Delta TM-105312 User Manual

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Delta Cooling Towers, Inc.

TM Series Cooling Tower

Installation, Operation & Maintenance

Manual

Revised 1-8-2007

Table of Contents

Delta Cooling Towers

Principle of Cooling Towers………………..…………….

2

 

 

Cooling Tower Terms and Definitions……………………

2

 

 

Water Treatment……..………………………….………..

3

 

 

 

 

 

General Information

Safety………………..………………………………….…

3

 

 

Approximate Weights………………..……………………

4

 

 

Dimensions & Other Physical Data……..………...………

4

 

 

 

 

 

Handling & Installation

On-SiteInspection………………..………..…….….…….

5

 

 

Off Loading……..……………..…………………………..

5

 

 

Anchoring……..……….…………………………..………

8

 

 

Electrical Wiring of Fan Motor & Accessories……..……..

8

 

 

Location, Piping & Connections……..…….……….……..

8

 

 

PVC Solvent Cementing Instructions………………...……

10

 

 

 

 

 

Operation and Maintenance

Safety in Operation of the Fan..…..………..…….….…….

11

 

 

Water Distribution System……..………………………….

11

 

 

Fan & Mechanical Drive System….………………..…...…

12

 

 

Start-upInstructions………………………………..……..

12

 

 

Water Level in Tower Sump…..……..…….……….……..

13

 

 

Cold Weather Operation…………...………………...……

14

 

 

Trouble-ShootingGuide.…………...……………….….…

16

 

 

Motor Trouble-ShootingGuide…………...………....……

18

 

 

 

 

 

Other Information

Cooling Tower Optional Accessories..…..…...….….…….

19

 

 

Recommended Replacement Parts……..………………….

19

 

 

Preventative Maintenance Checklist….……………….…..

20

 

Important: Delta’s cooling towers have been designed to providetrouble-freeservice over an extended period of time. To obtain the design performance, it is necessary that the cooling tower be installed, operated and maintained as prescribed in these instructions.

Only persons possessing the skill and experience described herein should attempt to install this equipment. Prior to installation, these instructions should be read carefully by the person who is to install the cooling tower to be certain that its installation, operation and maintenance are thoroughly understood.

Questions regarding the installation, operation or maintenance of this equipment should be directed to Delta Cooling Towers, Inc., Rockaway, New Jersey, (Telephone: 973/586-2201).

Step-by-stepinstructions contained in this brochure are based on normal installation conditions only. Abnormal or unusual combinations of field conditions should be brought to the attention of Delta Cooling Towers or its representative prior to installation of the equipment. The information contained herein is subject to change without notice in the interest of product improvement.

Revised 1-8-2007

1

Delta Cooling Towers

Principle of Cooling Towers

All Cooling Towers operate on the principle of removing heat from water by evaporating a small portion of the water that is recirculated through the unit.

The heat that is removed is called the latent heat of vaporization.

Each one pound of water that is evaporated removes approximately 1,000 BTU's in the form of latent heat.

Cooling Tower Terms and Definitions

BTU - A BTU is the heat energy required to raise the temperature of one pound of water one degree Fahrenheit in the range from 32° F. to 212° F.

Cooling Range - The difference in temperature between the hot water entering the tower and the cold water leaving the tower is the cooling range.

Approach - The difference between the temperature of the cold water leaving the tower and thewet-bulbtemperature of the air is known as the approach. Establishment of the approach fixes the operating temperature of the tower and is a most important parameter in determining both tower size and cost.

Drift - The water entrained in the air flow and discharged to the atmosphere. Drift loss does not include water lost by evaporation. Proper tower design and operation can minimize drift loss.

Heat Load - The amount of heat to be removed from the circulating water within the tower. Heat load is equal to water circulation rate (gpm) times the cooling range times 500 and is expressed in BTU/hr. Heat load is also an important parameter in determining tower size and cost.

Ton - An evaporative cooling ton is 15,000 BTU's per hour.

Wet-Bulb Temperature - The lowest temperature that water theoretically can reach by evaporation.Wet-BulbTemperature is an extremely important parameter in tower selection and design and should be measured by a psychrometer.

Pumping Head - The pressure required to pump the water from the tower basin, through the entire system and return to the top of the tower.

Make-Up - The amount of water required to replace normal losses caused bybleed-off,drift, and evaporation.

Bleed Off (Blowdown) - The circulating water in the tower which is discharged to waste to help keep the dissolved solids concentration of the water below a maximum allowable limit. As a result of evaporation, dissolved solids concentration will continually increase unless reduced by bleed off.

Revised 1-8-2007

2

Water Treatment

The Delta Cooling Towers are manufactured from corrosion-resistantplastics which are resistant to water treatment chemicals including common fungicides and bactericides.

