Carrier 50DP020 - Service and Maintenance; Cleaning and Lubrication Guidelines; Fan Adjustment Procedures

SERVICE
A WARNING
Before performing service or maintenance operations
on unit, turn off main power switch to unit. Turn off
accessory heater power switch if applicable. Elec¬
trical shock could cause personal injury.
Cleaning — Inspect unit interior at beginning of each
heating and cooling season or as operating conditions
require. Remove unit top panel and/or side panels for
access to unit interior.
INDOOR COIL — Clean with a commercial coil cleaner.
OUTDOOR COIL — Clean outdoor coil annually or as
required by location or outdoor air conditions. Inspect
coil monthly — clean as required.
CONDENSATE DRAINS —Check and clean each year
at start of cooling season. In winter, keep drains and traps
dry or protect against freeze-up.
FILTERS — Clean or replace at start of each heating
and cooling season, or more often if operating conditions
require. Refer to Table 1 for type and size.
OUTDOOR AIR INLET SCREENS — Clean screens
with steam or hot water and a mild detergent. Do not use
throwaway filters in place of screens.
Lubrication
COMPRESSORS — Each compressor is charged with
correct amount of oil at the factory.
FAN SHAFT BEARINGS — No lubrication required.
Bearings are permanently lubricated.
FAN MOTOR BEARINGS — No lubrication of out¬
door fan or indoor blower motors are required for first
5 years of operation. Annually thereafter, clean and
repack bearings with a suitable bearing grease.
5. Set movable flange at nearest keyway of pulley hub
and tighten setscrew. (See Table 1 for speed change for
each full turn of pulley flange.)
To align fan and motor pulleys, loosen fan pulley set¬
screws and slide fan pulley along fan shaft. Make angular
alignment by loosening motor from mounting plate.
Fig. 21 — Indoor Air Fan Pulley Adjustment
(50DPE014 and 50DP016)
To Adjust Belt Tension — Loosen fan motor pivot
bolts. Move motor mounting plate up or down for proper
belt tension (1/2-in. deflection with one finger) and
tighten pivot bolts. Adjust lock bolt and nut on mounting
plate to secure in fixed position.
Outdoor Air Fan Adjustment (Fig. 22) — Shut off
unit power supply. Remove fan top grille assembly and
loosen fan hub screws. Adjust fan height on unit using a
straight edge placed across the fan orifice, tighten
setscrews and replace rubber hubcap to prevent hub from
rusting to motorshaft. Fill hub recess with permagum if
rubber hubcap is missing.
Indoor Air Fan Adjustment — Fan motor pulleys
are factory set for speed shown in Table 1. The 50DP020
units have fixed pulleys. Fan speed can be adjusted
only by changing the pulley. To change fan speed on
50DPE014 and 50DP016:
1. Shut off unit power supply.
2. Loosen belt by loosening fan motor mounting
plate nuts.
3. Loosen movable pulley flange setscrew (see Fig. 21).
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 1.
See Table 4 for air quantity limits.
Fig. 22 — Outdoor Air Fan Adjustment
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