Thermostat Designations

See unit wiring diagram for power supply connections.

If the indoor unit is not equipped with a blower relay, one must be field supplied and installed.

Do not connect C (common) connection between indoor unit and thermostat except when required by the indoor thermostat. Refer to thermostat installation instructions. C (common) connection between indoor unit and outdoor unit required for proper operation.

Figure 4

1.Install line voltage power supply to unit from a properly sized disconnect switch. Any excess high voltage field wiring should be trimmed or secured away from the low voltage field wiring.

2.Ground unit at unit disconnect switch or to an earth ground. To facilitate conduit, a hole is in the bottom of the control box. Connect conduit to the control box using a proper conduit fitting. Units are approved for use only with copper conductors. 24V Class II circuit connections are made in the low voltage junction box. Refer to Figure 4 for high voltage field wiring diagram. A complete unit wiring diagram is located inside the unit control box cover.

3.Install room thermostat on an inside wall that is not subject to drafts, direct sunshine, or other heat sources.

4.Install low voltage wiring from outdoor to indoor unit and from thermostat to indoor unit (See Figure 5).

5.Do not bundle any excess 24V control wire inside control box. Run control wire through installed wire tie and tighten wire tie to provide low voltage strain relief and to maintain seperation of field-installed low and high voltage circuits.

Refrigerant Piping

If the 4AC18LT unit is being installed with a new indoor coil and line set, the refrigerant connections should be made as outlined in this section. If an existing line set and/or indoor coil will be used to complete the system, refer to this section as well as the section that follows entitled - Flushing Existing Line Set and Indoor Coil.

If this unit is being matched with an approved line set or indoor coil which was previously charged with R-22 refrigerant, the line set and coil must be flushed prior to installation. If the unit is being used with and existing indoor coil which was equipped with a liquid line which served as a metering device (RFCI), the liquid line must be replaced prior to the installation of the 4AC18LT unit.

Field refrigerant piping consists of liquid and suction lines from the outdoor unit (sweat connections) to the indoor coil (flare or sweat connections).

Select line set diameters from Table 2 to ensure that oil returns to the compressor. Size vertical suction riser to maintain minimum velocity at minimum capacity. Recommended line length is 50’ or less. If more than 50’ line set is required, contact Technical Services. Table 2 shows the diameters for line sets up to 100’ although vertical lift applications and trapping requirements need to be reviewed with Technical Services for line sets over 50’.

Installing Refrigerant Line

During the installation of an air conditioning system, it is important to properly isolate the refrigerant line to prevent unnecessary vibration. Line set contact with the structure (wall, ceiling, or floor) may cause objectionable noise when vibration is translated into sound. As a result, more energy or vibration can be expected. Close attention to line set isolation must be observed.

Following are some points to consider when placing and installing a high-efficiency outdoor unit:

506469-01

Issue 1008

Page 4 of 24

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.