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

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

MODULATING POWER EXHAUST DAMPER MOTOR

ÐThe 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 Ð Access to these ®lters is through the door marked FILTER SECTION. Filters in upper and lower bag ®lter tracks can only be removed from the left side of the unit (when facing condenser end).

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

INLET GUIDE VANE MOTOR Ð 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.

LEGEND

CÐ Contactor

FB

Ð Fuse Block

FU

Ð Fuse

HC

Ð Heat Element Contactor

HTB Ð Heater Terminal Block

PL

Ð Plug Assembly

Fig. 42 Ð Typical Electric Heat Control Box

Cleaning Ð 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 ®lters 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 ®lter types, quantities, and sizes.

1.Remove economizer outdoor-air ®lters from the hoods by removing the ®lter retainers.

2.Clean ®lters with steam or hot water and mild detergent.

3.Reinstall ®lters in hoods after cleaning. Never replace clean- able ®lters with throwaway ®lters.

Lubrication

COMPRESSORS Ð 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 Ð 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) Ð These bearings are oil impregnated. Lubricate annually with a few drops of nondetergent SAE 20 oil.

FAN MOTOR BEARINGS Ð The condenser- and evaporator- fan motors have sealed bearings so no ®eld lubrication is required.

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

Fig. 43 Ð Inlet Guide Vane Motor

45

Page 45
Image 45
Carrier NP034-074 specifications Lubrication, Modulating Power Exhaust Damper Motor

NP034-074 specifications

The Carrier NP034-074 is an advanced rooftop unit designed for commercial heating, ventilation, and air conditioning (HVAC) applications. This unit is part of Carrier’s extensive range of rooftop units that are known for their energy efficiency, reliability, and innovative features. The NP034-074 series is particularly recognized for its robust performance in diverse environmental conditions, making it ideal for a variety of commercial building types.

One of the standout features of the NP034-074 is its high-efficiency compressor. Equipped with a scroll compressor, the unit offers enhanced performance and quieter operation compared to traditional reciprocating compressors. This design not only improves energy efficiency but also reduces operating costs over time. The unit is designed to meet or exceed the latest efficiency standards, ensuring that businesses can enjoy optimal indoor comfort while keeping energy consumption low.

The NP034-074 also integrates advanced control technologies that provide users with greater flexibility and ease of operation. The intuitive control system allows for precise temperature management and can be easily integrated with building automation systems. This enables users to monitor and adjust settings remotely, ensuring consistent and efficient climate control throughout the facility.

Another key characteristic of the NP034-074 is its robust construction. Built to withstand various weather conditions, the unit features a galvanized steel cabinet with a powder-coated finish for corrosion resistance. Its design also facilitates easy access for maintenance and service, which minimizes downtime and operational interruptions.

In terms of air distribution, the NP034-074 incorporates a powerful blower system that ensures even and effective airflow throughout the space. This design improves indoor air quality by enhancing ventilation while maintaining comfort levels. Additionally, the unit can be customized with options such as economizers and variable speed fans to optimize performance based on specific building needs.

The NP034-074 is a versatile and reliable choice for businesses looking to enhance their HVAC systems. With its combination of energy efficiency, advanced technology, and robust construction, this rooftop unit stands out as a top choice for commercial climate control solutions.