48HE,HJ

Table 45—Cooling Service Analysis

PROBLEM

CAUSE

REMEDY

Compressor and Condenser Fan

Power failure.

Call power company.

Will Not Start.

 

 

Fuse blown or circuit breaker tripped.

Replace fuse or reset circuit breaker.

 

Defective thermostat, contactor, transformer, or

Replace component.

 

control relay.

 

 

Insufficient line voltage.

Determine cause and correct.

 

Incorrect or faulty wiring.

Check wiring diagram and rewire correctly.

 

Thermostat setting too high.

Lower thermostat setting below room tempera-

 

 

ture.

Compressor Will Not Start

Faulty wiring or loose connections in compres-

Check wiring and repair or replace.

But Condenser Fan Runs.

sor circuit.

 

 

Compressor motor burned out, seized, or in-

Determine cause. Replace compressor.

 

ternal overload open.

 

 

Defective run/start capacitor, overload, start

Determine cause and replace.

 

relay.

 

 

One leg of 3-phase power dead.

Replace fuse or reset circuit breaker. Determine

 

 

cause.

Compressor Cycles (Other Than

Refrigerant overcharge or undercharge.

Recover refrigerant, evacuate system, and re-

Normally Satisfying Thermostat).

 

charge to nameplate.

 

Defective compressor.

Replace and determine cause.

 

Insufficient line voltage.

Determine cause and correct.

 

Blocked condenser.

Determine cause and correct.

 

Defective run/start capacitor, overload, or start

Determine cause and replace.

 

relay.

 

 

Defective thermostat.

Replace thermostat.

 

Faulty condenser-fan motor or capacitor.

Replace.

 

Restriction in refrigerant system.

Locate restriction and remove.

Compressor Operates Continuously.

Dirty air filter.

Replace filter.

 

Unit undersized for load.

Decrease load or increase unit size.

 

Thermostat set too low.

Reset thermostat.

 

Low refrigerant charge.

Locate leak, repair, and recharge.

 

Leaking valves in compressor.

Replace compressor.

 

Air in system.

Recover refrigerant, evacuate system, and re-

 

 

charge.

 

Condenser coil dirty or restricted.

Clean coil or remove restriction.

Excessive Head Pressure.

Dirty air filter.

Replace filter.

 

Dirty condenser coil.

Clean coil.

 

Refrigerant overcharged.

Recover excess refrigerant.

 

Air in system.

Recover refrigerant, evacuate system, and re-

 

 

charge.

 

Condenser air restricted or air short-cycling.

Determine cause and correct.

Head Pressure Too Low.

Low refrigerant charge.

Check for leaks, repair, and recharge.

 

Compressor valves leaking.

Replace compressor.

 

Restriction in liquid tube.

Remove restriction.

Excessive Suction Pressure.

High heat load.

Check for source and eliminate.

 

Compressor valves leaking.

Replace compressor.

 

Refrigerant overcharged.

Recover excess refrigerant.

Suction Pressure Too Low.

Dirty air filter.

Replace filter.

 

Low refrigerant charge.

Check for leaks, repair, and recharge.

 

Metering device or low side restricted.

Remove source of restriction.

 

Insufficient evaporator airflow.

Increase air quantity. Check filter and replace if

 

 

necessary.

 

Temperature too low in conditioned area.

Reset thermostat.

 

Outdoor ambient below 25 F.

Install low-ambient kit.

Evaporator Fan Will Not Shut Off.

Time off delay not finished.

Wait for 30-second off delay.

62

Page 61 Page 63
Page 62
Image 62
Carrier 48HE003---006, 48HJ004---007 installation instructions Cooling Service Analysis
Page 61 Page 63

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.
Top Page Image Contents