T58 Communicating Thermostat — Carrier also has a fully communicating thermostat which, if used, will be wired to the CCN communication connections on TB3 as described in the Carrier Comfort Network® Interface section below.

Carrier Comfort Network Interface — The rooftop units can be connected to the CCN system. The communication bus wiring is supplied and installed in the field. Wiring consists of shielded, 3-conductor cable with drain wire. The system elements are connected to the communication bus in a daisy chain arrangement. The positive pin of each system element communication connector must be wired to the positive pins of the system element on either side of it, the negative pins must be wired to the negative pins, and the signal pins must be wired to signal ground pins. Wiring connections for CCN should be made at the TB3 terminal block using the screw terminals. The TB3 board also contains an RJ14 CCN plug that can be used to connect a field service computer or other CCN device tempo- rarily. There is also an RJ14 LEN (local equipment network) connection that is used to connect a Navigatordevice or download software.

Conductors and drain wire must be 20 AWG minimum stranded, tinned copper. Individual conductors must be insulat- ed with PVC, PVC/nylon, vinyl, Teflon, or polyethylene. An aluminum/polyester 100% foil shield and an outer jacket of PVC, PVC/nylon, chrome vinyl, or Teflon with a minimum operating temperature range of –20 C to 60 C (–4 F to 140 F) is required. Table 9 lists cables that meet the requirements.

Table 9 — CCN Connection Approved Shield Cable

MANUFACTURER

CABLE PART NO.

Alpha

2413 or 5463

American

A22503

Belden

8772

Columbia

02525

IMPORTANT: When connecting to CCN communi- cation bus to system elements, use color coding system for the entire network to simplify installation and checkout. See Table 10.

Table 10 — Color Code Recommendations

SIGNAL TYPE

CCN BUS CONDUCTOR

CCN PLUG PIN

INSULATION COLOR

NO.

 

Positive (+)

RED

1

Ground

WHITE

2

Negative (–)

BLACK

3

If a cable with a different color scheme is selected, a similar color code should be adopted for the entire network. At each system element, the shields of the communication bus cables must be tied together. If the communication bus is entirely within one building, the resulting continuous shield must be connected to a ground at one point only. If the communication bus cable exits from one building and enters another, the shields must be connected to grounds at the lightning suppres- sor in each building where the cable enters or exits the building (one point per building only).

To connect the unit to the network:

1.Turn off power to the control box.

2.Cut the CCN wire and strip the ends of the red (+), white (ground), and black (–) conductors. (If a different net- work color scheme is used, substitute appropriate colors.)

3.Remove the 3-pin male plug from the base control board in the main control box, and connect the wires as follows:

a.Insert and secure the red (+) wire to terminal 1 of the 3-pin plug.

b.Insert and secure the white (ground) wire to termi- nal 2 of the 3-pin plug.

c.Insert and secure the black (–) wire to terminal 3 of the 3-pin plug.

4.Insert the plug into the existing 3-pin mating connector on the base module in the main control box.

VAV Units with Heat — For variable air volume units that will use heat, the variable air volume terminals should be interlocked with the unit at TB5 terminals 1 and 2.

Demand Ventilation — The unit can be equipped with a CO2 sensor for use in demand ventilation. This can be factory supplied and will be mounted in the return duct. It can also be field supplied and mounted in the return duct or in the space. Connect the field-installed 4 to 20 mA sensor to TB5 terminal 6 and 7. Do not remove the factory-installed 182-ohm resistor.

If an outdoor air quality sensor is used then it should be wired to terminal 11 and 12 on TB6. This will require the use of the optional controls expansion module.

Remote IAQ Override — If the control is being used with non Carrier building management system it supports the use of the remote IAQ override switch. This should be connected to TB6 terminal 13 and 14. Use of this will require the optional controls expansion module.

Remote Economizer Position Control — The ComfortLink™ controls will normally control the position of the economizer, but it can also support field control of the economizer position through a 4 to 20 mA signal. If this is used it should be con- nected to TB5 terminal 6 and 7. If the signal is a 4 to 20 mA signal then leave the 182-ohm resistor in place.

Remote Economizer Enable — If the control is being used with other building management systems and the system will control the enabling and disabling of the economizer free cool- ing, this switch input can be connected to TB6 terminals 1 and

2.Note that the controls also support integrated economizer changeover using outdoor dry bulb, differential dry bulb, outdoor enthalpy and differential enthalpy.

Remote Occupancy Switch — For interface to other building management systems the control also supports a switch input for remote occupancy signals. This wiring should be connected to terminal TB6 terminal 1 and 3.

Remote Economizer Minimum Position Control — If the ComfortLink control is controlling the economizer, but a remote minimum position is required, then an external 100K potentiom- eter can be connected to TB5 terminal 6 and 7. Remove the factory-installed 182-ohm resistor.

Smoke Sensor Interface — The ComfortLink control includes an optional factory-installed return air smoke detector. Remote alarm circuits can be wired to TB5 terminal 8 and 9.

Fire Shutdown and Smoke Control — The control supports interface to fire and smoke control systems and allows for the following system overrides from remote switch inputs.

Fire Shutdown — Connect to TB6 terminals 8 and 9.

Smoke Pressurization — Connect to TB6 terminal 12 and 13. This requires the use of the optional controls expansion module.

Smoke Evacuation — Connect to TB6 terminal 12 and 14. This requires the use of the optional controls expan- sion module.

Smoke Purge — Connect to TB6 terminal 12 and 15. This requires the use of the optional controls expansion module.

Demand Limiting — The control can also be used with demand limiting control from remote building management systems. If a two stage system is going to be used with Redline Limiting where the machine is not allowed to increase load and Load Shed where the load is decreased to a configurable limit in capacity then these can be connected to TB6 terminals 4 and 5 and 5 and 6. This requires use of the controls expansion module.

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Carrier 48AJ installation instructions CCN Connection Approved Shield Cable, Color Code Recommendations

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.

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