Honeywell INTELLIKNIGHT 5820XL - Manual (Page 46)

IntelliKnight 5820XL Installation Manual
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4.4 SBUS Wiring
This section contains information on calculating SBUS wire distances and the types
of wiring configurations (Class A and B).
4.4.1 Calculating 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 ac-
cessory modules 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 Ex-
pander 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.
Note: Refer to Table 3-3 for maximum number of each type of device that can be used per system.
After calculating the total worst case current draw, Table 4-1 specifies the maximum
distance the modules can be located from the panel on a single wire run. The table
ensures 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.
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 Annunciator .200 amps
5895XL Intelligent Power Supply .010 amps
5496 Intelligent Power Supply .010 amps