Wiring Specifications; Length Limitations; Calculating Wiring Distance For Sbus Modules - Honeywell SILENT KNIGHT Farenhyt Series Installation And Operation Manual

Model RPS-1000 Installation Manual
** If you are using door holders, you do not need to consider door holder current for alarm/battery standby,
because power is removed during that time. However, during normal operation, door holders draw current
and must be included in the 6.0 A total current that can be drawn from the panel.
*** Use next size battery with capacity greater than required.
2.7

Wiring Specifications

2.7.1

Length Limitations

This section contains information on calculating SBUS wire distances and the types
of wiring configurations (Class A and B).
2.7.2

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 SBUS accessory modules.
To calculate the wire gauge that must be used to connect SBUS modules to the
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 modules are required, and the worst case current draw will exceed the 1 amp limit,
then the current draw must be distributed using RPS-1000 Power Expanders. Each RPS-1000
Power Expander provides an additional SBUS, with an additional 1 amp of SBUS current. Wiring
distance calculations are done separately for each RPS-1000, and separately for the panel itself.
RA-1000 Fire Annunciator
RA-100 Remote Annunciator
5824 Parallel/Serial Interface
5880 LED IO Expander
5865 LED Fire Annunciator
RPS-1000 Intelligent Power Supply
5496 Intelligent Power Module
After calculating the total worst case current draw, Table 2-5 specifies 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.
Model Number
2-7
Worst Case Current Draw
.100 amps
.100 amps
.040 amps
.250 amps
.200 amps
.010 amps
.010 amps
151153