ZX Fire Alarm Control Panels
MORLEY-IAS
Installation Manual
Document No. 996-174-000-1, Revision: 01
Page 15
It is recommended that Short Circuit Isolators be installed. Install the isolators at strategic points
in the loop (i.e. zonal boundaries) to prevent an external short circuit from removing more than
32 addressable points from the system.
Note: The loop driver modules have built-in isolators so it is not required to place isolator modules
on the outputs of the FACP.
Refer to the following diagram for information.
FACP Connections
Figure 11 – Loop Wiring with Isolators– Preferred Alternative
DO NOT loop wiring under any terminals.
EN54-2 requires that an isolator must be sited between each zone. You may use more than
this, however, you must ensure that the loop wiring is broken at each isolation point.
3.4.3.2 EMC
Compliance
For EMC Compliance, fit the
Ferrite Absorbers supplied
with the loop driver board
around the SLC Loop cables.
Cables should be screened
and should be terminated in
appropriate glands to meet
local wiring codes and to
preserve the integrity of the
screen connection. The
cable screen is to be
clamped inside the cable
gland, which must be fitted
to ensure a 360° bond is
formed with the metal of the
back box. Alternatively,
terminate the cable screens
(drain wires) at the nearest
earth stud provided on the
inner top surface of the back
box.
The figure opposite shows
the arrangement for a typical
installation.
+ - E + -
Connect Earth drain
wire of cables to nearest
earth stud on inner, top
wall of back box
- keep length
as short as possible
Absorber
Large
Affix cable tie
around wires
below ferrite
Figure 12 – SLC Loop – EMC Absorber Installation
Data / Power (+) OUT
Data / Power (-) OUT
ISOLATORS
Data / Power (+) RETURN
Data / Power (-) RETURN
