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2 Safety
2.3.3.2 Basic Device
Check the following items prior to commissioning:
• Valves must be assigned correctly to valve outputs on CMS.
• Correct setting of time parameters (especially safety and pre-purge times).
• Flame sensor functioning well in case of:
• flame blow-off during operation (incl. flame-out response time)
• ambient light is present during pre-purge period
• at a missing flame formation while end of safety period starts
• Whether an ionisation or approved self-checking flame sensor is used as only these types
allow continuous operation.
• Functioning of flame sensor
– in case of flame blow-off during operation
– parasitic light being present during pre-purge period
– missing flame formation at the end of the safety-period
• Activated valve leakage control function for gas valves if required for application purposes.
– Ensure a correct leakage quantification.
2.3.3.3 Parameter Settings
Check the following:
• Correct setting of time parameters (especially safety and pre-purge periods).
• Activated valve leakage control function for gas valves if required for application purposes.
– If necessary, ensure the correct valve leakage quantification/monitoring time.
2.3.3.4 FFS/ION/Terminal - Flame Tolerance Time
The software processes the flame tolerance time
*
configurable in P801 and the pilot flame tol-
erance time
**
configurable in P816 in the same way.
To calculate the total response time in case of flame failure, the delay time of the related flame
scanner at terminal must be added. The following must be observed for each Flame sensor/
flame scanner:
• The overall time in accordance with the standard is from flame failure to safety shutdown
 must be checked in the plant context.
• External flame scanner at terminal:
– Time starts as soon as the external digital input signal drops out.
– The time of the external flame scanner must also be taken into account.
• Internal flame scanner as an add on FFS or ION:
– Time starts with drop of the internally formed flame signal.
– The time of the sensor (FFS07/08) and the internal flame scanner (flame card) must
also be considered.
*
Response time of the main flame at flame OFF
**
Response time of the pilot flame at flame OFF
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