Ntron SIL O2, User'S Operation Manual, Page: 19 / 56

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3. Operational safety and maintenance instructions.
If it is assumed that safe operation is no longer possible, the device must be taken out of service and protected
against accidental use. The reasons can be:
visible damage to the device
failure of the electrical function
long shelf life at temperatures above 85 ° C
Transport damage
Before the device can be put back into service, a professional routine check must be carried out in accordance
with DIN EN 61010, part. 1. This examination must be carried out by the manufacturer. Repair work on Ex devices
may only be carried out in accordance with § 9 of Ex. (Elex V).
3.1 Fault conditions
The SIL O2 Analyzer failure operation is not locked out by a fault. When a fault condition is repaired, the trip
relay RL3 and the red fault indicator will return to their "healthy" or "operational" state after a few seconds
following an automatic internal cyclic check.
3.2 Wire break
When manually disconnecting the sensor (for example for maintenance) or following a break in the sensor
connection cable, the SIL O2 Analyzer RL3 fault relay switches off and interrupts the safety circuit.
The red fault indicator will illuminate on the SIL O2 analyzer and the 4-20 mA analog output will reach a constant
high value of 22.0 mA. At the same time, the setpoint relays RL1 and RL2 will be deactivated.
When the sensor is reconnected or the cable fault is corrected, the RL3 relay automatically resets after about 30
seconds and the red LED goes out. At the same time, RL1 and RL2 are reset according to their setpoints and the
measured gas level. See also note on page 13 of this manual for reset requirements under specific conditions.
3.3 System faults
A number of internal faults in the SIL O2 analyzer generate a fault output and interrupt the safety circuit. In some
cases, cycling the power supply of the SIL O2 analyzer may be sufficient to remedy the problem. Otherwise,
please contact Ntron for assistance.