Installation
7
English
NOTE: the mini USB socket is not intended for customer use,
connecting this to a computer is likely to damage both Xsafe Bright
and the computer.
2.4 General Cabling Requirement
Cabling to
Xsafe Bright
must be in accordance with the recognised standards
of the appropriate authority in the country concerned and meet the electrical
requirements of the detector.
2.5 Cabling Requirement 4 to 20 mA Current Loop
Fulfils the requirements for 4 to 20 mA current loop and HART connections,
allows for connection and powering of accessory beacon or sounder subject to
current consumption, cable resistance and panel voltage. Current consumption
should consider worst case e.g. when the accessories are powered.
Example Calculation 1
What is the longest cable for a Bright to operate using point to point
connection and powering a sounder with 250mA current consumption.
Use parameters of 1.5mm2 cable, where the controller has a guaranteed
minimum output voltage of 18V.
This type of cable has resistance of 12.1
Ω
/km, therefore the there and back
cable resistance is 24.2.
Xsafe Bright
has min voltage requirement of 10V.
The alarm 2 current for
Xsafe Bright
(pellistor) is 95mA and the sounder
output max current is 0.25 A, so a total current in alarm driving the sounder
output is:
Max current = 0.25 + 0.095 = 0.345 A.
18V = 10V + (0.345 x 24.2 x d), where d is distance in km
d = (18 – 10) / (0.345 x 24.2) = 0.958 km
Xgard Bright
Beacon/
Sounder
Power +V
Signal
Power 0V
Detector
Control
Panel
