DIFFERENTIAL ENTHALPY CONTROL (Fig. 29) --

Diffemntifd enthalpy control mquiles both fin enthalpy switch/

receiver (33CSENTHSW) and fin enthalpy sensor

(33CSENTSEN). The enthalpy switchkeceiver is mounted in the outdoor air inlet and calculates outdoor air enthalpy. Tile

enthalpy sensor is mounted in the return airstream and cfflcu- lates the enthalpy of the indoor all:

The enthalpy switclffleceiver energizes the HI Enthalpy re- lay output when the outdoor enthalpy is greater than file indoor enthalpy. The LOW Enthalpy terminal is energized when the

outdoor enthalpy is lower than the indoor enthalpy. The relay output is wired to the unit economizer which will open or close depending on the output of the switch.

NOTE: The enthalpy calculation is done using an average alti- tude of 1000 fl above sea level.

Mounting -- Mount the enthalpy switch/receiver in a location where the outdoor air can be sampled (such as the outdoor air

intake). The enthalpy switch/receiver is not a NEMA 4 enclo- sure fred should be mounted in a location that is not exposed to outdoor elements such as rain, snow. or dilect sunlight. Use two field-supplied no. 8 x 3/4-in. TEK screws. Insert the screws

through the holes in the sides of the enthalpy switclffreceivel:

Mount the enthalpy sensor in a location whele the indoor air can be smnpled (such as the return air duct). The enthalpy sensor is not a NEMA 4 enclosure and should be mounted in a

location that is not exposed to outdoor elements such as rain or snow. Use two field-supplied no. 8 x 3/4-in. TEK screws. Insert the screws through the holes in the sides of the enthalpy sensol:

Wiring -- Carrier recommends the use of 18 to 22 AWG twisted pair or shielded cable for all wiring. All connections must be made with I/4-in. female spade connectors.

120 VAC

LINE VOLTAGE

The PlemierLink TM board provides 24-vac to power the

enthfflpy switch/receivel: Connect the GND and 24 VAC termi-

nals on the enthfflpy switch/receiver to the terminals on

the transformer On some applications, the power from the economizer hmness can be used to power the enthalpy switch/

leceivel: To power the enthalpy switchkeceiver from the economizer harness, connect power of the enthalpy switch/ receiver to the led and brown wires (1 and 4) on the econo- mizer harness.

Connect the LOW Enthalpy terminal on the enthalpy

switch/receiver to J4 -- pin 2 of the PlemierLink control on the HVAC unit. The switch can be powered through the Premier- Link control board if desired. Wire file 24VAC terminal on the

enthalpy switclffreceiver to J4 -- pin 1 on the PremierLink

control. Wire the GND terminal on the enthalpy switch/

receiver to Jl -- pin 2 on the PremierLink control. The HI Enthalpy terminal is not used. See Fig. 28.

Connect the 4-20 mA IN terminal on the enthalpy switch/ receiver to the 4-20 mA OUT terminal on the return air en-

thalpy sensor. Connect the 24-36 VDC OUT terminfd on the enthalpy switch/leceiver to the 24-36 VDC IN terminal on the return air enthalpy sensor. See Fig. 29.

Enthalpy Switch/Receiver Jumper Settings -- There are two jumpers. One jumper determines the mode of the enthalpy

switch/receivel: The other jumper is not used. To access the

jumpers, lemove the 4 screws holding the cover on the enthalpy switclffreceiver find then remove the covel: The fac-

tory settings for the jumpers me M I and OFE

The mode jumper should be set to M2 for differential en-

thalpy control. The factory test jumper should remain on OFF or the enthalpy switch/receiver will not calculate enthalpy.

_jk.jM.Z.__/

24 VAC OUTPUT FROM N/C CONTACT WHEN THE

OUTDOOR

ENTHALPY

IS LESS THAN THE

f

INDOOR

ENTHALPY

 

,i ORN

24 VAC OUTPUT FROM N/O CONTACT WHEN THE 4--

INDOOR ENTHALPY IS GREATER THAN THE

OUTDOOR ENTHALPY

HI LOW GND 24

ENTHALPY VAC

33CSENTHSW

]

4-20 24-36 mA VDC IN OUT

f

j!

/

24-36 4-20

VDC mA

IN OUT

33CSENTSEN

J

JUMPER SETTINGS FOR 33CSENTHSW

LEGEND

N/C -- Normally Closed

N/O -- Normally Open

JUMPER SETTINGS FOR 33CSENTSEN

O o on

[l°°°l

O0000

Fig. 29 --Differential Enthalpy Control Wiring

21

Page 20 Page 22
Page 21
Image 21
Carrier 48TJ016-028 specifications Differential Enthalpy Control Wiring
Page 20 Page 22

48TJ016-028 specifications

The Carrier 48TJ016-028 is a notable model in the range of packaged rooftop units designed by Carrier, a leader in heating, ventilation, and air conditioning (HVAC) solutions. Tailored specifically for commercial applications, these units provide a blend of efficiency, durability, and reliability, making them suitable for a variety of settings, including offices, retail spaces, and industrial environments.

One of the standout features of the 48TJ series is its energy-efficient performance. Equipped with high-efficiency scroll compressors, these units offer superior cooling capacity while minimizing energy consumption. This aligns with modern sustainability goals, helping businesses reduce their carbon footprint and operational costs. Additionally, the 48TJ units comply with stringent industry standards, such as the ASHRAE 90.1 energy efficiency guidelines, ensuring that users receive a product that meets modern energy performance benchmarks.

The 48TJ016-028 units also include advanced technologies that enhance performance and user comfort. The inclusion of a sophisticated microprocessor control system facilitates precise temperature regulation, allowing for an optimal balance of cooling and heating based on real-time conditions. Moreover, the user-friendly controls make it easy for facility managers to monitor system performance and make adjustments as necessary.

Another notable characteristic of the 48TJ series is its flexible installation options. These rooftop units are designed for easy integration into existing building structures and can be installed on flat or pitched roofs. Their compact design and lightweight construction simplify the installation process while minimizing structural impacts on buildings.

Durability is paramount in the design of the 48TJ units as well. The cabinets are constructed from high-quality materials with corrosion-resistant coatings, ensuring a long lifespan even in harsh environmental conditions. The systems are also equipped with robust insulation to reduce sound levels and improve overall operating efficiency.

Furthermore, the Carrier 48TJ016-028 units offer various options for customization. Users can choose from different airflow configurations, heating options, and accessories, allowing for tailored solutions that meet specific requirements. Whether you are looking for a unit with enhanced filtration, economizer capabilities, or advanced humidity control, the 48TJ series provides the flexibility needed for diverse applications.

In summary, the Carrier 48TJ016-028 units deliver a compelling combination of energy efficiency, advanced technology, and robust construction, making them an ideal choice for commercial HVAC needs. With their versatile features and customizable options, they stand out as reliable solutions for maintaining comfortable indoor environments.
Top Page Image Contents