Follow appropriate water treatment practices as required and take frequent sample tests to avoid possible water contamination. We also recommend water treatment maintenance as a measure of protection of the environment in the vicinity of any cooling tower or other equipment open to atmosphere.

To determine the appropriate water treatment practices for your particular application, it is suggested that you contact a water treatment firm for their recommendation. A list of water treatment firms is available for your reference. It is not necessarily complete nor do we recommend a specific firm. The list will be mailed to you on request or consult your local yellow pages.

Bleed-offis also important to water quality. Evaporation of the recirculated water does not remove the dissolved solids that are present in the water. Withoutbleed-off,the continual buildup of these solids will impair the proper functioning of the piping and other equipment in the system.

A bleed line can be connected in any part of the system for routing to the sewer. Normally, it is most desirable to make this connection in the hot water line at the cooling tower. A petcock type valve, installed in the bleed line is recommended. Normally, bleed-offof 1% to 2% of the recirculation water flow is satisfactory. The required amount ofbleed-offwater must be substituted with properly controlled amounts ofmake-upwater.

General Information

Safety

When handling, lifting, installing or operating the cooling tower, always employ safe work procedures, according to best practices of the trade and according to applicable construction, electrical and safety standards, regulations and codes.

Follow all safety practices described in these instructions.

Revised 1-8-2007

3

Approximate Weights

The TM Series cooling towers are manufactured in three basic sections; a polyethylene tower body, a polyethylene sump, and a fan assembly section. The tower body ships with the fan assemblies installed. The tower sump ships as a separate piece.

 

Approximate Weights (lbs.)

Overall

 

Dimensions

 

 

 

 

 

 

 

(inches)

Model Group

 

Shipping

Operating

L x W x H

 

 

Body

Sump

 

 

TM-105312TM-115412

 

4,850

1,660

11,800

198” x 102” x 186”

 

 

 

 

 

 

 

TM-205312TM-215412

(2)

4,850

(2)

1,660

23,600

198” x 204” x 186”

 

 

 

 

 

 

 

 

TM-305312

TM-315412

(3)

4,850

(3)

1,760

35,400

198” x 306” x 198”

 

 

 

 

 

 

 

 

TM-405312

TM-415412

(4)

4,850

(4)

1,760

47,200

198” x 408” x 198”

 

 

 

 

 

 

 

 

TM-505312

TM-510412

(5)

4,850

(5)

1,760

59,000

198” x 510” x 198”

 

 

 

 

 

 

 

 

TM-605312

TM-610412

(6)

4,850

(6)

1,760

70,800

198” x 612” x 198”

 

 

 

 

 

 

 

 

Dimensions and Other Physical Data

For cooling tower dimensions, design for foundations, assembly and layout, refer to the following drawings which are a part of these instructions:

 

Model Group

Title

Drawing No.

 

TM-105312TM-115412

1

Cell

DT-D-87-901

 

TM-205312TM-215412

2 Cell (5 - 7.5 HP)

DT-D-87-902

 

 

 

2 Cell (10 – 15 HP)

DT-D-87-903

 

 

 

 

 

 

TM-305312TM-315412

3

Cell

DT-D-87-904-1

 

 

 

 

 

DT-D-87-904-2

 

TM-405312

TM-415412

4

Cell

DT-D-87-905-1

 

 

 

 

 

DT-D-87-905-2

 

TM-505312

TM-510412

5

Cell

DT-D-87-906-1

 

 

 

 

 

DT-D-87-906-2

 

 

 

 

 

 

 

TM-605312

TM-610412

6

Cell

DT-D-87-907-1

 

 

 

 

 

DT-D-87-907-1

 

 

 

 

 

 

Revised 1-8-2007

 

 

4

 

Handling and Installation of Your TM Series Cooling Tower

On -SiteInspection

Upon arrival at the job site, carefully inspect the shipment for any damage. If shipping damage has occurred, notify the driver or the carrier immediately and make a notation of the damage on the shipping bill of lading. Check that all items listed B/L have been received.

Offloading

The TM Series cooling towers are normally delivered to the site on a 30 inch high drop deck trailer. Both the tower body assembly and sump assembly are strapped down to the truck bed. The sump assembly should be unloaded first.

Lifting with crane:

Use fabric slings of sufficient strength for better load distribution and protection of the plastic tower body.

Wrap slings underneath tower sump assembly to lift and set into place.

Lift tower body by attaching slings, kept separate by spreader bars, to the four lifting bars as shown below.

Spreader bars must be used to lift vertically on the lifting bar. Above the spreader bars use adequate length straps specifically designed for vertical lifting in order to maintain an angle of 60° or less between slings.

Lifting Bar

Revised 1-8-2007

5

Store tower assembly as shipped until the time of installation, in a secure, level and debris free location at the job site.

