Smoothing; Delay Drop-Out; Flame Pick-Up - ABB Uvisor SF910i User Manual

9 Program-Mode

9.5 Smoothing

9.5 Smoothing
Smoothing filters are algorithms to smooth variations in the Measured-Value values.
Smoothing provides more consistent signals for analysis. This allows for more sensitive
trip points without causing unnecessary Flame-Off conditions.
There are 11 stages of smoothing available for Measured-Values.
Smoothing function values can be set to NONE, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10.
– A value of NONE disables smoothing filters.
– Disabling smoothing will maximize the rate of flame detection.
– A value of 1 provides the minimum amount of smoothing.
– A value of 10 provides the maximum amount of smoothing.
9.6

Delay Drop-Out

Delay Drop-Out function is a "Time-Delay on Drop-Out" feature for flame detection. If a
flame proven condition exists, and one or more of the Measured-Values travel below or
above their trip points, this function will provide a delay before:
– Voting a Flame-Off condition
– De-energizing Flame-Relays
This feature allows the Flame Scanner to ride through transient events.
The user can set the amount of Time-Delay from 0.2 to 2.5 seconds.
9.7

Flame Pick-Up

Flame Pick-Up function is a "Time-Delay on Pull-In" feature for flame detection. If a
proven Flame-Off condition exists, and one or more of the active Measured-Values
exceed the programmed Pull-In values, the SF910i will delay before:
– Providing a Flame-On signal
– Energizing the Flame-relay(s)
The user can set the amount of time for the delay, and this only allows enough time to
ensure that the fuel-supply-valves clear the fully-opened limits before the SF910i proves
flame.
This feature allows the Flame Scanner to ride through transient events. The user can
set the amount of Time-Delay from 0.1 to 10.0 seconds.
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