Carrier 50TCA04-A07 - Manual (Page 5)

5
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 PuronR 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
Condenser Coil
The condenser coil is fabricated with round tube copper
hairpins and plate fins of various materials and/or coatings
(see Model Number Format in the Appendix to identify
the materials provided in this unit). The coil may be
one--row or composite--type two--row. Composite two--row
coils are two single--row coils fabricated with a single
return bend end tubesheet.
Condenser 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 a very low velocity water stream to avoid damaging
the fin edges. Monthly cleaning as described below is
recommended.
Routine Cleaning of Coil Surfaces
Periodic cleaning with TotalineR environmentally sound
coil cleaner is essential to extend the life of coils. This
cleaner is available from Carrier Replacement
Components Division as part number P902--0301 for a one
gallon container, and part number P902--0305 for a 5
gallon container. It is recommended that all coils,
including standard aluminum, pre--coated, copper/copper
or E--coated coils be cleaned with the Totaline
environmentally sound coil cleaner as described below.
Coil cleaning should be part of the unit’s regularly
scheduled maintenance procedures to ensure long life of
the coil. Failure to clean the coils may result in reduced
durability in the environment.
Avoid use of:
S coil brighteners
S acid cleaning prior to painting
S high pressure washers
S poor quality water for cleaning
Totaline environmentally sound coil cleaner is
nonflammable, hypo allergenic, non bacterial, and a
USDA accepted biodegradable agent that will not harm
the coil or surrounding components such as electrical
wiring, painted metal surfaces, or insulation. Use of
non--recommended coil cleaners is strongly discouraged
since coil and unit durability could be affected.
One--Row Coil
Wash coil with commercial coil cleaner. It is not
necessary to remove top panel.
50TC