48HE,HJ

Step 7 Loss-of-Charge Switch

The loss-of-charge switch contains a Schrader core depressor, and is located on the compressor liquid line. This switch opens at 7 psig and closes at 22 psig. No adjustments are necessary.

Step 8 Freeze-Stat

The freeze-stat is a bimetal temperature-sensing switch that is located on the “hair-pin” end of the evaporator coil. The switch protects the evaporator coil from freeze-up due to lack of airflow. The switch opens at 30_F and closes at 45_F. No adjustments are necessary.

Step 9 Refrigerant Charge

Amount of refrigerant charge is listed on unit nameplate (also refer to Table 1). Refer to HVAC Servicing Procedures literature available at your local distributor and the following procedures.

Unit panels must be in place when unit is operating during charging procedure. Unit must operate a minimum of 10 minutes before checking or adjusting refrigerant charge.

An accurate superheat, thermocouple-type or thermistor-type thermometer, and a gauge manifold are required when using the superheat charging method for evaluating the unit charge. Do not use mercury or small dial-type thermometers because they are not adequate for this type of measurement.

No charge

Use standard evacuating techniques. After evacuating system to 500 microns, weigh in the specified amount of refrigerant. (Refer to Table 1 or 2 and unit information plate.)

Low charge cooling

Using Cooling Charging Charts, Fig. 60-63, vary refrigerant until the conditions of the charts are met. Note the charging charts are different from type normally used. Charts are based on charging the units to the correct superheat for the various operating conditions. Accurate pressure gage and temperature sensing device are required. Connect the pressure gauge to the service port on the suction line. Mount the temperature sensing device on the suction line and insulate it so that outdoor ambient temperature does not affect the reading. Indoor-air cfm must be within the normal operating range of the unit.

HUMIDI-MIZERSYSTEM CHARGING

The system charge for units with the Humidi-MiZer adaptive dehumidification system is greater than that of the standard unit alone. The charge for units with this option is indicated on the unit nameplate drawing. Also refer to Fig. 64-67. To charge systems using the Humidi-MiZer adaptive dehumidification system, fully evacuate, recover, and recharge the system to the nameplate specified charge level. To check or adjust refrigerant charge on systems using the Humidi-MiZer adaptive dehumidification system, charge per Fig. 64-67.

C06139

Fig. 60 ---Cooling Charging Chart,

Standard 48HJ004

C06140

Fig. 61 ---Cooling Charging Chart,

Standard 48HJ005

52

Page 52
Image 52
Carrier 48HE003---006, 48HJ004---007 installation instructions HUMIDI-MIZERSYSTEM Charging

48HJ004---007, 48HE003---006 specifications

Carrier has long been a trusted name in the HVAC industry, and its models 48HJ004---007 and 48HE003---006 continue that legacy, offering efficient, reliable climate control solutions. These models are designed for different applications, ensuring optimal performance in a variety of environments.

The 48HJ series features advanced rooftop units that are ideal for commercial settings. They come equipped with high-efficiency scroll compressors that provide superior cooling and heating capabilities. This series is noted for its compact design, allowing for easy installation on rooftops or other constrained spaces. The units offer variable capacity operation, which enables them to efficiently meet varying heating and cooling demands without unnecessary energy consumption.

One of the standout features of the 48HJ series is its use of advanced microprocessor controls. This technology allows for precise temperature management and system diagnostics, enhancing the ease of operation while ensuring maximum comfort. Additionally, the series supports advanced connectivity options, enabling integration with building management systems. This allows for remote monitoring and control, making it easier for facility managers to keep track of performance and energy usage.

On the other hand, the 48HE series specializes in high-efficiency heating and cooling performance. These units are designed for larger commercial spaces and come with robust features for enhanced durability and efficiency. Like the 48HJ series, the 48HE models utilize scroll compressors and are equipped with a high-efficiency fan setup for improved airflow and reduced noise levels.

The 48HE also includes an innovative heat pump option, which allows the system to reverse the cooling process to provide heating, making it versatile across different seasonal demands. Both series are designed with eco-friendly refrigerants that comply with the latest environmental regulations, ensuring a minimized ecological footprint.

In terms of energy efficiency, both the 48HJ and 48HE series hold impressive SEER and EER ratings, contributing to reduced operational costs over time. The units are also built with durable, corrosion-resistant materials, ensuring longevity and low maintenance needs.

In conclusion, Carrier 48HJ004---007 and 48HE003---006 models are designed with cutting-edge technology, energy efficiency, and flexibility in mind. Their robust features make them ideal choices for commercial applications, providing reliable comfort and operational excellence. Whether for cooling or heating, these systems stand out in performance and sustainability, earning Carrier's reputation as a leader in the HVAC market.