BCU 460, BCU 465 · Edition 11.19 12
Application
1.1.5 Two-stage-controlled burner
VR..L
BCU 460
LM..F3
60 61 62 65
22
µC
81
82
95
96
Process control (PCC)
FCU 500
VAS VAG
V1 V2
V3
VAS 1
UVS
4
A
2
1
Start
1
3
P
35
6
HT
PLC
Control:
ON/OFF or High/Low
The BCU provides the cooling and purging processes.
Parameter A078 = 4 is selected so that the two-stage
burner starts at low-fire rate. When the operating state
is reached, the BCU advises the control unit. Depend-
ing on the parameter setting, the air valve on terminal
65 is actuated to open and close by the program or ex-
ternally via the input at terminal4.