Carrier 50LC 07, Инструкции по обслуживанию и техническому обслуживанию, Страница: 5 / 100

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Bearings
This fan system uses bearings featuring concentric split
locking collars. The collars are tightened through a cap
screw bridging the split portion of the collar. The cap
screw has a Torx T25 socket head. To tighten the locking
collar, hold the locking collar tightly against the inner race
of the bearing and torque the cap screw to 65--70 in--lb
(7.4--7.9 Nm). (See Fig. 7.)
C08121
Fig. 7 -- Tightening Locking Collar
Motor
When replacing the motor, also replace the external--tooth
lock washer (star washer) under the motor mounting base;
this is part of the motor grounding system. Ensure the
teeth on the lock washer are in contact with the motor’s
painted base. Tighten motor mounting bolts to 120 +/-- 12
in--lbs.
Changing Fan Wheel Speed by Changing Pulleys
The horsepower rating of the belt is primarily dictated by
the pitch diameter of the smaller pulley in the drive
system (typically the motor pulley in these units). Do not
install a replacement motor pulley with a smaller pitch
diameter than provided on the original factory pulley.
Change fan wheel speed by changing the fan pulley
(larger pitch diameter to reduce wheel speed, smaller
pitch diameter to increase wheel speed) or select a new
system (both pulleys and matching belt(s)).
Before changing pulleys to increase fan wheel speed,
check the fan performance at the target speed and airflow
rate to determine new motor loading (bhp). Use the fan
performance tables or use the Packaged Rooftop Builder
software program. Confirm that the motor in this unit is
capable of operating at the new operating condition. Fan
shaft loading increases dramatically as wheel speed is
increased.
To reduce vibration, replace the motor’s adjustable pitch
pulley with a fixed pitch pulley (after the final airflow
balance adjustment). This will reduce the amount of
vibration generated by the motor/belt--drive system.
COOLING
UNIT OPERATION AND SAFETY HAZARD
Failure to follow this warning could cause personal
injury, death and/or equipment damage.
This system uses Puron
R
refrigerant which has
higher pressures than R--22 and other refrigerants. No
other refrigerant may be used in this system. Gauge
set, hoses, and recovery system must be designed to
handle Puron refrigerant. If unsure about equipment,
consult the equipment manufacturer.
!
WARNING
Evaporator Coil
The evaporator coil is traditional round--tube, plate--fin
technology. Tube and fin construction is of various
optional materials and coatings (see Model Number
Format). Coils are multiple--row.
Coil Maintenance and Cleaning Recommendation
Routine cleaning of coil surfaces is essential to maintain
proper operation of the unit. Elimination of contamination
and removal of harmful residues will greatly increase the
life of the coil and extend the life of the unit. The
following maintenance and cleaning procedures are
recommended as part of the routine maintenance activities
to extend the life of the coil.
Remove Surface Loaded Fibers
Surface loaded fibers or dirt should be removed with a
vacuum cleaner. If a vacuum cleaner is not available, a
soft non--metallic bristle brush may be used. In either
case, the tool should be applied in the direction of the fins.
Coil surfaces can be easily damaged (fin edges can be
easily bent over and damage to the coating of a protected
coil) if the tool is applied across the fins.
NOTE : Use of a water stream, such as a garden hose,
against a surface loaded coil will drive the fibers and dirt
into the coil. This will make cleaning efforts more
difficult. Surface loaded fibers must be completely
removed prior to using low velocity clean water rinse.
Periodic Clean Water Rinse
A periodic clean water rinse is very beneficial for coils
that are applied in coastal or industrial environments.
However, it is very important that the water rinse is made
with very low velocity water stream to avoid damaging
the fin edges. Monthly cleaning as described below is
recommended.
Routine Cleaning of Evaporator Coil Surfaces
Monthly cleaning with Totaline

environmentally sound
coil cleaner is essential to extend the life of coils. This
cleaner is available from Carrier Replacement parts
division as part number P902--0301 for one gallon
container, and part number P902--0305 for a 5 gallon
container. It is recommended that all round tube coil
cleaner as described below. Coil cleaning should be part
of the unit’s regularly scheduled maintenance procedures