Table 34 — 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 temperature.

Compressor will not start but

Faulty wiring or loose connections in compressor

Check wiring and repair or replace.

condenser fan runs.

circuit.

 

 

Compressor motor burned out, seized, or internal

Determine cause. Replace compressor.

 

overload open.

 

 

Defective run/start capacitor, overload, start relay.

Determine cause and replace.

 

One leg of three-phase power dead.

Replace fuse or reset circuit breaker. Determine cause.

Compressor cycles (other than

Refrigerant overcharge or undercharge.

Recover refrigerant, evacuate system, and recharge to

normally satisfying thermostat).

 

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

Dirty air filter.

Replace filter.

continuously.

 

 

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 recharge.

 

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 recharge.

 

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 head 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.

Compressor makes excessive

Compressor rotating in wrong direction.

Reverse the 3-phase power leads as described in the

noise (48TF007 scroll only).

 

Start-Up section on page 36.

45

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Image 45
Carrier 48TF004-007 specifications Cooling Service Analysis
Page 44 Page 46

48TF004-007 specifications

The Carrier 48TF004-007 is part of the brand's renowned rooftop unit series, designed to deliver efficient, reliable performance for commercial applications. Ideal for spaces such as offices, retail stores, and small manufacturing facilities, these units encapsulate advanced technology to enhance indoor air quality and optimize climate control.

One of the standout features of the Carrier 48TF004-007 units is their variable speed compressor technology. This innovation not only allows for precise temperature control but also reduces energy consumption by modulating the compressor's speed according to the cooling or heating demand. By operating at lower speeds during less demanding conditions, these units significantly decrease energy usage compared to traditional single-speed compressors, contributing to lower utility bills and a reduced carbon footprint.

Energy efficiency is further enhanced with the inclusion of high-performance scroll compressors, which are known for their reliable operation and quiet performance. Coupled with an Energy Efficiency Ratio (EER) that meets or exceeds industry standards, these systems are designed to offer economical operation without sacrificing comfort.

Incorporating smart controls and connectivity features, the Carrier 48TF004-007 units allow for easy integration into building management systems (BMS). This enhances the ability to monitor and manage energy usage in real time, further promoting efficiency. The units are also compatible with various thermostat options, allowing for user-friendly operation and customization of settings.

Another significant characteristic of the Carrier 48TF004-007 is its durable construction. Built with galvanized steel and powder-coated finishes, these units are designed to withstand the rigors of outdoor installation, ensuring long-lasting performance even in harsh weather conditions. Additionally, the units come equipped with advanced filtration systems that help improve indoor air quality by effectively removing dust, allergens, and other particulate matter from the air.

Maintenance is simplified with the Carrier 48TF004-007, providing easy access to vital components, which supports reduced downtime and service costs. The units also feature low operating sound levels, making them suitable for noise-sensitive applications.

In conclusion, the Carrier 48TF004-007 rooftop units stand out for their energy efficiency, advanced technology, durability, and ease of maintenance, making them an excellent choice for any commercial space looking to enhance comfort while effectively managing operational costs.
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