CAUTION: For extended lifts, use duplicate rigging, fabric slings around body as shown, as an additional safety precaution.

Installing

The cooling tower should be assembled in place on the previously prepared foundation.

After re-checkingthe rigging, lift the sump section of each cell and secure properly to the foundation.

Attach the fiberglass sump box to the center support post using the hardware provided as shown.

Revised 1-8-2007

6

The body section should then be lifted and carefully position to align the support post of the sump with the corresponding groove of the tower body. Note that the four corner posts are slightly higher than other post to ease installation alignment.

Set one end of the tower body onto the corner post at one end of the sump first. This can be accomplished by use of a rope tether attached to the lifting bar at one end of the housing. Continue setting and aligning support post along the sides of the tower moving from one end to the other. This step may require a couple installers to align multiple posts simultaneously. You may use a rubber mallet or blocking wood to aid aligning post.

IMPORTANT: Make sure that all posts are correctly seated into the pocket of the tower body.

For single cell units, the four corner sump posts should then be secured to the main housing with the provided stainless steel angle brackets and hardware. On Multi-celltowers, the outermost four corner posts should be secured to the main housing with the provided stainless steel angle brackets and hardware.

Before installing PVC louver panels, verify that all post are correctly seated into the pockets of the tower body.

Install PVC louver panels between each support post. Panels are numbered and marked on top of each panel, and should be installed with corresponding numbered window opening. Insert bottom of panel into window opening and work your way up to the top. Panels should be mounted flush with inside top of louver opening inside tower and should direct incoming air downward. Secure panels with self-tappingscrews provided.

Revised 1-8-2007

7

On multi cell towers, install PVC water redirector panels between each sump usingself-tappingscrews provided (See sketch below). Start with screwing the PVC post from the bottom up. Next apply a heavy bead of RTV sealant on the end of each redirector panel. Start screwing the redirector panels from the end nearest the post toward the center. Do not screw overlapping panels to allow for expansion and contraction.

(Side View of Redirector Panels)

Multi Cell Water Redirectors.

Secure tops of adjacent multi cell units together by bolting the two steel support angle brackets provided to the lifting lugs of each cooling tower shell. The angle brackets should then be bolted together with hardware provided.

Anchoring

The foundation must be flat, smooth and rigid enough to be capable of independent support of the cooling tower assembly and water load in the sump at its maximum level. The tower assembly can also be mounted on I-beamsusing the integrally moldedI-beampockets (See tower drawings).

Four hold-downanchor lugs are provided on the sump of each tower cell.

Support beams and anchor bolts are to be furnished by others.

Beams should be sized at least 7” wide and in accordance with acceptable structural practices. These beams should be located in the integrally molded I-beampockets, and should run the length of the unit.

Use anchor bolts sized for a minimum of 15,000 lbs. pull-outload per anchor lug for wind loading.

Revised 1-8-2007

8

Electrical Wiring of Fan Motor and Accessories

Installation of a vibration cut-outswitch is recommended. (Refer to tower accessories available).

All electrical work should be performed only by qualified personnel and in accordance to prevailing electrical codes, practices and safety standards.

The motor starter should be sized on voltage, nominal horsepower, and maximum full load current. This current value can be found on the motor nameplate. If the starter cannot accept the maximum full load motor current, the next size should be used.

Motor heaters should be selected on the basics of maximum full load current and service factors based on the motor nameplate.

Standard “Cooling Tower Service” motors are supplied with a minimum of a 1.15 Service Factor.

Optional two speed motors are single winding variable torque.

Run flexible conduit with some slack from the motor conduit box to terminal box outside the tower where rigid conduit can be used.

Conduit holding clip screws can be tapped directly into the tower wall. Use maximum 3/8” long screws.

For the typical wiring schematic of fan motor and tower accessories, see Delta dwg. DT –B-78-001,included with these instructions.

Location, Piping and Connections

Piping should be adequately sized in accordance with accepted standard practices.

Gravity drain to indoor storage sump requires proper head differential and piping design considerations. Allowance must be made for flow, pipe size, piping layout and distance of cooling tower from the indoor storage sump.

On multiple cell installations, valving and/or pipe sizing should balance pressure drops to provide equal inlet pressures. Equalizing fittings are provided in the sumps of each cell and can piped together to balance sump water level. Each cell should be valved separately to allow for flow balancing or isolation from service.

Prior to start-upcheck that the PVC locknuts on all bulkhead fittings are properly tightened to prevent nuisance leaks. A chain wrench can be used to check and tighten the locknuts.

Check that the SS hexagonal nuts on the inlet and outlet PVC flanges are properly tightened to prevent nuisance leaks. While tightening the nuts, do not allow the bolt to rotate. This could damage the rubber seal under the flat washer on the bolt head located inside the cooling tower.

