Bryant 551J Connecting Discrete Inputs, Filter Status, Fan Status, Remote Occupancy

On 551J units equipped with factory-installed Smoke Detector(s), the smoke detector controller implements the unit shutdown through its NC contact set connected to the unit’s CTB input. The FSD function is initiated via the smoke detector’s Alarm NO contact set. The RTU-MP controller communicates the smoke detector’s tripped status to the BAS building control. See Fig. 38, the RTU-MP System Control wiring schematic.

The Fire Shutdown Switch configuration, MENU→Config→Inputs→input 5, identifies the normally open status of this input when there is no fire alarm.

Connecting Discrete Inputs

551J		Filter Status
	j	The filter status accessory is a field-installed accessory.
		This accessory	detects	plugged	filters. When		installing
		this accessory, the unit must be configured for filter status
		by setting MENU→Config→Inputs→input 3, 5, 8, or 9
		to Filter Status and normally open (N/O) or normally
		closed (N/C). Input 8 or 9 is recommended for easy of
		installation. Refer to Fig. 36 and Fig. 38 for wire
		terminations at J5.
		Fan Status
		The fan status accessory is a field-installed accessory.
		This accessory detects when the indoor fan is blowing air.
		When installing this accessory, the unit must be
		configured	for	fan	status	by	setting

MENU→Config→Inputs→input 3, 5, 8, or 9 to Fan Status and normally open (N/O) or normally closed (N/C). Input 8 or 9 is recommended for easy of installation. Refer to Fig. 36 and Fig. 38 for wire terminations at J5.

Remote Occupancy

The remote occupancy accessory is a field-installed accessory. This accessory overrides the unoccupied mode and puts the unit in occupied mode. When installing this accessory, the unit must be configured for remote occupancy by setting MENU→Config→Inputs→input 3, 5, 8, or 9 to Remote Occupancy and normally open (N/O) or normally closed (N/C).

Also set MENU→Schedules→occupancy source to DI on/off. Input 8 or 9 is recommended for easy of installation. Refer to Fig. 36 and Table 3 for wire terminations at J5.

Power Exhaust (output)

Connect the accessory Power Exhaust contactor coil(s) per Fig. 51.

Power Exhaust
	PEC		TAN		J11-3
				CTB
				THERMOSTAT
		GRA			C
					C08464

Fig. 51 - RTU-MP Power Exhaust Connections

Communication Wiring - Protocols

General

Protocols are the communication languages spoken by control devices. The main purpose of a protocol is to communicate information in the most efficient method possible. Different protocols exist to provide different kinds of information for different applications. In the BAS application, many different protocols are used, depending on manufacturer. Protocols do not change the function of a controller; just make the front end user different.

The RTU-MP can be set to communicate on four different protocols: BACnet, Modbus, N2, and LonWorks. Switch 3 (SW3) on the board is used to set protocol and baud rate. Switches 1 and 2 (SW1 and SW2) are used to set the board’s network address. See Fig. 52 for the switch setting per protocol. The 3rd party connection to the RTU-MP is through plug J19.

NOTE: Power must be cycled after changing the SW1-3 switch settings.

Refer to the RTU-MP 3rd Party Integration Guide for more detailed information on protocols, 3rd party wiring, and networking.

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