140.925-IOM (APR 2019)
Page 18
XLP3 EVAPORATIVE CONDENSERS
OPERATION
Maintenance Requirements During Storage
• Rotate all fans and motor shafts monthly by hand. Hand-
turning will ensure that the shafts and bearings are free
and will redistribute grease within the bearings.
• Inspect the cold water basin monthly to ensure that the
drain is open and remove any leaves or debris that may
have accumulated in the cold water basin.
• Inspect the axial fans annually to ensure the blades are
tight and there is no obvious corrosion between the hub
and the fan blade.
• Inspect the rust preventative coating on all motor external
machined surfaces including shaft extensions monthly. If
necessary, re-coat the surfaces with RUST VETO®.
Start-Up Preparation After Prolonged Storage
Keep in mind that start-up procedures after long periods of
storage are just as important as pre-shutdown procedures.
• Motors should be thoroughly inspected, cleaned, and
restored to pre-storage condition.
• Inspect axial fans prior to start-up to ensure that the
blades are tight and that there is no obvious corrosion
between the hub and the fan blade. Do not energize the
fans if there is obvious corrosion of fan components. Loose
fan blades could result in fan failure and possible injury or
damage.
• Reinstall all fan belts, motors, door gaskets, and drain
plugs (as applicable), and remove all protective coverings.
• For units stored prior to installation, conduct rigging
procedures as directed in the unit’s Rigging and
Assembly Instructions, or by contacting your local Frick
Representative.
• Perform an insulation test of motor windings to ensure
satisfactory insulation resistance.
• Conduct full start-up procedure as stated in the “Start-Up
Procedure” on page 15. Be especially thorough for cleaning
and inspection prior to start-up.
COLD WEATHER OPERATION
Inspection and Maintenance
Frick products can be operated at subfreezing ambient tem-
peratures provided proper operating methods are established
and diligently followed.
• Carry out frequent visual inspections and routine
maintenance services during operation in subfreezing
weather.
• Ensure all controls for capacity and freeze protection are
set properly and functioning normally.
• Prevent excessively high water levels and possible overflow
of the cold water basin due to over pumping, clogged
strainers, or make-up valve malfunction.
• Some unit icing can be expected in very cold weather.
Usually this will not affect the operation of the unit.
Resolve any icing conditions that may damage the unit or
the supports, impair the system performance, or create a
safety hazard.
Fan Section Icing Protection
There are three basic operational methods which can be used to
provide the system’s required cooling: temperature setting, fan
control, and dry operation. The method of control employed on a
given application depends upon the climatic extremes which are
expected, the variations in heat load that will be encountered,
and the compatibility of the control system with other portions
of the installation.
In subfreezing ambient temperatures, effective icing control may
require a combination of these three methods. Operate each unit
with the highest thermal load it can handle, rather than evenly
dividing the total heat load across all cells. During prolonged
cold weather periods, bypass the idle units and drain the basins.
Fan Control
Reduce the unit capacity by cycling the fans, thus modulating
the airflow through the unit. Rapid on-off cycles can cause the
fan motor to overheat. Set the controls to allow a maximum
of six on-off cycles per hour. Periodically, cycle the fans off to
prevent ice formation and/or to melt ice that accumulates on
the combined inlet shields.
The following are fan control methods:
•
Variable Frequency Drives:
VFDs offer the most precise
method of capacity control by modulating fan motor speed.
When using VFDs, avoid operating at or near resonant
speeds. Units with VFDs require premium efficient/inverter
duty motors.
•
Fan Cycling:
Cycle the fan off for five minutes every 15 to
20 minutes for each cell. If ice continues to build on the air
intake, decrease the on-time. Observe the air intake of the
unit at least every four to eight hours.
NOTICE
Modulating the water flow rate to the unit is NOT a recom-
mended method of controlling cooling capacity.
Dry Operation
One method to prevent icing is dry operation. Dry operation of
the unit protects fans from ice formation due to mist and splash
from the cold water basin. The water in the cold water basin
must be drained in dry operation. For dry operation switch points
and recommendations, contact your local Frick representative.
BASIN WATER AND INTERNAL PIPING
FREEZE PROTECTION
Cold Water Basin Protection
It is important to protect the basin and internal piping. The basin
water could freeze when the unit is shutdown and exposed to
subfreezing ambient temperatures.
•
Remote Sump:
The ideal method of protection is a
remote sump located in a heated indoor space. When the
circulating pump stops, the water in the connecting piping
will drain by gravity to this indoor sump.
•
Basin Heaters:
On applications without a remote sump,
heat must be provided to the cold water basin. Electrical
immersion heaters can provide the required function.
Contact your local Frick Representative for details.