GESTRA NRS 1-41, Original Installation Instructions

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System Malfunctions
Malfunctions occur if CAN bus components have been mounted, wired or configured incorrectly or
if electronic component parts are defective, or in the event of excessive heat in the equipment or
electrical interference in the supply system. In the event of a system malfunction the safety circuit
(terminals 25 and 29) will be interrupted instantaneously.
There are four malfunction conditions for the control unit and the measuring transducer:
n
Admissible temperature in electrode terminal box exceeded
n
No or faulty communication between control unit and sensor
n
Malfunction in CAN bus
n
Failure of 24 V power supply unit or failure of external PSU
A selftest is performed in the control unit every 3 seconds and in the measuring sensor (e.g. level
electrode) every 10 seconds. Any error messages will be saved in the control unit during the self
testing routine. The error messages are stored in the control unit until the cause of the error has been
eliminated. During an error message the signal output will be switched off and on (terminals 7 and 8) in
a clockpulse controlled way. As part of the selftest the output relays are also checked every six hours.
The terminal strips of the equipment are live during operation.
This presents risk of severe cases of electric shock!
Cut off power supply to the equipment before mounting or removing the terminal strips
or the housing cover!
Danger
Causes