Taktis Incite Fire S3, Operating Instructions Manual

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Calculations C
Taktis Fire Control Panel - Installation Manual
Man-1154-In, Revision E01.02
134 of 156
Cabling
This appendix contains tables for identifying the voltage loss of a given cable type and length. Cable length
values in the tables represent worst case conditions with the total load at the farthest point from terminals of
the fire control panel.
Tables are provided for Detection Loops Cabling, Sounders Cabling and Aux 24V Cabling. Determine the
voltage-drop of a given cable-type and length and then compare this loss to the 24 volt source.
Use this information to determine the number of devices that can safely operate on the fire control circuit as
well as the capacity of the standby-batteries.
Two Cable Circuits
Two cables connect from terminals of the Taktis Fire Control Panel to detection loops.
All tabular data provided in this Appendix for Detection Loops Cabling, Sounders Cabling and Aux 24V
Cabling include values from two cable-conductors.
Detection Loop Cabling
The maximum allowable volt drop of 5.5 volts is necessary on the detection loops in order to maintain a
threshold above the minimum device operating voltage of 17 volts. The worst case voltage drop occurs when
the load is located at the farthest point from the terminals of the fire control panel.
The worst case range of loop operating voltage is 23 volts to 30.5 volts.
Example Voltage Drop Condition
The following example demonstrates the impact of cable size and length on output circuits of the Taktis Fire
Control Panel. A twin cable of 1.5 mm wire is connected to Detection Loop 1 of the Taktis Fire Control Panel.
The length of the 1.5 mm cable is 300 M and the device-current-load on the loop is 400 mA. The device-
current-load of 400 mA is determined from manufacturer data sheets.
A voltage drop of 2.88V DC is determined from the 1.5 mm cable table for a cable length of 300 M and a
current load of 400 mA.
Voltage drop of the twin cable:
(Vcable 1 + Vcable 2) = (2.88V/2 ) = 2.88V
The voltage drop of the twin cable, 2.88V is obtained from the table for 1.5 mm cable where length of the cable
is 300 M and the load of the circuit is 400 mA.
Voltage available at the load:
Vload = Vsource - (Vcable 1 + Vcable 2)
9 99
Voltage drop of the circuit:
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9 99