Power Availability; Bus Cabling Requirements; Cable Type; Cable Segregation - Cooper Security i-on30EX Installation Manual

Power Availability

Before connecting any external devices to
the control unit, you must make sure that
the control unit can provide sufficient
current to power the system during a mains
failure for the time required to meet the
appropriate standard.
EN51031-1 Grade 2 and PD6662 Grade 2
both require 12 hours standby time.
Note: When calculating the average load
during the standby time period you must
allow for at least two periods in alarm. To
take the worst case these two periods of
alarm should each be 15 minutes long, the
maximum permitted in EN50131-1 section
8.6.
The amount of current available from the
control unit depends on the size of battery
fitted and its health. The current taken by
the control unit pcb, communicator and
keypads is given in Technical Specifications
– EN50131-6 Ratings on page 28.
The following calculation shows a simplified
example: in an alarm system with an i-
on30EX control unit, two i-kp01 keypads,
and 20 wired PIRs the system takes the
following total quiescent current:
Device
Control unit PCB
15 x PIRs at 15mA each
1 x (wired expander)
2 x i-kp01 at 30mA each
(backlights off)
Siren (quiescent)
During an alarm, these figures become:
Device
Control unit PCB
15 x PIRs at 15mA each
1 x (wired expander)
2 x i-kp01 at 60mA each
(backlights off)
Siren (in alarm)
The total amp hours required =
(0.430 A x 11.5h) + (0.885A x 0.5h) =
5.39Ah
One new, fully charged, 7Ah battery can
provide the charge required by the example
system and would meet the Grade 2
requirements.
Page 8
Current
100mA
225mA
20mA
60mA
25mA
Total 430mA
Current
120mA
225mA
20mA
120mA
400mA
Total 885mA
Note: All current drawn from the Aux
terminals (12V) must be included in the
overall calculation.
CAUTION: Ensure that the system does not
demand more than the maximum current
available from the control unit during an
alarm, see page 28.
Bus Cabling
Requirements

Cable Type

In general, the control unit requires
standard 7/0.2 un-screened four core alarm
cable for wiring the bus.
For maximum performance in harsh
environments use twisted pair screened
cable with a characteristic impedance of
100-120ohms eg: Belden 8132 or cable
designed for RS485.
Use one pair for data lines A and B. Use the
other pair for 12V and 0V. For optimum
performance the voltage at the keypads
and expanders should be greater than 12V.
Screened cable may prove necessary if the
installation site has equipment that
produces high levels of R.F. (Radio
Frequencies). For example, welding
equipment is known to produce a large
amount of radio interference. If screened
cable is required, you should keep to the
following guidelines:
1. Avoid earth loops by connecting the
screen on the cable to mains earth at
the control unit but not at the keypad or
expander.
2. The continuity of the cable screen is
most important and screens MUST be
continuous along the full length of the
cable.
3. Where the cable enters any metal
enclosure, ensure the screen is isolated
from the case.

Cable Segregation

Segregate the bus cabling from any other
wiring, such as mains supply cables,
telephone cables, computer network cables
and R.F. cables. Use cable ties to keep
cables separated.
Keep the bus cable clear of cables supplying
sounders, extension loudspeakers or any
other high current devices.
i-on30EX