All supply and return piping must be independently supported.

Revised 1-8-2007

9

PVC Solvent Cementing Instructions

The following procedure is recommended for the preparation and cementing of internal and external piping for Delta Cooling Towers:

Cut ends of pipe square using a handsaw and miter box. Tube cutters with wheels designed for use with PVC are acceptable, providing they do not leave a raised bead on the outside diameter of the pipe.

Use a chamfering tool or file to put a 10° to 15° chamfer on the end of the pipe. Lightly sand the area to be cemented to remove gloss. Using a clean rag, wipe pipe surface and fitting socket to remove dirt, moisture and grease. Acetone or similar solvent is recommended for cleaning.

Check "dry fit" of pipe and fitting by inserting pipe at least 1/3 of the way into the fitting. Position pipe and fitting to assure alignment. Pipe and fitting should be at same temperature condition.

Using a clean, natural bristle brush about 1/2 the size of the pipe diameter, apply a primer to the fitting socket. Apply primer with a scrubbing motion until the surface is penetrated. Primer should never be applied with a rag. Repeated applications may be necessary to achieve the desired dissolving action. In the same manner, apply primer to the pipe surface equal to the depth of the fitting socket, making sure the surface is well penetrated. Reapply primer to the fitting socket to make sure it is still wet.

While both surfaces are still wet with primer, use a clean brush to apply a liberal coat of solvent cement to the male end of the pipe. The amount should be more than sufficient to fill any gap. Next apply a light coat of solvent cement to the inside of the socket, using straight outward strokes to keep excess cement out of the socket.

While both surfaces are still wet with solvent cement, insert the pipe into the socket with a quarter-turntwisting motion. The pipe must be inserted the full length of the socket. The application of solvent cement to pipe and fitting, and the insertion of the pipe into the fitting, should be completed in less than one minute. If necessary, two persons should apply solvent cement to the pipe and fitting simultaneously.

Hold the joint together for approximately 30 seconds until both surfaces are firmly gripped. After assembly, a properly made joint will usually show a bead of cement around its entire perimeter. This should be brushed off. It is recommended that the joint be allowed to cure for 24 hours before pressure testing or operation.

Revised 1-8-2007

10

Operation and Maintenance of Your TM Series Cooling Tower

Safety in Operation of the Fan

NEVER operate the fan when the access panel or the entire fan guard is removed.

NEVER remove access manhole cover while fan is in operation.

NEVER operate fan when any work, access, maintenance,trouble-shooting,etc. is being performed on the inside of the fan ring assembly or inside the tower plenum.

Normally, electrical codes dictate a disconnect box at the cooling tower.

The handle of the disconnect box must be locked in the off position and an OSHA DANGER tag

(DO NOT OPERATE) must be attached to handle securely.

Note: Removing fuses from the disconnect box may provide further assurance, but only when done by qualified personnel.

The foregoing precautions apply when any type of internal access to the tower is required, including the following examples:

Checking, maintenance or replacement of any fan assembly component.

Checking, maintenance or replacement of the water distribution system inside the tower.

Cleaning of the fill.

Any work that necessitates removal of any access door, the fan guard or the manhole cover.

Water Distribution System

Water distribution is accomplished by a low pressure, non-rotating,spray nozzle system designed to accommodate the specified flow rate.

IMPORTANT:

The flow rate of the cooling tower must be as close to the design gpm as possible. The water distribution system, including spray nozzles, is provided for the design flow condition. Under-pumpingorover-pumpingwill cause the cooling tower to perform inefficiently.

Design pressure at the inlet connection must be maintained for proper water distribution.

If the pressure is less or greater than the design, proper water dispersion over the internal wet decking will be impaired. If inlet pressure is low, water spray will not cover the entire wet decking surface. This causes channeling of air, and does not make maximum use of the heat transfer media. High inlet pressures will cause the water to over-spraythe wet decking media, hit the internal side walls of the tower shell and drop in a vertical flow along the shell walls without the opportunity for water / air contact through the heat exchange media. Excessive high spray pressure may also cause wet decking fatigue and damage.

The operating inlet pressure should be between 4.0 and 5.5 psi at the tower inlet.

Revised 1-8-2007

11

The maximum operating inlet water temperature should not exceed 140° F.

CAUTION:

When stepping on top of the fill, distribute the body weight by means of two plywood plates as described earlier in these instructions.

Fan and Mechanical Drive System and Its Maintenance

Safety

Follow all safety instructions previously discussed.

Motor:

The standard motor is a totally enclosed motor , Class F insulation, 1.15 minimum service factor, epoxy coating on outside frame, and is specifically designed for cooling tower duty to the exclusive specifications of Delta Cooling Towers.

