Specifications

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Cable Specifications

Installation Handbook, Autroprime Interactive Fire Detection System, 116-P-APRIME-INSTALL/DGB Rev. E, 2011-08-16,

Autronica Fire and Security AS

Page 17

Maximum

resistance /

capacitance

Wire

Dimensions

(examples)

Maximu

m cable

length

Remarks

( / μF)

(mm

) (AWG) (m)

Panel Bus

Capacitance pr. 1km cable

Capacitance < 200 nF

Capacitance < 100 nF

Maximum cable segment length

< 600 m

< 1000 m Cat 5 or better

Cable shall be twisted pair, characteristic

impedance 100 ohm.

Panel Bus

Power supply

2-wire 24V supply:

Calculation vs power loss

The power loss in these cables has to take into consideration the maximum current at

startup due to the Lamp test, which is 300 mA. Cable loss shall be limited to ensure at

least 18V supply to each panel in this situation.

RS 232

For cabinet internal connections only, limited to 10m.

For USCG installations the length is limited to 6m (20 feet).

RS485/422

Shielded cable is required if cable is >3m. Cable shall be twisted pair, 100 ohm

characteristic impedance (Cat 5 cable recommended).

For USCG installations the length is limited to 6m (20 feet).

If multi-stranded cables are used, cable crimps shall be used.

8.2 Detection Loop Cables

8.2.1 General Considerations

The maximum cable length is determined by both cable loss and the

at-site designed power consumption. Increasing current implies a

demand for less cable loss, hence increased copper area or reduced

cable length (refer to Guidance Table on the next page).

In the system service menu (Unit Configuration/Detection Loops) it is

possible to limit the maximum possible current consumption for a

selected detection loop. There are 4 different settings, 100mA (the

default setting), 150mA, 200mA and 250mA. The current consumption

per device is found in the data sheets of the respective units.

Note: The current consumption of LED indicators (on detectors or loop

units) in the event of an alarm has to be included.

The current consumption of other loads has to be included (for

example, loads applied to the output connection of detectors).

Units with varying current consumption, like sounders or strobe

devices have to be included according to the configured setting, for

example, the sound level may vary.