HOOD SIDE (SLOTTED)

HOOD

TOP

Fig. 28 Ð Adding Foam Strip to Hood Side

BLOCKOFF BAFFLE

GRAY FOAM STRIP

Fig. 29 Ð Adding Foam Strip to Blockoff Baffle

MOUNTING ANGLE (WITHOUT TABS)

FILTER TRACK

ASSEMBLY

Fig. 30 Ð Mounting Angle (Without Tabs) Attached

to Filter Track Assembly

The outdoor-air damper closes. The control allows 90 sec- onds for the damper to close in case it is in the full open position. Next, the indoor-fan contactor will energize. The outdoor-air damper will remain at 0% for 30 seconds. It will then move to the 10% position for another 30 seconds. This will be repeated at every 10% increment for 30 seconds until the damper reaches 100% open. Close DIP switch no. 4 dur- ing the 30 seconds immediately after the desired outdoor air minimum damper position. The 30-second time period is to allow time where DIP switch no. 4 can be closed. The de- fault value of the minimum outdoor air damper position is 20%. If the desired minimum position is 30%, allows the damper position to go to 10% for 30 seconds, then 20% for 30 seconds, and when it reaches 30% close DIP switch no. 4 during the 30-second period following the 30% position.

The minimum outdoor air damper position is now set. Close DIP switch no. 6.

ECONOMIZER SETTINGS

Accessory Enthalpy Control (Fig. 33) Ð The control (HH57AC077) is mounted in the economizer hood. See Fig. 24. The enthalpy setting adjustment is on the enthalpy control. For maximum bene®t of outdoor air, set enthalpy control to A. See Fig. 34 and 35.

Enthalpy Control Installation Ð The outdoor air enthalpy con- trol is installed on the inside panel of the outdoor air hood. The enthalpy control should be mounted when the outdoor air hoods are assembled. To install the control, perform the following procedure:

1.Turn off all power. Ensure disconnect is locked out.

2.Remove the economizer inlet ®lters from the bottom of the right hand economizer hood. See Fig. 24. See Fig. 36 for economizer details.

3.Mount the outdoor air enthalpy sensor inside the right econo- mizer hood on the right side panel of the hood, adjacent to the outdoor-air thermistor.

4.Locate the red, violet, and brown wires near the outdoor air thermistor. Remove the splice from the red and violet wires. Remove the cap from the brown wire.

5.Install a 1¤4-in. push on terminal (®eld-supplied) on the violet and brown wires.

6.Connect a 1¤4-in. push on terminal (®eld provided) to one end of a 18-gage, 6-in. jumper wire (®eld-provided). Con- nect the other end to the red wire and attach a 1¤4-in. push on connector (®eld provided).

7.Connect the red wire with the jumper to terminal TR1. Connect the jumper to terminal 2. Connect the brown wire to terminal TR. Connect the violet wire to terminal 3. All connections are on the enthalpy control.

8.Replace the economizer ®lters.

9.Return power to unit.

Accessory Differential Enthalpy Control (Fig. 33) Ð The control (HH57AC077), in conjunction with the accessory en- thalpy sensor (HH57AC078), controls economizer opera- tion according to the differential enthalpy. The control is mounted in the economizer hood. The sensor is mounted in the return duct (48EJ/EK) or return air plenum (48EW/EY).

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Carrier EK, 48EJ, EW, EY024-048 installation instructions Adding Foam Strip to Hood Side
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EW, EY024-048, EK, 48EJ specifications

The Carrier 48EJ, 48AW, 48EK, 48AJ, and 48EY024-068 are cutting-edge rooftop air conditioning units designed for commercial applications. These models are renowned for their reliability, energy efficiency, and innovative technologies aimed at providing optimal indoor comfort.

One of the standout features of these units is their advanced cooling and heating capabilities. They employ a multi-stage compressor system that allows for precise temperature control, accommodating various load requirements. This flexibility is particularly beneficial in commercial settings where the cooling load can fluctuate throughout the day.

Energy efficiency is paramount in today’s environmental landscape, and Carrier has ensured that these models meet stringent efficiency standards. They incorporate high-efficiency scroll compressors, which significantly reduce energy consumption while delivering powerful performance. The units are also equipped with variable speed fans that adjust airflow based on demand, further optimizing energy use.

In terms of construction, these rooftop units feature a robust design that enhances durability and longevity. The cabinet is constructed to withstand harsh weather conditions, ensuring reliable performance year-round. Additionally, the units are equipped with corrosion-resistant coatings, particularly useful in coastal environments where salt exposure can be a concern.

The Carrier 48EJ, 48AW, 48EK, 48AJ, and 48EY models utilize advanced controls and connectivity features, allowing for easy integration into building management systems. This connectivity enables remote monitoring and control, facilitating quick response to changing conditions and simplifying maintenance tasks.

Noise reduction is another key characteristic of these models. They are designed with sound-absorbing insulation and low-noise fan blades to ensure quiet operation, making them suitable for noise-sensitive environments such as schools and hospitals.

These units are also available with various options for air filtration and dehumidification. The use of high-efficiency air filters enhances indoor air quality by trapping dust, pollen, and other airborne particles. Enhanced dehumidification capabilities ensure that spaces remain comfortable even in humid conditions.

In conclusion, the Carrier 48EJ, 48AW, 48EK, 48AJ, and 48EY024-068 rooftop units are engineered to offer exceptional performance, energy efficiency, and durability. With their advanced technologies and user-friendly features, they stand out as reliable solutions for meeting diverse commercial cooling and heating needs, making them a popular choice for many businesses.
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