SPX Cooling Technologies Fluid Cooler Marley MC - Manual (Page 15)

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normal fan and motor sizes utilized on MC Fluid Coolers, anticipate
that approximately 4 to 5 starts per hour are allowable.
If your fluid cooler is equipped with a two-speed motor(s), you will
enjoy greater opportunity for process temperature control. When the
process fluid temperature becomes too cold, switching the fan to
half-speed will cause the cold process fluid temperature to rise—
stabilizing at a temperature a few degrees higher than before. With a
further reduction in fluid temperature, the fan may be cycled alternately
from half-speed to off—subject to the same constraint of 30 seconds
of allowable acceleration time per hour as outlined above.
If your fluid cooler consists of two or more cells, cycling of motors
may be shared between cells, increasing your steps of operation ac-
cordingly.
Multiple fan motors serving a single coil section must be cycled simulta-
neously. This applies to all 7055 and 7075 MC Fluid Cooler models.
Multicell fluid coolers 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 process fluid temperature control, please read
“Cooling Tower Energy and its Management”, Technical Report
#H-001-A, available at spxcooling.com.
Wintertime Operation:
It is the operator's responsibility to prevent the formation of destruc-
tive (hard) ice on the fluid cooler coil. Certain guidelines should be
followed:
1. Do not allow the fluid cooler's leaving process fluid temperature to
drop below 45°F . If such low temperature operation is necessary or
beneficial to your process, establish the minimum allowable level as
follows:
During the coldest days of the first winter of operation, observe whether
any ice is forming on the air inlet, particularly near the bottom part of
the louver face. If hard ice is present on the air inlet, you must increase
the allowable cold water temperature.
Operation
➠
Note
Caution