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If your tower is equipped with a single-speed motor, the motor may be
shut off when the water temperature becomes too cold. This will cause
the water temperature to rise. When the water temperature then becomes
too warm for your process, the motor can be restarted.
Fan Cycling Limits:
Considering the normal fan and motor sizes utilized on MD towers,
anticipate that approximately 4 to 5 starts per hour are allowable.
If your tower is equipped with a two-speed motor, you will enjoy greater
opportunity for temperature control. When the water temperature becomes
too cold, switching the fan to half-speed will cause the cold water tem-
perature to rise—stabilizing at a temperature a few degrees higher than
before. With a further reduction in water temperature, the fan may be
cycled alternately from half-speed to off.
Do not start the motor more than four to five times per hour (each
low speed start and each high speed start count as one start).
If your tower consists of two or more cells, cycling of motors may be
shared between cells, increasing your steps of operation accordingly.
Multicell towers equipped with two-speed motors will maximize energy
savings and minimize sound levels if fans are staged so that all fans are
brought up to low speed before any fan goes to high speed.
For greater insight on cold water temperature control, please read
“Cooling Tower Energy and its Management”, Technical Report
H-001, available on our website.
Freezing Weather Operation
During operation in subfreezing weather, the opportunity exists for ice to
form in the colder regions of the tower. Your primary concern is to prevent
the formation of destructive ice on the cooling tower fill air inlet and louvers.
Your understanding of cold weather operation will be enhanced if you read
Marley Technical Report H-003 “Cooling Towers and Freezing Weather”.
Note
Note
operation
