Carrier 48SD/48SDN Single-Packaged Gas Heating/Electric Cooling Units
Product Overview
The Carrier 48SD/48SDN series offers single-packaged gas heating and electric cooling units designed for residential and light commercial applications. These units provide a compact, fully self-contained solution for heating and cooling needs, featuring energy-saving technologies, ease of installation, and dependable performance.
Available in nominal cooling capacities ranging from 2 to 5 tons, and nominal heating input from 40,000 to 130,000 Btuh, these units are engineered for efficiency and quiet operation.
Key Features and Benefits
- Energy-Saving Design: Features direct spark ignition for gas heating and high-efficiency components.
- High Efficiency Ratings: Achieves up to 81% AFUE for heating and 13.0 SEER for cooling.
- Low Sound Levels: Engineered for quiet operation, with sound ratings as low as 72dB.
- Easy Installation: Factory-assembled, pre-wired, and pre-piped units simplify installation. Lightweight design and composite basepan enhance installation flexibility.
- Convertible Duct Configuration: Designed for easy conversion between downflow and horizontal duct applications.
- Durable Components: Features hermetically sealed compressors with vibration isolation, turbo-tubular™ heat exchangers, and heavy-duty cabinets built to withstand 500 hours of salt spray.
- Advanced Controls: Integrated Gas Control (IGC) board for efficient heating control and troubleshooting, with optional Time Guard® II anti-short cycle protection.
- Low NOx Models: 48SDN models are available to meet California's Low NOx emission requirements.
Specifications Summary
The 48SD/48SDN units offer a range of capacities and performance metrics:
| Model Series | Nominal Cooling Capacity | Nominal Heating Input | SEER | AFUE | Sound Level (dB) |
|---|---|---|---|---|---|
| 48SD/48SDN | 2 to 5 Tons | 40,000 to 130,000 Btuh | Up to 13.0 | Up to 81% | As low as 72 |
Detailed cooling and heating capacities, along with sound data, are available in the performance tables within the full documentation.
Installation and Application
Units are designed for rooftop or ground-level installation and offer convertible duct configurations. Key considerations for installation include:
- Ductwork: Secure downflow discharge ductwork to roof curb; attach ductwork with flanges for horizontal discharge.
- Condensate Management: A 2-inch condensate trap is required.
- Ambient Operation: Standard units operate down to 40°F ambient cooling. An optional low-ambient kit allows operation down to 0°F.
- High Altitude: Orifice kits are available for proper gas heat operation at altitudes from 2001 to 6000 ft.
The document includes diagrams illustrating typical piping and wiring for vertical and horizontal discharge configurations, as well as base unit dimensions and roof curb dimensions.
Electrical Data Summary
Units are available for various voltage configurations, including 208/230V (1-phase and 3-phase) and 460V (3-phase). Key electrical specifications include:
| Unit Size (48SD) | Voltage (V-PH-Hz) | RLA (A) | LRA (A) | Outdoor Fan FLA (A) | Indoor Fan FLA (A) | MCA (A) | Fuse/HACR BKR (A) |
|---|---|---|---|---|---|---|---|
| 024 | 208/230-1-60 | 10.9 | 54.0 | 0.9 | 2.0 | 16.5 | 20 |
| 030 | 208/230-1-60 | 14.0 | 72.5 | 0.9 | 2.0 | 20.4 | 25 |
| 036 | 208/230-1-60 | 16.0 | 88.0 | 0.9 | 3.1 | 24.0 | 30 |
| 042 | 208/230-1-60 | 18.4 | 104.0 | 0.9 | 4.1 | 28.0 | 35 |
| 048 | 208/230-1-60 | 18.3 | 109.0 | 1.5 | 4.1 | 28.5 | 35 |
| 060 | 208/230-1-60 | 25.0 | 148.0 | 1.5 | 6.2 | 39.0 | 50 |
Note: RLA (Rated Load Amps), LRA (Locked Rotor Amps), FLA (Full Load Amps), MCA (Minimum Circuit Amps), and Fuse/HACR Breaker ratings are provided for various models and voltage configurations. Refer to the full document for complete electrical data and notes on NEC compliance.
Controls and Operation
The units feature an operating sequence for both heating and cooling modes. In heating, the induced draft motor starts, followed by burner ignition and then the indoor fan motor. In cooling, the thermostat call energizes the compressor and outdoor fan motor simultaneously, followed by the indoor fan motor. The system includes safety features like compressor overload protection and optional Time Guard® II for short-cycle prevention.
Options and Accessories
Various factory-installed options and field-installed accessories are available to enhance unit functionality, including:
- Louvered Grilles
- Copper/Copper and Vinyl-Coated Coil Options
- Economizers
- Filter Racks
- Flat Roof Curbs
- Manual Outdoor Air Dampers
- Thermostats (programmable and non-programmable)
- Conversion Kits (Natural-to-Propane)
- Low Ambient Kits
- High Altitude Kits
Diagram Descriptions
The document includes several diagrams:
- Unit Illustration: A visual representation of the single-packaged rooftop unit.
- Economizer, Filter Rack, Manual Outdoor Air Damper: Diagrams showing the components and installation of these accessories.
- Base Unit Dimensions: Orthographic views (Rear, Top, Side, Front) with detailed measurements for different unit sizes, crucial for installation planning and clearances.
- Roof Curb Dimensions: Diagrams illustrating roof curb configurations for small and large cabinets, with specific measurements for installation.
- Corner Weights: A diagram indicating the weight distribution at the four corners of the unit, important for structural considerations.
- Piping and Wiring Diagrams: Schematics illustrating typical field connections for vertical and horizontal discharge units, including connections to indoor thermostats and power sources.
- Wiring Schematic: A detailed electrical schematic showing the internal component connections for a typical 208/230-1-60 unit.
Guide Specifications
The Guide Specifications section details the product requirements, including system description, quality assurance standards (ARI, UL, ISO 9001), unit cabinet construction, fan types, compressor details, coil specifications, heating section features (induced-draft, direct spark ignition), refrigerant components, filters, controls, safeties, and operating characteristics. It also outlines electrical requirements and motor specifications.
