SPX Cooling Technologies F400 User Manual

Marley Class F400 Cooling Tower

User Manual 93-1288A

Warning

Caution

Note

Contents

The following deﬁned terms are used throughout this manual to

bring attention to the presence of hazards of various risk levels, or

to important information concerning the life of the product.

Indicates presence of a hazard which can cause severe personal

injury, death or substantial property damage if ignored.

Indicates presence of a hazard which will or can cause personal injury

or property damage if ignored.

Indicates special instructions on installation, operation or maintenance

which are important but not related to personal injury hazards.

Note

These instructions assist in obtaining efﬁcient, long life from Marley

counterﬂow cooling towers. Direct questions concerning cooling tower

operation and maintenance to your Marley sales representative. Al-

ways include your tower serial number when writing for information

or ordering parts. Look for this number on the sidewall casing.

Before Startup ........................................................................................ 3

Starting Procedure ................................................................................. 4

Operation ................................................................................................ 4

Tower Maintenance ................................................................................ 6

Water Treatment ..................................................................................... 8

Spare Parts ........................................................................................... 12

Seasonal Shutdown Instructions .......................................................... 12

Tower Cleaning ..................................................................................... 13

Troubleshooting .................................................................................... 14

Safety ................................................................................................... 15

Inspection and Maintenance Schedule ................................................ 16

Inspection Checklist ............................................................................. 18

Warning

Before Start-up

Among other sources, outbreaks of Legionnaires’ disease have re-

portedly been traced to cooling towers. Maintenance procedures

that prevent ampliﬁcation and dissemination of Legionella and other

airborne bacteria should be formulated and implemented BEFORE

systems are operated and continued reqularly thereafter to avoid the

risk of sickness or death

CLEANING–New installations should be cleaned and treated with biocides

by a water treatment expert before startup. Remove any dirt and trash which

has accumulated in the cold water basin. Remove any sediment from the

cold water collection basin, sump, and screens. Use a water hose to ﬂush

cold water collection basins.

OPERATE WATER SYSTEM–Start the circulating water pumps. Increase

the ﬂow of circulating water gradually to match design water ﬂow rate.

Circulate water over the cooling tower continuously for several days

before starting the mechanical equipment and placing the cooling tower

into continuous operation.

Note

When starting in cold weather, follow procedures outlined in Cold

Weather Operation.

INSPECTION–It is imperative that all operating assemblies be inspected

before they are placed in operation. The following is a list of components

to be checked before starting the tower:

1–Check drive shaft alignment. Realign if necessary. See Marley Drive

Shaft Service Manual.

2– Check tightness of bolts in fan cylinder joints.

3–Check tightness of the following bolted joints in the fan and drive as-

semblies:

a–Fan hub clamp bolts. See Marley Fan User Manual for correct torque

setting).

b–Fan hub cover bolts.

c–Geareducer® and motor mounting bolts.

d—Drive shaft coupling and guard bolts.

4–Check Geareducer oil for sludge or water by draining off and testing a

sample as outlined in the Geareducer User Manual. Check Geareducer

oil level at “oil level” mark on the side of the case. Add oil as required.

➠

The oil level placard must be adjusted so that its “full” mark is at the

same elevation as the “full” mark on the side of the Geareducer case.

Check oil lines to be sure there are no leaks. See Geareducer User

Manual for oil ﬁlling procedure and list of recommended lubricants.

5–Rotate fan by hand to be sure of free rotation and ample tip clearance.

See Fan User Manual.

6–Check motor insulation with a “Megger”. See Maintenance Section of

Marley Electric Motor User Manual.

7–Lubricate the motor according to motor manufacturer’s instructions.

8–Test run each fan separately for a short time. Check for excessive vibra-

tion or unusual noise. If either is present, see Troubleshooting Guide

on pages 14 and 15 of this manual. Fan must rotate clockwise when

viewed from above. Recheck Geareducer oil level.

9–Check functioning of make-up water supply.

10–Make sure the blowdown will carry the proper amount of water.

Starting Procedure

WATER SYSTEM–Fill the cold water collection basin and circulating water

system until the operating water level is reached. See Operation Section,

below. Prime and start the circulating water pumps. Increase the ﬂow of

circulating water gradually to design water ﬂow rate to avoid water ham-

mer which could damage the distribution piping system.

Note

Caution

Clean the sump screens several times during the ﬁrst weeks of op-

eration. After this, clean sump screens weekly.

