wet and dry performance.

Dry Operation During colder winter months it is possible to turn off the spray pump, drain the cold water basin, and just cycle the fans. Be sure to leave the basin drain open during this time to prevent collection of rain water, snow, etc. If the unit has positive closure dampers they should be fully opened before the fans turn on. If dry operation will be used on a centrifugal fan, forced draft unit, be sure to verify that the motor and drives have been properly sized to handle the reduction in static pressure experienced when the spray water is turned off.

NOTE: Minimum control point for process fluid should never be lower than 42º F.

NOTE: When a unit is provided with a discharge damper assembly, the control sequence should cycle the dampers open and closed once a day regardless of capacity requirements to prevent the assembly from seizing. The fan motor should be shut off whenever the dampers are closed.

NOTE: ESW4 or PHC product lines should not operate dry.

NOTE: The eco-ATWB, eco-ATWB-E, and eco-ATWB-H sequence of operation is unique and is explained in detail in the Sage® Control System manual.

Basic Closed Circuit Cooler/Condenser Sequence of Operation for Wet or Evaporative Mode

The fan systems of both centrifugal and axial driven units are rugged; however, the fan system must be checked regularly and lubricated at the proper intervals. The following maintenance schedule is recommended.

Fan Motor Bearings EVAPCO evaporative cooling units use either a TEAO (Totally Enclosed Air Over) or a TEFC (Totally Enclosed Fan Cooled) fan motor.

These motors are built to “Cooling Tower Duty” specifications. They are supplied with permanently lubricated bearings and special moisture protection on the bearings, shaft and windings. After extended shutdowns, the motor should be checked with an insulation tester prior to restarting the motor.

Fan Shaft Ball Bearings For induced draft units, lubricate the fan shaft bearings every 1,000 hours of operation or every three months. For forced draft units, lubricate the fan shaft bearings every 2,000 hours of operation or every six months. Use any of the following synthetic waterproof, polyurea inhibited greases which are suitable for operation between -20°F and 350°F. (For colder operating temperatures, contact the factory).

Mobil Polyrex™ EM Chevron® SRI Grease Timken® Ball Bearing Pillow Block Grease

Feed grease slowly into the bearings or the seals may be damaged. A hand grease gun is recommended for this process. When introducing new grease, all grease should be purged from the bearings.

Most EVAPCO units are supplied with extended grease lines to allow easy lubrication of the fan shaft bearings as shown in Table 1.

UNIT DESCRIPTION LOCATION OF LUBE LINE FITTINGS

Induced Draft Units:

4’, 7’, 8’, 8.5’, 14’ (ATWB), 17’ wide

Located just beside the fan casing access door

Induced Draft Units:

10’, 12’, 14’ (ESW4), 20’, 24’, 28’ wide

Located inside the fan casing access door

Forced Draft Units Located on the bearing support or on the side of the unit

PHC-E Units Located inside access door at bottom of casing/ above the field seam

Table 1 — Location of Grease Lube Line Fittings for Belt Driven Units

Fan System

Fan System (Continued)

Fan Belt Adjustment (Direct drive units do not require any adjustment)

The fan belt tension should be checked at startup and again after the first 24 hours of operation to correct for any initial stretch. To properly adjust the belt tension, position the fan motor so that the fan belt will deflect approximately 3/8” when moderate pressure is applied midway between the sheaves. Figure 1 and Figure 2 show two ways to measure this deflection. Belt tension should be checked on a monthly basis. A properly tensioned belt will not “chirp” or “squeal” when the fan motor is started.

Figure 1 — Method 1 Figure 2 — Method 2

Induced Draft: On induced draft belt-driven units provided with externally mounted motors, see Figure 3.

Figure 3 — Externally Mounted Motor, Induced Draft

ADJUSTMENT NUT

ADJUSTMENT

TOOL

NUTS

On induced draft belt driven-units with internally mounted motors (10-, 12-, 14-, 20-, 24-, and 28-foot wide units). PHC-S, L and D units, a motor adjustment tool is provided on the adjustment nut. To use, place the hex end over the adjustment nut and tension the belt by turning the nut counterclockwise. When the belts are properly tensioned, tighten the lock nut.

