Carrier 48TCA04---A12 RTU-MP Control System, Recommended Cables, Color Code Recommendations

48TC

At any baud (9600, 19200, 38400 baud), the number of controllers is limited to 239 devices maximum. Bus length may not exceed 4000 ft, with no more than 60 total devices on any 1000-ft section. Optically isolated RS-485 repeaters are required every 1000 ft.

NOTE: Carrier device default is 9600 band.

COMMUNICATION BUS WIRE SPECIFICATIONS — The CCN Communication Bus wiring is field-supplied and field-installed. It consists of shielded 3-conductor cable with drain (ground) wire. The cable selected must be identical to the CCN Communication Bus wire used for the entire network.

See Table 19 for recommended cable.

Table 19 – Recommended Cables

MANUFACTURER	CABLE PART NO.
Alpha	2413 or 5463
American	A22503
Belden	8772
Columbia	02525

NOTE: Conductors and drain wire must be at least 20 AWG, stranded, and 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 temperature range of -20 C to 60 C is required. Do not run communication wire in the same conduit as or next to any AC voltage wiring.

The communication bus shields must be tied together at each system element. If the communication bus is entirely within one building, the resulting continuous shield must be connected to ground at only one single point. If the communication bus cable exits from one building and enters another building, the shields must be connected to the grounds at a lightning suppressor in each building (one point only).

Connecting CCN bus:

NOTE: When connecting the communication bus cable, a color code system for the entire network is recommended to simplify installation and checkout. See Table 20 for the recommended color code.

Table 20 – Color Code Recommendations

SIGNAL TYPE	CCN BUS WIRE	CCN PLUG PIN
	COLOR	NUMBER
+	Red	1
Ground	White	2
---	Black	3

Connect the CCN (+) lead (typically RED) to the unit￿s TB1-12 terminal. Connect the CCN (ground) lead (typically WHT) to the unit’s TB1-14 terminal. Connect the CCN (-) lead (typically BLK) to the unit’s TB1-16 terminal. See Fig. 58.

CCN Bus
	TB1	PL
+ (RED)	12	J2-1

TB1

GND (WHT) 14 J2-2

TB1

– (BLK) 16 J2-3

C08276

Fig. 58 - PremierLink CCN Bus Connections

RTU-MP CONTROL SYSTEM

The RTU-MP controller, see Fig. 59, provides expanded stand-alone operation of the HVAC system plus connection and control through communication with several Building Automation Systems (BAS) through popular third-party network systems. The available network systems are BACnet MP/TP, Modbus and Johnson J2. Communication with LonWorks is also possible by adding an accessory interface card to the RTU-MP. Selection of the communication protocol and baud rate are made at on-board DIP switches.

Carrier’s diagnostic display tools BACviewer6 Handheld and Virtual BACview (loaded on a portable PC) must be used with the RTU-MP controller. Connection to the RTU-MP board is at the J12 access port, see Fig. 59.

The RTU-MP control is factory-mounted in the 48TC unit’s main control box, to the left of the LCTB. See Fig.

60.Factory wiring is completed through harnesses connected to the LCTB. Field connections for RTU-MP sensors will be made at the Phoenix connectors on the RTU-MP board. The factory-installed RTU-MP control includes the supply-air temperature (SAT) sensor. The outdoor air temperature (OAT) sensor is included in the FIOP/accessory EconoMi$er 2 package.

Refer to Table 21, RTU-MP Controller Inputs and Outputs for locations of all connections to the RTU-MP board.

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