Brooks Firetracker FT128 CIE - 22 Cable Types; COM Loop Cables; Remote Display Units Cables; Conventional Zone Line Cables

Technical / Programming Manual
FT128 Rev 2.2
162
22 Cable Types
A fire alarm installation is a safety system and it is important that the cables used are
suitable and of the correct types. Fire alarm cables should, when possible, be installed as
far as possible from mains power cables or any other cables that may generate noise or
have strong EMF in order to avoid disturbances from these cables.
The maximum cable length is dependent on the cable type e.g. cross sectional area, units
current consumption, etc.
22.1 COM Loop Cables
Loop topology is used for highest safety, i.e. the cable connected in FT128, returns back
to FT128. In case of a single break on the loop, communication starts on both directions
and a fault is generated, a fault message will also be displayed.
The cable length is dependent on the number and type of loop units, type of cable, etc.
See chapter “FT128 cable length calculation” page 164 and drawing number F784-01 and
F784-02.
Note: For applications where the environment is noisy, screened cable is recommended.
If screened cable is used, the screen should be connected close to each loop unit and
only incoming (or outgoing) screen to the CIE earth point.
In order to maximise the COM Loop cable length, Brooks recommend using 7/0.52mm
(1.5mm
2
) twisted pair (shielded or unshielded) e.g. Brooks BAC0898 1.50mm
2
TPS 2 Core
Twisted cable unshielded or equivalent.
When feeder line is required, use suitable multi core twisted pair cable 1.5mm
2
.
22.2 Remote Display Units Cables
For RS-485, CAT5 (twisted) cable can be used, cable length < 1200 m to the furthest away
situated external EPU / AAU.
For 24VDC supply, Cable type Brooks BAC0898 1.5 mm
2
is recommended (or equivalent).
22.3 Conventional Zone Line Cables
Zone expansion board 4580 and Multipurpose I/O unit 3361, recommended cable is Brooks
BAC0898 1.5 mm
2
or equivalent. Refer to Table 15 below.
22.4 Alarm Device Cables
Alarm devices (OWS, strobes, external sounders, etc.), recommended cable is Brooks
BAC0898 1.5 mm
2
twin TPS or equivalent unless fire rated cables required.
When feeder line is required, use suitable multi core twisted pair cable 1.5mm
2
. Refer to
Table 15 below
Note: Addressable Alarm devices e.g. 3379, 4477, etc. are connected directly on the
COM loop.
22.5 Other Equipment Cables
Intrinsically safe equipment for hazardous areas, RIL, MDH, etc, recommended cable
Brooks BAC0898 1.5 mm
2
twin TPS or equivalent.
The maximum cable length and maximum COM loop current, are dependent on the number
and type of loop units and the type of cables used. The cable length for the COM loop is
the total cable length from the CIE and returning back to CIE thus completing the loop.