Figure 4 — Internally Mounted Motor, Induced Draft

Figure 5 — Internally Mounted Motor, PHC-D Unit

Figure 6 — Internally Mounted Motor, PHC-S & Tandem Fan Units

Forced Draft: LS and PM Style forced draft units, both J-type adjustment bolts on the adjustable motor base should have an equal amount of exposed thread for proper sheave and belt alignment.

Figure 7 — PM Style Motor Adjustment

Figure 8a — Externally Mounted Motor, Large LS, 8X & 3M Units

Figure 8b — Externally Mounted Motor, Small LS, 4X & 5X Units

Figure 9 — LR Motor Adjustment

Gear Drives Induced draft units with gear drive systems require special maintenance. Please refer to the gear manufacturer’s recommended maintenance instructions. These will be enclosed and shipped with the unit.

Air Inlet Inspect the air inlet louvers (induced draft units) or fan screens (forced draft units) monthly to remove any paper, leaves or other debris that may be blocking airflow into the unit.

Coil Inlet Inspect the top coil, air inlet, and spray section on all PHC units monthly.

There are several methods for capacity control of the evaporative cooling unit. Methods include: fan motor cycling, the use of two speed motors, and the use of variable frequency drives (VFDs).

NOTE: For the eco-ATWB series of closed circuit coolers with Sage® Control System, consult the manual.

Fan Motor Cycling Fan motor cycling requires the use of a single stage thermostat which senses the fluid temperature (closed circuit coolers) or condensing temperature (evaporative condensers). The contacts of the thermostat are wired in series with the fan motor’s starter holding coil. For individual fan motor cyclings, interlock fan motors before fan start to prevent issues with reversing idle fans.

Sequence of Operation for Fan Motor Cycling Fan motor cycling is often found to be inadequate where the load has a wide fluctuation. In this method, there are only two stable levels of performance: 100% of capacity when the fan is on, and approximately 10% of capacity when the fan is off. Please note that rapid cycling of the fan motors can cause the fan motor to overheat. Controls should be set to only allow a maximum of six start/stop cycles per hour. The recirculation pump may not be used as a means of capacity control and should not be cycled frequently. Excessive cycling can lead to scale buildup, resulting in reduced wet and dry performance.

Variable Frequency Drives The use of a variable frequency drive (VFD) provides the most precise method of capacity control. A VFD is a device that converts a fixed AC voltage and frequency into an adjustable AC voltage and frequency used to control the speed of an AC motor. By adjusting the voltage and frequency, the AC induction motor can operate at many different speeds.

The use of VFD technology can benefit the life of the mechanical components with fewer and smoother motor starts and built-in motor diagnostics. VFD technology has particular benefit on evaporative cooling units operating in cold climates where airflow can be modulated to minimize icing and reversed at low speed for de-icing cycles. Applications using a VFD for capacity control must also use an inverter-capable motor built in compliance with NEMA standard MG-1.

NOTE: VFDs should not be used on pump motors. The pumps are designed to be operated at full speed and are not intended to be used as capacity control.

The type of motor, manufacturer of the VFD, motor lead lengths (between the motor and the VFD), conduit runs and grounding can dramatically affect the response and life of the motor. Select a high quality VFD that is compatible with the fan motor(s) in the EVAPCO unit(s). Many variables in the VFD configuration and installation can affect motor and VFD performance. Two particularly important parameters to consider when choosing and installing a VFD are switching frequency and the distance between the motor and VFD often referred to as lead length. Consult the VFD manufacturer’s recommendations for proper installation and configuration. The motor lead length restrictions can vary with the vendor. Regardless of motor supplier, minimizing lead length between the motor and drive is good practice.

VFD Lockout Notification Sequence of Operations / Guidelines for Multi-fan Units with a VFD during Peak Load

For eco-ATWB, eco-ATWB-E, and/or eco-ATWB-H, see Sage® Control Panel O&M

1. Both fan motors off – Pump running on one cell.

2. Both fan motors off – Pump running on both cells.

3. Both VFDs turn on at the manufacturer’s recommended minimum operating speed (25%) – Pump running on both cells.

4. Both VFDs speed up uniformly (they should be synchronized on startup) – Pump running on both cells.

5. Both VFDs are on full speed – Pump running on both cells.

NOTE: The VFDs need to have a preset shutoff to prevent water temperatures from becoming too cold and to prevent the drive from trying to turn the fan at near zero speed. Operating below 20% of motor speed achieves very little return in fan energy savings and capacity control. Check with your VFD supplier if operating below 20% is possible.

