Capacity Control; Bcu..f1/F2, The Control Element Is Activated By The - Honeywell Krom Schroder BCU 580 Technical Information

Air control

4 .1 Capacity control

4 .1 .1 BCU . .F1/F2
V1
VAS
Process control (PCC)
FCU 500
ϑ1 A
1 2
17 18 37 38
BCU 580..C0F1
42
46
43
µC
HT
49
P
50
57
52 53 54 55 56
M
IC 20 + BVA
The BCU..F1/F2 activates a control element via the out-
puts for capacity control (terminals 53 to 56) for purg-
ing, cooling or starting the burner. This control element
moves to the required position for the relevant operat-
ing situation.
BCU 580 · Edition 11.15l
V2
VAG
VAS 1
V4
PLC
ϑ2
3
4
41
1
2
13
14
9
8
5
As soon as there is a purge signal at terminal 50 of

BCU..F1/F2, the control element is activated by the

outputs for capacity control to approach the position
for pre-purge. The protective system (e.g. FCU 500)
starts the pre-purge time if there is adequate air flow.
After the elapse of the pre-purge time, the control ele-
ment moves to the ignition position. Once the protec-
tive system (terminal 46, safety interlocks) has issued
the enable signal, the pilot and main burners can be
started by the start-up signals at terminals 1 and 4. The
control element can be activated to control the burner's
capacity dependent on parameters 48 and 49.
TZI/TGI
▼
26