System/Sensor Bus and Supply Power Wiring Guidelines - Verasys - VAC1000 - VAC1001

Table 1 provides information about the functions, ratings, and requirements for the communication bus and supply power terminals. The table also provides guidelines for wire sizes, cable types, and cable lengths when wiring the controller's communication buses and supply power.

In addition, use these guidelines to wire a sensor or system bus and the 24 VAC supply power:

Run all low-voltage wiring and cables separate from high-voltage wiring.
All sensor or system bus cables, regardless of wire size, should be twisted, insulated, stranded copper wire.
Using shielded cable is best practice for all sensor or system bus cables.
Refer to the Verasys BACnet MS/TP Communications Technical Bulletin (LIT-12012362) for detailed information on wire size and cable length requirements for the sensor or system buses.

Table 1. Communication Bus and Supply Power Terminal Blocks, Functions, Ratings, Requirements, and Cables
Terminal Block/Port Label	Terminal Labels	Function, Electrical Ratings/Requirements	Cable Type
System Bus (Upper)	+	System Bus Communications	0.6 mm (22 AWG) stranded, 3-wire twisted, shielded cable shielded cable is best practice.
	-	System Bus Communications
	COM	Signal Reference (Common) for Bus communications
	SHD	Isolated terminal (optional shield drain connection)
Sensor Bus (Port)	Sensor BUS	RJ-12 6-Position Modular Connector provides: Sensor Bus Communications Sensor Bus Signal Reference and 15 VDC Common 15 VDC, 71.5 ohms at 4 W	24 AWG 3-pair CAT3 cable <30.5 m (100 ft)
Sensor Bus Terminal (Lower)	+	Sensor Bus Communications	0.6 mm (22 AWG) stranded, 4-wire (2 twisted-pairs), shielded cable is best practice. Note: The + and - wire are one twisted pair, and the COM and sensor PWR are the second twisted pair of wires.
	-	Sensor Bus Communications
	COM	Sensor Bus Signal Reference and 15 VDC Common
	PWR	15 VDC Supply Power for Devices on the Sensor bus. Maximum total current draw for Sensor bus is 240 mA.
24~ INPUT	HOT	24 VAC Power Supply - Hot Supplies 20–30 VAC Nominal 24 VAC	0.8 mm to 1.5 mm² (18 AWG) 2-wire
24~ INPUT	COM	24 VAC Power Supply Common Isolated from all other Common terminals on controller 20 VA at 24 VAC nominal	0.8 mm to 1.5 mm² (18 AWG) 2-wire
24~ OUT	24~	24 VAC Utility Supply for actuators 80 mA continuous	0.8 mm to 1.5 mm²(18 AWG) 2-wire
24~ OUT	COM	24 VAC Power Supply Common	0.8 mm to 1.5 mm²(18 AWG) 2-wire
MOD BUS	+	Modbus communications	0.6 mm (22 AWG) stranded, 4-wire(2 twisted pairs), shielded cable is best practice.
	-	Modbus communications
	COM	Signal Reference (Common) for bus communications

System/Sensor Bus and Supply Power Wiring Guidelines - Verasys - VAC1000 - VAC1001 - VAC1002

Verasys 18 Point 24 VAC Application Controller Installation Guide