Gravity Flow Method; Forced Circulation Method; Fan Motor Lubrication; Fan Bearing Lubrication - Carrier Omnizone 50BV020-064 Installation, Start-Up, Service And Controls Operation And Troubleshooting

GRAVITY FLOW METHOD

Do not add solution faster than the vent can exhaust the generated
gases.
When condenser is full, allow the solution to remain overnight;
then drain the condenser and flush with clean water. Follow acid
manufacturer's instructions. Refer to Fig. 40.

FORCED CIRCULATION METHOD

Fully open the vent pipe when filling the condenser. The vent may
be closed when the condenser is full and the pump is operating.
Regulate the flow to the condenser with a supply line valve. If the
pump is the non-overloading type, the valve may be fully closed
while the pump is running.
For average scale deposit, allow the solution to remain in the con-
denser overnight. For heavy scale deposit, allow a full 24 hours.
Drain the condenser and flush with clean water. Follow acid man-
ufacturer's instructions. Refer to Fig. 41.
Fig. 40 — Gravity Flow Method
Fig. 41 — Forced Circulation Method

Fan Motor Lubrication

The fan motor was properly lubricated at the time of manufacture.
Lubricate the fan motor(s) with SAE-20 (Society of Automotive
Engineers) non-detergent electric oil.
IMPORTANT: PILLOW BLOCK STYLE FAN BEARINGS:
Bearings have been prelubricated with high quality grease.
Bearings must be relubricated once every 6 months or every
2500 hours of operation, whichever comes first.

Fan Bearing Lubrication

Inspect the fan bearings for proper lubrication every 6 month or
2500 hours of operation, whichever comes first. Standard units
have grease fittings on the fan shaft bearings, located on each side
of the blower wheel. Lubricate bearings with a lithium-based
grease (NLGI Grade 2).

Fan Sheaves

Factory-supplied drives are pre-aligned and tensioned; however, it
is recommended that the belt tension and alignment be checked
before starting the unit. Always check the drive alignment after
adjusting belt tension.
To install sheaves on the fan or motor shaft:
1. Isolate power to the unit.
2. Remove side unit access panel(s).
3. Remove any rust-preventive coating on the fan shaft.
4. Make sure the shaft is clean and free of burrs. Add grease or
lubricant to bore of sheave before installing.
5. Mount sheave on the shaft; to prevent bearing damage, do not
use excessive force.
Each factory-assembled fan, shaft, and drive sheave assembly is
precision aligned and balanced. If excessive unit vibration occurs
after field replacement of sheaves, the unit should be rebalanced.
To change the drive ratio, follow the steps in the Evaporator Fan
Performance Adjustment section (page 55).
After 1 to 3 minutes of operation, check the belt tension. Also
check tension frequently during the first 24 hours of operation and
adjust if necessary. Periodically check belt tension throughout the
run-in period, which is normally the initial 72 hours of operation.
ALIGNMENT
Make sure that fan shafts and motor shafts are parallel and level.
The most common causes of misalignment are nonparallel shafts
and improperly located sheaves. Where shafts are not parallel,
belts on one side are drawn tighter and pull more than their share
of the load. As a result, these belts wear out faster, requiring the
entire set to be replaced before it has given maximum service. If
misalignment is in the sheave, belts enter and leave the grooves at
an angle, causing excessive belt and sheave wear.
Shaft Alignment
Check shaft alignment by measuring the distance between the
shafts at 3 or more locations. If the distances are equal, then the
shafts are parallel.
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