48DJ,DK,NP034-074 50DJ,DK,DW,DY,NB,NP034-074 Single Package Heating and Cooling Units

Installation, Start-Up and

Service Instructions

CONTENTS

Page

GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . 2

INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-37

Rigging and Unit Placement . . . . . . . . . . . . . . . . . . 2

Roof Curb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Roof Mount . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Slab Mount . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Positioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Field-Fabricated Ductwork . . . . . . . . . . . . . . . . . . . . 6

Condensate Drains . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Install Outdoor Hoods . . . . . . . . . . . . . . . . . . . . . . . 10

·UNIT SIZES 034 AND 044

·UNIT SIZES 054-074

Outdoor-Air Inlet Adjustments . . . . . . . . . . . . . . . 10

·MANUAL OUTDOOR-AIR DAMPER

·ECONOMIZER SETTINGS

Field Wire Routing . . . . . . . . . . . . . . . . . . . . . . . . . . 17

·UNIT SIZES 034 AND 044

·UNIT SIZES 054-074

Field Electrical Connections . . . . . . . . . . . . . . . . . 17

·POWER WIRING

·CONTROL WIRING

Gas Piping (48 Series Units Only) . . . . . . . . . . . . 36

Installing Flue/Inlet Hoods (48 Series Units

Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

·UNIT SIZES 034 AND 044

·UNIT SIZES 054-074

PRE-START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38-41

Unit Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Compressor Mounting . . . . . . . . . . . . . . . . . . . . . . . 38

Evaporator-Fan Shipping Brackets . . . . . . . . . . . 38

·UNIT SIZES 034 AND 044

·UNIT SIZES 054-074

Internal Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Refrigerant Service Valves . . . . . . . . . . . . . . . . . . . 38

Crankcase Heaters . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Compressor Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Gas Manifold Pressure (48 Series

Units Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Unit Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Leak Test and Dehydration . . . . . . . . . . . . . . . . . . 39

Evaporator-Fan Belts, Pulleys, and Sheaves . . 39

Condenser Fans and Motors . . . . . . . . . . . . . . . . . 40

Return-Air Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Economizer Inlet Screens . . . . . . . . . . . . . . . . . . . 40

Economizer Dampers . . . . . . . . . . . . . . . . . . . . . . . 40

25% Outdoor-Air Damper . . . . . . . . . . . . . . . . . . . . 40

Initial Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41,42

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Operating Sequences . . . . . . . . . . . . . . . . . . . . . . . 41

·COOLING, UNITS WITHOUT ECONOMIZER

·HEATING, UNITS WITHOUT ECONOMIZER

Page

·COOLING, UNITS WITH ECONOMIZER

·HEATING, UNITS WITH ECONOMIZER

·VENTILATION AIR CIRCULATION (Continuous Fan)

·AUTOMATIC CHANGEOVER USING AUTOMATIC CHANGEOVER THERMOSTAT

Head Pressure Control . . . . . . . . . . . . . . . . . . . . . . 42

SERVICE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42-53

Service Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

·COMPRESSORS

·LIQUID SERVICE VALVES, FILTER DRIERS, AND SIGHT GLASSES

·EVAPORATOR-FAN MOTORS, PULLEYS, AND BELTS

·POWER EXHAUST MOTORS, PULLEYS, AND BELTS

·UNIT CONTROL BOX

·GAS HEAT SECTION (48 Series Units Only)

·MAIN AND PILOT BURNERS (48 Series Units Only)

·FLUE GAS PASSAGEWAYS (48 Series Units Only)

·COMBUSTION AIR BLOWER (48 Series Units Only)

·ECONOMIZER DAMPER MOTOR

·ELECTRIC HEATER CONTROL BOX (50 Series Units Only)

·HEATER BOX (50 Series Units Only)

·25% OUTDOOR-AIR DAMPER

·MODULATING POWER EXHAUST DAMPER MOTOR

·RETURN-AIR FILTERS

·CONDENSER FANS AND FAN MOTORS

·INLET GUIDE VANE MOTOR

Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

·COMPRESSORS

·FAN SHAFT BEARINGS

·INLET GUIDE VANE BEARINGS (Units With Optional Inlet Guide Vanes)

·FAN MOTOR BEARINGS

·DOOR HINGES

Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

·EVAPORATOR FAN AND POWER EXHAUST MOTOR PLATE

·MODULATING POWER EXHAUST DIFFERENTIAL PRESSURE SWITCH

·INLET GUIDE VANE DIFFERENTIAL PRESSURE SWITCH (Units With Optional Inlet Guide Vanes and Static Pressure Control)

·BELT INSTALLATION AND TENSIONING

·PULLEY ALIGNMENT

·INSTALLING ALTERNATE MOTOR PULLEY (Evaporator Fan Only)

·CONDENSER FAN ADJUSTMENT

·25% OUTDOOR-AIR DAMPER

·REFRIGERANT CHARGE

·PILOT LIGHT OFF (48 Series Units Only)

Manufacturer reserves the right to discontinue, or change at any time, speci®cations or designs without notice and without incurring obligations.

Book

1

1

 

PC 111

Catalog No. 564-818

Printed in U.S.A.

Form 48/50D,N-9SI

Pg 1

3-96

Replaces: 48DJ,DK-3SI;

Tab

1a

1b

 

 

 

 

 

 

48/50NB,NP-1SI; 50DJ,DK-9SI

 

 

 

 

 

 

 

 

 

 

 

Page 1 Page 2
Page 1
Image 1
Carrier NP034-074 specifications Installation, Start-Up Service Instructions
Page 1 Page 2

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.
Top Page Image Contents