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2. Cover area in front of the unit service panel with a terry
cloth shop towel to absorb lubricant spills and prevent
run-offs. Towel will also protect dropcloth from tears
caused by tools or components.
3. Place terrycloth 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 and dispose of any oil contaminated material per
local codes.
FAN SHAFT BEARINGS — Lubricate bearings at least ev-
ery 6 months with suitable bearing grease. Typical lubricants
are given below:
*Preferred lubricant because it contains rust and oxidation inhibitors.
FAN MOTOR BEARINGS — Fan motor bearings are of the
permanently lubricated type. No field lubrication is required.
No lubrication of the condenser or evaporator motors are
required.
Manual Outdoor Air Damper —
If manual outdoor
air damper blade adjustment is required, refer to unit Installa-
tion Instructions.
Economizer Adjustment —
If economizer adjustment
is required, refer to unit Installation Instructions.
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 panel.
3. Remove three no. 10 screws at front of slide-out fan deck.
Save screws. See Fig. 38.
4. Disconnect the limit switch wires located on the right side
of the fan deck (48PG only). Other wires do not need to
be disconnected.
5. Fan deck can now be slid out to access serviceable
components.
6. To replace fan deck to operating position, slide fan deck
back into the unit. Secure with the three no. 10 screws
removed in Step 3.
7. Re-attach electrical plugs and wires.
8. Close fan section access door.
9. Restore power to unit.
Evaporator Fan Performance Adjustment
(Fig. 38 and 39) —
Fan motor pulleys are factory set
for speed shown in Table 57.
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. 39).
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 unit Installation
Instructions.
See Tables 27 and 28 for air quantity limits.
5. Set movable flange at nearest keyway of pulley hub and
tighten setscrew. (See Tables 33 and 34 for speed change
for each full turn of pulley flange.)
6. Replace and tighten belts (see Evaporator Fan Belt
Tension Adjustment section below).
7. Restore power to unit.
To align fan and motor pulleys:
1. Loosen fan pulley setscrews.
2. Slide fan pulley along fan shaft.
3. Make angular alignment by loosening motor from
mounting plate.
MANUFACTURER
LUBRICANT
Texaco
Regal AFB-2*
Mobil
Mobilplex EP No. 1
Sunoco
Prestige 42
Texaco
Multifak 2
DO NOT SLIDE FAN DECK OUT PAST THE STOP
BRACKET. If further access is required, the fan deck must
be supported. Make sure plugs and wiring are not pinched
between fan housing and unit center post. Damage to unit
may result.
FAN
PULLEY
MOTOR
MOUNTING
BASE
MOTOR
PULLEY
(HIDDEN)
SLIDE-OUT
FAN DECK
LIMIT
SWITCH
QUICK
CONNECT
(48PG ONLY)
Fig. 38 — Evaporator-Fan Motor Adjustment
Fig. 39 — Evaporator-Fan Alignment and
Adjustment
a48-7807
a48-5091
Summary of Contents for 48PG24
Page 68: ...68 Fig 14 Low Voltage Control Schematic 48PG20 28 Units without Humidi MiZer System a48 7627...
Page 69: ...69 Fig 15 Low Voltage Control Schematic 48PG20 28 Units with Humidi MiZer System a48 8227...
Page 70: ...70 Fig 16 Low Voltage Control Schematic 50PG20 28 Units without Humidi MiZer System a48 7778...
Page 71: ...71 Fig 17 Low Voltage Control Schematic 50PG20 28 Units with Humidi MiZer System a50 8101...
Page 72: ...72 Fig 18 Power Schematic Units without Humidi MiZer System a48 7628...
Page 73: ...73 Fig 19 Power Schematic Units with Humidi MiZer System a48 8228...
Page 74: ...74 Fig 20 Component Arrangement Units without Humidi MiZer System a48 8229...
Page 75: ...75 Fig 21 Component Arrangement Units with Humidi MiZer System a48 8230...
Page 105: ......