Smart Connect
Single Loop Touch Screen Panel
Doc: GLT-229-7-1
21
Issue: 3
Date: 12/05/2017
4.4 MAXIMUM LOOP CABLE LENGTH RECOMMENDATIONS
With an addressable system, some care must be taken when calculating the appropriate cable gauge for the system. The main
limitation is that during an alarm condition (maximum current draw), the voltage at all devices must be at least 24 Volts with at
least 2.5V of superimposed data signal.
The exact calculation equations are beyond the scope of this manual, because of the distributed load of the sounders on the loop,
but the following table gives a rough guide for maximum cable lengths at various current loads for 3 different cable gauges.
MAXIMUM LOOP CURRENT (IN ALARM)
500 mA
400 mA
300 mA
200 mA
1mm CSA cable
500m
625m
830m
1250m
1.5mm CSA cable
750m
930m
1250m
1870m
2.5mm CSA cable
1000m
1250m
1660m
2500m
EG. A system with a maximum load of 300mA using 1.5mm cable can have a maximum loop run of 1250m end to end. When
Installed the cable characteristics should meet the following parameters:-
+ve in to +ve out less than 22 ohms.
-ve in to -ve out less than 22 ohms (may need to temporarily disable isolators to measure).
+ve to –ve greater than 500k ohm.
+ve to Earth greater than 1M ohm.
-ve to Earth greater than 1M ohm.
+ve to –ve less than 50 mV pickup (on AC & DC scales).
+ve to –ve Capacitance Less than 0.5uF.
+ve to Earth Capacitance Less than 0.5uF.
-ve to Earth Capacitance Less than 0.5uF
4.5 BATTERY CALCULATIONS
All systems will have a required stand by time and alarm time. The usual Standby times are 24 hours, 48 hours, or 72 hours,
depending on the type of system. Generally 30 minutes of alarm time is considered sufficient.
Information on calculating the required battery size can be found later in this manual. Alternatively, a battery calculation
spreadsheet is available. Please contact your distributor for details.
4.6 CHOOSING AUDIBLE & VISIBLE WARNING DEVICES
There are a number of options for Audible & visual Devices that can be directly or indirectly connected to the loop of a Smart
Connect panel:
A maximum of 64 loop powered sounders are permitted on each loop (which can be either stand-alone sounders or
sounder bases.
A maximum of 254 devices can be connected to the loop, with addresses 1 to 254 which can occur in any order.
Short circuit isolators should be used to prevent losing the whole loop in the event of a single short circuit fault. They
should be fitted to each zone boundary, such that any short circuit will only affect the devices in 1 zone.
4.6.1 ADDRESSABLE SOUNDER
This type of sounder takes one of the 254 addresses available on each loop. The address is set with the programming tool. It can be
activated individually, or in groups related to its zone number, as determined by the cause and effect programmed.
4.6.2 ADDRESSABLE SOUNDER BASE
This consists of an addressable sounder in the base of an addressable detector. The sounder and detector are set to different
addresses, i.e. two devices are located at the same position on a loop but occupy two addresses. The address is set with the
programming tool, or with dip switches, depending on the model used. It can be activated individually, or in groups related to its
zone number, as determined by the cause and effect programmed.
