Honeywell 5820XL manual Sbus Wiring, Calculating Wiring distance for Sbus modules

IntelliKnight 5820XL Installation Manual

4.4SBUS Wiring

This section contains information on calculating SBUS wire distances and the types of wiring configurations (Class A and B).

4.4.1Calculating Wiring distance for SBUS modules

The following instructions will guide you in determining the type of wire and the maximum wiring distance that can be used with control panel SBUS accessory modules.

To calculate the wire gauge that must be used to connect SBUS modules to the control panel, it is necessary to calculate the total worst case current draw for all modules on a single 4- conductor bus. The total worst case current draw is calculated by adding the individual worst case currents for each module. The individual worst case values are shown in the table below.

Note: Total worst case current draw on a single SBUS cannot exceed 1 amp. If a large number of accessory mod- ules are required, and the worst case current draw will exceed the 1 amp limit, then the current draw must be distributed using 5895XL Power Expanders. Each 5895XL Power Expander provides an additional SBUS, with an additional 1 amp of SBUS current. Wiring distance calculations are done separately for each 5895XL, and separately for the control panel itself.

	Model Number	Worst Case Current Draw
5860	Fire Annunciator	.100 amps
5824	Serial/Parallel Printer Interface Module	.040 amps
5880 LED I/O Module		.250 amps
5865	LED Fire Annunciator	.200 amps
5895XL Intelligent Power Supply		.010 amps
5496	Intelligent Power Supply	.010 amps

Note: Refer to Table 3-2for maximum number of each type of device that can be used per system.

After calculating the total worst case current draw, Table 4-1specifies the maximum distance the modules can be located from the panel on a single wire run. The table insures 6.0 volts of line drop maximum. In general, the wire length is limited by resistance, but for heavier wire gauges, capacitance is the limiting factor.

4-6 151209