Should there be a problem with the motor, which may be covered under our standard warranty, the motor must only be inspected and serviced by an authorized motor manufactures warranty shop, and Delta Cooling Towers, Inc. must be notified, otherwise the warranty is void.

If the motor bearings have grease fittings, follow the lubrication recommendations as outlined in instructions from motor manufacturer. The majority of motors do not require greasing.

Start-upInstructions

Complete all start-upinstructions before applying heat load.

Clean any accumulated debris or packaging material from inside tower sump.

Check to be sure that the fan motor is properly wired for correct rotation as viewed from the top of the fan. Reverse leads will cause incorrect rotation and reverse direction of airflow.

Note: Fan rotation should always agree with rotation labels. Standard fan rotation is clockwise, (C.W.) however; non-standardfans may be designed to rotate counter clockwise, (C.C.W.)

Check for free rotation of the fan and fan blade tip clearance.

Fill the cooling tower sump or the cold water storage reservoir on gravity drain applications.

Water recirculation pump should be primed and all piping below the tower sump filled with water. Check pump for proper shaft rotation.

Start water recirculation pump and adjust flow to design. A flow metering device installed in the inlet is recommended but if not available, use the pressure differential across the pump in conjunction with the pump curve.

Revised 1-8-2007

12

Check spray pattern from nozzles to be sure there is no clogging. Remove drift eliminators for nozzle inspection, then return to proper position.

Start up fan motor and check amperage and voltage against motor nameplate data.

The standard make-upvalve assembly is shipped with the plastic float ball strapped against the tower side to prevent damage. To set the ball for proper operation, loosen the screw in the fulcrum arm, lift or depress the arm with the plunger pressed against the valve seat and tighten. Repeat until the proper operating level is obtained (Refer to operating level table below). It is recommended that ashut-offvalve be installed in themake-upline.

After 24 hours of operation:

Check spray nozzles for clogging.

Check tower sump water level.

Water Level in Tower Sump

When the cooling tower is being operated with pump-suction,themake-upvalve assembly with float ball should be adjusted to set the water operating level as follows:

Tower Model #

Operating level (from

 

bottom of sump)

All Towers

10 inches

 

 

Access the make-upvalve through the window louver marked “Access Panel”.

A lower water level than recommended may cause air to be drawn into the tower outlet piping and cause pump "cavitation."

A water level higher than recommended will cause continuous overflow and waste of water as a result of potential “pull-down”from the piping when the system is shut down.

The overflow should NEVER be capped, or its elevation altered by raising external piping.

Note: On gravity drain cooling tower(s), make-upassembly, overflow, drain and vortex breaker are not provided.

Revised 1-8-2007

13

Cold Weather Operation

Cold Weather Protection

The cooling tower may require protection against freezing at light heat loads when the wet-bulbtemperature is under 32°F., or during shutdown when the temperature drops below 32°F.

The following methods are recommended for use in Delta Cooling towers for protection during cold weather conditions. Recommended equipment is optional and may be ordered from the factory. Consult the factory for further information on which equipment to choose for your specific application.

Separate Indoor Sump

This method is virtually a foolproof antifreeze protection system with the added advantage of minimum maintenance. The indoor sump tank should be large enough to fill the entire recirculation system without danger of pump cavitation. As a general rule, the tank should be sized to hold three times the rate of circulation in gallons per minute (gpm).

The tank should be provided with properly sized overflow, make-updrain and suction connections. When a separate sump is ordered with a cooling tower, the watermake-upvalve assembly and the overflow and drain connections are installed in the indoor sump only.

When a sump tank is used, the cooling tower should be located high enough above it to allow free cold water gravity drain. A bottom outlet can be provided for gravity drain to indoor sump tank installations.

Reverse siphoning is a back flow of non-potable,recirculating water into a potable water system, which can occur through themake-upfloat valve assembly located in the water reservoir. Should the valve malfunction, blockage of the overflow or outlet lines would cause water level to rise in the reservoir, and themake-upwater pressure could drop below the atmospheric pressure creating a vacuum at themake-upinlet. Although precautions to prevent reverse siphoning are incorporated in the cooling tower design, we also recommend installing a check valve in the watermake-upsupply line, as a backup precaution.

Electric Immersion Heater

Cooling towers can be ordered with an anti-freezeimmersion heater systems, which consist of a 6KW heating element, water level sensor, adjustable thermostat and contactor. Components are factory installed, but will require field wiring.

Thermostatic On/Off Control

A thermostatically controlled fan for on/off operation, should be considered as an energy saving feature, for capacity control during winter operation. The thermostatic control can be field set to insure automatic fan shut-downwhen cold water drops below design temperatures, as well as fanstart-upwhen cold water rises to design temperature.

