8
Malfunctions
Interruptions or short circuits in the sensor wiring along with other malfunctions are indicated
on the display with the blinking symbol
. Additionally, they are indicated over the fault in-
dication output BA6. In the operating level,
– – – –
appears on the display instead of a
measured value when a sensor has failed.
Fault alarm output
The binary output BA6 is an open collector output. Er It is activated when the error status
register is > 0. A maximum of 24 V DC may be applied to this output; the electric current
should not exceed 10 mA when being switched.
8.1
Sensor failure
The controller reacts to a fault as described below:
4
Supply air control:
When the supply air sensor fails, all control outputs run a 0 % control signal and
the binary outputs for pumps and fans maintain their operating states; when the frost pro-
tection is active, the fans are switched off.
4
Exhaust air or room control (without supply air sensor):
When the exhaust air or room sensor fail, all control outputs run a 0 % control signal and
the binary outputs for pumps and fans maintain their operating status; when the frost pro-
tection is active, the fans are switched off.
4
Exhaust air or room control/cascade control (with supply air sensor):
Control to supply air maximum limit
4
When other sensors fail, the system operation is fixed as if these sensors have not been
configured.
8.1.1 Status register (FSR)
If one of the function blocks Fb25 to Fb36 is activated, the messages of the corresponding bi-
nary inputs BE01 to BE12 are entered in the status register.
Function
WE
Configuration
BE01 to 12 to status register
OFF
Fb25 to Fb36 = ON
STEIG: Message when the binary input ma-
kes contact
FALL: Message when the binary input breaks
contact
EB 5477 EN
77
Malfunctions