Fan System - Capacity Control

Fan System - Capacity Control (Continued)

Variable Frequency Drive Lockout Notification

Qualified personnel should use proper care, procedures and tools when maintaining the fan/drive system in order to prevent personal injury and/or property damage.

Identify and lock out harmful resonant frequencies.

A variable frequency drive (VFD) fan system, unlike traditional fixed-speed systems, is designed to operate between 20% (15Hz) and 100% (60Hz) speeds, which creates an opportunity for operation where resonant frequencies exist. Sustained operation at resonant frequencies may lead to excessive vibration, fatigue of structural components, and/or drive system noise and failure. Owners and operators must anticipate the existence of resonant frequencies and lockout frequencies during startup and commissioning in order to prevent drive system operational problems and structural damage. As a part of the normal startup and commission processes, resonant frequencies should be identified and locked out in the VFD’s software.

The unit’s supporting structure, external piping, and accessories contribute to the overall harmonic makeup and stiffness of the system.

The choice of VFD will also have a significant influence on how the system behaves. Consequently, not all resonant frequencies can be determined in advance at the manufacturer’s factory during final inspection and testing. Relevant resonant frequencies (if they occur) can only be identified accurately after the unit installation in the system.

To check for resonant frequencies in the field, a run-up and run-down test must be performed. Additionally, VFD carrier frequencies should be adjusted to best align the VFD with the electrical system. Refer to your drive’s startup procedures for additional information and instruction.

The procedure of checking for resonant frequencies requires stepping through the VFD’s operating range at (2) Hz intervals from the lowest operating frequency to full speed. At each step, pause long enough for the fan to reach steady-state. Note changes in unit vibration during this time. Repeat from full speed to minimum speed. Should vibration-inducing frequencies exist, the run-up and run-down test will isolate the resonant frequencies which then must then be locked out in the VFD programming.

For more details on the use of variable frequency drives, please download a copy of EVAPCO’s Engineering Bulletin 39 from evapco.com.

Two-Speed Motors The use of a two-speed motor provides an additional step of capacity control when used with the fan cycling method. The low speed of the motor will provide approximately 60% of full speed capacity.

Two-speed capacity control systems require not only a two-speed motor, but also a two-stage thermostat and the proper two-speed motor starter. The most common two-speed motor is a single winding type. This is also known as a consequent pole design. Two-speed two-winding motors are also available. All multi-speed motors used in evaporative cooling units should be variable torque design.

NOTE: When two-speed motors are to be used, the motor starter controls must be equipped with a decelerating time delay relay.

The time delay should be a minimum of 30 seconds when switching from high speed to low speed.

Sequence of Operation for Two Cell Units with Two Speed Motors during Peak Load

For the eco-ATWB, eco-ATWB-E, and/or eco-ATWB-H, see Sage® Control System O&M.

1. Both fan motors off – Pump running on one cell.

2. Both fan motors off – Pump running on both cells.

3. One fan motor on low speed, one fan motor off – Pump running on both cells.

4. Both fan motors on low speed – Pump running on both cells.

5. One fan motor on high speed, one fan motor on low speed – Pump running on both cells.

6. Both fan motors on full speed – Pump running on both cells.

ANTI-VORTEXING

HOOD

STRAINER

HANDLE

STRAINER

ASSEMBLY

Suction Strainer in Cold Water Basin The pan strainer as shown in Figures 10 through 14 should be removed and cleaned monthly or as often as necessary. The suction strainer is the first line of defense in keeping debris out of the system. Make certain that the strainer is properly located over the pump suction, alongside the anti-vortexing hood.

