Carrier 48AJ installation instructions A48-8243, A48-6854

Page 30

Staged Gas Control Option Thermistors — If the unit is equipped with the staged gas heat option, supply-air ther- mistors must be installed. Three supply-air thermistors are shipped with staged gas units and are inside the heating sec- tion. The supply-air thermistors should be located in the supply duct with the following criteria:

•Downstream of the heat exchanger cells

•Equally spaced as far as possible from the heat exchanger cells

•In a duct location where none of the supply-air ther- mistors are within sight of the heat exchanger cells

•In a duct location with good mixed supply-air portion of the unit.

SPT (Space Temperature Sensor) — For constant volume ap- plications the ComfortLink™ controls can also be used with T55 and T56 space temperature sensors that use a 10K ther- mistor. The T56 sensor also has the capability for a config- urable temperature set point offset. For variable air volume ap- plications only the T55 sensor can be used.

Install sensor according to the installation instructions included with accessory sensor. Locate sensor assembly on a solid interior wall in the conditioned space to sense average temperature.

Run wiring to the space sensor as shown in Fig. 21.

Note that when the remote sensor is used, the red jumper wires provided must be connected from TB4 terminal 4 to 5 and TB4 terminal 5 to 1.

Both the T55 and T56 have a CCN communications port and this should be wired to the CCN Communications TB3 board if it is desired to have access to the CCN through the sensor. If more than one T-55 sensor is being used and averaged, sensors must be wired in multiples of 4 or 9 as shown in Fig. 22.

FIELD-SUPPLIED THERMOSTAT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

LIGHT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R

 

RC

 

Y1

 

Y2

 

W1

 

W2

 

G

 

C

 

X

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R

 

 

 

Y1

 

Y2

 

W1

 

W2

 

G

 

C

 

X

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1 a48-8243

2

3

4

5

6

7

8

 

TB4

Fig. 20 — Field Control Thermostat Wiring

T55 SPT

 

T56 SPT

 

 

 

 

 

 

 

 

 

 

T1

 

T2

 

TH

 

C

 

SN

 

 

 

 

 

 

 

 

 

 

1

 

3

 

5

 

7

 

9

 

11

 

13

 

15

UNIT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

TB5

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2

 

4

 

6

 

8

 

10

 

12

 

14

 

16

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

a48-6854

Fig. 21 — Space Temperature Sensor Wiring

TB5

3

4

RED

BLK

SENSOR 1

SENSOR 2

SENSOR 3

SENSOR 4

SPACE TEMPERATURE AVERAGING (4 SENSOR APPLICATION)

TB5

3

4

SENSOR 1

SENSOR 2

SENSOR 3

SENSOR 4

SENSOR 5

SENSOR 6

SENSOR 7SENSOR 8SENSOR 9

SPACE TEMPERATURE AVERAGING (9 SENSOR APPLICATION)

NOTE: Use T55 sensor only.

Fig. 22 — Space Temperature Averaging Wiring

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Contents Installation Instructions Make Unit Duct Connections Instructions onRoof Curb 48AJ,AK020-035 Units Roof Curb 48AJ,AK036-050 Units Roof Curb 48AJ,AK051 and 060 Units Base Unit Dimensions 48AJ,AK020-035 A48-8235Base Unit Dimensions 48AJ,AK036-050 A48-8236Base Unit Dimensions 48AJ,AK051 Base Unit Dimensions 48AW,AY020-035 A48-8380Base Unit Dimensions 48AW,AY036-050 Base Unit Dimensions 48AW,AY051 A48-8240Center of Gravity and Weights 48AJ,AK,AW,AY051,060 A50-8102Physical Data 48AJ,AK,AW,AY Units Compressor035 036 040 041 Nominal Capacity tons 050 051 060 Nominal Capacity tons Rigging Information A48-8246Unit Operating Weights Option and Accessory WeightsConstant Volume Fan Motor Weights Evaporator Fan Motor Data Air Distribution Thru-the-BottomA48-3823 Install Flue HoodA48-3712 A48-3714Make Electrical Connections 48A Series Staged Gas ControlA48-2524 Unit Voltage 48A Min Max 46.2 203.6 225 Unbalanced 3-Phase Supply Voltage Electrical Data 48AJ,AK,AW,AY Units with Convenience Outlet FLA MCA030 040 Hacr Size Stage A48-8243 A48-6854CCN Connection Approved Shield Cable Color Code RecommendationsMake Outdoor-Air Inlet Adjustments Adding Seal Strip to Top of Hood SidesA48-4328 48-110448-1105 A48-8499Route VAV Static Pressure Sensors A48-8244A48-3808 Field Modifications Pressure Transducer LocationsSide Return Air Conversion A48-8245
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48AJ 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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