When starting in cold weather, follow procedures outlined in Cold

Weather Operation.

STARTING FAN–Start the fan. After 30 minutes of operating time to permit

Geareducer oil to come up to operating temperature, check motor load

with watt meter, or take operating volt and ampere readings and calculate

motor hp. Refer to Marley Fan User Manual for instructions. Pitch fans

to pull correct contract horsepower when circulating design water rate at

design hot water temperature.

Operation

Entering water temperature in excess of 125°F may result in ﬁll de-

formation.

TOWER PERFORMANCE–Keep the cooling tower clean and water dis-

tribution uniform to obtain continued maximum cooling capacity.

The capacity of a cooling tower to cool water to a given cold water tem-

perature varies with the wet-bulb temperature and the heat load applied

to the cooling tower.

As the wet-bulb temperature drops, the cold water temperature also

drops. However, the cold water temperature does not drop linearly with

the wet-bulb temperature.

A cooling tower will not control heat load. The ﬂow rate of water circulated

through the cooling tower will determine the temperature range of cool-

ing in conjunction with a given heat load. The hot water and cold water

temperatures will increase with higher heat loads.

HOT WATER DISTRIBUTION SYSTEM–Maintain uniform water distribu-

tion at the nozzles (uniform spray cone). The amount of water circulated

should approximate the contract requirements and the nozzle pressure

should be kept constant. Lower pressures may indicate excessive losses

in the piping system and/or insufﬁcient pump capacity; greater pressures

might indicate clogged nozzles and/or overpumping. If a greatly reduced

water ﬂow rate is desired, it may be advisable to change nozzle sizes to

obtain the desired pressure and maintain proper water distribution. An

SPX Cooling Technologies engineer can advise minimum and maximum

ﬂow rates for even distribution.

COLD WATER COLLECTION BASIN–A suitable depth must be maintained

to keep the pumps from pulling air into the line. The amount of “make-up”

water required to keep the water in the collection basin at the required

depth depends upon the “evaporation loss” and “blowdown” .

FAN DRIVE–When using two-speed motors, allow a time delay of 20

seconds minimum after de-energizing the high-speed winding and before

energizing the low-speed winding. Tremendous stresses are placed on

driven machinery and motors unless the motors are allowed to slow to

low-speed RPM or less before the low-speed winding is energized.

COLD WEATHER OPERATION–During periods of low temperature op-

eration, 35°F to 40°F or below, ice will form on the relatively dry parts of

the cooling tower that are in contact with the incoming air. Primarily, this

includes the air inlet and adjacent structural framing. Your understanding of

➠

cold weather operation will be enhanced if you read “Operating Cooling

Towers in Freezing Weather” Marley Technical Report #H-003.

Ice forming characteristics on any given cooling tower will vary, depending

on velocity and direction of wind, circulating water rate, and heat load.

Excessive ice formation may be controlled by regulating air and water ﬂow

through the tower by one or more of the following procedures:

1–Shut the fan down. This reduces the cooling air rate to a minimum and

increases the quantity of warm water at the air inlet to a maximum.

However, normal “fan off” operation causes reverse air ﬂow by aspira-

tion and may cause water blowout and therefore must be done with

caution and monitoring. For automatic operation, a timer switch can be

provided to shut the fan down for a few minutes each hour.

2–When a cooling tower has two-speed motors, operate the fans at half

speed forward. This reduces the cooling air rate (heat transfer) and

increases the quantity of warm water at the air inlet.

3–With no heat load on the circulating water, icing cannot be controlled.

Towers must not be operated with reduced water rate and/or no heat

load during freezing weather. If a bypass directly into the cold water

basin is used, all water must be bypassed.

Caution

Warning

Reverse operation of fans is not recommended . See “Fan Drive” for

fan speed change precautions.

INTERMITTENT OPERATION–When the unit is operated intermittently

during winter weather, it is necessary that the water be drained from the

tower piping to insure protection against freezing and possible rupture.

Tower Maintenance

Always shut off electrical power to the tower fan motor prior to

performing any inspections that may involve physical contact with

the mechanical or electrical equipment in or on the tower. Lock out

and tag out any electrical switches to prevent others from turning

the power back on. Service personnel must wear proper personal

protective clothing and equipment.

Well-maintained equipment gives the best operating results and the least

maintenance cost. SPX recommends setting up a regular inspection

schedule to insure effective, safe operation of the cooling tower. Use the

schedule on page 16 to obtain continuously good performance with the

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