114
3. Place terry cloth shop towel inside the unit directly under
components to be serviced to prevent spills through the
bottom of the unit.
4. Perform the required service.
5. Remove an dispose of any oil contaminated material per
local codes.
Indoor Fan Shaft Bearings (Sizes 03--14)
The indoor fan has permanently sealed bearings. No field
lubrication is necessary.
Indoor Fan Shaft Bearings (Size 16)
Lubricate bearings at least every 6 months with suitable bearing
grease. Typical lubricants are given below:
MANUFACTURER
LUBRICANT
Texaco
Regal AFB-2*
Mobil
Mobilplex EP No. 1
Sunoco
Prestige 42
Texaco
Multifak 2
* Preferred lubricant because it contains rust and oxidation inhibitors.
INDUCED
DRAFT
MOTOR
COMBUSTION
FAN HOUSING
MAIN GAS
VALVE
MAIN BURNER SECTION
HEAT EXCHANGER
SECTION
ROLLOUT
SWITCH
C07037
Fig. 42
---
Typical Gas Heating Section
(48PG03--07 Shown)
Condenser and Evaporator--Fan Motor Bearings
The condenser-fan and evaporator-fan motors have permanently
sealed bearings, so no field lubrication is necessary.
Evaporator Fan Service and Replacement
The 48/50PG units feature a slide-out fan deck for easy servicing
of the indoor-fan motor, pulleys, belt, and bearings. To service
components in this section, perform the following procedure:
1. Turn off unit power.
2. Open the fan section access door.
3. Remove two no. 10 screws at front of slide-out fan deck.
Save screws. (See Fig. 43.)
4. Disconnect the electrical wires connected to the slide-out
fan deck (supply air thermistor and fan status switch if
installed). Wires may be damaged if not disconnected.
5. Fan deck can now be slid out to access serviceable
components.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in damge to the
unit.
DO NOT SLIDE FAN DECK OUT PAST THE FAN
DECK STOP. If further access is required, the fan deck
must be supported. Make sure plugs and wiring are not
pinched between fan housing and unit sheet metal post.
CAUTION
!
6. To replace fan deck to operating position, slide fan deck
back into the unit. Secure with the two no. 10 screws
removed in Step 3.
7. Re-attach electrical wires.
8. Close fan section access door.
9. Restore power to unit.
Evaporator Fan Performance Adjustment (Fig.
43 and 44)
Fan motor pulleys are factory set for speed shown in Table 83.
To change fan speeds:
1. Shut off unit power supply.
2. Loosen nuts on the 4 carriage bolts in the mounting base.
Using adjusting bolts and plate, slide motor and remove
belt.
3. Loosen movable-pulley flange setscrew. (See Fig. 44.)
4. Screw movable flange toward fixed flange to increase
speed and away from fixed flange to decrease speed.
Increasing fan speed increases load on motor. Do not
exceed maximum speed specified in Table 81.
See Table 79 for air quantity limits.
5. Set movable flange at nearest keyway of pulley hub and
tighten setscrew. (See Table 81 for speed change for each
full turn of pulley flange.)
6. Replace belts.
7. Realign fan and motor pulleys:
a. Loosen fan pulley setscrews.
b. Slide fan pulley along fan shaft.
c. Make angular alignment by loosening motor from
mounting plate.
8. Tighten belts.
9. Restore power to unit.
Evaporator Fan Belt Tension Adjustment
To adjust belt tension:
1. Turn off unit power.
2. Slide out fan deck to service position as shown in
Evaporator Fan Service and Replacement section above.
3. Loosen motor mounting plate bolts.
4. Move motor mounting plate to adjust to proper belt
tension. Motor adjuster bolts may be used to tighten belts.
(See Fig. 43.) Do not overtighten belt.
5. Check for proper belt alignment. Adjust if necessary.
6. Tighten motor mounting plate bolts to lock motor in
proper position.
7. Return fan deck back into operating position.
8. Restore power to unit.
Condenser-Fan Adjustment (Fig. 45)
1. Shut off unit power supply.
2. Remove condenser-fan assembly (grille, motor, motor
cover, and fan) and loosen fan hub setscrews.
3. Adjust fan height as shown in Fig. 45.
48/
50P
G
C
03
--
16