Operation

Outdoor unit and indoor blower cycle on demand from the room thermostat. When the thermostat blower switch is moved to the ON position, the indoor blower operates continuously.

System Diagnostic Module

4AC18LT units contain a diagnostic module for troubleshooting air conditioning system failures. By monitoring and analyzing data from the compressor and thermostat demand, the module can accurately detect the cause of electrical and system related failure without any sensors. If a system problem occurs, a flashing LED indicator communicates the failure code.

LED Description

POWER LED (Green) indicates voltage is present at the power connection of the module.

ALERT LET (Yellow) communicates an abnormal system condition through a unique flash code. The ALERT LED will flash a number of times consecutively, pause, and then repeat the process. The number of consecutive flashes correlates to a particular abnormal condition.

TRIP LED (Red) indicates there is a demand signal from the thermostat but no current to the compressor is detected by the module. The TRIP LED typically indicates the compressor protector is open or may indicate missing supply power to the compressor.

Interpreting the Diagnostic LEDs

When an abnormal system condition occurs, the diagnostic module displays the appropriate ALERT and/or TRIP LED. The yellow ALERT LED will flash a number of times consecutively, pause, and then repeat the process. To identify a flash code number, count the number of consecutive flashes. Refer to Table 9 on page 18 and Table 10 on page 19 for information on the flash codes.

Every time the module powers up, the last ALERT LED flash code that occurred prior to shutdown is displayed for 60 seconds. The module will continue to display the previous flash code until the condition returns to normal or 24 VAC is removed from the module. TRIP and ALERT LEDs flashing at the same time means control circuit voltage is too low for operation.

24 VAC Power Wiring

The diagnoctic module requires a constant nominal 24VAC power supply. The wiring to the module’s R and C terminals must be directly from the indoor unit or thermostat.

Thermostat Demand Wiring

The diagnostic module requires a thermostat demand signal to operate properly. The thermostat demand signal input, labeled Y on the module, should always be connected to the compressor contactor coil so that when the coil is energized, the demand signal input is 24VAC. When the Coil is not energized, the demand signal input should be less than 0.5VAC.

Miswired Module Codes

Depending on the system configuration, some ALERT flash codes may not be active. The presence of safety switches affects how the system alerts are displayed by the module.

Miswiring the diagnostic module will cause false LED codes. Table 11 on page 19 describes LED opeation when the module is miswired and what troubleshooting action is required to correct the problem.

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4AC18LT specifications

Allied Air Enterprises has made significant strides in the HVAC industry with the introduction of its 4AC18LT air conditioner. This model is part of a premium line of products that emphasizes efficiency, reliability, and advanced cooling technology. The 4AC18LT is specifically designed to meet the diverse needs of both residential and light commercial applications, making it a versatile choice for many consumers.

One of the standout features of the 4AC18LT is its impressive Seasonal Energy Efficiency Ratio (SEER) rating. With a SEER rating of up to 18, this unit is engineered to provide excellent energy efficiency, significantly reducing electricity consumption while delivering consistent cooling performance. As energy costs continue to rise, homeowners and businesses can benefit greatly from this efficiency, leading to lower monthly utility bills and a reduced carbon footprint.

The 4AC18LT employs advanced R-410A refrigerant, which is known for its environmentally friendly properties. Unlike older refrigerants that contribute to ozone depletion, R-410A is more stable and offers better heat transfer capabilities, which enhances the overall performance of the unit. This focus on eco-friendliness aligns with contemporary environmental standards and regulations, ensuring that users are making a responsible choice for their cooling needs.

In terms of design, the 4AC18LT features a robust and compact frame that is built to withstand the rigors of outdoor installation. The unit's durability is further enhanced by its corrosion-resistant finish, which protects the coil and cabinet from harsh weather conditions, extending the life span of the system.

Noise reduction technology is another highlight of the 4AC18LT. This model is designed with a quieter operation in mind, utilizing a sound blanket and insulated compressor compartment. These features work together to minimize noise levels, allowing users to enjoy a comfortable indoor environment without disruptive sound.

The 4AC18LT also supports advanced controls and compatibility with smart thermostats, providing users with greater flexibility and convenience. Homeowners can take advantage of programmable features, enabling them to optimize cooling schedules for energy savings and increased comfort.

Overall, Allied Air Enterprises’ 4AC18LT air conditioner combines efficiency, environmental responsibility, durability, and user-friendly features, making it an excellent choice for those in need of reliable cooling solutions. Whether installed in a residential or light commercial setting, the 4AC18LT promises to deliver exceptional performance and peace of mind.