A thermostatic control provides excellent cooling tower anti-freezeprotection while reducing operating costs throughout cold weather operation.

Revised 1-8-2007

14

PVC Distribution System

To prevent damage to the PVC distribution system during cold weather shut-down,install an automatic or manual drain line from the hot water inlet piping as close to the cooling tower inlet as possible. The entire inlet and distribution system must be drained forshut-downin subfreezing weather.

Piping

When the cooling tower is located outdoors, adequate measures including the use of heating tapes and insulation should be considered to protect water lines from freezing.

Operation at Sub-freezingAmbients

See Thermostatic On/Off control

1. Insure that the cooling tower is operating at the maximum possible heat load - An operating cooling tower will continuously extract heat from the circulating water. Without a heat load, the water will end up either at the air wet bulb temperature, or as ice, whichever occurs first.

2.Maintain Design Water Flow Rate Over The Fill - Reducing water flow over the fill area can produce semi-dryregions that are subject to rapid freezing.

3.Make sure a thermostat is installed to control fan operation to off at low cold-watertemperatures.

4.If tower is equipped with two speed motors, operate at low speed to increase leaving water temperature.

5.Cycle fans periodically to prevent ice from forming on louvers.

6.It may also be necessary to reverse fans for a short period of time to help melt ice by forcing warm water into tower.

De-energizethe fan(s) for two full minutes before reversing.

Reverse fan(s) no more than 2 minutes at a time (repeat as necessary). Extended reverse operation can cause ice to form on fan blades causing an out-of-balancecondition.

If the tower is equipped with a two-speedmotor, reverse only at low speed.

On multi-celltowers, fans immediately adjacent to reversed fans should be shut off during reversal.

After reversal, let fan(s) stand idle 5 to 10 minutes before forward operation.

Monitor the tower closely for unusual vibrations or sounds.

7.Frequent visual inspections and routine maintenance during sub-freezingoperation is very important and should not be overlooked.

15

Trouble-ShootingGuide For TM Series

Induced Draft Cooling Towers

Problem

Possible Causes

Corrective Actions

Increase in the leaving water

1.

Excess water flow; over pumping.

1.

Adjust to the design flow.

temperature

2.

Recirculation of hot discharge air, back into

2.

Eliminate obstructions which impede air discharge.

 

 

the cooling tower air intakes. Obstructed air

 

For proper location of cooling tower(s), see Delta

 

 

intakes

 

dwgs. Baffle air discharge, if necessary.

 

3.

Proximity of other heat source or discharge

3.

Remove source or relocate tower.

 

 

of moist air.

4.

See water distribution system instructions.

 

4.

Improper operation of spray system.

 

 

A. Orifices clogged.

 

A. Flush spray nozzles, clean orifices, clean

 

 

B. Actual water flow is lower than design

 

system, install outlet strainer.

 

 

sprinkler rating.

 

B. Install properly rated spray nozzles or increase

 

 

 

 

to design flow.

 

5.

Clogged fill.

5.

Clean the fill.

 

6.

Damaged fill.

6.

Replace the fill.

 

7.

Additional heat load on system.

7.

Contact Delta for possible upgrade or addition of

 

 

 

 

another cooling tower selected for additional load.

 

8.

Wet-bulbtemperature higher than design.

8.

None required if condition is temporary. Otherwise

 

 

 

 

consult Factory for upgrade.

Drop in the water flow rate.

1.

Blockage of spray Nozzle orifices.

1.

Flush spray nozzle. Clean whole system. Install

Low water flow rate

 

 

 

outlet strainer.

 

2.

Low water level in sump causing air to be

2.

Adjust float valves. Be sure the system is flooded

 

 

drawn into pump and piping.

 

and balanced.

 

3.

Improper selection of water circulating

3.

Replace with proper size pump designed for flow

 

 

pump.

 

and head requirements. Check pump “Net positive

 

 

 

 

suction head.”

 

4.

Blockage of strainers.

4.

Backwash or clean.

 

5.

Pump malfunction.

5.

Consult pump specialist.

Noise and vibration

1.

Loose bolts.

1.

Recheck and tighten all bolts to specified torque.

 

2.

Mechanical interference of rotating parts.

2.

Inspect propeller for free rotation. Check propeller

 

 

 

 

for mechanical interference. Adjust, repair or

 

 

 

 

replace, as necessary.

 

3.

Fan propeller damaged or out of balance.

3.

Replace components, as necessary and check

 

 

 

 

balance. Install vibration cut-outswitch.

 

4.

Air intake at pump.

4.

Check basin water level and irregular piping design.

 

 

 

5.

Match pump NPSH with system hydraulics.

 

5.

Pump cavitation.

6.

Check and replace motor.

 

6.

Damaged motor bearings.

 

 

Sudden or short term irregularities of

1.

