Carrier NP034-074 User Manual

Page 45

NOTE: Only the heater element contactors are located in the
heater box. The heaters are located in the unit airstream.

25% OUTDOOR-AIR DAMPER — Access to adjust the
damper is through the hoods. Remove filters to gain access
into unit to adjust linkage arms.

MODULATING POWER EXHAUST DAMPER MOTOR
— The modulating power exhaust damper motor is located
in the return-air end of the unit.

On unit sizes 034 and 044, it is accessed by removing the

access panel on the left-hand corner post. See Fig. 35.

IMPORTANT: When replacing panel, be sure to prop-
erly secure it in order to prevent water from being drawn
into the unit.

On unit sizes 054-074, the motor is accessed through the

small door below the side economizer hoods on the left side
of the unit. See Fig. 36.

RETURN-AIR FILTERS — Access to these filters is through
the door marked FILTER SECTION. Filters in upper and
lower bag filter tracks can only be removed from the left
side of the unit (when facing condenser end).

CONDENSER FANS AND FAN MOTORS — Remove the
wire fan guard on top of the unit to gain access to the con-
denser fans and motors.

INLET GUIDE VANE MOTOR — The inlet guide vane mo-
tor is located on the evaporator-fan sled on the side opposite
the fan motor. See Fig. 43. Access is through the door la-
beled FAN SECTION on the left side of the unit.

Cleaning —

Inspect unit at the beginning of each heating

and cooling season and during each season as operating con-
ditions may require.

Clean condenser coil with a vacuum cleaner, fresh water,

compressed air, or a bristle brush (not wire). Coil cleaning
should be a part of the planned maintenance program. Clean
evaporator coil with a stiff bristle brush (not wire), vacuum
cleaner, or compressed air.

Check and clean condensate drain annually at the start of

the cooling season.

Replace return-air filters at the start of each heating and

cooling season or as often as necessary during each season,
depending on operating conditions. See Tables 1A and 1B
for filter types, quantities, and sizes.
1. Remove economizer outdoor-air filters from the hoods by

removing the filter retainers.

2. Clean filters with steam or hot water and mild detergent.
3. Reinstall filters in hoods after cleaning. Never replace clean-

able filters with throwaway filters.

Lubrication

COMPRESSORS — Each compressor is correctly charged
at the factory. Refer to 06D and 06E Compressor Service
Manuals if additional information regarding compressor lu-
brication system is required. See Compressor Oil section on
page 38 and Table 8.

FAN SHAFT BEARINGS — Lubricate fan shaft bearings at
least once a year with suitable bearing grease. Extended grease
lines are provided on pulley side of blower. Typical lubri-
cants 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.

INLET GUIDE VANE BEARINGS (Units With Optional
Inlet Guide Vanes) — These bearings are oil impregnated.
Lubricate annually with a few drops of nondetergent
SAE 20 oil.

FAN MOTOR BEARINGS — The condenser- and evaporator-
fan motors have sealed bearings so no field lubrication is
required.

DOOR HINGES — All door hinges should be lubricated at
least once a year.

LEGEND

— Contactor

— Fuse Block

— Fuse

— Heat Element Contactor

HTB — Heater Terminal Block
PL

— Plug Assembly

Fig. 42 — Typical Electric Heat Control Box

Fig. 43 — Inlet Guide Vane Motor