Safety Functions - ABB i-bus KNX Product Manual

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ABB i-bus KNX
Planning and application
4.3

Safety functions

Wind alarm
To protect the blind/shutter against wind and storms, the JRA/S can receive wind alarm telegrams (1 bit). If
a wind alarm occurs, then the blind/shutter is moved to the parameterized wind alarm position and cannot
be operated until the wind alarm is deactivated again.
The JRA/S can be activated by up to 3 wind monitors. It is possible to select freely for each output which of
the three monitors should be reacted to and whether the Wind alarm function should be activated for this
function at all. In addition, the position for wind alarms can be set separately for each output. The wind
monitors assigned to an output are linked by an OR operation, i.e. if an alarm is triggered on at least one
of the assigned wind monitors, then the alarm position will be moved to.
Rain alarm and frost alarm
To protect the blind/shutter, e.g. awnings, against rain or to avoid freezing during periods of frost, the
JRA/S can receive 1-bit rain alarm and frost alarm telegrams. If an alarm occurs, then the blind/shutter is
moved to a parameterized position and cannot be operated until the alarm is rescinded. The position for
the rain alarm and the position for the frost alarm can be set separately for each output.
Note on wind, rain and frost alarm
The wind monitors and the rain and frost sensors are monitored cyclically by the JRA/S, i.e. the sensors
send the alarm status cyclically and the JRA/S expects this signal. If there is no signal, then the JRA/S
assumes that the sensor is defective or that the bus line has been interrupted. All the blinds/shutters,
upon which the sensor has an effect, move to the parameterized alarm position and operation is
disabled. The monitoring time in the JRA/S should be at least double the cyclic sending time of the wind
monitor or rain/frost sensor. If there is no signal, e.g. due to excessive bus load, this stops the
blinds/shutters from being move to the position for wind, rain or frost alarm.
When a wind, rain or frost alarm is rescinded, the blind/shutter is moved to the parameterized position
for rescinding of Weather alarm, Block or Forced operation and operation is enabled.
114 2CDC 506 051 D0204 | JRA/S