Page 44
Configur
ation O
ptions in Detail
© JVA Technologies. www.jva-fence.com
JVA JMB User Manual
11.15 ANTI-BRIDGING
Anti-bridging has been designed to detect a section of fence being by
-
passed, and removed from circuit, by an intruder bridging the feed to re
-
turns together and then cutting the live wires in between.
While Armed, a fence alarm will trigger if the fence voltage rises OR falls
quickly by more than the threshold. A slow change to the voltage will not
trigger a fence alarm until the voltage is less than the Fence Voltage alarm
level (option 20 or 21). The Anti-bridging Threshold is a percentage value
of the current fence voltage.
For Example, if you have a 10% Anti-bridging Threshold. At this level a
fence (return) voltage normally reading 7.5kV will trigger a fence alarm if
the voltage quickly rises to over 8.3kV or falls to less than 6.7kV.
NOTE: Fence Voltage Power Level (option 2 or 3) must be set higher than
the normal fence running voltage, otherwise if the load is released (fence
bridged) voltage control will limit the voltage rise and the anti-bridging
alarm will not activate. This feature will not operate in low power mode.
For the above example, option 2 (or 3 if you are using Zone 2) must be set
to 7.0kV or greater to allow the un-loaded fence to rise to 8.3kV or higher,
thus triggering the Alarm.
Range 0% to 90%. Default 0%
Virtual Keypad:
Enter the
Configuration
page and adjust
Anti-bridge
ac
-
cordingly. Click
Save Settings.
