Flame Control; With Ionization Sensor; With Uv Sensor - Honeywell Krom Schroeder BCU 480 Manual

Flame control

7 Flame control

7 .1 With ionization sensor

The BCU generates an alternating voltage (230 V AC)
between the sensing electrode and burner ground. The
flame rectifies this voltage. Only the DC signal (> 1 μA) is
detected by the burner control unit.
A flame cannot be simulated.
Ignition and monitoring with a single electrode is pos-
sible.
For ionization control, the BCU is suitable for Safety
Integrity Level SIL 3, see page 76 (Safety-specific
characteristic values).

7 .2 With UV sensor

A UV tube inside the UV sensor detects the ultraviolet
light of a flame. It does not respond to sunlight, incan-
descent bulb light or infrared radiation emitted by hot
workpieces or red-hot furnace walls.
In the event of incident UV radiation, the UV sensor rec-
tifies the supplied alternating voltage. As with ioniza-
tion control, the burner control unit only detects this DC
signal.
When using UV sensors of Type UVS, the burner control
unit may be used for intermittent operation only. This
means that operation must be interrupted at least once
every 24 hours. This can be programmed using param-
eter 35.
BCU 480 · Edition 03.16l
Further information can be found in brochure UVS at
www.docuthek.com.
The burner control unit BCU..U is prepared for UV sen-
sor UVD 1. This enables continuous operation.
No safety-specific characteristic values are available for
flame control with UVS sensor.
For flame control with UVD sensor, safety-specific cha-
racteristic values are available for the Safety Integrity
Level SIL.
Further information can be found in TI UVD 1 at www.
docuthek.com.
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