Lubrication; Evaporator Fan Performance Adjustment; Evaporator Fan Coupling Assembly - United Technologies Carrier Weathermaker 48A2 Controls, Start-Up, Operation, Service, And Troubleshooting

MICROCHANNEL HEAT EXCHANGER (MCHX) CON-
DENSER COIL MAINTENANCE AND CLEANING
RECOMMENDATIONS
CAUTION
Do not apply any chemical cleaners to MCHX condenser
coils. These cleaners can accelerate corrosion and damage
the coil.
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 steps should
be taken to clean MCHX condenser coils:
1. Remove any foreign objects or debris attached to the coil
face or trapped within the mounting frame and brackets.
2. Put on personal protective equipment including safety
glasses and/or face shield, waterproof clothing and
gloves. It is recommended to use full coverage clothing.
3. Start high pressure water sprayer and purge any soap or
industrial cleaners from sprayer before cleaning condens-
er coils. Only clean potable water is authorized for clean-
ing condenser coils.
4. Clean condenser face by spraying the coil steady and uni-
formly from top to bottom while directing the spray
straight toward the coil. Do not exceed 900 psig or
30 degree angle. The nozzle must be at least 12 in. from
the coil face. Reduce pressure and use caution to prevent
damage to air centers.
CAUTION
Excessive water pressure will fracture the braze between
air centers and refrigerant tubes.
CONDENSATE DRAIN — Check and clean each year at
start of cooling season. In winter, keep drains and traps dry.
FILTERS — Clean or replace at start of each heating and cool-
ing season, or more often if operating conditions require. Refer
to Installation Instructions for type and size.
NOTE: The unit requires industrial grade throwaway filters
capable of withstanding face velocities up to 625 fpm.
OUTDOOR-AIR INLET SCREENS — Clean screens with
steam or hot water and a mild detergent. Do not use disposable
filters in place of screens.

Lubrication

FAN SHAFT BEARINGS — Lubricate bearings at least ev-
ery 6 months with suitable bearing grease. Do not over grease.
Typical lubricants are given below:
MANUFACTURER
Texaco
Mobil
Sunoco
Texaco
*Preferred lubricant because it contains rust and oxidation inhibitors.
CONDENSER AND EVAPORATOR-FAN MOTOR BEAR-
INGS — The condenser and evaporator-fan motors have perma-
nently sealed bearings, so no field lubrication is necessary.

Evaporator Fan Performance Adjustment

Fan motor pulleys are designed for speed
(Fig. 44) —
shown in Physical Data table in unit Installation Instructions
(factory speed setting).
IMPORTANT: Check to ensure that the unit drive matches
the duct static pressure using Tables 3-26.
LUBRICANT
Regal AFB-2*
Mobilplex EP No. 1
Prestige 42
Multifak 2
132
To change fan speeds, change pulleys.
To align fan and motor pulleys:
1. Shut off unit power supply.
2. Loosen fan shaft pulley bushing.
3. Slide fan pulley along fan shaft.
4. Make angular alignment by loosening motor from
mounting plate.
5. Retighten pulley.
6. Return power to the unit.
Fig. 44 — Evaporator-Fan Alignment
and Adjustment
Evaporator Fan Coupling Assembly —
pling has been removed for other blower assembly component
repair or replacement, it is critical that the coupling be reassem-
bled and aligned correctly to prevent premature failures.
REASSEMBLING THE COUPLING INTO THE UNIT
(Fig. 45)
1. Prior to reassembling the coupling, loosen the 4 bearing
mounting bolts, which secure the 2 bearings on either side
of the coupling. Remove the drive belts.
2. Reassemble the coupling with the bearings loose. This
allows the coupling to find its own self-alignment position.
3. Check the hub-to-shaft fit for close fitting clearances.
Replace hubs if high clearances are determined.
4. Check the key for close-fitted clearances on the sides and
0.015 in. clearance over the top of the key. Replace key if
necessary.
5. Be sure that hub flanges, flex members, spacer, and hard-
ware are clean and free of oil.
6. Place the flanges onto the shafts with the hub facing out-
ward. Do not tighten the set screws at this time.
7. Outside of the unit, assemble the flex members to the cen-
ter drive shaft with 4 bolts and nuts. The flex members
have collars that need to be inserted into the smaller hole
of the drive shaft flange.
8. Assemble the flex member/drive shaft assembly to one of
the shaft flanges, using 2 bolts and nuts. Slide the other
shaft flange towards the assembly and assemble using
2 bolts and nuts. If the shafts are not misaligned, the collar
in the flex member should line up with the shaft flange
holes.
A48-4036
If the cou-