PRE-START-UP

!WARNING

FIRE, EXPLOSION, ELECTRICAL SHOCK HAZARD

Failure to follow this warning could result in personal injury, death and/or property damage:

1.Follow recognized safety practices and wear protective goggles when checking or servicing a refrigerant system.

2.Do not operate the compressor or provide any electric power to the unit unless the compressor terminal cover is in place and secured.

3.Do not remove the compressor terminal cover until all electrical sources are disconnected and tagged with lockout tags.

4.Relieve all pressure from the system before touching or disturbing anything inside the terminal box if a refrigerant leak is suspected around the compressor terminals. Use accepted methods to recover the refrigerant.

5.Never attempt to repair a soldered connection while the refrigerant system is under pressure.

6.Do not use a torch to remove any component. The system contains oil and refrigerant under pressure. To remove a component, wear protective goggles and proceed as follows:

a.Shut off electrical power to the unit and tag disconnect.

b.Recover refrigerant to relieve all pressure

from the system using both high-pressure and low-pressure ports.

c. Cut component connection tubing with a tubing cutter, and remove the component from the unit.

d. Carefully unsweat the remaining tubing stubs when necessary. Oil can ignite when exposed to a torch flame.

Proceed as follows to inspect and prepare the unit for initial start-up:

1.Remove all access panels.

2.Read and follow instructions on all WARNING, CAUTION, and INFORMATION labels attached to, or shipped with, unit.

3.Make the following inspections:

a.Inspect for shipping and handling damages such as broken lines, loose parts, or disconnected wires, etc.

b.Inspect for oil at all refrigerant tubing connections and on unit base. Detecting oil generally indicates a refrigerant leak. Leak-test all refrigerant tubing connections using electronic leak detector, halide torch, or liquid-soap solution.

c.Inspect all field-wiring and factory-wiring connections. Be sure that connections are completed and tight. Be sure that wires are not in contact with refrigerant tubing or sharp edges.

d.Inspect coil fins. If damaged during shipping and handling, carefully straighten fins with a fin comb.

4.Verify the following conditions:

a.Make sure that condenser-fan blade are correctly positioned in fan orifice. See Condenser-Fan Adjustment section for more details.

b.Make sure that air filter(s) is in place.

c.Make sure that condensate drain trap is filled with water to ensure proper drainage.

d. Make sure that all tools and miscellaneous loose parts have been removed.

START-UP

Step 1 Unit Preparation

Make sure that the unit has been installed in accordance with installation instructions and applicable codes.

Step 2 Gas Piping

Check gas piping for leaks.

!WARNING

ELECTRICAL SHOCK HAZARD

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

Disconnect gas piping from unit when leak testing at pressure greater than 1/2 psig. Pressures greater than 1/2 psig will cause gas valve damage resulting in hazardous condition. If gas valve is subjected to pressure greater than 1/2 psig, it must be replaced before use. When pressure testing field- supplied gas piping at pressures of 1/2 psig or less, a unit connected to such piping must be isolated by manually closing the gas valve.

Step 3 Return-Air Filters

Make sure the correct filters are installed in the unit (See Table 1 or 2). Do not operate the unit without return-air filters.

Step 4 Outdoor-Air Inlet Screens

Outdoor-air inlet screen(s) must be in place before operating the unit.

Step 5 Compressor Mounting

Compressors are internally spring mounted. Do not loosen or remove the compressor holddown bolts.

Step 6 Internal Wiring

Check all electrical connections in unit control boxes; tighten them as required.

Step 7 Refrigerant Service Ports

Each unit system has 4 Schrader-type service ports: one on the suction line, one on the liquid line, and 2 on the compressor discharge line. Be sure that caps on the ports are tight. Two additional Schrader valves are located under the high-pressure and low-pressure switches, respectively.

Step 8 High Flow Refrigerant Valves

Two high flow valves are located on the hot gas tube coming out of the compressor and the suction tube going into the compressor. Large black plastic caps identify these valves. These valves have O-rings inside which screw the cap onto a brass body to prevent leaks. No field access to these valves is available at this time. Ensure the plastic caps remain on the valves and are tight or the possibility of refrigerant leakage could occur.

Step 9 Compressor Rotation

On 3-phase units be certain that the compressor is rotating in the proper direction. To determine whether or not compressor is rotating in the proper direction:

1.Connect the service gauges to suction and discharge pressure fittings.

2.Energize the compressor.

3.The suction pressure should drop and the discharge pressure should rise, as is normal on any start-up.

If the suction pressure does not drop and the discharge pressure does not rise to normal levels:

1.Note that the indoor fan (006 and 007 three-phase units only) is probably also rotating in the wrong direction.

48HE,HJ

45

Page 45
Image 45
Carrier 48HJ004---007 Unit Preparation, Gas Piping, Return-Air Filters, Outdoor-Air Inlet Screens, Compressor Mounting

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.