48HC

Field Connections . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Space Temperature (SPT) Sensors . . . . . . . . . . . . 40 Indoor Air Quality (CO2) Sensor . . . . . . . . . . . . . 40 Outdoor Air Quality Sensor . . . . . . . . . . . . . . . . . 41 Space Relative Humidity Sensor or Humidistat . . 41 Smoke Detector/Fire Shutdown (FSD) . . . . . . . . . 42 Connecting Discrete Inputs . . . . . . . . . . . . . . . . . . 42

Communication Wiring - Protocols . . . . . . . . . . . . 43 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Local Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 RTU Open Troubleshooting . . . . . . . . . . . . . . . . . 44 Outdoor Air Enthalpy Control . . . . . . . . . . . . . . . . . 45 Differential Enthalpy Control . . . . . . . . . . . . . . . . 45 Smoke Detectors . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Return Air Sensor Tube Installation . . . . . . . . . . . 46 Smoke Detector Test Magnet . . . . . . . . . . . . . . . . 47 Additional Application Data . . . . . . . . . . . . . . . . . 47 Step 13 - Adjust Factory-Installed Options . . . . . . . . 50 Step 14 - Install Accessories . . . . . . . . . . . . . . . . . . . 50

SAFETY CONSIDERATIONS

Improper installation, adjustment, alteration, service, maintenance, or use can cause explosion, fire, electrical shock or other conditions which may cause personal injury or property damage. Consult a qualified installer, service agency, or your distributor or branch for information or assistance. The qualified installer or agency must use factory-authorized kits or accessories when modifying this product. Refer to the individual instructions packaged with the kits or accessories when installing.

Follow all safety codes. Wear safety glasses and work gloves. Use quenching cloths for brazing operations and have a fire extinguisher available. Read these instructions thoroughly and follow all warnings or cautions attached to the unit. Consult local building codes and appropriate national electrical codes (in USA, ANSI/NFPA70, National Electrical Code (NEC); in Canada, CSA C22.1) for special requirements.

It is important to recognize safety information. This is the

safety-alert symbol . When you see this symbol on the unit and in instructions or manuals, be alert to the potential for personal injury.

Understand the signal words DANGER, WARNING, CAUTION, and NOTE. These words are used with the safety-alert symbol. DANGER identifies the most serious hazards which will result in severe personal injury or death. WARNING signifies hazards which could result in personal injury or death. CAUTION is used to identify unsafe practices, which may result in minor personal injury or product and property damage. NOTE is used to highlight suggestions which will result in enhanced installation, reliability, or operation.

!WARNING

FIRE, EXPLOSION HAZARD

Failure to follow this warning could result in personal injury or death.

Disconnect gas piping from unit when leak testing at pressure greater than 0.5 psig (3450 Pa). Pressures greater than 0.5 psig (3450 Pa) will cause gas valve damage resulting in hazardous condition. If gas valve is subjected to pressure greater than 0.5 psig (3450 Pa), it must be replaced before use. When pressure testing field-supplied gas piping at pressures of 0.5 psig (3450 Pa) or less, a unit connected to such piping must be isolated by closing the manual gas valve.

!WARNING

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could cause personal injury or death.

Before performing service or maintenance operations on unit, always turn off main power switch to unit and install lock(s) and lockout tag(s). Unit may have more than one power switch.

!WARNING

UNIT OPERATION AND SAFETY HAZARD

Failure to follow this warning could cause personal injury, death and/or equipment damage.

Puronr (R-410A) refrigerant systems operate at higher pressures than standard R-22 systems. Do not use R-22 service equipment or components on Puron refrigerant equipment.

!WARNING

PERSONAL INJURY AND ENVIRONMENTAL HAZARD

Failure to follow this warning could cause personal injury or death.

Relieve pressure and recover all refrigerant before system repair or final unit disposal.

Ware safety glasses and gloves when handling refrigerants. Keep torches and other ignition sources away from refrigerants and oils.

!CAUTION

CUT HAZARD

Failure to follow this caution may result in personal injury.

Sheet metal parts may have sharp edges or burrs. Use care and wear appropriate protective clothing, safety glasses and gloves when handling parts and servicing air conditioning equipment.

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Carrier 48HC installation instructions Safety Considerations

48HC specifications

The Carrier 48HC is a highly efficient rooftop HVAC unit designed for commercial applications that prioritize both performance and energy savings. This unit embodies Carrier's commitment to innovation by integrating advanced technologies and features that address the modern demands of building climate control.

One of the standout features of the Carrier 48HC is its exceptional energy efficiency. Employing the latest in variable-speed compressor technology, the unit adjusts its output based on the specific cooling needs of the space, which not only enhances comfort levels but also significantly reduces energy consumption. This feature is crucial for businesses looking to lower their operational costs while minimizing their environmental impact.

The Carrier 48HC is also equipped with a comprehensive range of control options. Through its intelligent control systems, users can utilize features such as demand ventilation, which optimizes indoor air quality while maintaining energy efficiency. The integration with building management systems (BMS) further enhances operational effectiveness, allowing real-time monitoring and adjustments from a centralized point.

Additionally, the 48HC is designed with durability in mind. Its robust construction resists harsh weather conditions and ensures long-lasting performance. The unit features advanced corrosion-resistant materials and coatings, which prolong its lifespan and reduce maintenance needs. This durability makes the 48HC a reliable choice for varying environments, whether it’s an industrial setting or a more delicate commercial space.

The unit’s compact design also deserves mention, as it facilitates easier installation on rooftops without taking up excessive space. The modular design allows for customization, enabling businesses to tailor their systems to fit specific heating and cooling requirements.

In terms of comfort, the Carrier 48HC employs efficient air distribution technology that ensures even airflow throughout the space. This greatly enhances occupant comfort by eliminating hot or cold spots, promoting a consistent indoor climate.

Finally, the 48HC complies with stringent environmental regulations and standards. With options for environmentally-friendly refrigerants, it supports businesses in their sustainability efforts while operating effectively under current regulations.

In summary, the Carrier 48HC stands out in the crowded HVAC market due to its advanced technology, energy efficiency, durability, and adaptability for commercial applications, making it a top choice for those looking to invest in a reliable and effective climate control solution.