Figure 10 — ATC/ATWB Single Strainer Assembly Figure 11 — LSWE/LSC-E/PMC-E Strainer Assembly

ANTI-

VORTEXING

HANDLE

Figure 12 — LRWB/LRC Strainer Assembly

Figure 13 — PHC-S/PHC-L Strainer Assembly

ANTI-

VORTEXING

Figure 14 — PHC-D Strainer Assembly

Recirculated Water System - Routine Maintenance

ANTI-VORTEXING

HOOD

STRAINER

ASSEMBLY

Recirculated Water System - Routine Maintenance (Continued)

Cold Water Basin The cold water basin should be flushed out quarterly, and checked monthly or more often if necessary, to remove any accumulation of dirt or sediment which normally collects in the basin. Sediment can become corrosive and cause deterioration of basin materials. When flushing the basin, it is important to keep the suction strainers in place to prevent any sediment from entering the system. After the basin has been cleaned, the strainers should be removed and cleaned before refilling the basin with fresh water.

Operating Level of Water in Cold Water Basin The operating level should be checked monthly to make sure the water level is correct. Refer to Table 3 for unit specific levels.

EVAPORATIVE

CONDENSERS

CLOSED CIRCUIT COOLERS OPERATING

WATER LEVEL*

ATC-E Products 50E to 165E 170E to 3714E

ATWB & eco-ATWB Products 4’ wide units

7’ wide to 24’ wide units

9” 11” eco-ATC-H 8.5’ wide to 24’ wide units eco-ATWB-H 8.5’ wide to 24’ wide units eco-ATC Products 122A to 3846A eco-ATWB-E 8.5’ wide to 24’ wide units

LRC Products 25 to 379

LRWB & eco-LRWB Products 3’ wide to 8’ wide units

8”

LSC-E Products 36 to 170 185 to 385

400 to 515, 800 to 1030 550 to 805, 1100 to 1610

PMC-E & eco-PMC 175E to 375E, 183 to 387

332E to 2019E, 275 to 2191

LSWE & eco-LSWE Products 4’x6’ to 4’x12’

5.5’x12’, 5.5’x18’ 8’x12’, 8’x24’, 10’x12’, 10’x24’ 8’x18’, 8’x36’, 10’x18’, 10’x36’

12” 15”

10” 14”

ESW4 Products 8.5’ and 14’ wide units

12’ wide unit

9” 10”

PHC-S and -D Products S79-84E - S718-335E S86-74E - S818-405E

S1012-210E - S1018-553E S1212-221E - S1236-123E

D1224-619E - D1224-879E D1426-742E - D1426-1060E D2424-1238E - D2424-1758E

*Measured from lowest point on basin floor.

Table 3 — Recommended Operating Water Level

At initial startup or after the unit has been drained, the unit must be filled to the overflow level. Overflow is above the normal operating level and accommodates the volume of water normally in suspension in the water distribution system and the riser piping.

The water level should always be above the strainer. Check by running the pump with the fan motors off and observing the water level through the access door or remove the air inlet louver.

Water Makeup Valve A mechanical float valve assembly is provided as standard equipment on the evaporative cooling unit (unless the unit has been ordered with an optional electronic water level control package or the unit is arranged for remote sump operation). The makeup valve is easily accessible from outside the unit through the access door or removable air inlet louver. The makeup valve is a bronze valve connected to a float arm assembly and is activated by a large foam filled plastic float. The float is mounted on an all-thread rod held in place by wing nuts. The water level in the basin is adjusted by repositioning the float and all-thread using the wing nuts. Refer to Figure 15 for details.

After initial startup or after the unit has been drained, the unit must be filled to the overflow level. Overflow is above the normal operating level and accommodates the volume of water normally in suspension in the water distribution system and some of the piping external to the unit.

The water level should always be above the strainer. Check by running the system

Figure 15 – Mechanical Water Makeup Valve pump with the fan motors off and observing the water level through the access door or remove the air inlet louver.

The makeup valve assembly should be inspected monthly and adjusted as required. The valve should be inspected annually for leakage and if necessary, the valve seat should be replaced. The makeup water pressure for the mechanical valve should be maintained between 20 and 50 PSIG.

Pressurized Water Distribution Systems Check the water distribution system monthly to make sure it is operating properly. Always check the spray system with the pump on and the fans off. On forced draft models, remove one or two eliminator sections from the top of the unit and observe the operation of the water distribution system. On induced draft models, lifting handles are provided along the top layer of eliminators. Eliminators can be easily removed from the access door and the distribution system observed. The diffusers are essentially non-clogging and should seldom need cleaning or maintenance.

