BAC HXV Operation & Maintenance Manual page 12

NOTICE: Draining the coil will not
completely protect the coil from
corrosion; some corrosion will still
occur.
DANGER: Rotating equipment
will cause severe personal injury
or death to persons who come in
contact. Do not perform any service,
maintenance, or inspection on or
near the fans, motors, and drives,
or inside the unit without first
ensuring that the fans and pump
motors are disconnected, locked
out, and tagged out.
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• Units (with coils) that have been installed and operated should remain filled. If the
unit is stored in a freezing climate, the coil must be protected from freezing. For
protection against coil freeze-up, BAC recommends the use of an inhibited glycol
solution. If protecting the coils with glycol is not possible, the galvanized steel coils
should be drained completely and capped once as much water and moisture is
removed from the coil as possible.
• For extended shutdown periods after start-up, coils should be charged with nitrogen
at 15 psi in the field and capped by adding a threaded connection or a welded cap.
Prior to start-up, bleed off the nitrogen, then cut off the caps so the coil connections
can be piped.
• Apply a good quality, corrosion inhibiting grease, such as one of those recommended
for lubricating the fan shaft bearings, to the adjustable motor base and threaded rod.
• Spray coat electrical component housings (if supplied) with a suitable protective
coating, such as Cosmoline
taking care to leave openings for free air circulation.
• Inspect the protective finish on the unit. Clean and refinish as required. Refer to
"Corrosion Protection" on page 22 for more details.
Motor Recommendations
BAC standard motors are designed for storage at ambient temperatures of -20ºF to 104ºF
(-28.9ºC to 40ºC). Prolonged periods of exposure above or below these specified conditions
could degrade components of the motor and cause malfunction or premature failure.
• Motors should be removed and stored inside whenever possible. When indoor storage
is not possible the motors must be covered with a loose fitting tarpaulin. Do not
use plastic/plastic film. This cover should extend below the motor and be secured;
however, it should not tightly wrap the motor. This will allow the captive air space to
breathe, minimizing formation of condensation.
• Care must also be taken to protect the motor from flooding or from harmful chemical
vapors.
• The storage area should be free from ambient vibration. Excessive vibration can cause
bearing damage.
• Precautions should be taken to prevent rodents, snakes, birds, or other small animals
from nesting inside the motors. In areas where they are prevalent, precautions must
also be taken to prevent insects from gaining access to the interior of the motor.
• If motors are not stored indoors in a controlled environment, some form of heating
must be utilized to prevent condensation from accumulating in the motor. This
heating should maintain the winding temperature at a minimum of 9ºF (5ºC) above
the ambient temperature of the room, keeping it from dropping below the dew point
where condensation could form inside the motor. If space heaters are supplied, they
should be energized. If none are available, single phase or "trickle" heating may be
utilized by energizing one phase of the motor's winding with a low voltage. Request
the required voltage and transformer capacity from BAC. A third option is to use an
auxiliary heat source and keep the winding warm by either convection or blowing warm
air into the motor.
• Rotate the motor shaft monthly to redistribute bearing grease.
Weathershed, and individually cover them with plastic,
®