Peculiarities of specific system and its

1.

Inspect system and review operation procedures.

cold water level in basin

 

operation.

 

Correct, as applicable valve settings, loss of water in

 

 

 

 

system, fill system to flooded capacity.

Excessively high water level in sump on

1. Gravity flow restrictions due to insufficient

1.

 

gravity drain installation

 

head differential.

A. Outlet piping should terminate below sump tank

 

 

 

 

water level.

 

 

 

B. Increase discharge pipe size.

 

 

 

C.

Increase head by mean other than A.

16

Problem

Possible Causes

Corrective Actions

 

2.

Airlock.

2.

Install an air bleed valve at highest point

 

3.

Unnecessary obstruction of waterflow

 

of piping, usually at a vertical angle.

 

 

(i.e., partially closed valve).

3.

Remove obstruction.

 

4.

Undersized piping.

4.

Increase pipe size.

 

5.

Horizontal pipe run too long.

5.

Shorten, if possible.

 

6.

Improper hydraulic pipe design.

6.

Correct design.

 

7.

Outlet vortex breaker provided.

7.

Remove vortex breaker.

Excessively high water level in tower basin

1.

Make-upvalve float set too high.

1.

Readjust float arm.

on closed loop system installations

2.

Valve or float damaged or

2.

Repair or replace.

 

 

malfunctioning.

3.

Reduce pressure or contact Delta for

 

3.

Make-upwater pressure too high.

 

 

 

 

alternate solutions.

Uneven water level in tower basins of multi-

1.

Unbalanced system hydraulics.

1.

A. Install equalizer line with isolation

cell installations

 

 

 

valves between modules.

 

 

 

 

C. Adjust inlet water flow to insure equal

 

 

 

 

distribution to each cooling tower

 

 

 

 

module.

 

 

 

 

D. Review outlet header hydraulics and

 

 

 

 

correct piping design, if applicable.

 

 

 

 

E. Contact Delta for assistance.

 

2.

More than one make-upvalve

2.

A. Adjust float level settings relative

 

 

operating, and set for different water

 

To one another.

 

 

levels.

 

B. Shut-offand or/throttle flow to

 

 

 

 

one or more valves.

 

 

 

 

C. Installation of equalizers is

 

 

 

 

highly recommended.

Excessive water carry over (drift)

1.

Surfaces of top layer of fill damaged

1.

Replace top layer. Protect fill when working

 

 

causing “pooling” of water.

 

inside tower.

 

2.

Eliminator(s) not in place.

2.

Reinstall.

 

3.

Damaged eliminator.

3.

Replace.

 

4.

Excess water flow.

4.

Reduce water flow or install spray nozzles

 

 

 

 

designed for the actual operating flow.

 

5.

Orifices in spray nozzles clogged

5.

Install outlet strainer. Clean whole system

 

 

causing improper water dispersement.

 

and spray nozzles.

 

6.

Blockage of fill.

6.

Clean fill.

Premature or excessive corrosion of fan

1.

Excessive drift.

1.

See “ Excessive Water Carry Over (Drift)”

drive components

 

 

 

above.

 

2.

Presence of corrosive chemicals in air

2.

Remove source of corrosion or contact Delta

 

 

or water that was not known at time of

 

for alternative materials, premium coatings

 

 

supply.

 

or other precautions.

17

Motor Trouble Shooting Guide (General)

Problem

Possible Causes

Corrective Actions

High current draw (all 3 phases)

1.

Low line voltage (5 to 10% lower

1.

Consult power company.

 

 

than nameplate).

2.

Change to 230V motor.

 

2.

200V motor on 230/240V system.

 

3.

230V motor on 208V system.

3.

Change to 200V or 280V motor.

 

4.

Incorrect propeller.

4.

Consult factory.

 

5.

Incorrect pitch if adjustable

5.

Reduce pitch / consult factory

Low motor current draw

1.

Incorrect propeller.

1.

Consult factory

 

2.

Incorrect pitch if adjustable.

2.

Increase pitch / consult factory

Unbalanced current

1.

Unbalanced line voltage due to:

1.

Consult power company and/or

(5% from average)

 

A.

Power supply.

 

electrician.

 

 

B.

Unbalance system loading.

 

 

 

 

C.

High resistance connection.

 

 

 

 

D.

Undersized supply lines.

2.

Replace motor.

 

2.

Defective Motor.

Excessive voltage drop

1.

Inadequate power supply.

1.

Consult power company.

(2 or 3% of supply voltage)

2.

Undersized supply lines.

2.

Increase line sizes.

 

3.

High resistance connections.

3.

Check motor leads and other

 

 

 

 

 

connections.

Overload relays tripping

1.

Overload.

1.

Reduce load on motor or increase

 

 

 

 

 

motor size.

 

2.