If the water diffusers are not functioning properly, it is a sign that the pan or system strainer has not been working properly and that foreign matter or dirt has accumulated in the water distribution pipes. The nozzles can be cleared by taking a small pointed probe and moving it rapidly back and forth in the diffuser opening.

If an extreme buildup of dirt or foreign matter occurs, remove the end cap in each branch to flush the debris from the header pipe. The branches or header can be removed for cleaning, but do so only if necessary. Check the strainer in the pan to make sure it is in good condition and positioned properly so that cavitation or air entrainment does not occur.

All evaporative condensers and closed circuit coolers, except the ESW4 closed circuit coolers, are supplied with ZMII® spray nozzles as standard. The ZMII® spray nozzles do not need to be oriented a specific way to achieve proper coil coverage. Figure 16 shows the standard orientation of the ZMII® spray nozzles.

Figure 16 — ZMII® Spray Nozzle Orientation All Coil Products except the ESW4

ADJUSTMENT

WINGNUTS

FLOAT ARM

FLOAT BALL

MAKEUP

VALVE

For the ESW4, wide orifice water diffusers are supplied, shown in Figure 17. When inspecting and cleaning the water distribution system, always check that the orientation of the water diffusers is correct as shown in Figures 17 and 18. For EvapJet® nozzles, make sure that the top edge of the EVAPCO logo is parallel to the top of the water distribution pipe.

Figure 17 — Proper Water Diffuser Orientation (EvapJet®)

ESW4 Models Only

Figure 18 — Gravity Fed Distribution Pan ESW4 Models Only

Bleed-Off Valve The bleed-off valve, whether factory or field installed, must be checked weekly to make sure it is functioning and set properly. Additional information can be found under “Water Treatment and Water Chemistry”.

Pump (When Supplied) The pump and pump motor should be lubricated and serviced in accordance with the pump manufacturer’s instructions as supplied with the unit. The recirculation pump should not be used as a means of capacity control, used with a VFD or be cycled frequently. Excessive cycling can lead to scale buildup, and reduce wet and dry performance. On 18-foot-long ESW4 units supplied with two pumps per cell, both pumps should be energized at the same time. One pump should not be on while the other pump is off.

The pump motor shaft and impeller should be turned by hand if the pump assembly sits idle (for a month or more).

Disconnect the power and lock out/tag out the pump disconnect. Remove the pump motor fan guard and rotate the pump fan/shaft several turns by hand. Reassemble the fan guard and return to service.

NOTE: For the eco-ATWB, eco-ATWB-E, and/or eco-ATWB-H, please consult the Sage® Control System manual.

Proper water treatment is an essential part of the maintenance required for evaporative cooling equipment. A well designed and consistently implemented water treatment program will help to ensure efficient system operation while maximizing the equipment’s service life. A qualified water treatment company should design a site-specific water treatment protocol based on equipment including all metallurgies in the cooling system, location, makeup water quality, and usage.

Bleed or Blowdown Evaporative cooling equipment rejects heat by evaporating a portion of the recirculated water into the atmosphere as warm, saturated discharge air. As the pure water evaporates it leaves behind the impurities found in the system’s makeup water and any accumulated airborne contaminants. These impurities and contaminants, which continue to recirculate in the system, must be controlled to avoid excessive concentration which can lead to corrosion, scale, or biological fouling.

Evaporative cooling equipment requires a bleed or blowdown line, located on the discharge side of the recirculating pump, to remove concentrated (cycled up) water from the system. EVAPCO recommends an automated conductivity controller to maximize the water efficiency of your system. Based on recommendations from the water treatment company, the conductivity controller should open and close a motorized ball or solenoid valve to maintain the conductivity of the recirculating water. If a manual valve is used to control the rate of bleed it should be set to maintain the conductivity of the recirculating water during periods of peak load at the maximum level recommended by the water treatment company.

Bleed Rate (GPM) =

Evaporation Rate (GPM)

( Cycles of Concentration - 1 )

*Cycles of concentration is the ratio of the concentration of dissolved icons in the recirculating water, divided by the concentration of dissolved ions in the makeup water.

Galvanized Steel – Passivation ‘White rust’ is a form of premature corrosion of the protective zinc layer on hot dip or mill galvanized steel which can occur as a result of improper water treatment control during the startup of new galvanized equipment.