Panasonic Eco Solutions Nordic AB
MEW01472
Rev: -
Planning Instructions Fire alarm system EBL512 G3, United version 2.7.x
23
a Mounting plate for inflammable wall 5021, which can be provided
with cable glands.
5.2
COM loops
Each control unit has four COM loops (0-3) to which the loop units
are connected. Connections according to dwg 512 G3 – 25, - 31, - 36,
- 37 & - 38.
On each COM loop can up to 127 COM loop units be connected
(COM loop address 001 – 127). Regarding type and number of COM
loop units in relation to the cable length / type, see dwg 512 G3 – 41
and chapters "COM loop cable length", page 145 and "Current
consumption", page 148.
Each COM loop unit has a COM loop address (e.g. 123) and
depending on the loop number (e.g. 0) and the control unit number
(e.g. 04) each COM loop unit gets a technical number (04
0
123).
Each alarm point and zone line input has a fire alarm presentation
number (Zone-Address), e.g. 001-01. See EBL512 G3 Operating
Instructions MEW01473 for more information.
Normally the control unit communicates with the COM loop units in
the COM loop A-direction only. In the B-direction is only the COM
loop voltage checked, which has to be > 12 V DC.
A break or short circuit on a COM loop has to generate a fault in the
control unit within 60-100 seconds (EN54-2 requirement).
If one or more Addressable short circuit isolators (4313) are used
6
, the
loop will be divided into "segments" (i.e. the part between two short
circuit isolators or between the control unit and one short circuit
isolator). Only the affected segment will be isolated, which will
minimise the number of units disabled by a short circuit.
The fault messages will also show between which isolators the short
circuit or the break is situated.
If no addressable short circuit isolator (4313) are used, the whole
COM loop will be disabled in case of short circuit on the loop.
COM loop return voltage <12 V DC
or
COM loop break(s)
or
COM loop short circuit
:
This will start a “cycle” as follows.
- The whole loop will be disabled, i.e. no voltage on the loop which
means that the relay in all isolators will be powerless, i.e. there will be
a “break” on the L (SA) wire in each isolator.
6
One short circuit isolator per 32 alarm points is required according to
EN54-2.