Unbalanced input current.

2.

Balance supply voltage.

 

3.

Single phasing.

3.

Eliminate.

 

4.

Excessive voltage drop.

4.

Eliminate (see above).

 

5.

Frequent starting or intermittent

5.

Reduce frequency of starting and

 

 

overloading.

 

overloading or increase motor size.

 

6.

High ambient starter temperature.

6.

Reduce ambient temperature.

 

7.

Wrong size relays.

7.

Correct size per nameplate current

 

 

 

 

 

and service factor.

 

8.

Improper overload settings of

8.

Readjust to motor FL Amps x S.F.

 

 

adjustable relays.

 

 

Motor runs very hot

1.

Overloaded.

1.

Reduce overload.

 

2.

Blocked ventilation.

2.

Fouled fill or air restriction.

 

3.

High ambient temperature.

3.

Reduce ambient temperature.

 

4.

Unbalanced input current.

4.

Balanced supply voltage.

 

5.

Single phased.

5.

Eliminate.

Motor will not start

1.

Single phased.

1.

Shut power off – eliminate.

 

2.

Rotor or bearings locked.

2.

Shut power off – check shaft

 

 

 

 

 

rotation.

Excessive vibration (Mechanical)

Out of balance

1.

Check to be sure motor mounting

 

1.

Motor mounting.

 

 

 

 

 

hardware is tight.

 

2.

Motor.

2.

Replace motor.

Note: Consult Warranty page prior to replacing or repairing any cooling tower components. Delta recommendation and consent to remedy material and workmanship defects is necessary, to avoid breach of Warranty.

18

TM Series Optional Accessories

TM Series Optional Accessories Available

Aluminum Ladder(s) with a step platform and railing at the fan elevation custom designed for the cooling tower.

Safety cage(s).

Two speed motor(s) designed for cooling tower duty to the exclusive specifications of Delta Cooling Towers.

Vibration cut-outswitch provides for fan motor circuit disconnect for shutdown protection should abnormal fan vibration develop during service. Installation of vibrationcut-outswitchesare recommended as good design practice.

Thermostat on/off control of fan operation through sensing the temperature of water leaving the tower. Basin anti-freezesystem for cold weather operation.

Custom designed top platform with handrails.Pre-wiredcontrol panels.

Elevated mounting frame structures. Pumps

Polyethylene Sump tanks up to 2,000 gallons for indoor installation for anti-freezeprotection during winter operation.

Motor space heaters are recommended for unusually high relative humidity conditions where extreme day to night temperatures can cause excessive condensation in the motor, when in operation during this period. Plastic outlet sump strainer.

Plastic equalizer fittings.

Variable frequency drive on fan motors, controlled by temperature controller. High sump level switch

Automatic drain valve

Consult factory or a Delta representative for further information and an updated list of accessories.

TM Series Recommended Replacement Parts

To avoid costly cooling tower downtime, the following replacement parts should be carried in inventory at the installation site:

Make-upfloat, or completemake-upvalve assembly.

Cartridge of recommended moisture resistant lubricant.

Fan Motor.

Spray Nozzles.

When ordering, include model number and serial number of the cooling tower as it appears on the tower nameplate. Under normal conditions, shipment of factory replacement parts is made within one day after the order is received. Spare pumps and pump parts, as well as control panel components, such as fuses and heaters for magnetic starters, are also available.

19

Preventative Maintenance Checklist

Procedure

Monthly

Every

Every

 

 

3 Months

6 months

Inspect General Condition of cooling tower.

¨

 

 

 

 

 

 

Check Water Level in cold water basin.

¨

 

 

Adjust if needed.

 

 

 

 

 

 

 

Check float ball & Make-up Valve for

¨

 

 

proper operation.

 

 

 

 

 

 

 

Check Line Voltage, Motor Amperage,

¨

 

 

Water Pressure.

 

 

 

 

 

 

 

Clean Sump Strainers, if installed.

¨

 

 

 

 

 

 

Lubricate Motor Bearing, (if motor has

 

 

 

fittings for greasing. The majority of motors

 

¨

 

require no external greasing). Use Proper

 

 

Lubricants. Increase frequency, as necessary

 

 

 

depending on conditions of service.

 

 

 

 

 

 

 

Check for obstructed Water Flow Through

 

¨

 

Orifices. Clean and flush spray nozzles, as

 

 

 

required.

 

 

 

 

 

 

 

Check All Bolts which can cause unbalance

 

¨

 

and vibration and tighten specified torque.

 

 

 

 

 

 

 

Check Condition of Waterfor proper

 

 

 

treatment to prevent build-upof algae and

 

¨

 

solids concentration

 

 

 

 

 

 

 

Clean and flush Cold Water Sump

 

 

¨

 

 

 

 

20