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Menvier300
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.
PD6662:2010 Grade 3 requires 12 hours provided
that the control unit is fitted with an ATS4
communicator capable of transmitting a mains fail
signal.
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 34.
The following calculation shows a simplified
example: in an alarm system with an Menvier300
control unit, five i-kp01 keypads, three expanders
and 40 wired PIRs the system takes the following
total quiescent current:
Device
Control unit PCB
40 x PIRs at 15mA each
3 x (wired expanders)
5 x i-kp01 at 30mA each
(backlights off)
Siren (quiescent)
During an alarm, these figures become:
Device
Control unit PCB
40 x PIRs at 15mA each
3 x (wired expander)
5 x i-kp01 at 60mA each
(backlights off)
Siren (in alarm)
The total amp hours required =
(0.975 A x 11.5h) + (1.58A x 0.5h) = 12.00Ah
Note that this example assumes that the
communicator has its own power supply.
A single new, fully charged, charged 17A battery
can provide the charge required by the example
system for PD6662 Grade 3 requirements.
Note: All current drawn from the Aux terminals
(12V and 14.4V) must be included in the overall
calculation.
Current
140mA
600mA
60mA
150mA
25mA
Total
975mA
Current
220mA
600mA
60mA
300mA
400mA
Total
1580mA
CAUTION: Ensure that the system does not
demand more than the maximum current available
from the control unit during an alarm, see page
33.
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.
Cable Configuration and Length
You can connect up to 45 devices to the control
unit bus. You may connect the devices either in
daisy chain (serially), or in star (parallel)
configuration at the control unit connector.
Before You Begin
Page 11
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