Carrier 48/50AJ specifications Accessory Navigator Display

UNIT CONTROL BOX

TB4

1 2 3 4 5 6 7

1	2	3
		1
		2
	J4
3
2		J3
1
J5
OVERRIDE	J6
B4

TB5

1 2 3 4 5 6 7

A48-7306

Fig. 33 — CO2 and Space Temperature Sensor Wiring (33ZCT55CO2 and 33ZCT56CO2)

Green LED — The boards also have a green LED, which is the indicator of the operation of the LEN communications, which is used for communications between the boards. On the MBB board the Local Equipment Network (LEN) LED should always be blinking whenever power is on. All other boards have a LEN LED that will blink whenever power is on and there is communication occurring. If LEN LED is not blinking, check LEN connections for potential communication errors (J3 and J4 connectors). A 3-wire sensor bus accomplishes commu- nication between modules. These 3 wires run in parallel from module to module.

Yellow LED — The MBB has one yellow LED. The Carrier Comfort Network® (CCN) LED will blink during times of network communication. The other boards do not have a CCN communications port.

It is important when connecting to a CCN communication bus that a color-coding scheme be used for the entire network to simplify the installation. It is recommended that red be used for the signal positive, black for the signal negative and white for the signal ground. Use a similar scheme for cables contain- ing different colored wires.

At each system element, the shields of its communication bus cables must be tied together. If the communication bus is en- tirely within one building, the resulting continuous shield must be connected to a ground at one point only. If the communica- tion bus cable exits from one building and enters another, the shields must be connected to grounds at the lightning suppressor in each building where the cable enters or exits the building (one point per building only).

CARRIER COMFORT NETWORK INTERFACE — The 48/50A Series units can be connected to the CCN interface if desired. The communication bus wiring is a shielded, 3-conduc- tor cable with drain wire and is field supplied and installed. See the Installation Instructions for wiring information. 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 elements on either side of it. This is also required for the negative and signal ground pins of each system element. Wiring connections for CCN should be made at TB3. See Fig. 35. Consult the CCN Contractor’s Manual for further information.

NOTE: Conductors and drain wire must be 20-AWG (American Wire Gage) minimum stranded, tinned copper. Individual conductors must be insulated 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 tempera- ture range of –20 C to 60 C is required.

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Fig. 34 — Accessory Navigator Display

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