SilentKnight 5820XL - Manual (Page 38)

Model 5820XL / 5820XL-EVS Installation Manual LS10061-001SK-E
4-5
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 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.
Note: Refer to if using SD SLC devices and Table 3-2 if using SK SLC devices for maximum number of each type
of device that can be used per system
* All devices must use the same SBUS and VBUS.
** When doing wire calculations, use .080 amps per device with .105 amps for the last device.
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
EVS-50W .010 amps
EVS-125W .010 amps
EVS-100W .010 amps
EVS-100W with EVS-100WBU .010 amps
EVS-VCM / EVS-VCM with EVS-SW24* ** .080 amps / .105 amps
EVS-RCU / EVS-RCU with EVS-SW24* ** .080 amps / .105 amps